Biotechnological approaches for cocoa waste management: A review

Optimization of subcritical water extraction for pectin extraction from cocoa pod husks using the response surface methodology

This study optimized subcritical water extraction (SWE) conditions to maximize pectin yield from cocoa pod husk (CPH) and compared the characteristics of CPH pectin extracted through SWE with those of CPH pectin obtained through conventional extraction (CE) with citric acid. The Box-Behnken experimental design was employed to optimize SWE and examine the influence of process parameters, including temperature (100 °C-120 °C), extraction time (10-30 min), and solid:liquid ratio (SLR) (1:30-2:30 g/mL), on pectin yield. The maximum pectin yield of 6.58% was obtained under the optimal extraction conditions of 120 °C for 10 min with 1:15 g/mL SLR and closely corresponded with the predicted value of 7.29%. Compared with CE, SWE generated a higher yield and resulted in a higher degree of esterification, methoxyl content, and anhydrouronic acid value but a lower equivalent weight. The extracted pectin was pure, had low-methoxyl content, and similar melting and degradation temperatures.

Biosorption of Cr(VI) by Theobroma cacao pericarp

This paper reports a comprehensive study of Theobroma cacao pericarp (TCP) residues, which has been prepared, characterized, and tested as an inexpensive and efficient biosorbent of Cr(VI) from aqueous solutions. The maximum adsorption capacity of TCP obtained at optimal conditions (pH = 2, dose = 0.5 g L-1, C0 = 100 mg L-1) was qmax = 48.5 mg g-1, which is one of the highest values reported by the literature. Structural and morphological characterization has been performed by FTIR, SEM/EDX, and pHPZC measurements. FTIR analysis revealed the presence of O-H, -NH, -NH2, C = H, C = O, C = C, C-O, and C-C functional groups that would be involved in the Cr(VI) biosorption processes. The experimental equilibrium data of biosorption process were successfully fitted to non-linear Langmuir (R2 = 0.95, χ2 = 11.0), Freundlich (R2 = 0.93, χ2 = 14.8), and Temkin (R2 = 0.93, χ2 = 14.7) isotherm models. Kinetics experimental data were well adjustment to non-linear pseudo-2nd (R2 = 0.99, χ2 = 2.08)- and pseudo-1st-order kinetic models (R2 = 0.98, χ2 = 2.25) and also to intra-particle Weber-Morris (R2 = 0.98) and liquid film diffusion (R2 = 0.99) models. These results indicate that Cr(VI) biosorption on heterogeneous surfaces as well as on monolayers of TCP would be a complex process controlled by chemisorption and physisorption mechanisms. The thermodynamic results indicate that the Cr(VI) biosorption on TCP is a feasible, spontaneous, and endothermic process. TCP can be regenerated with NaOH and reused up to 3 times.

Improving the Extraction of Polyphenols from Cocoa Bean Shells by Ultrasound and Microwaves: A Comparative Study

The extraction of bioactive compounds from food by-products is one of the most important research areas for the nutraceutical, pharmaceutical, and food industries. This research aimed to evaluate the efficiency of Ultrasound-Assisted Extraction (UAE) and Microwave-Assisted Extraction (MAE), either alone or in combination, of phenolic compounds from cocoa bean shells (CBSs). These extraction techniques were compared with conventional methods, such as under simple magnetic stirring and the Soxhlet apparatus. After the preliminary characterization of the gross composition of CBSs, the total polyphenol content and radical scavenging of extracts obtained from both raw and defatted cocoa bean shells were investigated. Quantification of the main polyphenolic compounds was then performed by RP-HPLC-DAD, identifying flavonoids and phenolic acids, as well as clovamide. The application of MAE and UAE resulted in a similar or superior extraction of polyphenols when compared with traditional methods; the concentration of individual polyphenols was variously influenced by the extraction methods employed. Combining MAE and UAE at 90 °C yielded the highest antiradical activity of the extract. Spectrophotometric analysis confirmed the presence of high-molecular-weight melanoidins, which were present in higher concentrations in the extracts obtained using MAE and UAE, especially starting from raw material. In conclusion, these results emphasize the efficiency of MAE and UAE techniques in obtaining polyphenol-rich extracts from CBS and confirm this cocoa by-product as a valuable biomass for the recovery of antioxidant compounds, with a view to possible industrial scale-up.

Cocoa by-products: A comprehensive review on potential uses, waste management, and emerging green technologies for cocoa pod husk utilization

Cocoa is considered to be one of the most significant agricultural commodities globally, alongside Palm Oil and Rubber. Cocoa is the primary ingredient in the manufacturing of chocolate, a globally popular food product. Approximately 30 % of cocoa, specifically cocoa nibs, are used as the primary constituent in chocolate production., while the other portion is either discarded in landfills as compost or repurposed as animal feed. Cocoa by-products consist of cocoa pod husk (CPH), cocoa shell, and pulp, of which about 70 % of the fruit is composed of CPH. CPH is a renewable resource rich in dietary fiber, lignin, and bioactive antioxidants like polyphenols that are being underutilized. CPH has the potential to be used as a source of pectin, dietary fibre, antibacterial properties, encapsulation material, xylitol as a sugar substitute, a fragrance compound, and in skin care applications. Several methods can be used to manage CPH waste using green technology and then transformed into valuable commodities, including pectin sources. Innovations in extraction procedures for the production of functional compounds can be utilized to increase yields and enhance existing uses. This review focuses on the physicochemical of CPH, its potential use, waste management, and green technology of cocoa by-products, particularly CPH pectin, in order to provide information for its development.

Influences of Depulping, Pod Storage and Fermentation Time on Fermentation Dynamics and Quality of Ghanaian Cocoa

This study investigated the impact of the depulping of cocoa beans after pod opening, as well as the influences of pod storage (PS) and fermentation time on the fermentation dynamics and the overall quality of beans and liquors made thereof. Twelve variations were conducted in three experimental runs (with/without depulping; 1-/3-day PS; and fermentation times of 3, 4, 5, 6 or 7 days). Fermentation dynamics (e.g., temperature and pH) and the quality of dried beans (e.g., cut-test and fermentation index) and liquors (sensory assessment, quantification of cocoa key-odorants and tastants) were investigated. It was demonstrated that 17-20% of cocoa pulp, relative to the total bean-pulp-mass weight, could be mechanically removed without negatively affecting the bean quality. No significant differences were found in the percentages of well-fermented beans after 5-6 days fermentation with 1-day PS, resulting in 49 ± 9% with, and 48 ± 12% without depulping. There were no significant differences in key tastants present in the liquors; however, significantly less volatile acids and esters were found when liquors were produced from 5-6 day-fermented depulped beans, with 1-day PS, without negatively affecting the sensory profiles. This strategy allows producers to maximize the cacao fruit's value by integrating part of the pulp into the cocoa value chain.

Effect of Carbohydrase Treatment on the Dietary Fibers and Bioactive Compounds of Cocoa Bean Shells (CBSs)

Cocoa bean shells (CBSs) are a byproduct of the chocolate production process, representing the external layer of the cocoa bean. CBSs exhibit many interesting chemical and nutritional characteristics resulting in a very rich content of dietary fiber (DF) and antioxidant compounds such as phenolic acids and flavan-3-ols. The DF fraction of CBSs is notably rich in soluble dietary fibers (SDFs), which may be associated with fermentability and prebiotic properties. The objective of this study was the valorization of CBSs through enzymatic treatments, thereby increasing the solubility of DF and potentially augmenting fermentability. CBSs were treated both raw and defatted. Three sets of carbohydrases were used in order to impact the dietary fiber profile. Cellulase, xylanase, pectinase and their combinations were used to perform enzymatic treatments. The application of cellulase, xylanase and a combination of both enzymes proved effective in achieving a high SDF destructuring of the insoluble dietary fiber (IDF) fraction in both defatted and raw CBSs. Notably, the SDF/IDF ratio was significantly elevated in the enzymatically hydrolyzed samples (1.13-1.33) compared to the untreated CBSs (0.33). Furthermore, the various treatments did not affect the antioxidant activity or the content of the main bioactive compounds. These results provide a foundation for new opportunities in the biovalorization of CBSs through green techniques for a range of potential industrial applications in the food and nutraceutical sectors.

A critical review of consumer responsibility in promoting sustainable cocoa production

Consumer buying behavior can be defined as all the different steps that consumers follow before purchasing a good or service. Web browser research, involvement in online networking discussions, and a range of other activities might be a part of this process. Despite the negative effects of its production chain on the environment, and on the socio-economical condition of local farmers, chocolate products are among the most distributed food and beverage items in the world. In this review, the consumer responsibility for sustainable cocoa production is described. This study determines the consumer opinions and attitudes on the different operations pursued in the production chain of chocolate, from the collection of cocoa beans to their processing into different final products. For this, data on life cycle assessment from some studies was gathered to identify and investigate links between the production chain of different types of chocolate (dark, white, milk) and its impact on natural resources so that the sensitivity of consumers to purchase more sustainable products can be evaluated. This approach revealed that consumers will not only purchase chocolate because of its good quality or health benefits, but they also consider it the most sustainable product.

The Development of Biocomposite Filaments for 3D Printing by Utilizing a Polylactic Acid (PLA) Polymer Matrix Reinforced with Cocoa Husk Cellulose Fibers

Vegetable fibers are increasingly used in biocomposites, but there is a need for further development in utilizing by-products like cocoa husks. Three-dimensional printing, through Fused Filament Fabrication (FFF), is advancing rapidly and may be of great interest for applying biocomposite materials. This study focuses on developing innovative and fully biodegradable filaments for the FFF process. PLA filaments were prepared using cellulose fibers derived from cocoa husks (5% mass ratio). One set of filaments incorporated fibers from untreated husks (UCFFs), while another set utilized fibers from chemically treated husks (TCFFs). The fabricated materials were analyzed using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) techniques, and they were also tested for tensile strength. ANOVA reveals that both UCFFs and TCFFs significantly predict tensile strength, with the UCFFs demonstrating an impressive R2 value of 0.9981. The optimal tensile strength for the filament test specimens was 16.05 MPa for TCFF8 and 13.58 MPa for UCFF8, utilizing the same printing parameters: 70% infill and a layer thickness of 0.10 mm. Additionally, there was an 18% improvement in the tensile strength of the printed specimens using the filaments filled with chemically treated cocoa husk fibers compared to the filaments with untreated fibers.

Green Methods to Recover Bioactive Compounds from Food Industry Waste: A Sustainable Practice from the Perspective of the Circular Economy

The worrying and constant increase in the quantities of food and beverage industry by-products and wastes is one of the main factors contributing to global environmental pollution. Since this is a direct consequence of continuous population growth, it is imperative to reduce waste production and keep it under control. Re-purposing agro-industrial wastes, giving them new life and new directions of use, is a good first step in this direction, and, in global food production, vegetables and fruits account for a significant percentage. In this paper, brewery waste, cocoa bean shells, banana and citrus peels and pineapple wastes are examined. These are sources of bioactive molecules such as polyphenols, whose regular intake in the human diet is related to the prevention of various diseases linked to oxidative stress. In order to recover such bioactive compounds using more sustainable methods than conventional extraction, innovative solutions have been evaluated in the past decades. Of particular interest is the use of deep eutectic solvents (DESs) and compressed solvents, associated with green techniques such as microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), pressurized liquid extraction (PLE) and pulsed-electric-field-assisted extraction (PEF). These novel techniques are gaining importance because, in most cases, they allow for optimizing the extraction yield, quality, costs and time.

Cocoa Mucilage as a Novel Ingredient in Innovative Kombucha Fermentation

Cocoa tree plantations aim to harvest grains found in the cob to produce cocoa and chocolate. There has been a growing interest in valorizing the secondary components of the cocoa fruit, such as the peel, placenta, and mucilage/pulp, as valuable sources of nutrients for healthy food preparation. In other words, by-products derived from these raw materials are an exploitable source of nutrients in the preparation of healthy food. In the present study, two varieties of cocoa, National Cocoa Fino de Aroma (NCFA) and Colección Castro Naranjal 51 (CCN-51), were evaluated and harvested during both dry and rainy seasons. This evaluation was based on the profiling of the cob, peel, grain, placenta, and mucilage in different stages of ripeness (underripe, ripe, and overripe). Also, from the ripe raw material, a fermented beverage prototype was developed, such as kombucha, with different concentrations of mucilage (40, 60, 80, and 100 g/L). Physicochemical analyses, such as acidity, °Brix, pH, moisture, ash, protein, fat, fiber, vitamins, sugars, and polyphenols of the raw mucilage material and acidity, °Brix, and pH values of the fermented kombucha, were carried out. The best performances were obtained with the CCN-51 variety in the rainy season. Among the fermented drink panelists, the CN40 treatment (Nacional Mucilage + 40 g/L of sugar) received the highest acceptability and was considered the best. Given its efficiency, nutritional content, and potential applications, this product presents a promising strategy to address Sustainable Development Goals related to zero hunger, health and well-being, and climate action.

Bioactive Compounds from Organic Waste

The reuse and reincorporation of waste are the principles of circular economies. Compost, biofuels, animal feed, dyes, and bioactive compounds can be obtained from the revaluation of organic waste. Research on this subject is scarce and limited to specific sectors, such as agriculture and agroindustry, leaving aside others that generate large quantities of organic waste, such as floriculture. The remains of these sectors have a low decomposition rate compared to other organic wastes. They are a source of bioactive compounds (e.g., essential oils, pigments, phenols) that can be reincorporated into the production chain of various industries. This review describes the composition of waste from agroindustry, agriculture, and floriculture, analyzing their potential revalorization as a source of bioactive compounds and an alternative supply source.

Synergistic microwave and acidic deep eutectic solvent-based pretreatment of Theobroma cacao pod husk biomass for xylooligosaccharides production

The bioconversion of lignocellulosic biomass into novel bioproducts is crucial for sustainable biorefineries, providing an integrated solution for circular economy objectives. The current study investigated a novel microwave-assisted acidic deep eutectic solvent (DES) pretreatment of waste cocoa pod husk (CPH) biomass to extract xylooligosaccharides (XOS). The sequential DES (choline chloride/citric acid, molar ratio 1:1) and microwave (450W) pretreatment of CPH biomass was effective in 67.3% xylan removal with a 52% XOS yield from total xylan. Among different XOS of varying degrees of polymerization, a higher xylobiose content corresponding to 69.3% of the total XOS (68.22 mg/g CPH) from liquid fraction was observed. Enzymatic hydrolysis of residual xylan from pretreated CPH biomass with low commercial xylanase (10 IU/g) concentration yielded 24.2% XOS. The MW-ChCl/citric acid synergistic pretreatment approach holds great promise for developing a cost-effective and environmentally friendly method contributing to the sustainable production of XOS from agricultural waste streams.

Physicochemical characterization of the pod husk of Theobroma cacao L. of clones CCN51, FEAR5, and FSV41 and its agroindustrial application

In cocoa production, the harvest and postharvest processes tend to generate residues that, if not properly treated or disposed of, become a source of pests or diseases for the crop and the farmer. The residues are environmental contaminants, which are equivalent to 70%-80% of the total fruit (husk, placenta, leachates). In the case of cacao pod husk (CPH), it is hollow form contributes to the accumulation of water or leachates. These residues with no apparent profitable use may have components of agroindustrial interest, such as pectins, cellulose, and starches, in products with high added value. Thus, the physicochemical characterization CPH of clones Castro Naranjal Collection 51 (CCN51), FEDECACAO Arauquita 5 (FEAR5), and FEDECACAO San Vicente 41 (FSV41) is presented to identify different applications such as biopolymers, bioremediation, and renewable energies and their potential biotechnological use in contributing to the circular economy according to the characteristics of each clone. In conclusion, it is important to continue with the research on CPHs of the different clones and to promote the sustainable development of cocoa in the Department of Risaralda, Colombia.

Fermentation of cocoa pod husks with Pleurotus salmoneo-stramineus for food applications

Cocoa pod husks (CPHs), the major side-stream from cocoa production, were valorized through fermentation with Pleurotus salmoneo-stramineus (PSS). Considering ergosterol as a biomarker for the fungal content, the mycelium accounted for 54% of the total biomass after 8 days in submerged cultures. The crude protein content of fermented CPH (CPHF) increased from 7.3 g/100 g DM in CPH to 18.9 g/100 g DM. CPH fermentation resulted in a high biological value of 86 for the protein. The water and oil binding capacities of CPHF were 3.5 mL/g and 2.1 mL/g, respectively. The particle diameter dv,0,90 of CPHF was 373 μm as compared to 526 μm for CPH. The total dietary fiber was 73.4 g/100 g DM in CPHF and 63.6 g/100 g DM in CPH. The amount of soluble fiber was 2.3 g/100 g DM in CPHF and 10.1 g/100 g DM in CPH; the insoluble fraction accounted for 71.1 g/100 g DM and 53.6 g/100 g DM, respectively. Bread doughs with CPH or CPHF were characterized for texture, color, and farinographic properties. The dough hardness, consistency, and browning index increased with the concentration of CPH, whereas for CPHF, springiness and peak viscosities declined. We demonstrate the upcycling of CPH into nutritious and functional ingredients through PSS fermentation.

An overview of fermentation in the food industry - looking back from a new perspective

Fermentation is thought to be born in the Fertile Crescent, and since then, almost every culture has integrated fermented foods into their dietary habits. Originally used to preserve foods, fermentation is now applied to improve their physicochemical, sensory, nutritional, and safety attributes. Fermented dairy, alcoholic beverages like wine and beer, fermented vegetables, fruits, and meats are all highly valuable due to their increased storage stability, reduced risk of food poisoning, and enhanced flavor. Over the years, scientific research has associated the consumption of fermented products with improved health status. The fermentation process helps to break down compounds into more easily digestible forms. It also helps to reduce the amount of toxins and pathogens in food. Additionally, fermented foods contain probiotics, which are beneficial bacteria that help the body to digest food and absorb nutrients. In today's world, non-communicable diseases such as cardiovascular disease, type 2 diabetes, cancer, and allergies have increased. In this regard, scientific investigations have demonstrated that shifting to a diet that contains fermented foods can reduce the risk of non-communicable diseases. Moreover, in the last decade, there has been a growing interest in fermentation technology to valorize food waste into valuable by-products. Fermentation of various food wastes has resulted in the successful production of valuable by-products, including enzymes, pigments, and biofuels.

Atomization of Cocoa Honey Using Whey Protein Isolate to Produce a Dry Formulation with Improved Shelf Life for Industrial Application

Cocoa honey, a by-product obtained during the processing of cocoa, is a juice rich in pectin, organic acids, minerals and phenolic compounds with antioxidant properties. Fresh cocoa honey is quickly fermented due to its high content of reducing sugars, such as fructose and glucose, which limits its shelf life. Currently, cocoa honey is only commercialized in frozen form, as logistical challenges prevent the wide distribution or export of this by-product for applications in the market of sweets, jellies, beverages, confectionery, and nutraceutical foods among others. Spray-drying technology is a viable prospect for the large-scale stabilization of products such as cocoa honey, with less heat exposure compared to other conventional drying methods. This work aimed to evaluate the efficacy of drying adjuvants for a rapid removal of the water present in cocoa honey via atomization, since this process minimizes the effects of glass transition temperature (Tg) related to materials with high sugar contents. Physical parameters such as the moisture content, hygroscopicity, particle size, and yield of the products obtained were determined. Cocoa honey presented 85.3 ± 0.20 g/100 g of moisture. The formulations successfully decreased moisture content, which was lower than 11.72 ± 0.08 g/100 g in the formulations. Water activity ranged between 0.1464 ± 0.0043 and 0.1562 ± 0.029, with no significant difference between the formulations. The hygroscopicity of cocoa honey powders ranged from 29.29 to 29.87 g of water/100 g of cocoa honey. The combination of 20% maltodextrin and 1% whey protein isolate (WPI) led to the best yield, resulting in a free-flowing powder as the final product. On the other hand, the formulation composed of maltodextrin and whey protein isolate in the ratio of 29:1, respectively, led to the most stable product, with less loss of phenolic compounds during the drying process (6.04%). Regarding particle diameter, 90% of the accumulated distribution did not exceed 57 μm. The greatest dispersion of particles occurs in the Ma20W10 formulation with a span of 2.72, inferring greater variation in size between small (7.01 ± 0.06 μm), medium (18.25 ± 0.37 μm), and large (56.65 ± 1.17 μm) particles. The use of whey protein isolate as an adjuvant proved to be an efficient drying process in the production of cocoa honey powder, and was also advantageous for enriching the nutritional content of the final product due to its protein origin. Furthermore, the combination of spray-drying technology and the use of whey protein isolate as adjuvant led to a free-flowing cocoa honey powder with an adequate particle size and benefits in terms of shelf-life extension, providing new opportunities for the commercialization of cocoa honey as an ingredient for the food industry, with benefits for the circular economy.

Structural alteration of cocoa bean shell fibers through biological treatment using Penicillium roqueforti

Lignocellulosic residues, such as cocoa bean shell (FI), are generated in large quantities during agro-industrial activities. Proper management of residual biomass through solid state fermentation (SSF) can be effective in obtaining value-added products. The hypothesis of the present work is that the bioprocess promoted by P. roqueforti can lead to structural changes in the fibers of the fermented cocoa bean shell (FF) that confer characteristics of industrial interest. To unveil such changes, the techniques of FTIR, SEM, XRD, TGA/TG were used. After SSF, an increase of 36.6% in the crystallinity index was observed, reflecting the reduction of amorphous components such as lignin in the FI residue. Furthermore, an increase in porosity was observed through the reduction of the 2θ angle, which gives the FF a potential candidate for applications of porous products. The FTIR results confirm the reduction in hemicellulose content after SSF. The thermal and thermogravimetric tests showed an increase in the hydrophilicity and thermal stability of FF (15% decomposition) in relation to the by-product FI (40% decomposition). These data provided important information regarding changes in the crystallinity of the residue, existing functional groups and changes in degradation temperatures.

Optimizing vacuum drying process of polyphenols, flavanols and DPPH radical scavenging assay in pod husk and bean shell cocoa

The objective of this study was to optimize different vacuum drying conditions for cocoa pod husk and cocoa bean shell in order to enhance these by-products for commercial applications. To carry out the optimization, the response surface methodology was applied using a Box-Behnken experimental design with 15 experiments for which different conditions of temperature (X1), drying time (X2) and vacuum pressure (X3) were established. The response variables were the content of total polyphenols, the content of flavanols and the radical scavenging activity evaluated in the extracts of the different experiments. Temperature (50-70 °C), drying time (3-12 h) and vacuum pressure (50-150 mbar) were considered as independent variables. The main factors affecting the response variables were temperature, followed by vacuum pressure. For the content of polyphenols, the optimal response values predicted for the cocoa pod husk was 11.17 mg GAE/g with a confidence limit (95%) of 9.05 to 13.28 mg GAE/g (optimal conditions: 65 °C, 8 h and 75 mbar), while for the cocoa bean shell cocoa was 29.61 mg GAE/g with a confidence limit (95%) of 26.95 to 32.26 mg GAE/g (optimal conditions: 50 °C, 5 h and 100 mbar). Therefore, results of this study suggest a high content of phenolic compounds obtained from these by-products that show relevance as functional ingredients for application in the food, nutraceutical, and cosmeceutical industries.

Profile of Bioactive Components of Cocoa (Theobroma cacao L.) By-Products from Ecuador and Evaluation of Their Antioxidant Activity

The aim of the study was to determine the profile of bioactive compounds in cocoa residues (mucilage and bean shells), and to evaluate their antioxidant activity in two cocoa varieties, Nacional X Trinitario type (Fine Aroma) and the variety CCN-51. The extraction of phytonutrients from the residues was carried out selectively. The characterization and quantification of the total polyphenol content (TPC), and the total flavonoid content (TFC) were determined by UV-VIS spectrophotometry. High-performance liquid chromatography (HPLC) was used to determine the phenolic profile and methylxanthines. The antioxidant activity was evaluated by the methods of 2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) cation bleaching (ABTS), ferric-reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC). The exudate mucilage samples from Nacional X Trinitario-type cocoa presented the highest content of TPC 105.08 mg gallic acid equivalents (GAE)/100 mL, TFC 36.80 mg catechin equivalents (CE)/100 mL, catechin (CAT) 35.44 mg/g, procyanidins (PCB2: 35.10; PCB1: 25.68; PCC1: 16.83 mg/L), epicatechin (EPI) 13.71 mg/L, caffeine (CAF) 0.90% and theobromine (TBR) 2.65%. In the cocoa bean shell, the variety CCN-51 presented a higher content of TPC (42.17 mg GAE/100 g) and TFC (20.57 mg CE/100 g). However, CAT (16.16 mg/g), CAF (0.35%) and TBR (1.28%) were higher in the Nacional X Trinitario cocoa type. The EPI presented no significant differences between the two samples studied (0.83 and 0.84 mg/g). The antioxidant activity values (ABTS, FRAP and ORAC methods) were higher in the samples of CCN-51 than in the Nacional X Trinitario type. The bean shell samples presented antioxidant values of 171.32, 192.22 and 56.87 mg Trolox equivalents (TE)/g, respectively, and the bean shell samples presented antioxidant values of 167.06, 160.06 and 52.53 mg TE/g, respectively. The antioxidant activity (ABTS, FRAP and ORAC) of the residues was correlated with the bioactive compounds of the mucilage and bean shells, showing a strong positive correlation (<0.99) with the procyanidins (B1, B2 and C1), EPI and CAT and a positive/moderate correlation (0.94) with methylxanthines.

Cocoa Bean Shell: A By-Product with High Potential for Nutritional and Biotechnological Applications

Cocoa bean shell (CBS) is one of the main solid wastes derived from the chocolate industry. This residual biomass could be an interesting source of nutrients and bioactive compounds due to its high content in dietary fibres, polyphenols and methylxanthines. Specifically, CBS can be employed as a raw material for the recovery of, for example, antioxidants, antivirals and/or antimicrobials. Additionally, it can be used as a substrate to obtain biofuels (bioethanol or biomethane), as an additive in food processing, as an adsorbent and, even, as a corrosion-inhibiting agent. Together with the research on obtaining and characterising different compounds of interest from CBS, some works have focused on the employment of novel sustainable extraction methods and others on the possible use of the whole CBS or some derived products. This review provides insight into the different alternatives of CBS valorisation, including the most recent innovations, trends and challenges for the biotechnological application of this interesting and underused by-product.

Valorization of cocoa, tea and coffee processing by-products-wastes

The growing threat of food insecurity together with some challenges in demography, health, malnutrition, and income instability around the globe has led researchers to take sustainable solutions to ensure secure production and distribution of food. The last decades have been remarkable in the agri-food supply chain for many food industries. However, vast quantities of food by-products and wastes are generated each year. These products are generally disposed in the environment, which could have remarkable adverse effects on the environment and biodiversity. However, they contain significant quantities of bioactive, nutritional, antioxidative, and aroma compounds. Their sustainable use could meet the increased demand for value-added pharmaceutical, nutraceutical, and food products. The amount of agri-food wastes and their disposal in the environment are predicted to double in the next decade. The valorization of these by-products could effectively contribute to the manufacture of cheaper functional food ingredients and supplements while improving regional economy and food security and mitigating environmental pollution. The main aim of this chapter is to present an understanding of the valorization of the wastes and by-products from cacao, coffee and tea processing with a focus on their bioactive, nutritional, and antioxidant capacity.

Quantitative Analysis and 2D/3D Elemental Imaging of Cocoa Beans Using X-ray Fluorescence Techniques

As an important raw material for the confectionery industry, the cocoa bean (Theobroma cacao L.) has to meet certain legal requirements in terms of food safety and maximum contaminant levels in order to enter the cocoa market. Understanding the enrichment and distribution of essential minerals but also toxic metals is of utmost importance for improving the nutritional quality of this economically important raw food material. We present three X-ray fluorescence (XRF) techniques for elemental bio-imaging of intact cocoa beans and one additional XRF technique for quantitative analysis of cocoa pellets. The interrelation of all the methods presented gives a detailed picture of the content and 3D-resolved distribution of elements in complete cocoa beans for the first time.

Implementation of pre-harvest techniques in emerging agroforestry systems to increase the yield of cocoa tree (Theobroma cacao L.)

Cocoa is one of the most important tropical fruits worldwide, its importance lies in its use in the food, cosmetic and pharmaceutical industries. Cocoa yield has been affected by different environmental, cultural and phytosanitary aspects. The emergence of new growing areas allows exploring the possibility of generating new economic and ecological systems that comply with current trends in organic farming. For them, pre-harvest practices such as pruning and soil fertilization are two necessary tools to control the productivity of cocoa agroecosystems. Therefore, the objective of this research was to analyses the implementation of pre-harvest techniques and the quality soil to increase the yield in a cocoa agroecosystem in an emerging zone in the Huasteca Potosina of Mexico. The work was carried out in an emerging zone in the cultivation of cocoa in three different zones delimited in 30 × 30 m. Thinning and pruning practices were carried out to keep the space clear and observe the influence on fruit yield. In addition, the quality of the soil was measured in terms of physical conditions and nutrient content. 25 kg/ha of nitrogen, 22 kg/ha of P2O5, 24 kg/ha of K2O and 4 kg/ha of magnesium were added following the recommendation of the fertilization laboratory. The physical properties of the pod were also analyzed, such as size, weight, number of grains and color. And some of the cocoa bean such as size, weight and hardness, all these parameters to measure the average yield of cocoa pods. The results show a clear influence of the soil quality and pre-harvest practices on the physical properties of the fruit and the total yield from 472.36 ± 52.01 to 520.06 ± 104.91 kg. However, other aspects are also modified, such as the increase in the size of the pod and the cocoa bean. Other aspects such as the color of the pod and the hardness of the grain do not present statistical difference. In conclusion, pre-harvest practices together with the application of fertilizers are factors that positively influence the yield of cocoa fruit. Some of the limitations of this research were the age of the plants and the local plant species.

The potential of imidazole as a new solvent in the pretreatment of agro-industrial lignocellulosic biomass

Lignocellulosic biomass is a renewable material of great abundance. However, its recalcitrant characteristic requires the application of pretreatments. Sugarcane bagasse (SB), soybean hulls (SH), cocoa pod husks (CPH) and oil palm empty fruit bunches (OPEFB) were subjected to imidazole pretreatment in order to evaluate chemical composition variations and influence over enzymatic hydrolysis efficiency. Non-treated SH, SB and OPEFB have higher content of holocellulose, while CPH is rich in lignin polymers (31.2%). After imidazole-pretreatment, all biomasses presented structural disorganization of lignocellulosic fibres and enrichment in the percentage of cellulose. Levels of up to 72% delignification were obtained, which allowed an enzymatic conversion greater than 95% for SB, SH and OPEFB, while only 83% was reached for CPH. Imidazole is then emerging as a potential catalyst for the pretreatment of agro-industrial by-products, allowing the valorisation of these residues and their reinsertion into the production chain under a biorefinery concept.

Effectiveness of various cacao pod husk extraction byproducts in promoting growth and immunocompetence in Litopenaeus vannamei

Extracts from plant products can promote growth, can act as immunostimulants, and have antibacterial and antiparasitic properties. These extracts can be used as alternatives to the chemical treatments commonly used to prevent and control disease in aquatic species. Research on the subject has focused on identifying invasive plants or agricultural waste products that can be used as immunostimulants. The present study further identified an optimal means of extracting pectin from cacao pod husks to promote growth performance and immunocompetence in Litopenaeus vannamei that would both reduce production costs and enable waste recycling. The byproducts of pectin extraction from cacao pod husks, that is, dried cacao pod husk powder (DCP), steamed DCP (sDCP), hot water-treated cacao pod husk powder (HCP), hot water-treated cacao pod husk supernatant (HCS), and cacao pod husk pectin (CPH pectin), were used to create five experimental diets, which were administered to five groups. The control group was fed a basal diet. The growth and immunocompetence of the shrimp were determined after 30, 60, 90 and 120 days of feeding. To identify the most cost-effective means of obtaining dried cacao pod husks, this study firstly determined the costs and effectiveness of the sun-drying, dehumidification, and heated-wind drying techniques. According to the results of growth performance, the CPH pectin group had higher survival but lower weight gain than the DCP, sDCP, HCP, and HCS groups did. At 30, 60, and 90 days, the clearance efficiency of the experimental groups was higher than that of the control group. At 60 days, the experimental groups had significantly higher phagocytic activity than the control group did. However, at 30 and 90 days the HCP, HCS and CPH pectin group had higher phagocytic activity. The total hemocyte count, differential hemocyte count, phenoloxidase activity, and respiratory bursts of the CPH pectin group were higher at 30 days but the same as those of the control group at 60 and 90 days. After 120 days of feeding trial, the resistance of L. vannamei fed with diets containing byproducts of pectin extraction from cacao pod husks significantly enhanced compared to that in BD group when they were infected with Vibrio aliginolyticus for 168 h, and the related higher survival rate can be observed in HCP, HCS and CPH pectin groups. The study findings suggest that diet-administered HCP and HCS have long-term immunostimulant potential and that CPH pectin has potential in the early stages of feeding. In addition, when heated air drying was employed, a moisture level of below 10% was obtained within 12 h. The results of this study indicate that adding HCP obtained from heated air-dried cacao pod husks to the feed of L. vannamei is the most cost-effective and sustainable means of promoting long-term growth performance and immunocompetence in the species.

Pectin Extraction from Residues of the Cocoa Fruit (Theobroma cacao L.) by Different Organic Acids: A Comparative Study

Ecuador is the world's fifth largest cocoa producer, generating hundreds of tons of residues from this fruit annually. This research generates value from the residual (cocoa pod husk) by using it as raw material to obtain pectin, which is widely used in the food and pharmaceutical industries. Extraction of three different organic acids with GRAS status (safe for use), the citric, malic and fumaric acids, was studied. In addition, two other factors, temperature (70-90 °C) and extraction time (60-90 min), were explored in a central composite design of experiments. We determined the conditions of the experiments where the best yields were garnered for citric acid, malic acid and fumaric acid, along with a ~86 min extraction time. The temperature did not show a significant influence on the yield. The pectin obtained under optimal conditions was characterised, showing the similarity with commercial pectin. However, the equivalent weight and esterification degree of the pectin obtained with fumaric acid led us to classify it as having a high equivalent weight and a low degree of esterification. In these regards, it differed significantly from the other two acids, perhaps due to the limited solubility of fumaric acid.

Alkaline Modification of Arabica-Coffee and Theobroma-Cocoa Agroindustrial Waste for Effective Removal of Pb(II) from Aqueous Solutions

Arabica-coffee and Theobroma-cocoa agroindustrial wastes were treated with NaOH and characterized to efficiently remove Pb(II) from the aqueous media. The maximum Pb(II) adsorption capacities, qmax, of Arabica-coffee (WCAM) and Theobroma-cocoa (WCTM) biosorbents (qmax = 303.0 and 223.1 mg·g−1, respectively) were almost twice that of the corresponding untreated wastes and were higher than those of other similar agro-industrial biosorbents reported in the literature. Structural, chemical, and morphological characterization were performed by FT-IR, SEM/EDX, and point of zero charge (pHPZC) measurements. Both the WCAM and WCTM biosorbents showed typical uneven and rough cracked surfaces including the OH, C=O, COH, and C-O-C functional adsorbing groups. The optimal Pb(II) adsorption, reaching a high removal efficiency %R (>90%), occurred at a pH between 4 and 5 with a biosorbent dose of 2 g·L−1. The experimental data for Pb(II) adsorption on WACM and WCTM were well fitted with the Langmuir-isotherm and pseudo-second order kinetic models. These indicated that Pb(II) adsorption is a chemisorption process with the presence of a monolayer mechanism. In addition, the deduced thermodynamic parameters showed the endothermic (ΔH0 > 0), feasible, and spontaneous (ΔG0 < 0) nature of the adsorption processes studied.

Arabica-coffee and teobroma-cocoa agro-industrial waste biosorbents, for Pb(II) removal in aqueous solutions

Agro-industrial waste biosorbents of arabica-coffee (WCA) and theobroma-cocoa (WCT) have been characterized and tested to remove Pb(II) from aqueous media. The maximum adsorption capacity of WCA and WCT (q_max = 158.7 and 123.5 mg·g^-1, respectively) is comparable or even higher than for several other similar agro-industrial waste biosorbents reported in the literature. Structural and morphological characterization were performed by infrared spectrometry with Fourier transform (FT-IR), scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), and charge measurements at the zero point charge (pH_PZC). Both biosorbents, WCA and WCT, show cracked surfaces with heterogeneous plates which ones include functional adsorption groups such as OH, C = O and C-O-C. Optimal Pb(II) adsorption occurs for a pH between 4 and 5 at [WCA] and [WCT] dose concentrations of 2 g·L^-1. We found that the adsorption process follows pseudo-second order kinetics with a rapid growth rate (almost six times larger for WCA than for WCT), basically controlled by the chemisorption process. The regeneration of both biosorbents was carried out in an eluent of 0.1M HNO₃ and they can be efficiently reused up to 5 times.

N-doped and activated porous biochar derived from cocoa shell for removing norfloxacin from aqueous solution: Performance assessment and mechanism insight

Environmental pollution has worsened as a result of antibiotic overuse. Nitrogen doping of biochar increases its ability to adsorb antibiotics and has been widely applied as an adsorbent. In this study, we synthesized nitrogen-doped biochar (N-A) from cocoa shell wastes calcined with urea and sodium bicarbonate (NaHCO₃) as nitrogen sources and green activators, respectively. An analysis of the biochar morphology, structure, specific surface area, and functional groups provided an understanding of its properties. As indicated by increased surface area, micropores, and surface functional groups, biochar was enhanced in its performance for norfloxacin adsorption when activated using NaHCO₃ and nitrogen doped. Adsorption experiments revealed that N-A biochar at 700 and 400 °C had a high adsorption capacity for NOR of 134 mg/g (N-A-CSB700) and 112.31 mg/g (N-A-CSB400) when compared to pristine biochar at 59.27 mg/g (CSB700) and 56.34 mg/g (CSB400), indicating that N-A doped modification on biochar greatly improved adsorption capacity. The Langmuir model demonstrated better NOR adsorption isotherms. The pseudo-second order and Elovich models closely followed the adsorption kinetics. Further investigations were conducted to determine how environmental factors influence biochar interaction with NOR. The results indicated a stable NOR removal efficiency was kept at a wide pH range, whereas the ionic strength inhibited the NOR adsorption process. The investigation into the sorption mechanism revealed that pore filling, H-bonding, π-π EDA interactions, ion exchange, and electrostatic attraction may all be implicated in the NOR adsorption process. Specifically, pore filling played the dominant role for N-A-CSB700, while N-A-CSB400 sorption occurred mainly via H-bonding. Since N-A-CSB700 doped biochar combines high adsorption capacity with a low inhibition effect of environmental factors (Na⁺/Ca²⁺), it has a high potential for future practical applications as an environmentally sustainable alternative. It uses low-cost solid waste to produce an adsorbent to cope with emerging contaminants such as antibiotics.

Adsorption Study of Continuous Heavy Metal Ions (Pb2+, Cd2+, Ni2+) Removal Using Cocoa (Theobroma cacao L.) Pod Husks

The serious toxicological effects of heavy metal ions in aquatic ecosystems have motivated the search for alternatives to reduce contamination of water sources from industrial wastewater. In this work, continuous adsorption of nickel, cadmium, and lead was assessed using a packed bed column filled with Cocoa (Theobroma cacao L.) pod husks widely available in the northern region of Colombia. The physicochemical characterization of the agricultural biomass was performed to quantify its chemical composition by bromatological, FT-IR, and energy-dispersive X-ray spectroscopy (EDS). The breakthrough curves were constructed for all heavy metal ions with bed depth of 4 and 7.5 cm, taking aliquots at 10, 30, 60, 90, 120, 150, 180, 210, 240, and 270 min. Moreover, experimental data were fitted to adsorption models in continuous mode to predict adsorptive performance (Adams−Bohart, Thomas, and Yoon−Nelson). For the FT-IR analysis of biomass before and after adsorption, the most representative bands occur around 3200−3900 cm−1 attributed to the presence of hydroxyl groups, showing the destruction of the peaks of lignocellulosic materials. The breakthrough curves revealed that for a 7.5 cm bed, adsorption performance reported the following order of promising results: Pb2+ > Ni2+ > Cd2+; while for a 4 cm bed, Pb2+ > Ni2+. The mechanism of adsorption of the evaluated metals onto cocoa pod husk was attributed to cationic exchange and microprecipitation due to the presence of Ca, K, and Si in the structure of the bio-adsorbent. Finally, the continuous adsorption was modeled under the mathematical expressions of Adams−Bohart, Thomas, and Yoon−Nelson reporting good fitting with correlation coefficient above 0.95.

Mass Balance and Compositional Analysis of Biomass Outputs from Cacao Fruits

The global chocolate value chain is based exclusively on cacao beans (CBs). With few exceptions, most CBs traded worldwide are produced under a linear economy model, where only 8 to 10% of the biomass ends up in chocolate-related products. This contribution reports the mass balance and composition dynamics of cacao fruit biomass outputs throughout one full year of the crop cycle. This information is relevant because future biorefinery developments and the efficient use of cacao fruits will depend on reliable, robust, and time-dependent compositional and mass balance data. Cacao husk (CH), beans (CBs), and placenta (CP) constitute, as dry weight, 8.92 ± 0.90 wt %, 8.87 ± 0.52 wt %, and 0.57 ± 0.05 wt % of the cacao fruit, respectively, while moisture makes up most of the biomass weight (71.6 ± 2.29 wt %). CH and CP are solid lignocellulosic outputs. Interestingly, the highest cellulose and lignin contents in CH coincide with cacao's primary harvest season (October to January). CB contains carbohydrates, fats, protein, ash, and phenolic compounds. The total polyphenol content in CBs is time-dependent, reaching maxima values during the harvest seasons. In addition, the fruit contains 4.13 ± 0.80 wt % of CME, a sugar- and nutrient-rich liquid output, with an average of 20 wt % of simple sugars (glucose, fructose, and sucrose), in addition to minerals (mainly K and Ca) and proteins. The total carbohydrate content in CME changes dramatically throughout the year, with a minimum of 10 wt % from August to January and a maximum of 29 wt % in March.

UHPLC-MS Characterization, and Antioxidant and Nutritional Analysis of Cocoa Waste Flours from the Peruvian Amazon

Cocoa (Theobroma cacao) is a food product used worldwide and a key raw material for chocolate manufacturing. Cocoa possesses bioactive compounds such as methylxanthines, flavonoids, procyanidins, and related molecules with medicinal or health-promoting properties. Cocoa shell and pod husk have been proposed as a by-product with several interesting bioactivities, and the gummy residue or glue (a sticky, gluey by-product known as “mucilage” in Spanish) is used to produce liquors and is eaten as a food in Perú. However, little is known about the chemical composition and bioactivity of flours made from Peruvian cocoa ecotype wastes such as those from the vein and pod husk of the fruits. This study aimed to characterize the in vitro antioxidant properties and nutritional values of flours made from the waste from a special ecotype of cocoa (CCN-51). The chemical fingerprinting was performed using UHPLC–HESI orbitrap mass spectrometry and allowed the detection of 51 compounds. GC-FID was used for the determination of individual fatty acid contents, and the antioxidant activity was assessed by several assays (DPPH, FRAP, and ABTS). The flours obtained were composed of a good amount of dietary fiber, carbohydrates, and minerals, as well as several bioactive polyphenolic compounds, fatty acids, and amino acids with nutraceutical properties, making the flours a rich and promising food as well as a good source for the preparation of functional foods or nutraceuticals.

Bioactive Compounds from Cocoa Husk: Extraction, Analysis and Applications in Food Production Chain

Cocoa husk is considered a waste product after cocoa processing and creates environmental issues. These waste products are rich in polyphenols, methylxanthine, dietary fibers, and phytosterols, which can be extracted and utilized in various food and health products. Cocoa beans represent only 32–34% of fruit weight. Various extraction methods were implemented for the preparation of extracts and/or the recovery of bioactive compounds. Besides conventional extraction methods, various studies have been conducted using advanced extraction methods, including microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), subcritical water extraction (SWE), supercritical fluid extraction (SFE), and pressurized liquid extraction (PLE). To include cocoa husk waste products or extracts in different food products, various functional foods such as bakery products, jam, chocolate, beverage, and sausage were prepared. This review mainly focused on the composition and functional characteristics of cocoa husk waste products and their utilization in different food products. Moreover, recommendations were made for the complete utilization of these waste products and their involvement in the circular economy.

Acoustic Characterization and Modeling of Silicone-Bonded Cocoa Crop Waste Using a Model Based on the Gaussian Support Vector Machine

The sustainable management of waste from agricultural crops represents an urgent challenge. One possible solution considers waste as possible secondary raw materials for specific uses. Among these, the use of agricultural waste as a product for the assembly of panels for the sound absorption of living environments represents a particularly suitable solution. In this study, the acoustic properties of the cocoa pod husk were evaluated, using silicone as a binder. Different proportions of materials and thicknesses were evaluated. A Support Vector Machine (SVM)-based model with a Gaussian kernel was then used to predict the acoustic performance of composite materials. The results obtained suggest the adoption of this material for the acoustic correction of living environments and this methodology for the prediction of the acoustic behavior of materials.

Cocoa By-Products: Characterization of Bioactive Compounds and Beneficial Health Effects

The annual production of cocoa is approximately 4.7 million tons of cocoa beans, of which only 10% corresponds to the cocoa bean and the remaining value corresponds to a high number of residues, cocoa bean shell, pulp and husk. These by-products are a source of nutrients and compounds of notable interest in the food industry as possible ingredients, or even additives. The assessment of such by-products is relevant to the circular economy at both environmental and economic levels. Investigations carried out with these by-products have shown that cocoa husk can be used for the production of useful chemicals such as ketones, carboxylic acids, aldehydes, furans, heterocyclic aromatics, alkylbenzenes, phenols and benzenediols, as well as being efficient for the removal of lead from acidic solutions, without decay in the process due to the other metals in this matrix. The fibre present in the cocoa bean shell has a considerable capacity to adsorb a large amount of oil and cholesterol, thus reducing its bioavailability during the digestion process, as well as preventing lipid oxidation in meats, with better results compared to synthetic antioxidants (butylated hydroxytoluene and β-tocopherol). Finally, cocoa pulp can be used to generate a sweet and sour juice with a natural flavour. Thus, this review aimed to compile information on these by-products, focusing mainly on their chemical and nutritional composition, simultaneously, the various uses proposed in the literature based on a bibliographic review of articles, books and theses published between 2000 and 2021, using databases such as Scopus, Web of Science, ScieLO, PubMed and ResearchGate.

Agro-residues for clean electricity: in-lab trial of power generation from blended cocoa-kolanut wastes

As a way of wastes-to-voltage conversion, experimental benchtest trial of electricity generation from a blend of cocoa and kolanut harvest by-products is presented in this study. Bioethanol obtained from the blend, through a process of alcoholic fermentation, was mixed with gasoline at specific proportion and employed to fire a spark ignition engine that served as a prime-mover in driving a four-pole three-phase salient-pole synchronous machine. Performance of the driving machine, as the fuel-mix proportion and its speed of rotation varied, was studied. Likewise, the electric power output characteristic of the driven machine, when operated at its rated synchronous speed, was examined. It was found that the driving machine performed better on mixed fuel than pure gasoline. There were gradual increases in the torque and the power developed by the machine as the proportion of ethanol in the fuel-mix and the rotational speed increased. While the highest values of torque and power developed on using pure gasoline were 12.4 Nm and 2574 W respectively at 1900 rpm, 13.1 Nm torque and 2953 W power were obtained from the machine when ignited with 10%-bioethanol fuel-mix at the same speed. Also, with 90 V_dc excitation voltage and rotation at 1500 rpm synchronous speed, the driven machine continuously generated electricity at 207.6 V_rms (line-to-line), 1.169 A, 0.698 power factor, 48.17 Hz, 0.294 kW output. This study demonstrated the possibility of continuous generation of electric power from cocoa and kolanut wastes. Result obtained from the laboratory-based trial indicates that at such agricultural regions that are advantaged in the production of the two crops, harvest residues of the crops can be explored as a steady source of biofuel for off-grid microgrid electrification.

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Biofuel from a blend of cocoa/kolanut wastes was used in spark ignition engine to drive electricity generation.

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During an experimental trial, the driven machine unceasingly produced electric power at its maximum rating.

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Off-grid microgrid electrification by wastes-to-voltage conversion of the farm by-products was demonstrated.

Inclusion of Cocoa Bean Shell in the Diet of Dairy Goats: Effects on Milk Production Performance and Milk Fatty Acid Profile

The use of agro-industrial by-products in animal nutrition is a promising strategy to reduce the food-feed competition, the diet cost at farm level and the environmental impact of animal-derived food production. In this study, the suitability of cocoa bean shell (CBS), a by-product of the cocoa industry, as a feed ingredient in the diet of dairy goats was evaluated, with a focus on the related implications on feed intake, milk yield, milk main constituents, and fatty acid (FA) profile of milk fat. Twenty-two Camosciata delle Alpi goats were divided into two balanced groups. All the goats were fed mixed hay ad libitum. The control group (CTRL; n = 11) also received 1.20 kg/head × day of a commercial concentrate, while in the experimental group (CBS; n = 11) 200 g of the CTRL concentrate were replaced by the same amount of pelleted CBS. The total dry matter intake of the goats was reduced by the dietary inclusion of CBS (P ≤ 0.01). The milk yield, as well as the milk fat, protein, and casein contents and yields were unaffected by the treatment. Milk from the CBS-fed goats showed decreased urea content when compared to the CTRL group (P ≤ 0.001). Milk from the CBS group of goats also showed increased concentrations of total branched-chain FA (both iso and anteiso forms; P ≤ 0.001) and total monounsaturated FA (P ≤ 0.05), as well as a decreased ∑ n6/∑ n3 FA ratio (P ≤ 0.05). De novo saturated FA, total polyunsaturated FA, total conjugated linoleic acids, and the majority of ruminal biohydrogenation intermediates remained unaffected by the dietary treatment. These results suggest that CBS can be strategically used as an alternative non-conventional raw material in diets intended for lactating goats, with no detrimental effects on their milk production performance. The use of CBS in goat nutrition may be hindered by the presence of theobromine, a toxic alkaloid. Special attention is needed by nutritionists to avoid exceeding the theobromine limits imposed by the current legislation. Detheobromination treatments are also suggested in literature to prevent toxic phenomena.

A biorefinery approach for pectin extraction and second-generation bioethanol production from cocoa pod husk

A biorefinery approach was applied for pectin extraction, xylooligosaccharides' (XOs) and bioethanol production from cocoa pod husk (CPH) using citric acid-assisted hydrothermal pretreatment. Under optimal conditions at 120° C, 10 min and 2% w.v^-1 of citric acid a high pectin recovery (19.5%) with high content of uronic acids (41.9%) was obtained. In addition, the liquid fraction presented a XOs concentration of 50.4 mg.g^-1 and 69.7 mg.g^-1 of fermentable sugars. Enzymatic hydrolysis of solid fraction showed glucan conversion of 60%. Finally, the hydrothermal and enzymatic hydrolysates of CPH were used in bioethanol production by Candida tropicalis and Saccharomyces cerevisiae, reaching 30.9 g and 45.2 g of bioethanol per kg of CPH, respectively. An environmentally friendly and rapid pretreatment method was development for pectin extraction, XOS and second-generation bioethanol production from CPH with great perspectives for the application of these biomolecules in food and bioenergy industry.

Added-value biomolecules' production from cocoa pod husks: A review

Cocoa beans are produced through on-farm processing where residual biomass is discarded, including cocoa pod husks (CPH), cocoa bean shells and cocoa sweatings. CPH represents about 80% of these residues that are generated during the initial cocoa bean processing steps and their disposal occupies large areas, causing social and environmental concerns. In the last decades, the lignocellulosic composition of CPH has attracted the attention of the scientific and productive sector. Recently, some studies have reported the use of CPH in the production of medium to high value-added molecules, with potential applications in food and feed, agriculture, bioenergy, and other segments. This review presents biotechnological approaches and processes for the exploitation of CPH, including pre-treatment methods for the production of different biomolecules. Great perspectives and innovations were found concerning CPH exploitation and valorisation, but still more efforts are needed to valorise this potential feedstock and give support to producers in-development countries.

Citric acid assisted hydrothermal pretreatment for the extraction of pectin and xylooligosaccharides production from cocoa pod husks

The main purpose of this work was the development of a new citric acid assisted hydrothermal pretreatment of cocoa pod husks (CPH), which has not yet been exploited for pectin recovery. CPH́s pectin recovery was improved with concomitant production of xylooligosaccharides (XOS) through efficient enzymatic hydrolysis of the solid fraction. A central composite experimental design was planned to analyze the effect of pretreatment conditions. Under optimal conditions at 120 °C, 10 min and 2% w.v^-1, the recovery of pectin accounted for 19.3% of the biomass submitted to pretreatment with 52.2% of methyl esterification degree. Additionally, 51.9 mg.g^-1 of XOS were also produced. The enzymatic conversion efficiency of the cellulosic fraction was 58.9%, leading to a production of 92.4 kg of glucose per ton of CPH. Great perspectives were observed in the implementation of CPH hydrothermal pretreatment for the production of value-added biomolecules under a biorefinery concept.

By-Products Revalorization with Non-Thermal Treatments to Enhance Phytochemical Compounds of Fruit and Vegetables Derived Products: A Review

The aim of this review is to provide comprehensive information about non-thermal technologies applied in fruit and vegetables (F&V) by-products to enhance their phytochemicals and to obtain pectin. Moreover, the potential use of such compounds for food supplementation will also be of particular interest as a relevant and sustainable strategy to increase functional properties. The thermal instability of bioactive compounds, which induces a reduction of the content, has led to research and development during recent decades of non-thermal innovative technologies to preserve such nutraceuticals. Therefore, ultrasounds, light stresses, enzyme assisted treatment, fermentation, electro-technologies and high pressure, among others, have been developed and improved. Scientific evidence of F&V by-products application in food, pharmacologic and cosmetic products, and packaging materials were also found. Among food applications, it could be mentioned as enriched minimally processed fruits, beverages and purees fortification, healthier and "clean label" bakery and confectionary products, intelligent food packaging, and edible coatings. Future investigations should be focused on the optimization of 'green' non-thermal and sustainable-technologies on the F&V by-products' key compounds for the full-utilization of raw material in the food industry.

Aroma Properties of Cocoa Fruit Pulp from Different Origins

Cocoa pulp occurs as a by-product of cocoa bean production and can be repurposed to different food applications, such as jams, fruit preparations and beverages, improving the sustainability of cocoa production, as well as the livelihoods of cocoa farmers. In this work, aroma-active compounds of fresh cocoa fruit pulps from different origins were investigated by applying aroma extract dilution analyses in combination with gas chromatography-mass spectrometry/olfactometry for identification. In total, 65 aroma-active compounds were determined in four different pulps originating from Indonesia, Vietnam, Cameroon, and Nicaragua. Vietnamese pulp showed the highest number of aroma-active regions, while Cameroonian pulp accounted for the lowest. Moreover, Cameroonian cocoa pulp showed the lowest FD factors. Overall, the odorants with the highest FD factors were trans-4,5-epoxy-(E)-decenal, 2- and 3-methylbutanoic acid, 3-(methylthio)propanal, 2-isobutyl-3-methoxypyrazine, (E,E)-2,4-nonadienal, (E,E)-2,4-decadienal, 4-vinyl-2-methoxyphenol, δ-decalactone, 3-hydroxy-4,5-dimethylfuran-2(5H)-one, dodecanoic acid, and linalool. This study provides insights into the aroma composition of fresh cocoa pulp from different origins for future food applications.

Chemical and Skincare Property Characterization of the Main Cocoa Byproducts: Extraction Optimization by RSM Approach for Development of Sustainable Ingredients

Methylxanthines and polyphenols from cocoa byproducts should be considered for their application in the development of functional ingredients for food, cosmetic and pharmaceutical formulations. Different cocoa byproducts were analyzed for their chemical contents, and skincare properties were measured by antioxidant assays and anti-skin aging activity. Musty cocoa beans (MC) and second-quality cocoa beans (SQ) extracts showed the highest polyphenol contents and antioxidant capacities. In the collagenase and elastase inhibition study, the highest effect was observed for the SQ extract with 86 inhibition and 36% inhibition, respectively. Among cocoa byproducts, the contents of catechin and epicatechin were higher in the SQ extract, with 18.15 mg/100 g of sample and 229.8 mg/100 g of sample, respectively. Cocoa bean shells (BS) constitute the main byproduct due to their methylxanthine content (1085 mg of theobromine and 267 mg of caffeine/100 g of sample). Using BS, various influencing factors in the extraction process were investigated by response surface methodology (RSM), before scaling up separations. The extraction process developed under optimized conditions allows us to obtain almost 2 g/min and 0.2 g/min of total methylxanthines and epicatechin, respectively. In this way, this work contributes to the sustainability and valorization of the cocoa production chain.

Potential Use of Industrial Cocoa Waste in Biofuel Production

Worldwide, the wastes derived from food production are generated in elevated volumes annually. In particular, the cocoa industrial wastes represent a source of usable biomass for the elaboration of new products such as food, livestock feed, cosmetics, and chemical products, and they can even be used for the generation of biofuels. The cocoa industrial wastes include cocoa pod husk, mucilage, and bean shells, which contain compounds of interest for different industries. However, the lignocellulose content of these by-products requires a pretreatment to fully utilize them; thus, different biofuels can be produced, depending on the conversion technology used to obtain the highest biomass yield. Recent studies reported the use of cocoa industrial wastes for the production of solid, liquid, and gaseous biofuels; nevertheless, the most common use reported is as a direct combustion source, which is used to supply the same production plants. Therefore, the objective of this work is to carry out a review on the uses of the by-products generated from cocoa for the generation of biofuels, as well as the technological concept applied for the transformation. In addition, the future trends indicate the relevance of using catalysts in production to increase reactions in the conversion of compounds, including the use of statistical models to optimize the processing variables.

Cellulose biosynthesis using simple sugars available in residual cacao mucilage exudate

Worldwide only 8% of the biomass from harvested cacao fruits is used, as cacao beans, in chocolate-based products. Cacao mucilage exudate (CME), a nutrient-rich fluid, is usually lost during cacao beans fermentation. CME's composition and availability suggest a potential carbon source for cellulose production. CME and the Hestrin and Schramm medium were used, and compared, as growth media for bacterial cellulose (BC) production with Gluconacetobacter xylinus. CME can be used to produce BC. However, the high sugar content, low pH, and limited nitrogen sources in CME hinder G. xylinus growth affecting cellulose yields. BC production increased from 0.55 ± 0.16 g L^-1 up to 13.13 ± 1.09 g L^-1 after CME dilution and addition of a nitrogen source. BC production was scaled up from 30 mL to 15 L, using lab-scale experiments conditions, with no significant changes in yields and production rates, suggesting a robust process with industrial possibilities.

Influence of S. cerevisiae and P. kluyveri as starters on chocolate flavour

BACKGROUND

Fermented cocoa beans (Theobroma cacao L.) are a pivotal raw material for chocolate production. A cocktail yeast applied in the cocoa fermentation process can promote the formation of pleasant metabolites. Saccharomyces, Pichia and Hanseniaspora have been widely used in fermentation to improve the final product organoleptic profile, highlighting that fermentation is a critical point for chocolate flavour precursor production. This study aims to evaluate the impact of Pichia kluyveri and Saccharomyces cerevisiae strains as starter cultures on the fermentation for two cocoa hybrids, FA13 and CEPEC2002.

RESULTS

During fermentation processes, volatile organic compounds (VOCs) and protein profiles were assessed. Chocolates produced were also assessed regarding the presence of VOCs. Eighty VOCs were identified using gas chromatography coupled to mass spectrometry analysis. Mass spectrometry provided the protein profile evolution during fermentation and showed that the profiles changed with inoculation type (spontaneous versus inoculated fermentation). Chocolate obtained from FA13 inoculated with S. cerevisiae strain contained a greater amount of organics acids, being categorised as sourer than chocolate produced by spontaneous fermentation of FA13. CEPEC2002 inoculated with S. cerevisiae strain in co-culture with P. kluyveri strain generated less sour and sweeter chocolate than spontaneous fermentation only.

CONCLUSIONS

Chocolates from inoculated assays with starter cultures were more accepted by evaluators, highlighting that P. kluyveri and S. cerevisiae influence the composition of VOCs. Besides, protein profiles also changed throughout fermentation. Further investigation should be conducted to clarify protein degradation dynamics during inoculated fermentations to define which of the microbial cultures positively affect the chocolate sensory characteristics. © 2021 Society of Chemical Industry.