Influence of roasting conditions on the biogenic amine content in cocoa beans of different Theobroma cacao cultivars

Effects of Lactic Acid Bacteria on Reducing the Formation of Biogenic Amines and Improving the Formation of Antioxidant Compounds in Traditional African Sourdough Flatbread Fermentation

This study investigated the safety and functionality of traditional African sourdough flatbread (kisra), based on the content of biogenic amines (BAs) and antioxidant compounds and their improvement using lactic acid bacteria (LAB) species. The primary BAs detected in naturally fermented kisra were tyramine, histamine, putrescine, and cadaverine, with putrescine being the most abundant after baking. In vitro BA production of microorganisms isolated from kisra sourdough revealed that the Enterococcus genus contributed to tyramine accumulation, whereas presumptive yeasts may contribute to putrescine and cadaverine accumulation. The use of LAB species, including Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Levilactobacillus brevis, and Weissella cibaria, significantly reduced putrescine content to less than about 23% of that of naturally fermented kisra, and eliminated tyramine, histamine, and cadaverine formation. Meanwhile, DPPH scavenging activity, total polyphenolic content, and tannin content in naturally fermented kisra were 85.16%, 1386.50 µg/g, and 33.16 µg/g, respectively. The use of LAB species did not affect the DPPH scavenging activity or tannin content but significantly increased the total phenolic content by up to 20% compared to naturally fermented kisra. Therefore, fermentation with LAB starter cultures might be a promising approach to improve the safety related to BAs as well as the functionality of kisra bread.

Counts of mesophilic aerobic, mesophilic anaerobic, thermophilic aerobic sporeforming bacteria and persistence of Bacillus cereus spores throughout cocoa powder processing chain

Sporeforming bacteria are a concern in some food raw materials, such as cocoa powder. Samples (n = 618) were collected on two farms and at several stages during cocoa powder manufacture in three commercial processing lines to determine the impact of each stage on bacterial spore populations. Mesophilic aerobic, mesophilic anaerobic, thermophilic aerobic, and Bacillus cereus spore populations were enumerated in all the samples. Genetic diversity in B. cereus strains (n = 110) isolated from the samples was examined by M13 sequence-based PCR typing, partial sequencing of the panC gene, and the presence/absence of ces and cspA genes. The counts of different groups of sporeforming bacteria varied amongst farms and processing lines. For example, the counts of mesophilic aerobic spore-forming (MAS) populations of cocoa bean fermentation were lower than 1 log spore/g in Farm 1 but higher than 4 log spore/g in Farm 2. B. cereus isolated from cocoa powder was also recovered from cocoa beans, nibs, and samples after roasting, refining, and pressing, which indicated that B. cereus spores persist throughout cocoa processing. Phylogenetic group IV was the most frequent (73%), along with processing. Strains from phylogenetic group III (14 %) did not show the ces gene's presence.

Yeast strains do have an impact on the production of cured cocoa beans, as assessed with Costa Rican Trinitario cocoa fermentation processes and chocolates thereof

The microbiological and metabolic outcomes of good cocoa fermentation practices can be standardized and influenced through the addition of starter culture mixtures composed of yeast and bacterial strains. The present study performed two spontaneous and 10 starter culture-initiated (SCI) cocoa fermentation processes (CFPs) in Costa Rica with local Trinitario cocoa. The yeast strains Saccharomyces cerevisiae IMDO 050523, Hanseniaspora opuntiae IMDO 020003, and Pichia kudriavzevii IMDO 060005 were used to compose starter culture mixtures in combination with the lactic acid bacterium strain Limosilactobacillus fermentum IMDO 0611222 and the acetic acid bacterium strain Acetobacter pasteurianus IMDO 0506386. The microbial community and metabolite dynamics of the cocoa pulp-bean mass fermentation, the metabolite dynamics of the drying cocoa beans, and the volatile organic compound (VOC) profiles of the chocolate production were assessed. An amplicon sequence variant approach based on full-length 16S rRNA gene sequencing instead of targeting the V4 region led to a highly accurate monitoring of the starter culture strains added, in particular the Liml. fermentum IMDO 0611222 strain. The latter strain always prevailed over the background lactic acid bacteria. A similar approach, based on the internal transcribed spacer (ITS1) region of the fungal rRNA transcribed unit, was used for yeast strain monitoring. The SCI CFPs evolved faster when compared to the spontaneous ones. Moreover, the yeast strains applied did have an impact. The presence of S. cerevisiae IMDO 050523 was necessary for successful fermentation of the cocoa pulp-bean mass, which was characterized by the production of higher alcohols and esters. In contrast, the inoculation of H. opuntiae IMDO 020003 as the sole yeast strain led to underfermentation and a poor VOC profile, mainly due to its low competitiveness. The P. kudriavzevii IMDO 060005 strain tested in the present study did not contribute to a richer VOC profile. Although differences in VOCs could be revealed in the cocoa liquors, no significant effect on the final chocolates could be obtained, mainly due to a great impact of cocoa liquor processing during chocolate-making. Hence, optimization of the starter culture mixture and cocoa liquor processing seem to be of pivotal importance.

Varietal Influence on the Formation of Bioactive Amines during the Processing of Fermented Cocoa with Different Pulp Contents

During cocoa processing, there can be the formation of bioactive amines, which are compounds that play relevant roles not only in plant development but also in human health. Thus, we aimed to investigate the presence and levels of bioactive amines during the processing of two important varieties of cocoa (PS 1319 and Parazinho). The seeds were fermented using five different pulp proportions: 100% (E1), 80% (E2), 60% (E3), and 0% (total pulp removal) (E4). The beans were fermented and dried on a farm following traditional procedures. Soon after, they were roasted and processed into chocolates with 60% cocoa in the laboratory. Bioactive amine contents were determined by ion-pair reversed-phase HPLC and fluorometric detection in the samples before, during, and after fermentation, after drying and roasting (nibs), and in the liquor and chocolate. The only amines found before processing in PS 1319 and Parazinho, respectively, in dry weight basis (dwb), were putrescine (pulp, 13.77 and 12.31; seed, 5.88 and 4.58) and serotonin (seed, 2.70 and 2.54). Fermentation was shorter for Parazinho (156 h) compared to PS 1319 (180 h). The changes in amines were affected by the cocoa variety. During drying, the presence of cadaverine stood out, appearing in all treatments of the PS 1319 variety, reaching 17.96 mg/kg dwb, and in two treatments of the Parazinho variety (100 and 60% pulp). During roasting, most of the amines decreased, except for phenylethylamine, which increased up to 2.47 mg/kg dwb for Parazinho and 1.73 mg/kg dwb for PS 1319. Most of the amines formed and built up (e.g., tyramine, putrescine, and cadaverine) during fermentation were not available or were at low levels in the nibs. Most of the amines found during processing did not reach the final product (chocolate), except for cadaverine in PS 1319 without pulp (7.54 mg/kg dwb). Finally, we confirmed how pulp content, processing, and variety influence the content of bioactive amines in cocoa and chocolate. These changes can be better demonstrated through a heatmap and principal component analysis.

The effect of cocoa alkalization on the non-volatile and volatile mood-enhancing compounds

Alkalization is a process to improve color, dispersibility and flavor of cocoa powder but is likely to have a negative effect on the phytochemicals. Hereto, the impact of alkalization degree (none, medium and high) on the potential mood-enhancing compounds corresponding to the four levels of the mood pyramid model (flavanols, methylxanthines, biogenic amines and orosensory properties) was investigated. The phytochemical content, analyzed via UPLC-HRMS, showed reduction of specific potential mood-enhancing compounds upon alkalization, implying a decrease in bitterness and astringency. Moreover, volatile compounds analysis via HS-SPME-GC-MS indicated that alkalization reduced the levels of volatile compounds, responsible for acidity, fruity, floral and cocoa aromas. With respect to the orosensory properties, the cocoa powder palatability was suggested to be increased due to reduced acidity, bitterness, and astringency, while the desired volatile compounds were reduced. However, sensorial analysis is required to link the volatile results with the overall effect on the flavor perception.

The Effects of Different Processing Methods on the Levels of Biogenic Amines in Zijuan Tea

This study aimed to evaluate the effects of processing methods on the content of biogenic amines in Zijuan tea by using derivatization and hot trichloroacetic acid extraction with HPLC-UV. The results showed that the most abundant biogenic amine in the original leaves was butylamine, followed by ethylamine, methylamine, 1,7-diaminoheptane, histamine, tyramine, and 2-phenethylamine. However, during the process of producing green tea, white tea, and black tea, the content of ethylamine increased sharply, which directly led to their total contents of biogenic amines increasing by 184.4%, 169.3%, and 178.7% compared with that of the original leaves, respectively. Unexpectedly, the contents of methylamine, ethylamine, butylamine, and tyramine in dark tea were significantly reduced compared with those of the original leaves. Accordingly, the total content of biogenic amines in dark tea was only 161.19 μg/g, a reduction of 47.2% compared with that of the original leaves, indicating that the pile-fermentation process could significantly degrade the biogenic amines present in dark tea.

Reducing biogenic amine in seriflux and huangjiu by recycling of seriflux inoculated with Lactobacillus plantarum JN01

High content of biogenic amine (BA) in huangjiu could pose serious quality concerns. More than 71% of BA in huangjiu were carried over from seriflux (rice soaking wastewater), which were produced by some BA producing bacteria during rice soaking process. A BA non-producing strain, Lactobacillus plantarum JN01, was introduced to rice soaking process, which decreased BA content in seriflux by 93.8% by niche competition at bench scale. Recycling of seriflux inoculated with L. plantarum JN01 at pilot run scale for ten batches demonstrated that BA in seriflux and huangjiu were reduced by 78.4% and 87.7%, respectively. The safety of huangjiu was enormously improved without affecting on the profiles of flavor compounds. Our results demostrated that seriflux recycling technology could reduce 50% of water consumption and achieve "zero effluents" in rice soaking process, which might potentially be a "green technology" not only for huangjiu brewing industry, but also for other related traditional fermented food industries.

Effects of Various Pre-Treatment and Cooking on the Levels of Biogenic Amines in Korean and Norwegian Mackerel

This study analyses the biogenic amines (BAs) formed in mackerel cooked by various methods and conditions. Five BAs, including tryptamine, β-phenylethylamine, putrescine, histamine, and spermidine, were analysed by high-performance liquid chromatography with UV detection. The level of total BAs was higher in the mackerel fillet (108.14 µg/g) than the headed and gutted fish (91.58 µg/g). Roasted, fried, and stewed mackerel recorded total BA concentrations of 54.28, 82.25, and 163.05 µg/g, respectively. Stewed mackerel contained about 3-fold more BAs than roasted mackerel. The level of total BAs in mackerel increased significantly up to 190%, 236% and 152% as the roasting temperature increased, upon frying, and as stewing temperature increased, respectively (p < 0.05).

Chemical and biological properties of cocoa beans affected by processing: a review

Cocoa (Theobroma cacao L.) is widely cultivated in tropical countries. The cocoa beans are a popular ingredient of confectionery. Cocoa beans contain various chemicals that contribute to their bioactivity and nutritional properties. There has been increasing interest in developing cocoa beans for "healthy" food products. Cocoa beans have special combination of nutrients such as lipids, carbohydrates, proteins and other compounds of biological activities. The bioactive phytochemicals include methylxanthines, polyphenols, biogenic amines, melanoidins, isoprostanoids and oxalates. These phytochemicals of cocoa are related to various in vivo and in vitro biological activities such as antioxidation, anti-cancer, anti-microbial, anti-inflammation, anti-diabetes, cardiovascular protection, physical improvement, anti-photoaging, anti-depression and blood glucose regulation. The potential of bioactive compounds in cocoa remains to be maximized for food and nutritional applications. The current processing technology promotes the degradation of beneficial bioactive compounds, while maximizing the flavors and its precursors. It is not optimized for the utilization of cocoa beans for "healthy" product formulations. Modifications of the current processing line and non-conventional processing are needed to better preserve and utilize the beneficial bioactive compounds in cocoa beans.

Effect of the growing area on the fat content and the fatty acid composition of Ecuadorian cocoa beans

Cocoa presents a high fat content and a unique fatty acid profile defining its technological and nutritional properties. This study evaluated the fat content and fatty acid composition of Nacional cocoas, a worldwide recognised "fine" variety, collected in 85 Ecuadorian farms while taking into account 3 geographical levels (region, province, and canton). The total fat content varied from 45.61 ± 1.27 to 52.13 ± 0.58 g/100 g DW and was higher in the provinces and cantons from the Amazonian region than in those from the Pacific Coast region. A remarkable effect of the region and the province was shown on the content of individual fatty acids of Nacional cocoa beans. Total amounts of saturated and unsaturated fatty acids also depended on the growing area. Multivariate analysis provided a comprehensive assessment of the cocoa fat composition according to the origin, which may be useful for the selection of cocoas with specific technological and nutritional characteristics.

Exploring the Capability of Yeasts Isolated from Colombian Fermented Cocoa Beans to Form and Degrade Biogenic Amines in a Lab-Scale Model System for Cocoa Fermentation

Yeast starters for cocoa fermentation are usually tested according to their enzymatic activities in terms of mucilage degradation and flavor improvement, disregarding their influence on the production or elimination of toxic compounds as biogenic amines (BAs), important for human health. In this work, we tested 145 strains belonging to 12 different yeast species and isolated from the Colombian fermented cocoa beans (CB) for their capability of producing BAs in vitro. Sixty-five strains were able to decarboxylate at least one of the amino acids tested. Pichia kudriavzevii ECA33 (Pk) and Saccharomyces cerevisiae 4 (Sc) were selected to evaluate their potential to modulate BAs, organic acids, and volatile organic compounds (VOCs) accumulation during a simulated cocoa fermentation. The growth of Sc or Pk in the presence of CB caused a significant reduction (p < 0.05) of 2-phenylethylamine (84% and 37%) and cadaverine (58% and 51%), and a significant increase of tryptamine and putrescine with a strong influence of temperature in BA formation and degradation. In addition, our findings pointed out that Pk induced a major production of fatty acid- and amino acid-derived VOCs, while Sc induced more VOCs derived from fatty acids metabolism. Our results suggest the importance of considering BA production in the choice of yeast starters for cocoa fermentation.

Chemical implications and time reduction of on-farm cocoa fermentation by Saccharomyces cerevisiae and Pichia kudriavzevii

The use of starters during fermentation has been gaining momentum as it can warrant high-quality chocolate. The objective of this study was to investigate the influence of Saccharomyces cerevisiae (Sc) and Pichia kudriavzevii (Pk) during on-farm fermentation on physico-chemical and microbiological characteristics and levels of methylxanthines and bioactive amines of cocoa. Four treatments were used: ScPk (1:1), only Sc, only Pk, and no starter (control). The starters lead to changes throughout fermentation, but provided fermented cocoa with similar pH, titratable acidity, reducing sugars and phenolic compounds. ScPk shortened fermentation time by 24 h. The ScPk fermented and dried cocoa had higher levels of monomeric phenols, methylxanthines, phenylethylamine and lower levels of the putrefactive amines - putrescine and cadaverine (p < 0.05). The results were confirmed by multivariate analysis. Based on these results, the mixture of both yeasts species is a promising starter for cocoa fermentation decreasing duration time and modulating high-quality components.

Roasting-induced changes in cocoa beans with respect to the mood pyramid

The mood pyramid of cocoa, which was previously proposed as a new concept, consists of four levels (flavan-3-ols, methylxanthines, minor compounds and orosensory properties). Roasting is a crucial process for flavor development in cocoa but is likely to have a negative impact on the phytochemicals. We investigated the effect of roasting time (10-50 min) and temperature (110-160 °C) on the potential mood-enhancing compounds corresponding to the distinct mood pyramid levels. Phytochemicals were analyzed using UPLC-HRMS, while the flavor was mapped via aroma (HS-SPME-GC-MS) and generic descriptive analysis (trained panel). Results revealed that roasting at 130 °C for 30 min did not significantly affect the levels of epicatechin, procyanidin B2 and theobromine, while salsolinol significantly increased. Moreover, bitterness and astringency were reduced and the desired cocoa flavor was developed. Thus, through selection of appropriate roasting time and temperature conditions phytochemicals of interest could be retained without comprising the flavor.

The biogenic amine tryptamine, unlike β-phenylethylamine, shows in vitro cytotoxicity at concentrations that have been found in foods

β-phenylethylamine and tryptamine are biogenic amines (BA) often found in foods. In general, BA are assumed to be toxic and their accumulation in food is not recommended. However, present knowledge regarding the toxicity of β-phenylethylamine and tryptamine is limited; more information is needed if qualitative and quantitative risk assessments of foods are to be successfully conducted. This study describes a real-time analysis of β-phenylethylamine and tryptamine toxicity on a human intestinal epithelial cell line. Both BA caused cell necrosis and apoptosis, although the former was the main mode of action of β-phenylethylamine, and the latter the main mode of action of tryptamine. Only tryptamine was cytotoxic at concentrations found in BA-rich foods. The results presented in this work may contribute to establish legal limits for β-phenylethylamine and tryptamine in food.

Effect of Fermentation, Drying and Roasting on Biogenic Amines and Other Biocompounds in Colombian Criollo Cocoa Beans and Shells

The composition of microbiota and the content and pattern of bioactive compounds (biogenic amines, polyphenols, anthocyanins and flavanols), as well as pH, color, antioxidant and reducing properties were investigated in fermented Criollo cocoa beans and shells. The analyses were conducted after fermentation and drying (T1) and after two thermal roasting processes (T2, 120 °C for 22 min; T3, 135 °C for 15 min). The fermentation and drying practices affected the microbiota of beans and shells, explaining the great variability of biogenic amines (BAs) content. Enterobacteriaceae were counted in a few samples with average values of 10³ colony forming units per gram (CFU g⁻¹), mainly in the shell, while Lactobacillus spp. was observed in almost all the samples, with the highest count in the shell with average values of 10⁴ CFU g⁻¹. After T1, the total BAs content was found to be in a range of 4.9÷127.1 mg kg⁻¹_DFW; what was remarkable was the presence of cadaverine and histamine, which have not been reported previously in fermented cocoa beans. The total BAs content increased 60% after thermal treatment T2, and of 21% after processing at T3, with a strong correlation (p < 0.05) for histamine (ß = 0.75) and weakly correlated for spermidine (ß = 0.58), spermine (ß = 0.50), cadaverine (ß = 0.47) and serotonine (ß = 0.40). The roasting treatment of T3 caused serotonin degradation (average decrease of 93%) with respect to unroasted samples. However, BAs were detected in a non-alarming concentration (e.g., histamine: n.d ÷ 59.8 mg kg⁻¹_DFW; tyramine: n.d. ÷ 26.5 mg kg⁻¹_DFW). Change in BAs level was evaluated by principal component analysis. PC1 and PC2 explained 84.9% and 4.5% of data variance, respectively. Antioxidant and reducing properties, polyphenol content and BAs negatively influenced PC1 with both polyphenols and BA increasing during roasting, whereas PC1 was positively influenced by anthocyanins, catechin and epicatechin.

The Kinetics of Total Phenolic Content and Monomeric Flavan-3-ols during the Roasting Process of Criollo Cocoa

Cocoa beans are the main raw material for the manufacture of chocolate and are currently gaining great importance due to their antioxidant potential attributed to the total phenolic content (TPC) and the monomeric flavan-3-ols (epicatechin and catechin). The objective of this study was to determine the degradation kinetics parameters of TPC, epicatechin, and catechin during the roasting process of Criollo cocoa for 10, 20, 30, 40, and 50 min at 90, 110, 130, 150, 170, 190, and 200 °C. The results showed a lower degradation of TPC (10.98 ± 6.04%) and epicatechin (8.05 ± 3.01%) at 130 °C and 10 min of roasting, while a total degradation of epicatechin and a 92.29 ± 0.06% degradation of TPC was obtained at 200 °C and 50 min. Reaction rate constant (k) and activation energy (Ea) were 0.02–0.10 min⁻¹ and 24.03 J/mol for TPC and 0.02–0.13 min⁻¹ and 22.51 J/mol for epicatechin, respectively. Degradation kinetics of TPC and epicatechin showed first-order reactions, while the catechin showed patterns of formation and degradation.

Non-volatile and volatile composition of West African bulk and Ecuadorian fine-flavor cocoa liquor and chocolate

Cocoa products are obtained from the seeds of Theobroma cacao L. In this research, cocoa liquor and chocolate produced from cocoa beans from West Africa (Forastero, "bulk" cacao) and Ecuador (Nacional variety, "fine-flavor" cacao), were investigated, using a novel approach in which various analytical techniques are combined in order to obtain in-depth knowledge of the studied cocoa samples. The levels of various classes of primary metabolites were determined and a wide range of secondary metabolites, including volatile organic acids, aldehydes, esters, pyrazines, polyphenols, methylxanthines and biogenic amines, were identified and/or quantified by HS-SPME GC-MS (headspace-solid phase microextraction gas chromatography - mass spectrometry). and UPLC-HRMS (ultra-performance liquid chromatography - high resolution mass spectrometry). Odor Activity Values (OAV) were calculated to assess the contribution of individual volatiles on the final aroma. Various volatile aroma compounds were more abundant in the West African cocoa liquor and chocolate, while the Ecuadorian samples were richer in most quantified non-volatile metabolites. Principal component analysis (PCA) confirmed that the four samples can be clearly distinguished. Alcohols, pyrazines, amino acids and biogenic amines were found to be highly influential in causing this differentiation. The proposed approach can be useful in future studies on more extensive cocoa sample collections, in order to highlight similarities and pinpoint typical differences in chemical composition among these samples.

Neuroactive compounds in foods: Occurrence, mechanism and potential health effects

Neuroactive compounds are synthesized by certain plants and microorganisms by undertaking different tasks, especially as a stress response. Most common neuroactive compounds in foods are gamma-aminobutyric acid (GABA), serotonin, melatonin, kynurenine, kynurenic acid, dopamine, norepinephrine, histamine, tryptamine, tyramine and β-phenylethylamine. Fermented foods contain some of these compounds, which can affect human health and mood. Moreover, food processing such as roasting and malting alter amount and profile of neuroactive compounds in foods. In addition to plant-origin and microbially-formed neuroactive compounds in foods, these substances are also formed by gut microbiota, which is the most attractive subject to assess the interaction between gut microbiota and mental health. The discovery of microbiota-gut-brain axis calls for the investigation of the effects of diet on the formation of neuroactive compounds in the gut. Furthermore, probiotics and prebiotics are indispensable elements for the understanding of the food-mood relationship. The focus of this comprehensive review is to investigate the neuroactive compounds found naturally in foods or formed during fermentation. Their formation pathways in humans, plants and microorganisms, potential health effects, effects of diet on the formation of microbial metabolites including neuroactive compounds in the gut are discussed throughout this review. Furthermore, the importance of gut-brain axis, probiotics and prebiotics are discussed.

The Chemistry behind Chocolate Production

Chocolate production is a complex process during which numerous chemical reactions occur. The most important processes, involving most of the reactions important for development of the proper chocolate flavor, are fermentation, drying and roasting of cocoa bean, and chocolate conching. During fermentation, formation of important precursors occurs, which are essential for further chemical reactions in the following processes of chocolate production. Roasting is one of the most important processes due to the occurrence of Maillard's reactions, during which aroma compounds are formed. In this paper, we have reviewed the most important chemical reactions that occur with proteins, carbohydrates, lipids, and polyphenols. Additionally, we present other components that may be naturally present or form during the production process, such as methylxanthines, aldehydes, esters, ketones, pyrazines, acids, and alcohols.

Comparison of the Total Polyphenol Content and Antioxidant Activity of Chocolate Obtained from Roasted and Unroasted Cocoa Beans from Different Regions of the World

The polyphenol content of cocoa beans and the products derived from them, depend on the regions in which they are grown and the processes to which they are subjected, especially temperature. The aim of the study was to compare the total content of polyphenols and antioxidant activity of chocolates obtained from roasted and unroasted cocoa beans. The chocolates produced from each of the six types of unroasted beans and each of the five types of roasted beans were investigated. The seeds came from Ghana, Venezuela, the Dominican Republic, Colombia and Ecuador. The highest total polyphenol content was determined in cocoa beans originating from Colombia and in the chocolates obtained from them. A higher content of total polyphenols was found in unroasted cocoa beans, which indicates the influence this process had on the studied size. The ability to scavenge free DPPH radicals was at a high level in both the beans and the chocolates produced from them, irrespective of the region where the raw material was grown. A positive correlation between the total polyphenol content and the ability to scavenge free radicals was found.

Biogenic Amines, Phenolic, and Aroma-Related Compounds of Unroasted and Roasted Cocoa Beans with Different Origin

Biogenic amines (BAs), polyphenols, and aroma compounds were determined by chromatographic techniques in cocoa beans of different geographical origin, also considering the effect of roasting (95, 110, and 125 °C). In all samples, methylxantines (2.22–12.3 mg kg⁻¹) were the most abundant followed by procyanidins (0.69–9.39 mg kg⁻¹) and epicatechin (0.16–3.12 mg kg⁻¹), all reduced by heat treatments. Volatile organic compounds and BAs showed variable levels and distributions. Although showing the highest BAs total content (28.8 mg kg⁻¹), Criollo variety presented a good aroma profile, suggesting a possible processing without roasting. Heat treatments influenced the aroma compounds especially for Nicaragua sample, increasing more than two-fold desirable aldehydes and pyrazines formed during the Maillard cascade and the Strecker degradation. As the temperature increased, the concentration of BAs already present in raw samples increased as well, although never reaching hazardous levels.

Chemometric approaches for postharvest quality tracing of cocoa: An efficient method to distinguish plant material origin

The aim of this study was to compare the quality of a mixture of cocoa harvested and fermented in three subregions of Antioquia (Colombia), from the chemometric profile based on multivariate statistical analysis. A mixture of clones CCN-52, ICS-1, FLE-2, and FEC-2 harvested in Bajo Cauca, Uraba and Magdalena Medio were subjected to a spontaneous fermentation. The characterization of raw and well-fermented cocoa was performed through 38 parameters, and results were compared by a Principal Component Analysis (PCA) and a Cluster Analysis (CA), followed by a Principal Factors Analysis (PFA- CA). The CA showed that there are differences among subregions only in raw cocoa from Bajo Cauca. PCA allowed identifying the variability between raw and fermented cocoa in a representative way and these results were consistent with the chemical profile. Besides, the number of parameters to differentiate raw cocoa from different subregions was reduced (11–13 parameters) and it was possible to characterize well fermented cocoa with only 10 parameters of 38. PFA-CA consolidated in three factors a grouping to identify the cocoa quality according to the process or interest of the sensory or functional properties. Factor 1 (cocoa quality indicators with functional properties), Factor 2 (indicators of quality of the beginning of fermentation) and Factor 3 (indicators of quality of well-fermented cocoa) each one with a weight of 39, 35 and 26 respectively.

An overview of the physical and biochemical transformation of cocoa seeds to beans and to chocolate: Flavor formation

Chocolate is a widely consumed product worldwide due to its exquisite flavor, which comes from the unique and fascinating cocoa flavor. This flavor depends on little controllable variables such as the genotype and the agroecological niche, and on the other side, on postharvest operations: (1) cocoa transformation from seeds to beans that comprises cocoa seeds preconditioning, fermentation, and drying, and (2) the production of chocolate from the bean in which roasting is highlighted. Postharvest transformation operations are critically important because during these, cocoa flavor is formed, allowing the differentiation of two categories: bulk and specialty cocoa. In this sense, this article presents an overview of cocoa postharvest operations, the variables and phenomena that influence and control the physical and biochemical transformation from seeds to cocoa beans, and their relation to the formation of chocolate flavor. Moreover, research perspectives in terms of control and management of postharvest practices in order to obtain cocoa with differentiated and specialty characteristics "from bean to bar" are discussed.

Cocoa Bean Proteins-Characterization, Changes and Modifications due to Ripening and Post-Harvest Processing

The protein fractions of cocoa have been implicated influencing both the bioactive potential and sensory properties of cocoa and cocoa products. The objective of the present review is to show the impact of different stages of cultivation and processing with regard to the changes induced in the protein fractions. Special focus has been laid on the major seed storage proteins throughout the different stages of processing. The study starts with classical introduction of the extraction and the characterization methods used, while addressing classification approaches of cocoa proteins evolved during the timeline. The changes in protein composition during ripening and maturation of cocoa seeds, together with the possible modifications during the post-harvest processing (fermentation, drying, and roasting), have been documented. Finally, the bioactive potential arising directly or indirectly from cocoa proteins has been elucidated. The “state of the art” suggests that exploration of other potentially bioactive components in cocoa needs to be undertaken, while considering the complexity of reaction products occurring during the roasting phase of the post-harvest processing. Finally, the utilization of partially processed cocoa beans (e.g., fermented, conciliatory thermal treatment) can be recommended, providing a large reservoir of bioactive potentials arising from the protein components that could be instrumented in functionalizing foods.

Chemosensors for biogenic amines and biothiols

There is burgeoning interest among supramolecular chemists to develop novel molecular systems to detect biogenic amines and bio-thiols in aqueous and non-aqueous media due to their potential role in biological processes. Biogenic amines are biologically important targets because of their involvement in the energy metabolism of human biological systems and their requirement is met through food and nutrition. However, the increasing instances of serious health problems due to food toxicity have raised the quality of food nowadays. Biogenic amines have been frequently considered as the markers or primary quality parameters of foods like antioxidant properties, freshness and spoilage. For instance, these amines such as spermine, spermidine, cadavarine, etc. may originate during microbial decarboxylation of amino acids of fermented foods/beverages. These amines may also react with nitrite available in certain meat products and concomitantly produce carcinogenic nitrosamine compounds. On the other hand, it is also well established that biothiols, particularly, thiol amino acids, provide the basic characteristics to food including flavor, color and texture that determine its acceptability. For instance, the reduction of thiol groups produces hydrogen sulfide which reduces flavour as in rotten eggs and spoiled fish, and the presence of hydrogen sulfide in fish is indicative of spoilage. Thus, biogenic amines and bio-thiols have attracted the profound interest of researchers as analytical tools for their quantification. Much scientific and technological information is issued every year, where the establishment of precise interactions of biogenic amines and bio-thiols with other molecules is sought in aqueous and non-aqueous media. This review summarizes the optical chemosensors developed for the selective detection of biogenic amines and bio-thiols.

Fast analysis of polyphenols and alkaloids in cocoa-based products by ultra-high performance liquid chromatography and Orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap-MS/MS)

The cocoa varieties Criollo, Forastero and Trinitario, which have different organoleptic properties, quite often are mixed together in cocoa-based products. The objective of this work was to develop a rapid method for the simultaneous determination of polyphenols (n = 35) and alkaloids (n = 2) in cocoa-based products by using the high throughput advantages provided by the Q Exactive Hybrid Quadrupole-Orbitrap Mass Spectrometer (HRMS). The proposed procedure was optimized and validated in terms of selectivity and specificity (mass accuracy <5 ppm), sensitivity (instrumental limit of detection from 15 to 30 fg), linearity (r² > 0.990), accuracy (recovery range from 89.1 to 112.4%) and precision (relative standard deviation <10%). The method was applied to 80 cocoa-based samples. Alkaloids represented on average the 57.7% of assayed compounds. Flavanols and procyanidins were the most abundant polyphenols being quantified in a range between 261 and 668 mg/kg and from 127 to 405 mg/g, respectively. Mass equivalents but structural isomers bioflavonoids were characterized by using the HRMS-Orbitrap methodology here developed.

Environmental Growing Conditions in Five Production Systems Induce Stress Response and Affect Chemical Composition of Cocoa (Theobroma cacao L.) Beans

Cocoa beans are produced all across the humid tropics under different environmental conditions provided by the region but also by the season and the type of production system. Agroforestry systems compared to monocultures buffer climate extremes and therefore provide a less stressful environment for the understory cocoa, especially under seasonally varying conditions. We measured the element concentration as well as abiotic stress indicators (polyamines and total phenolic content) in beans derived from five different production systems comparing monocultures and agroforestry systems and from two harvesting seasons. Concentrations of N, Mg, S, Fe, Mn, Na, and Zn were higher in beans produced in agroforestry systems with high stem density and leaf area index. In the dry season, the N, Fe, and Cu concentration of the beans increased. The total phenolic content increased with proceeding of the dry season while other abiotic stress indicators like spermine decreased, implying an effect of the water availability on the chemical composition of the beans. Agroforestry systems did not buffer the variability of stress indicators over the seasons compared to monocultures. The effect of environmental growing conditions on bean chemical composition was not strong but can contribute to variations in cocoa bean quality.

Bioactive amines and phenolic compounds in cocoa beans are affected by fermentation

Cocoa is the target of increased scientific research as it is one of the richest source of bioactive compounds. The formation of bioactive amines and their changes in cocoa beans during seven days of traditional fermentation was investigated for the first time. In addition, total phenolic compounds, anthocyanins contents and the scavenging capacity against ABTS radical were determined to monitor the fermentation process. Only two biogenic amines (tryptamine and tyramine) and two polyamines (spermidine and spermine) were detected in cocoa beans during fermentation. Fermentation was characterized by three stages: i) high levels of tryptamine, phenolics, and scavenging capacity; ii) high contents of spermine, total biogenic amines and total polyamines; and iii) the highest spermidine levels and total acidity, but the lowest total phenolic compounds and anthocyanins contents. The scavenging capacity of cocoa beans during fermentation correlated with total phenolic compounds and anthocyanins contents.

Extraction Efficiency of Different Solvents and LC-UV Determination of Biogenic Amines in Tea Leaves and Infusions

Biogenic amines (BAs), that is, spermine, spermidine, putrescine, histamine, tyramine, β-phenylethylamine, cadaverine, and serotonin, have been determined in several samples of tea leaves, tea infusions, and tea drinks by LC-UV method after derivatization with dansyl chloride. Different extraction solvents have been tested and TCA 5% showed better analytical performances in terms of linearity, recovery percentages, LOD, LOQ, and repeatability than HCl 0.1 M and HClO4 0.1 M and was finally exploited for the quantitative determination of BAs in all samples. In tea leaves total BAs concentration ranged from 2.23 μg g(-1) to 11.24 μg g(-1) and PUT (1.05-2.25 μg g(-1)) and SPD (1.01-1.95 μg g(-1)) were always present, while SER (nd-1.56 μg g(-1)), HIS (nd-2.44 μg g(-1)), and SPM (nd-1.64 μg g(-1)) were detected more rarely. CAD and PHE were determined in few samples at much lower concentrations while none of the samples contained TYR. Tea infusions showed the same trend with total BAs concentrations never exceeding 80.7 μg L(-1). Black teas showed higher amounts of BAs than green teas and organic and decaffeinated samples always contained much lower BAs levels than their conventional counterparts.

Flavor Chemistry of Cocoa and Cocoa Products-An Overview

Cocoa originates from beans of the cocoa tree (Theobroma cacao L.) and it is an important commodity in the world and the main ingredient in chocolate manufacture. Its value and quality are related to unique and complex flavors. Bulk cocoas (Forastero type) exhibit strong basic cocoa notes, whereas fine varieties (Criollo, Nacional) show aromatic, floral, or smoother flavor characteristics. About 600 various compounds (alcohols, carboxylic acids, aldehydes, ketones, esters, and pyrazines) have been identified as odor-active components. The specific cocoa aroma arises from complex biochemical and chemical reactions during the postharvest processing of raw beans, and from many influences of the cocoa genotype, chemical make-up of raw seeds, environmental conditions, farming practices, processing, and manufacturing stages. There has been much research on cocoa flavor components. However, the relationships between all chemical components that are likely to play a role in cocoa flavor, their sensory properties, and the sources and mechanisms of flavor formation are not fully understood. This paper provides an overview on cocoa flavor from a compositional and a sensory perspective. The nonvolatile and volatile chemical components of cocoa and chocolate flavor, and their sensory properties correlated to the main influences involved in flavor formation, are reviewed.