Estimation of Phenolic and Flavonoid Compounds and Antioxidant Activity of Spent Coffee and Black Tea (Processing) Waste for Potential Recovery and Reuse in Sudan

Characteristic study of Candida rugosa lipase immobilized on lignocellulosic wastes: effect of support material

For the first time is reported the comparison of solid biocatalysts derived from Candida rugosa lipase (CRL) immobilized on different lignocellulosic wastes (rice husk, brewer's spent grain, hemp tea waste, green tea waste, vine bark, and spent coffee grounds) focusing on the characterization of these materials and their impact on the lipase-support interaction. The wastes were subjected to meticulous characterization by ATR-FTIR, BET, and SEM analysis, besides lignin content and hydrophobicity determination. Investigating parameters influencing immobilization performance revealed the importance of morphology, textural properties, and hydrophobic interactions revealed the importance of morphology, textural properties and especially hydrophobic interactions which resulted in positive correlations between surface hydrophobicity and lipase immobilization efficiency. Hemp tea waste and spent coffee grounds demonstrated superior immobilization performances (7.20 U/g and 8.74 U/g immobilized activity, 102.3% and 33.5% efficiency, 13.4% and 15.4% recovery, respectively). Moreover, they demonstrated good temporal stability (100% and 92% residual activity after 120 days, respectively) and retained 100% of their immobilized activity after five reuses in the hydrolysis of p-nitrophenyl palmitate in hexane. In addition, the study of enzymatic desorption caused by ionic strength and detergent treatments indicated mixed hydrophobic and electrostatic interactions in rice husk, vine bark, and spent coffee grounds supports, while hemp tea waste and green tea waste were dominated by hydrophobic interactions.

Upcycling of tea processing waste into kombucha-derived bioactive cellulosic composite for prospective wound dressing action

The aim of the study was to utilize kombucha-derived bacterial cellulosic sheet [KBC], formed as a by-product of fermented, sugared black tea (in the presence of a symbiotic culture of bacteria and yeast), for potential wound dressing applications. KBC was functionalized using aqueous and ethanolic extracts of different phytochemical agents using two ex-situ methods- casting and impregnation. It was observed that casted KBC functionalized with ethanolic extract of Turmeric (1.2% w/w) yielded a maximum zone of inhibition (24.37 ± 0.42 mm) against Pseudomonas aeruginosa. The hemocompatibility test confirmed the composite's biocompatible nature as the percentage hemocompatibility was found to be less than 5%. The MTT assay established its viability and anti-cancerous properties with Turmeric extract loaded KBC showing higher efficiency compared to Tulsi extract. FTIR analysis and SEM imaging confirmed the functionalization of cellulose sheets and the change in morphology. The contact angle analysis showed improved hydrophilic properties of the sheets for absorbing wound exudates, and the water absorption study revealed maximum absorptivity of up to 321.20 ± 6.23%. Thus, it can be concluded from the study that tea processing waste can be reused to produce a value-added product that can act as an efficient, cost-effective biomaterial for wound dressing applications.

Investigation of the Effects of Phenolic Extracts Obtained from Agro-Industrial Food Wastes on Gelatin Modification

In this study, modified bovine gelatin was produced using the alkaline technique with four different oxidized agro-industrial food waste (pomegranate peel (PP), grape pomace and seed (GP), black tea (BT), and green tea (GT)) phenolic extracts (AFWEs) at three different concentrations (1, 3, and 5% based on dry gelatin). The effect of waste type and concentration on the textural, rheological, emulsifying, foaming, swelling, and color properties of gelatin, as well as its total phenolic content and antioxidant activity, was investigated. Significant improvement in gel strength, thermal stability, and gelation rate of gelatin was achieved by modification with oxidized agro-industrial waste extracts. Compared to the control sample, 46.24% higher bloom strength in the GT5 sample, 5.29 and 6.01 °C higher gelling and melting temperatures in the PP5 sample, respectively, and 85.70% lower tmodel value in the GT3 sample were observed. Additionally, the total phenolic content, antioxidant activity, foam, and emulsion properties of the modified gels increased significantly. This study revealed that gelatins with improved technological and functional properties can be produced by using oxidized phenolic extracts obtained from agricultural industrial food wastes as cross-linking agents in the modification of gelatin.

Valorization of tea waste: Composition, bioactivity, extraction methods, and utilization

Tea is the most consumed beverage worldwide and has many health effects. Although there are many different types of tea, black tea and green tea comprise 98% of total tea production in the world. Tea waste production consists of withering, crushing, fermentation, drying and finally packaging processes. All of the waste generated during this production line is called tea waste. Tea production results in a significant amount of waste that cannot be effectively used for value creation. This waste contains many different components including protein, fiber, caffeine, and polyphenols. Due to its rich composition, it can be revalorized for different purposes. In this study, the general composition and bioactive compounds of tea waste were reviewed. Despite the fact that there have been few studies on the bioactivity of tea waste, those studies have also been discussed. The extraction techniques that are used to separate the compounds in the waste are also covered. It has been indicated that these valuable compounds, which can be separated from tea wastes by extraction methods, have the potential to be used for different purposes, such as biogas production, functional foods, food additives, silages, soluble packaging materials, and adsorbents. Although there are some studies on the revalorization of tea waste, new studies on the extraction of bioactive compounds are necessary to improve its utilization potential.

Sustainable management of tea wastes: resource recovery and conversion techniques

As the demand for tea (Camellia sinensis) has grown across the world, the amount of biomass waste that has been produced during the harvesting process has also increased. Tea consumption was estimated at about 6.3 million tonnes in 2020 and is anticipated to reach 7.4 million tonnes by 2025. The generation of tea waste (TW) after use has also increased concurrently with rising tea consumption. TW includes clipped stems, wasted tea leaves, and buds. Many TW-derived products have proven benefits in various applications, including energy generation, energy storage, wastewater treatment, and pharmaceuticals. TW is widely used in environmental and energy-related applications. Energy recovery from low- and medium-calorific value fuels may be accomplished in a highly efficient manner using pyrolysis, anaerobic digestion, and gasification. TW-made biochar and activated carbon are also promising adsorbents for use in environmental applications. Another area where TW shows promise is in the synthesis of phytochemicals. This review offers an overview of the conversion procedures for TW into value-added products. Further, the improvements in their applications for energy generation, energy storage, removal of different contaminants, and extraction of phytochemicals have been reviewed. A comprehensive assessment of the sustainable use of TWs as environmentally acceptable renewable resources is compiled in this review.

Antioxidant, antimicrobial and healing properties of an extract from coffee pulp for the development of a phytocosmetic

Consumer demand for natural, chemical-free products has grown. Food industry residues, like coffee pulp, rich in caffeine, chlorogenic acid and phenolic compounds, offer potential for pharmaceutical and cosmetic applications due to their antioxidant, anti-inflammatory, and antibacterial properties. Therefore, the objective of this work was to develop a phytocosmetic only with natural products containing coffee pulp extract as active pharmaceutical ingredient with antioxidant, antimicrobial and healing activity. Eight samples from Coffea arabica and Coffea canephora Pierre were analyzed for caffeine, chlorogenic acid, phenolic compounds, tannins, flavonoids, cytotoxicity, antibacterial activity, and healing potential. The Robusta IAC-extract had the greatest prominence with 192.92 μg/mL of chlorogenic acid, 58.98 ± 2.88 mg GAE/g sample in the FRAP test, 79.53 ± 5.61 mg GAE/g sample in the test of total phenolics, was not cytotoxic, and MIC 3 mg/mL against Staphylococcus aureus. This extract was incorporated into a stable formulation and preferred by 88% of volunteers. At last, a scratch assay exhibited the formulation promoted cell migration after 24 h, therefore, increased scratch retraction. In this way, it was possible to develop a phytocosmetic with the coffee pulp that showed desirable antioxidant, antimicrobial and healing properties.

Extraction methods, physiological activities and high value applications of tea residue and its active components: a review

Tea is a traditional plant beverage originating from China as one of the most popular beverages worldwide, which has been an important companion in modern society. Nevertheless, as the waste after tea processing, tea residues from agriculture, industry and kitchen waste are discarded in large quantities, resulting in waste of resources and environmental pollution. In recent years, the comprehensive utilization of tea residue resources has attracted people's attention. The bioactive components remaining in tea residues demonstrate a variety of health benefits and can be recycled using advanced extraction processes. Furthermore, researchers have been devoted to converting tea residues into derivatives such as biosorbents, agricultural compost, and animal feeds through thermochemical techniques and biotechnology. This review summarized the chemical composition and physiological activities of bioactive components from tea residue. The extraction methods of bioactive components in tea residue were elucidated and the main high-value applications of tea residues were proposed. On this basis, the utilization of tea residues can be developed from a single way to a multi-channel or cascade way to improve its economic efficiency. Novel applications of tea residues in different fields, including food development, environmental remediation, energy production and composite materials, are of far-reaching significance. This review aims to provide new insights into developing the utilization of tea residue using a comprehensive strategy and exploring the mechanism of active components from tea residue on human health and their potential applications in different areas.HighlightsThe composition and function of tea residue active components were introduced.The extraction methods of active components from tea residue were proposed.The main high-value applications of tea residues were summarized.The current limitations and future directions of tea residue utilization were concluded.

The Bioactive Substances in Spent Black Tea and Arabic Coffee Could Improve the Nutritional Value and Extend the Shelf Life of Sponge Cake after Fortification

The study aimed to evaluate the potential use of spent coffee powder (SCP) and spent tea powder (STP) as bioactive supplements for sponge cake. To achieve this aim, we initially compared the chemical properties of spent tea and coffee powders with those of their raw forms. Subsequently, three supplemented cake blends were prepared (1, 2, and 3% of SCP and STP) to test the effect of their addition on the chemophysical characteristics, sensory attributes, and shelf life of the final products. Our results indicated that spent tea and coffee are prospective materials for polyphenols. Spent tea powder could retain up to 72% (theaflavin trigallate), while spent coffee powder could retain up to 63.9% (1-caffeoylquinic acid) of the identified compounds compared to the raw materials. Furthermore, spent tea and coffee powders contained high levels of dietary fiber (18.95 and 31.65 g/100 g dry weight) and the elements potassium (254.6 and 1218.2 mg/100 g of DW), phosphorus (189.8 and 161.3 mg/100 g of DW), calcium (904.1 and 237.8 mg/100 g of DW), and magnesium (158.8 and 199.6 mg/100 g of DW). In addition, the fortified samples with SCP and STP significantly enhanced the nutritional values while retaining good sensory qualities compared to those of the control sample. Moreover, cakes fortified with the highest concentrations of SCP and STP (3%) showed a significant decrease in malondialdehyde content (MDA; 17.7 and 18.0 μg/g) and microbiological counts (2.4 and 2.5 log cfu/g) compared to the control cake after 14 days of storage. These findings suggest that incorporating SCP and STP into cakes not only enhances their nutritional value but also extends their shelf life. By utilizing these waste products, we can contribute to a more sustainable and ecofriendly food industry.

Valorization of Food Waste to Produce Value-Added Products Based on Its Bioactive Compounds

The rapid growth of the global population and changes in lifestyle have led to a significant increase in food waste from various industrial, agricultural, and household sources. Nearly one-third of the food produced annually is wasted, resulting in severe resource depletion. Food waste contains rich organic matter, which, if not managed properly, can pose a serious threat to the environment and human health, making the proper disposal of food waste an urgent global issue. However, various types of food waste, such as waste from fruit, vegetables, grains, and other food production and processing, contain important bioactive compounds, such as polyphenols, dietary fiber, proteins, lipids, vitamins, organic acids, and minerals, some of which are found in greater quantities in the discarded parts than in the parts accepted by the market. These bioactive compounds offer the potential to convert food waste into value-added products, and fields including nutritional foods, bioplastics, bioenergy, biosurfactants, biofertilizers, and single cell proteins have welcomed food waste as a novel source. This review reveals the latest insights into the various sources of food waste and the potential of utilizing bioactive compounds to convert it into value-added products, thus enhancing people’s confidence in better utilizing and managing food waste.

Bioaccumulation of industrial heavy metals and interactive biochemical effects on two tropical medicinal plant species

Concentrations of heavy metals (Cr, Cu, Fe, Mn, Ni, Pb, and Zn) accumulation were studied in the leaves of two medicinal plant species, namely Holarrhena pubescens and Wrightia tinctoria, from two industrial areas and a control area. Our comparison study revealed that industrialization significantly increased the accumulation of heavy metals in both plant species. A comparison study in control and industrial areas exhibited that heavy metal accumulation was higher in the industrially affected area than in the control area. Heavy metal concentration exceeded the permissible limit recommended by the WHO in both species of two industrial areas. However, both species accumulated the least heavy metal concentration in the control area. Biochemical investigation specifies that in response to heavy metal accumulation, both species increased the activity of hydrogen peroxide (H₂O₂), malondialdehyde content, the activity of enzymatic (superoxide dismutase and peroxidase) and nonenzymatic (ascorbic acid) antioxidant, but decreased the primary (soluble carbohydrate and total protein), secondary metabolites (phenol and flavonoid) content and free radical scavenging (DPPH) activity. This study indicates that industrialization potentially harms medicinal plants by reducing the efficacy of their medicinal property.

Multiple response optimizations on the leached-spray-dried bancha green tea towards healthy ageing

Bancha is a popular type of green tea in Japan, rich in tea polyphenols (TPs) and has a more astringent aroma with a less aromatic and strong character that complements functional foods. The blanching process is used to extract TPs and remove unwanted microorganisms, as well as inhibit phenolic oxidation. This study proposed a green tea blanching process followed by spray drying the extracts with maltodextrin. Furthermore, it is focused on maximizing the major chemical components of green tea (i.e., catechins, caffeine, and phenolic contents) based on powder particle size obtained through Multiple Response Surface Methodology optimizations. The results show that the proposed model accurately predicts leached-spray dried green tea's total catechin and caffeine content, with a coefficient of 0.9475 and 0.8692, respectively. This process yielded composite desirability of 0.9751, while individual desirability yielded excellent results of 1.0000, 0.9188, 1.0000, and 0.9839 for catechin, caffeine, phenol content, and powder. The settings appear to yield functional results for entire responses. Due to the concerns in tropical skin nutrition applications, smaller particle size green tea can promote better adsorption than larger sizes.

Properties of Biochar Derived from Tea Waste as an Alternative Fuel and Its Effect on Phytotoxicity of Seed Germination for Soil Applications

Tea waste as a potential biofuel and bio fertilizer was analyzed. Samples were collected from various tea species and torrefied to five different temperatures. All samples were analyzed for their proximal composition and calorific value. From the results, stoichiometric properties were calculated. A phytotoxicity test was performed, and the germination index was measured. Tea waste torrefied at 350 °C may be suitable biofuel reaching the calorific value of 25-27 MJ kg^-1, but with quite a high share of ash, up to 10%, which makes its use technically challenging and may lead to operating issues in a combustion chamber. The same biochar may be a suitable fertilizer for increasing the germination index, therefore, applicable to the soil. The non-torrefied sample and the sample treated at 250 °C are not suitable as fertilizers for being toxic. The total phenolic content in waste black tea was reduced from 41.26 to 0.21 mg g^-1, depending on the torrefaction temperature. The total flavonoid content was also reduced from 60.49 to 0.5 mg g^-1. The total antioxidant activity in the non-torrefied sample was 144 mg g^-1, and after torrefaction at 550 °C, it was 0.82 mg g^-1. The results showed that black tea waste residues have the potential for further use, for example, in agriculture as a soil amendment or as a potential biofuel.

Black coffee mitigates diethyl phthalate disrupted folliculogenesis, reduced gonadotropins, and ovarian lesions in female albino mice

Phthalates are multifunctional compounds with extensive applications and emerging environmental pollutants. Due to their ubiquity in the environment and unavoidable exposure to humans, concerns have been voiced about public health dangers. This study was aimed to explore the diethyl phthalate (DEP) toxicity and the potential protective effect of black coffee in female Swiss albino mice. Four-week-old mice, weighing 12 ± 1 g were segregated into five groups (n = 10), designated as G-I (without any treatment), G-II (treated with corn oil), G-III (exposed to 1.5 mg/g body wt. (B.W.) DEP), G-IV (received 2 μg/g B.W coffee), and G-V (co-administrated with 1.5 mg/g DEP and 2 μg/g B.W coffee). Before dose administration, the coffee extract was assessed for its antioxidant potential through FRAP, TPC, and GC-MS analyses. Respective phthalates/coffee doses were administrated orally, once a day for 8 weeks consecutively starting from the prepubescent stage. After 56 days, mice were acclimated for 4 days then dissected. Morphological assessments showed an irregular shape of the ovaries in DEP-treated mice as compared to the control. The average bodyweight of DEP-intoxicated mice (p ≤ 0.05) increased notably against control, while DEP plus coffee group showed a regular gain in the average weight of mice. The gonado-somatic index showed non-significant variations among all groups. Micrometric studies showed that the diameter of secondary follicles (115 µm) in the ovaries of DEP-exposed mice (p ≤ 0.001) decreased significantly as compared to control (204 µm); conversely, follicular diameter in the coffee control group (248) increased significantly. Serum FSH and LH levels were significantly increased in DEP-exposed mice with a noteworthy decrease in estrogen level while hormonal levels of all other groups were comparable to control. Histological sections of DEP-exposed mice ovaries showed anatomical disruptions contrary to other groups, which were comparable with control. Antioxidant potential was checked in ovaries homogenates; FRAP values showed a notable decrease in DEP group in comparison with the control group, in contrast to G-V, when DEP was co-administrated with coffee. This study concluded that black coffee has protective effect, against DEP-instigated reproductive toxicity in Swiss albino female mice.

Biovalorisation of spent Konacha tea leaves via single-culture fermentation involving wine yeasts and lactic acid bacteria

AIMS

The objective of this study was to explore the potential of fermentation as a biovalorisation strategy for spent tea leaves (STL), a major agri-food waste generated from the tea extraction industry. Fermentation by wine yeasts or lactic acid bacteria (LAB) have shown promising results in previous studies across various substrates.

METHODS AND RESULTS

Konacha (green tea) STL slurries were inoculated with single strains of wine yeasts or LAB, respectively. After a 48-h fermentation, changes in selected non-volatile and volatile compositions were evaluated. Fermentation by LAB increased organic acid content by 5- to 7-fold (except Lactobacillus fermentum) and modulated the composition of major tea catechins, while wine yeast fermentation resulted in a 30% increase in amino acid content. Strain-specific production of specific volatile compounds was also observed, such as butanoic acid (L. fermentum), isoamyl acetate (Pichia kluyveri) and 4-ethylphenol (L. plantarum).

CONCLUSIONS

Both volatile and non-volatile compound compositions of Konacha STL were successfully modified via wine yeast and LAB fermentation.

SIGNIFICANCE AND IMPACT OF STUDY

Our findings indicate that Konacha STL is a suitable medium for biovalorisation by wine yeasts or LAB via the generation of commercially useful volatile and non-volatile compounds. Future optimizations could further render fermentation an economically viable strategy for the upcycling of STL.

Jelly Fig (Ficus awkeotsang Makino) Exhibits Antioxidative and Anti-Inflammatory Activities by Regulating Reactive Oxygen Species Production via NFκB Signaling Pathway

Antioxidant and anti-inflammatory activities of Ficus awkeotsang Makino extract (FAE) on Hs68 fibroblasts and BALB/c nude-mouse models are evaluated in this study. FAE was found to be non-toxic and showed high levels of DPPH, H₂O₂, and hydroxyl radical scavenging abilities; a ferrous chelating capacity; as well as ferric-reducing antioxidant capability. The antioxidant activity of FAE was strongly associated with polyphenolic content (flavonoids at 10.3 mg QE g⁻¹ and total phenol at 107.6 mg GAE g⁻¹). The anti-inflammatory activity of FAE and the underlying molecular mechanisms were also investigated. The a* value of the mouse dorsal skin after treatment with FAE at 1.5 mg/mL in addition to chronic UVB exposure was found to decrease by 19.2% during a ten-week period. The anti-inflammatory effect of FAE was evidenced by the decreased accumulation of inflammatory cells and skin thickness. Expression levels of UVB-induced inflammatory proteins, including ROS, NF-κB, iNOS, COX-2, and IL-6, were significantly reduced upon FAE treatment in vitro and in vivo. Collectively, our results suggest that the inhibition of ROS and UVB-induced activation of the NF-κB downstream signaling pathway by FAE, indicating considerable potential as a versatile adjuvant against free radical damage in pharmaceutical applications.

Advances in bioconversion of spent tea leaves to value-added products

Spent tea leaves (STL) are generated after the extraction of liquor from processed tea leaves and are regarded as an underutilized waste. STL are rich in essential amino acids, ω-6 and ω-3 fatty acids, alkaloids (theobromine and caffeine), polyphenols (catechin, theaflavins and rutin) and minerals (Ca, P, K, Mg, Mn) that could be utilized for the production of industrially important products. Vermicomposting, anaerobic digestion, silage preparation and fermentation are currently used as low cost methods for the bioconversion of STL to a usable form. Structural, morphological and chemical modification of STL after suitable bioconversion enables its application in the development of biopolymers, biofuels, catechin derivatives, biochar, absorbents for dye, and for removal of Cd, Hg, Cr(IV), As(V) and aspirin. This review discusses the composition, characterization, bioconversion and value added product generation from STL while highlighting prospective applications of STL in developing battery electrodes, nanocatalysts, insulation materials and edible bioactive peptides.

Comparison and Optimization of Operational Parameters in Removal of Heavy Metal Ions from Aqueous Solutions by Low-Cost Adsorbents

Removal of heavy metal ions such as cadmium, lead, chromium, and iron from industrial wastewater is one of the most critical environmental problems. In this research, natural and low-cost adsorbents like the tangerine peel, bovine gut, tea waste, and sunflower seed hull were used for adsorption of heavy metals, such as chromium and iron, from contaminated solutions. The effects of environmental factors such as contact time, pH, the amount of adsorbent dose, and the initial concentration of metal ions in synthetic solution were investigated to obtain optimal conditions for the adsorption of heavy metal ions. For separation of chromium metal ion from aqueous solution, tea waste, tangerine peel, bovine gut, and sunflower seeds hull showed adsorption capacity of 85%, 51%, 46%, and 34%, respectively, while for the adsorption of iron (III), the adsorption capacities of tea waste, bovine gut, tangerine peel, and sunflower seeds hull were 96%, 96%, and 87%, respectively. The adsorption isotherms were in decent correlation with the Langmuir and Freundlich isotherm models. The adsorption kinetics of iron and chromium has a proper validation with the pseudo-second-order kinetic model. The BET and FTIR analyses were also reported to investigate the adsorption properties. This study suggests these adsorbents as low-cost and economical materials for the adsorption of chromium and iron ions with a high adsorption rate.

Effect of germination, roasting, and variety on physicochemical, techno-functional, and antioxidant properties of chickpea (Cicer arietinum L.) protein isolate powder

Chickpeas are a very important part of the human diet due to their nutritional and bioactive composition. Ethiopia is one of the top chickpea producers and consumers of chickpea-based products daily. However, limited studies were conducted on the effect of common processing methods, roasting and germination, on techno-functional and nutritional properties of chickpea protein isolates. Two varieties of chickpea, Arerti (Kabuli type) and Natoli (Desi type), were selected and treated with different roasting temperature (150 and 180 °C) and germination time (24, 48, and 72 h). The protein was isolated with alkaline-solubilization followed by isoelectric precipitation. Freeze-dried isolates were investigated for proximate composition, techno-functional properties, antioxidant properties, and antinutritional content. Chickpea protein isolates (CPIs) mean protein content was between 79.72 and 87.43%, comparatively lower for those from roasted and higher for those from germinated chickpea. Mean values of CPIs’ water holding capacity (WHC), oil holding capacity (OHC), protein solubility (PS), foaming capacity (FC), and Emulsifying capacity (EC) for both varieties were in a range of 1.07–2.47 g/g, 1.40–2.21 g/g, 43.88–69.99%, 14.00–94.00%, and 56.44–84.16%, respectively. Roasting at 150 °C improved most of the techno-functional properties (WHC, OHC, PS, and FC) while roasting at 180 °C negatively affected almost all the techno-functional properties. Both heat treatments significantly increased the antioxidant properties of the isolates. Germination for 72 h was the best treatment in improving all antioxidant properties. CPIs from treated chickpea had lower antinutritional content than those from native chickpea except for phytate on Natoli variety where no statistical difference (p > 0.05) was observed. The finding showed that based on the intended use the different techno-functional properties of the isolates can be altered by applying those treatments. Proximate, techno-functional, antioxidant, and antinutritional characters indicated that CPIs can be a good ingredient for the food industry to formulate functional foods.

An analytical method for the simultaneous quantification of 30 bioactive compounds in spent coffee ground by HPLC-MS/MS

Spent coffee ground (SCG) is the remaining residue produced after extraction of coffee, and it is considered a source of unextracted bioactive compounds. For this, in the latest years, the attention has been focused to innovative reuses that can exploit the potentiality of SCG. Unfortunately, the content of bioactive compounds has not been thoroughly studied yet, and the major of publication has investigated the caffeine and chlorogenic acids levels, total polyphenol contents, and total flavonoid content. Hence, these approaches have determined only an estimation of flavonoids and polyphenols content and lack on single polyphenols investigation. Therefore, the objective of the current work was to provide a deep characterization of bioactive compounds in SCG. For this purpose, a new analytical method for the quantification of 30 molecules, including caffeine, chlorogenic acids, phenolic acids, flavonoids, and secoiridoids, has been developed using high-performance liquid chromatography tandem mass spectrometry. Moreover, several extraction procedures, that is, liquid-solid extraction assisted and not by ultrasounds, testing diverse solvents, were evaluated. Liquid-solid extraction assisted by sonication, with water/ethanol (30/70, v/v), resulted the best in terms of total bioactive compounds, and, once validated, the new analytical method was applied to five different espresso SCG samples. Data showed that caffeine (means: 1193.886 ± 57.307 mg kg^-1 ) and chlorogenic acids (means of total CQAs: 1705.656 ± 88.694 mg kg^-1 ) were the most abundant compounds in all SCG samples followed by phenolic acids such as caffeic, ferulic, gallic, p-coumaric, syringic, trans-cinnamic, and vanillic acid. Moreover, some flavonoids, that is, rutin, cyanidin 3-glucoside, and quercetin, occurred in almost all samples. This work provided a deepened characterization of bioactive compounds in SCG and can contribute to develop new strategies of reuses.

Optimization of the roasting conditions to lower acrylamide content and improve the nutrient composition and antioxidant properties of Coffea arabica

Roasting is the most common method of processing coffee. During roasting, aromatic compounds are generated due to various reactions, which are important for developing color, flavor and aroma. Acrylamide is an undesirable carcinogenic substance that is metabolically activated and formed during the coffee roasting process. Coffea arabica was first found in Ethiopia, and Ethiopia can produce a large volume of coffee. The major coffee-producing areas in Ethiopia are Hararghe, Sidama, Gimbi/Nekemte, Yergachefe and Limu. The primary purpose of this study was to quantify the acrylamide contents of brewed and roasted coffee collected from street coffee sellers and industrial processors found in Addis Ababa, Ethiopia, and optimize the roasting conditions for Sidama coffee. The acrylamide contents were determined by HPLC using a DAD at 210 nm, the antioxidant property were examined using a UV-spectrophotometer, and moisture and nutrient composition of coffee was determined using the method described by the AOAC (Association of Official Analytical Chemists). The roasting temperature and time were optimized based on the acrylamide content, nutritional composition and antioxidant property of the coffee using central composite design. The roasting temperature and time significantly affected (p<0.05) the acrylamide level, nutritional composition and antioxidant property of the coffee. The acrylamide contents of street and industrial processed powdered coffee were 346 ±19 to 701±38μg/kg and 442±14 to 906±7μg/kg, respectively. Brewed coffee from street vendors and industrial processing had acrylamide contents of 25±2 to 49±1μg/L and 63±2 to 89±4μg/L, respectively. The EC50 values for scavenging radicals for the optimized coffee ranged from 171±0 to 111±4 μg/L. The optimal roasting temperature and time were 190°C and 6 minutes, at this temperature and time the acrylamide content decreased, and the antioxidant and nutritional compositions of the coffee improved.

Valorization of spent black tea by recovery of antioxidant polyphenolic compounds: Subcritical solvent extraction and microencapsulation

Spent black tea (SBT), waste remaining after producing tea beverages, is potentially an underutilized source of antioxidant phenolic compounds. This study evaluated the integrated processes of subcritical solvent extraction of polyphenols from SBT followed by microencapsulation to improve the stability of obtained extract. Optimization of extraction conditions was carried out by response surface methodology for the best recovery of antioxidant phenolic compounds. Two variables [temperature (°C) and ethanol concentration (%)] were used to design the optimization model using central composite inscribed. Extraction temperature of 180°C and ethanol concentration of 71% were optimal for the highest yield of total polyphenols (126.89 mg gallic acid equiv./g SBT) and 2,2-diphenyl-1-picrylhydrazyl scavenging activity (69.08 mg gallic acid equiv./g SBT). The extract was encapsulated using pectin, sodium caseinate, and a blend of these compounds (ratio 1:1) as wall materials by spray drying. The wall material significantly influenced (p < .05) encapsulation efficiency, particle size, morphology, thermal stability, crystallinity, and storage stability. The blend of wall materials produced an amorphous powder with the highest phenolic retention (94.28%) in the accelerated storage at 45°C for 40 days. The microcapsules prepared with sodium caseinate were smaller with lowest mean diameter and highest thermal stability than the other types of materials. Obtained microencapsulates have potential use in different food systems to enhance their antioxidant property.

Evaluation of the Use of a Coffee Industry By-Product in a Cereal-Based Extruded Food Product

The evaluation of by-products to be added to food products is complex, as the residues must be analyzed to demonstrate their potential use as safe foods, as well as to propose the appropriate process and product for recycling. Since coffee is a very popular beverage worldwide, the coffee industry is responsible for generating large amounts of by-products, which include the coffee silverskin (CS), the only by-product of the roasting process. In this work, its characterization and food safety were evaluated by chemical composition assays, microbiological determinations, aflatoxin measurements and acute toxicity tests. The results showed that CS is safe for use in food, in addition to providing dietary fiber, protein and bioactive compounds. An extruded cereal-based ready-to-eat food product was developed through an extreme vertices mixture design, producing an extruded food product being a source of protein and with a high fiber content. Up to 15% of CS was incorporated in the extruded product. This work contributes to the establishment of routes for the valorization of CS; nevertheless, further research is necessary to demonstrate the sustainability of this food industry by-product.

Honey and Its Phenolic Compounds as an Effective Natural Medicine for Cardiovascular Diseases in Humans?

Honey is a sweet, viscous syrup produced by the honey bee (Apis mellifera). It is probably the first natural sweetener ever discovered, and is currently used as a nutritious food supplement and medicinal agent. The aim of the present mini-review is to summarize and update the current knowledge regarding the role of honey in CVDs based on various experimental models. It also describes the role of its phenolic compounds in treating CVDs. Many such phenolic and flavonoid compounds, including quercetin, kaempferol, apigenin, and caffeic acid, have antioxidant and anti-platelet potential, and hence may ameliorate cardiovascular diseases (CVDs) through various mechanisms, such as by decreasing oxidative stress and inhibiting blood platelet activation. However, as the phenolic content of a particular type of honey is not always known, it can be difficult to determine whether any observed effects on the human cardiovascular system may be associated with the consumption of honey or its constituents. Therefore, further experiments in this area are needed.