Changes in the flavan-3-ols, anthocyanins, and flavanols composition of cocoa beans of different Theobroma cacao L. groups affected by roasting conditions

Targeted metabolomics for quantitative assessment of polyphenols and methylxanthines in fermented and unfermented cocoa beans from 18 genotypes of the Brazilian Amazon

The bioactive compounds present in cocoa, such as polyphenols and methylxanthines, are known for their health benefits. The concentration of these compounds in cocoa beans is influenced by genotype and post-harvest processing. This study utilized a targeted metabolomics approach using UPLC-MS/MS to quantify polyphenols (flavan-3-ols, anthocyanins, flavonols, and phenolic acids) and methylxanthines in fermented and unfermented cocoa beans from 18 genotypes largely cultivated in the Brazilian Amazon region. The major compounds identified were theobromine, (-)-epicatechin, procyanidin C1, procyanidin B2, and caffeine. Fermentation significantly reduced the concentration of most compounds, except for protocatechuic acid, which increased. Principal component analysis revealed that chemical differences between fermented and unfermented cocoa beans are more pronounced than those between genotypes, mainly due to flavan-3-ols and anthocyanins. The concentrations of bioactive compounds varied significantly among the 18 genotypes both before and after fermentation. The fermented beans were grouped into three distinct clusters, the genotype CAB214 exhibited the lowest concentrations of bioactive compounds, while CCN51 had the highest. The observed chemical diversity has important implications for the selection of genotypes aimed at producing chocolate with high levels of bioactive compounds and for formulating products in other industries.

Impact of West African treatment practices on phenolic profiles in shea kernels

The triglyceride fraction of shea kernels is a sustainable alternative to palm fat. The phenolics, e.g. antioxidants like flavonoids, remain less explored. Local treatment practices are likely to impact the phenolic profile, and thus the biological value of shea. This study aimed to identify phenolics in shea kernels, and to investigate how 21 different treatment practices influenced the phenolic profile of kernels. To do so, a methanolic extraction combined with a RP-LC-ESI-TOFMS profiling method was implemented. 32 phenolics, one polyol, and two jasmonic acid derivatives were identified, 16 reported in shea for the first time. Short initial storage (< 7 days) and extended sun-drying (> 5.5 days) resulted in highest phenolic content, with boiled kernels containing relatively more flavan-3-ols (up to 120 mg/100 g) and condensed tannins. Fermentation resulted in increased quercetin levels (up to 115 mg/100 g). The study demonstrates kernel treatments to significantly influence their phenolic profile.

Dynamic changes in proanthocyanidin composition, biosynthesis, and histochemistry in spine grape (Vitis davidii Foëx) tissues during berry development

BACKGROUND

Spine grapes are widely cultivated in southern China because of their strong adaptability to hot and humid climates. As a wild species native to China, spine grape (Vitis davidii Foëx) was studied as a resource of proanthocyanidins (PAs). PA composition, biosynthesis, and histochemistry in different tissues (skins, seeds, and stems) during berry development were analyzed in this study.

RESULTS

The findings revealed that PA accumulation occurred in concurrence with flowering and was completed by veraison. High-performance liquid chromatographic results showed that the epicatechin type was the most dominant. The skins were more likely to accumulate PA polymers. Reverse transcription-quantitative polymerase chain reaction analysis revealed that the expression levels of structural genes (flavonoid-3'-hydroxylase, flavonoid-3'5'-hydroxylase, dihydroflavonol 4-reductase, leucoanthocyanidin reductase, and leucoanthocyanidin dioxygenase) were positively associated with PA dynamic changes. Histochemical results revealed that PAs in skins were mainly found in the hypodermis of the exocarp, PAs in seeds were mainly found in the middle layer of the outer integument of the testa, and PAs in stems were mainly found in the phloem.

CONCLUSION

This study provides a clear understanding of the spatial and temporal accumulation of PAs in spine grape, and forms a basis for the analysis of structural profiles and synthesis of PAs and their biological effects. © 2024 Society of Chemical Industry.

Changes in GC-MS metabolite profile, antioxidant capacity and anthocyanins content during fermentation of fine-flavor cacao beans from Ecuador

The fermentation of fine-flavor cacao beans is a key process contributing to the enhancement of organoleptic attributes and monetary benefits for cacao farmers. This work aimed to describe the dynamics of the gas chromatography-mass spectrometry (GC-MS) metabolite profile as well as the antioxidant capacity and anthocyanin contents during fermentation of fine-flavor cacao beans. Samples of Nacional x Trinitario cacao beans were obtained after 0, 24, 48, 72, 96, and 120 hours of spontaneous fermentation. Total phenolic content (TPC), ferric reducing antioxidant power (FRAP), and total anthocyanin content were measured by ultraviolet-visible (UV-Vis) spectrophotometry. Volatiles were adsorbed by headspace solid phase microextraction (HS-SPME) while other metabolites were assessed by an extraction-derivatization method followed by gas chromatography-mass spectrometry (GC-MS) detection and identification. Thirty-two aroma-active compounds were identified in the samples, including 17 fruity, and 9 floral-like volatiles as well as metabolites with caramel, chocolate, ethereal, nutty, sweet, and woody notes. Principal components analysis and Heatmap-cluster analysis of volatile metabolites grouped samples according to the fermentation time. Additionally, the total anthocyanin content declined during fermentation, and FRAP-TPC values showed a partial correlation. These results highlight the importance of fermentation for the improvement of the fine-flavor characteristics of cacao beans.

Dark-Chocolate-Coated BRS Clara Raisins: Phenolic Composition and Sensory Attributes

Dark chocolate dragée confectionary was made with BRS Clara raisins pre-treated with extra virgin olive oil (EVOO). The evaluation of the changes in the phenolic composition (flavonols, hydrocinnamic acid derivatives (HCADs), stilbenes and flavan-3-ol monomers, dimers, and proanthocyanidins (PAs)) resulting from the covering process showed that the chocolate coating was responsible for an increase in the concentrations of flavan-3-ols and PAs when compared to just the raisins. For the flavonols and HCADs, a reduction in the total concentration of compounds was observed when comparing the dragées to the raisins. Furthermore, there was a strong influence of chocolate in the qualitative profile with the emergence of new compounds (quercetin-3-pentoside, kampfterol-3-rutinoside, p-coumaric acid, and caffeoyl-aspartate). The combination of these ingredients (raisins and chocolate) resulted in a dark chocolate coated raisin (DC) with good sensory acceptance and a more complex phenolic composition that may positively contribute to its functional quality.

Release of phenolic compounds from fermented cocoa powder during fast heating in a novel hot plate reactor

This article studies the release of phenolic compounds during cocoa heating under vacuum, N₂, and air atmospheres, and proposes fast heating (60 °C • s^-1) as a methodology that allows the release of polyphenols from fermented cocoa powder. We aim to demonstrate that gas phase transport is not the only mechanism to extract compounds of interest and that convective-type mechanisms can facilitate the process by reducing their degradation. The oxidation and transport phenomena were evaluated both in the extracted fluid and in the solid sample during the heating process. Polyphenols transport phenomena were assessed based on the fluid (chemical condensate compounds) that was collected cold with an organic solvent (methanol) in a hot plate reactor. Out of all the polyphenolic compounds present in cocoa powder, we assessed specifically the release of catechin and epicatechin. We found that high heating rates combined with vacuum or N₂ favor the ejection of liquids; then, it is possible to extract compounds such as catechin-which is dissolved/entrained and transported in the ejected liquids-and avoid degradation phenomena.

Profiles of Free and Bound Phenolics and Their Antioxidant Capacity in Rice Bean (Vigna umbellata)

Rice bean (Vigna umbellata) is a medicinal and dietary legume rich in polyphenols. In this study, the free and bound phenolics in rice bean were extracted by water, 80% methanol, and acid, base, and composite enzymatic hydrolysis, respectively. The polyphenol profiles of the extracted fractions were analyzed. The outcome demonstrated that base hydrolysis was the most effective way to liberate bound phenolics from rice bean (14.18 mg GAE/g DW), which was 16.68 and 56.72 folds higher than those extracted by acid and enzymatic hydrolysis, respectively. The bound polyphenols released by base hydrolysis contributed to 71.15% of the total phenolic content. A total of 35 individual phenolics was identified, of which isoquercitrin, procyanidin B1, rutin, taxifolin, and catechin were the main monomeric phenolics in the free fraction, while gallic acid, protocatechuic acid, p-hydroxybenzoic acid, catechin, and phloroglucinol were the main monomeric phenolics in the bound fraction. In comparison to the free phenolics extracted by water and 80% methanol and the bound phenolics extracted using acid and composite enzymatic hydrolysis, the bound phenolics from base hydrolysis had a superior antioxidant capacity. The antioxidant activity of rice bean is primarily attributed to individual phenolics such as catechin, abundant both in free and bound fractions, and also p-hydroxybenzoic acid, gallic acid, and protocatechuic acid in bound fractions. The bound phenolics of rice bean were first reported and showed large differences with the composition of free phenolics. This work suggests that the bound fraction of rice bean must be taken into account in assessing its potential benefits to health.

Palm sap sugar an unconventional source of sugar exploration for bioactive compounds and its role on functional food development

Palm sap sugar is a sweetener which is made from the sap or nectar collected from different varieties/species of palm trees. It has huge scope as an alternative sweetener in Indian market. It is a natural alternative to unhealthy cane sugar and is more beneficial for farmers as well. Some of its characteristic features are low GI value and its macro (Glucose: 0.49-86.90 g/100 ml, Fructose: 0.26-1.61, Sucrose: 5.30-27.00 g/100 ml) and micro (K: 65.28-1326.0, Na: 2.85-117.5, Mg: 0.54-31.00, Ca: 0.24-79.00 mg/100 ml) nutritional content. Palm sugar also has impact on colour, aroma and taste profile of the final product. The taste, sensory profile and nutritional attributes of palm sugar vary on the basis of its species, region of growth and climatic conditions. At present, traditional processing of palm sap leads to lower yield and higher expenses. There is huge potential in the field of development in processing techniques (Traditional processing, spray drying, membrane technology, and vacuum drying) to optimize the production of palm sugar. Palm sugar and other products from different parts of palm can be used to make a variety of other value-added products like toffees, chocolates, cola, toddy wine, candy, and palm vinegar etc. The purpose of this review paper is to summarise the composition of palm sap, distinctive qualities of the extracted sap, various production procedures, nutritional and physico-chemical properties of palm sugar, and the development of functional foods using palm sugar.

Changes in bioactive compounds during fermentation of cocoa (Theobroma cacao) harvested in Amazonas-Peru

Cocoa (Theobroma cacao) is the main raw material for the production of chocolate; it is considered the food of the gods, as it possesses a diversity of bioactive compounds beneficial to human health. The abundance of bioactive compounds, among others, is conditioned by the post-harvest processing of cocoa beans, and fermentation is a major step in this regard. Consequently, this research evaluated the changes in phenolic compounds and methylxanthines occurred in the fermentation of Criollo and CCN-51 cocoa beans, varieties of great commercial interest for the cocoa-growing areas of Peru. For this purpose, samples were taken every 12 h of cocoa beans under fermentation for 204 h in which phenols (gallic acid, caffeic acid, catechin, and epicatechin) and methylxanthines (theobromine, caffeine and theophylline) were quantified by ultra-high performance liquid chromatography (UHPLC); total polyphenols by Folin Ciocalteu; antioxidant capacity by DPPH free radical capture method; total anthocyanins; pH; titratable acidity; and fermentation rate of beans. We found that during fermentation, phenolic content, antioxidant activity, and methylxanthines of cocoa beans decreased; on the other hand, the anthocyanin content increased slightly. Indeed, at distinctly degree, fermentation influences bioactive compounds in cocoa beans, depending on the variety cultivated.

Flavor Precursors and Volatile Compounds Improvement of Unfermented Cocoa Beans by Hydrolysis Using Bromelain

Cocoa fermentation is an essential process that produces flavor precursors. However, many small farmers in Indonesia directly dry their cocoa beans without fermentation due to low yield and long fermentation time, resulting in fewer flavor precursors and cocoa flavor. Therefore, this study aimed to enhance the flavor precursors, particularly free amino acids and volatile compounds, of unfermented cocoa beans by hydrolysis, using bromelain. Unfermented cocoa beans were previously hydrolyzed with bromelain at concentrations of 3.5, 7, and 10.5 U/mL for 4, 6, and 8 h, respectively. An analysis of enzyme activity, degree of hydrolysis, free amino acids, reducing sugar, polyphenols, and volatile compounds was then conducted using unfermented and fermented cocoa beans as negative and positive controls, respectively. The results showed that the highest degree of hydrolysis was 42.95% at 10.5 U/mL for 6 h, although it was not significantly different from the hydrolysis at 3.5 U/mL for 8 h. This indicates a higher reducing sugar and lower polyphenols content than unfermented cocoa beans. There was also an increase in free amino acids, especially hydrophobic amino acids, such as phenylalanine, valine, leucine, alanine, and tyrosine, and desirable volatile compounds, such as pyrazines. Therefore, this suggests that hydrolysis with bromelain increased the flavor precursors and cocoa-bean flavors.

Impact of using cocoa bean shell powder as a substitute for wheat flour on some of chocolate cake properties

The cocoa bean shell is a residue rich in bioactive compounds and its use as an ingredient in the food industry has been studied. This work had the objective of proposing the elaboration of chocolate cake with substitution of wheat flour by cocoa bean shell powder (CSp). Five formulations with different percentages of CSp were used: 25%, 50%, 75%, 100% and 0% (control). The cakes were evaluated by technological characteristics (volume, texture profile, firmness and colour), antioxidant profile (DPPH, β-carotene/linoleic acid system, phenolic compounds, anthocyanins and tannins) and sensory tests (TDS and acceptance). The technological characteristics and antioxidant activity of the cakes were influenced by the different concentrations of CSp compared to the control sample. The cakes containing up to 75% CSp presented satisfactory sensory acceptance. Therefore, CSp has been revealed to be a prominent alternative substitute ingredient to be used promisingly in the food industry.

Characterization and Classification of Cocoa Bean Shells from Different Regions of Venezuela Using HPLC-PDA-MS/MS and Spectrophotometric Techniques Coupled to Chemometric Analysis

The cocoa bean shell (CBS) is one of the main cocoa byproducts with a prospective to be used as a functional food ingredient due to its nutritional and sensory properties. This study aims to define the chemical fingerprint of CBSs obtained from cocoa beans of diverse cultivars and collected in different geographical areas of Venezuela assessed using high-performance liquid chromatography coupled to photodiodes array and mass spectrometry (HPLC-PDA-MS/MS) and spectrophotometric assays combined with multivariate analysis for classification purposes. The study provides a comprehensive fingerprint and quantitative data for 39 compounds, including methylxanthines and several polyphenols, such as flavan-3-ols, procyanidins, and N-phenylpropenoyl amino acids. Several key cocoa markers, such as theobromine, epicatechin, quercetin-3-O-glucoside, procyanidin_A pentoside_3, and N-coumaroyl-l-aspartate_2, were found suitable for the classification of CBS according to their cultivar and origin. Despite the screening methods required a previous purification of the sample, both methodologies appear to be suitable for the classification of CBS with a high correlation between datasets. Finally, preliminary findings on the identification of potential contributors for the radical scavenging activity of CBS were also accomplished to support the valorization of this byproduct as a bioactive ingredient in the production of functional foods.

Traceability of polyphenols in cocoa during the postharvest and industrialization processes and their biological antioxidant potential

Noncommunicable diseases, the leading cause of mortality around the world, are responsible for approximately 75% of premature adult deaths (ages 30-69). To tackle this issue, a healthy diet based on functional foods, including cocoa and its derivatives, has been increasingly promoted. The polyphenols present in cocoa have been of interest due to their antioxidant potential and their possible protective role in the context of noncommunicable diseases, such as diabetes and cardiovascular conditions. However, during cocoa postharvest and industrialization, the concentration of these bioactive compounds is reduced, possibly affecting their health-promoting properties. Therefore, this paper reviews in the literature in this field to find the total polyphenol content in cocoa during the postharvest and industrialization processes in order to define concentration ranges as a reference point for future research. In addition, it discusses in vitro and in vivo studies into the biological antioxidant potential of cocoa and its derivatives. This review covers publications in indexed databases from 2010 to 2020, their data were processed and presented here using box plots. As a result, we identified the concentration ranges of polyphenols depending on the type of matrix, treatment and country, as well as their relationship with the main bioactive compounds present in cocoa that are associated with their possible antioxidant biological potential and health-related benefits.

Reactivity of flavanols: Their fate in physical food processing and recent advances in their analysis by depolymerization

Flavanols, a subgroup of polyphenols, are secondary metabolites with antioxidant properties naturally produced in various plants (e.g., green tea, cocoa, grapes, and apples); they are a major polyphenol class in human foods and beverages, and have recognized effect on maintaining human health. Therefore, it is necessary to evaluate their changes (i.e., oxidation, polymerization, degradation, and epimerization) during various physical processing (i.e., heating, drying, mechanical shearing, high-pressure, ultrasound, and radiation) to improve the nutritional value of food products. However, the roles of flavanols, in particular for their polymerized forms, are often underestimated, for a large part because of analytical challenges: they are difficult to extract quantitatively, and their quantification demands chemical reactions. This review examines the existing data on the effects of different physical processing techniques on the content of flavanols and highlights the changes in epimerization and degree of polymerization, as well as some of the latest acidolysis methods for proanthocyanidin characterization and quantification. More and more evidence show that physical processing can affect content but also modify the structure of flavanols by promoting a series of internal reactions. The most important reactivity of flavanols in processing includes oxidative coupling and rearrangements, chain cleavage, structural rearrangements (e.g., polymerization, degradation, and epimerization), and addition to other macromolecules, that is, proteins and polysaccharides. Some acidolysis methods for the analysis of polymeric proanthocyanidins have been updated, which has contributed to complete analysis of proanthocyanidin structures in particular regarding their proportion of A-type proanthocyanidins and their degree of polymerization in various plants. However, future research is also needed to better extract and characterize high-polymer proanthocyanidins, whether in their native or modified forms.

Comparison of the Effects of Conching Parameters on the Contents of Three Dominant Flavan3-ols, Rheological Properties and Sensory Quality in Chocolate Milk Mass Based on Liquor from Unroasted Cocoa Beans

The content of polyphenols in chocolate depends on many factors related to the properties of raw material and manufacturing parameters. The trend toward developing chocolates made from unroasted cocoa beans encourages research in this area. In addition, modern customers attach great importance to how the food they consume benefits their bodies. One such benefit that consumers value is the preservation of natural antioxidant compounds in food products (e.g., polyphenols). Therefore, in our study we attempted to determine the relationship between variable parameters at the conching stage (i.e., temperature and time of) and the content of dominant polyphenols (i.e.,catechins, epicatechins, and procyanidin B2) in chocolate milk mass (CMM) obtained from unroasted cocoa beans. Increasing the conching temperature from 50 to 60 °C decreased the content of three basic flavan-3-ols. The highest number of these compounds was determined when the process was carried out at 50 °C. However, the time that caused the least degradation of these compounds differed. For catechin, it was 2 h; for epicatechin it was 1 h; and for procyanidin it was 3 h. The influence of both the temperature and conching time on the rheological properties of chocolate milk mass was demonstrated. At 50 °C, the viscosity and the yield stress of the conched mass showed its highest value.

Evaluation of the content of bioactive compounds in cocoa beans during the fermentation process

Cocoa (Theobroma cacao L.), one of the most important agricultural commodity products, is the key raw material for chocolate manufacturing. It is a source naturally occurring polyphenolic compounds and have been widely studied for their beneficial effects to human health. The objective of this study was to evaluate the fermentation time required to obtain more bioactive compounds and higher antioxidant activity in order to propose a mixture of unfermented and fermented cocoa beans in varying concentrations. Samples were collected every 12 h over a fermentation period of 144 h and evaluated according to their physico-chemical characteristics, as well as the content of bioactive compounds. It was verified that after 48 h of fermentation occurred a significant reduction in slate seeds, the appearance of partially fermented beans and the elevation of acidity and temperature. Until this period, a higher content of bioactive compounds with antioxidant activity was also observed. Thus, it is possible to propose a blend of cocoa beans fermented for 48 h and completely fermented beans to elaborate functional chocolates.

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.

Flavanol Polymerization Is a Superior Predictor of α-Glucosidase Inhibitory Activity Compared to Flavanol or Total Polyphenol Concentrations in Cocoas Prepared by Variations in Controlled Fermentation and Roasting of the Same Raw Cocoa Beans

Raw cocoa beans were processed to produce cocoa powders with different combinations of fermentation (unfermented, cool, or hot) and roasting (not roasted, cool, or hot). Cocoa powder extracts were characterized and assessed for α-glucosidase inhibitory activity in vitro. Cocoa processing (fermentation/roasting) contributed to significant losses of native flavanols. All of the treatments dose-dependently inhibited α-glucosidase activity, with cool fermented/cool roasted powder exhibiting the greatest potency (IC₅₀: 68.09 µg/mL), when compared to acarbose (IC₅₀: 133.22 µg/mL). A strong negative correlation was observed between flavanol mDP and IC₅₀, suggesting flavanol polymerization as a marker of enhanced α-glucosidase inhibition in cocoa. Our data demonstrate that cocoa powders are potent inhibitors of α-glucosidase. Significant reductions in the total polyphenol and flavanol concentrations induced by processing do not necessarily dictate a reduced capacity for α-glucosidase inhibition, but rather these steps can enhance cocoa bioactivity. Non-traditional compositional markers may be better predictors of enzyme inhibitory activity than cocoa native flavanols.

<i>In vitro </i>Antioxidant Activity and Profile of Polyphenol Compounds Extracts and their Fractions on Cacao Beans

BACKGROUND AND OBJECTIVE

The content of polyphenols in cacao beans can be modified during the processing of cacao. This study aimed to obtain the fraction of cacao bean extract polyphenols with the highest antioxidant activity and bioactive compounds profile of extracts and their fractions on cacao beans.

MATERIALS AND METHODS

The cacao beans (fermented for 5 days and unfermented) were blanched (5 min; 95°C), followed with defatted, freeze-dried and extracted uses 80% ethanol solvent. The extract obtained was then fractionated using n-hexane, chloroform, ethyl acetate, n-butanol and aqueous. Extracts and fractions obtained are calculated for yield, total polyphenol uses Folin-ciocalteu reagent, total flavonoid uses AlCl3, antioxidant activity uses DPPH and FRAP methods, functional group uses fourier transform infrared spectroscopy (FTIR) and polyphenol compound profiles uses UHPLC-MS/MS.

RESULTS

The results showed that the aqueous fraction had the highest yield but lowest chemical content and antioxidant activity. The unfermented cacao beans extract undergoing fractionation using ethyl acetate showed polyphenol content, flavonoids, DPPH free radical scavenging activity and highest ferric reducing activity. The FTIR analysis showed that the cacao bean extract and its fractions had O-H, C-H, C=O, C=C and C-O-C functional groups. Cacao beans extracts and ethyl acetate fractions were dominated by procyanidin compounds, especially dimer B2. Cacao bean fermentation caused a decrease in procyanidin compounds (monomer to nonamer) and alkaloids (theobromine and caffeine).

CONCLUSION

Unfermented cacao bean extraction is then followed by fractionation with ethyl acetate solvent, obtained the fraction with highest chemical and antioxidant activity.

Bioavailability and metabolism of selected cocoa bioactive compounds: A comprehensive review

Cocoa beans and their co-products are a rich source of beneficial compounds for health promotion, including polyphenols and methylxanthines. Knowledge of bioavailability and in vivo bioactivity of these phytochemicals is crucial to understand their role and function in human health. Therefore, many studies concerning bioavailability and bioactivity of cocoa bioactive compound have been done in both in vivo animal models and in humans. This critical review comprehensively summarizes the existing knowledge about the bioavailability and the major metabolic pathways of selected cocoa bioactive compounds (i.e. monomeric flavan-3-ols, procyanidins, anthocyanins, flavonols, phenolic acids, N-phenylpropenoyl-L-amino acids, stilbenes, and methylxanthines). The compiled results indicated that many of these compounds undergo extensive metabolism prior to absorption. Different factors have been suggested to influence the bioavailability of polyphenols and methylxanthines among them the role of gut microbiota, structure of these compounds, food matrix and occurrence of other substances were the most often considered. Aforementioned factors decided about the site where these bioactive compounds are digested and absorbed from the alimentary tract, as well as the pathway by which they are metabolized. These factors also determine of the type of transport through the intestine barrier (passive, involving specific enzymes or mediated by specific transporters) and their metabolic path and profile.

Development and Characterization of a Pilot-Scale Model Cocoa Fermentation System Suitable for Studying the Impact of Fermentation on Putative Bioactive Compounds and Bioactivity of Cocoa

Cocoa is a concentrated source of dietary flavanols—putative bioactive compounds associated with health benefits. It is known that fermentation and roasting reduce levels of native flavonoids in cocoa, and it is generally thought that this loss translates to reduced bioactivity. However, the mechanisms of these losses are poorly understood, and little data exist to support this paradigm that flavonoid loss results in reduced health benefits. To further facilitate large-scale studies of the impact of fermentation on cocoa flavanols, a controlled laboratory fermentation model system was increased in scale to a large (pilot) scale system. Raw cocoa beans (15 kg) were fermented in 16 L of a simulated pulp media in duplicate for 168 h. The temperature of the fermentation was increased from 25–55 °C at a rate of 5 °C/24 h. As expected, total polyphenols and flavanol levels decreased as fermentation progressed (a loss of 18.3% total polyphenols and 14.4% loss of total flavanols during fermentation) but some increases were observed in the final timepoints (120–168 h). Fermentation substrates, metabolites and putative cocoa bioactive compounds were monitored and found to follow typical trends for on-farm cocoa heap fermentations. For example, sucrose levels in pulp declined from >40 mg/mL to undetectable at 96 h. This model system provides a controlled environment for further investigation into the potential for optimizing fermentation parameters to enhance the flavanol composition and the potential health benefits of the resultant cocoa beans.

Phenylindanes in Brewed Coffee Inhibit Amyloid-Beta and Tau Aggregation

Coffee consumption has been correlated with a decreased risk of developing Alzheimer's disease (AD) and Parkinson's disease (PD), but the mechanism by which coffee may provide neuroprotection in humans is not fully understood. We hypothesized that compounds found in brewed coffee may elicit neuroprotective effects by inhibiting the aggregation of amyloid-beta (Aβ) and tau (AD) or α-synuclein (PD). Three instant coffee extracts (light roast, dark roast, decaffeinated dark roast) and six coffee components [caffeine (1), chlorogenic acid (2), quinic acid (3), caffeic acid (4), quercetin (5), and phenylindane (6)] were investigated for their ability to inhibit the fibrillization of Aβ and tau proteins using thioflavin T (ThT) and thioflavin S (ThS) fluorescence assays, respectively. Inhibition of Aβ and α-synuclein oligomerization was assessed using ELISA assays. All instant coffee extracts inhibit fibrillization of Aβ and tau, and promote α-synuclein oligomerization at concentrations above 100 μg/mL. Dark roast coffee extracts are more potent inhibitors of Aβ oligomerization (IC50 ca. 10 μg/mL) than light roast coffee extract (IC50 = 40.3 μg/mL), and pure caffeine (1) has no effect on Aβ, tau or α-synuclein aggregation. Coffee components 2, 4, and 5 inhibit the fibrillization of Aβ at 100 μM concentration, yet only 5 inhibits Aβ oligomerization (IC50 = 10.3 μM). 1-5 have no effect on tau fibrillization. Coffee component 6, however, is a potent inhibitor of both Aβ and tau fibrillization, and also inhibits Aβ oligomerization (IC50 = 42.1 μM). Coffee components 4 and 5 promote the aggregation of α-synuclein at concentrations above 100 μM; no other coffee components affect α-synuclein oligomerization. While the neuroprotective effect of coffee consumption is likely due to a combination of factors, our data suggest that inhibition Aβ and tau aggregation by phenylindane 6 (formed during the roasting of coffee beans, higher quantities found in dark roast coffees) is a plausible mechanism by which coffee may provide neuroprotection. The identification of 6 as a dual-inhibitor of both Aβ and tau aggregation is noteworthy, and to our knowledge this is the first report of the aggregation inhibition activity of 6.

The effects of baking conditions on acrylamide content in shortcrust cookies with added freeze-dried aqueous rosemary extract

The aim of the present study was to determine the effects of baking air humidity and dough supplementation with freeze-dried aqueous rosemary extract on acrylamide content in shortcrust cookies, as well as on their antioxidant properties and phenolic composition. Shortcrust cookies were baked at 170 °C in dry or humid (90%) air using 0.1, 0.2, or 0.5% of rosemary extract, and were compared to control samples without the extract. Acrylamide concentration in the obtained products ranged from 22.49 to 28.38 µg kg⁻¹. Furthermore, cookies baked in humid air had less acrylamide (by 6% on average) than those baked in dry air, irrespective of extract content. On the other hand, a significant relationship was found between humidity conditions and total phenolic content in the final products. Shortcrust cookies containing 0.5% of rosemary extract and baked in humid air revealed the best antioxidant properties as their total polyphenol content was approx. Three times higher than that in control samples. Furthermore, shortcrust cookies with 0.5% of rosemary extract showed superior DPPH radical scavenging capacity.

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.