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

Phenolic content and oxidative stability of chocolates produced with roasted and unroasted cocoa beans

The aim of this study was to produce chocolate using roasted (RB) and unroasted cocoa beans (URB). The effect of roasting on the total phenolic content (TPC), antioxidant activity [2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing antioxidant power (FRAP), and cupric ion reducing antioxidant capacity (CUPRAC) values], phenolic compounds, caffeine, oxidative stability [free fatty acid, peroxide, conjugated dienes, conjugated trienes, and thiobarbituric acid reactive substances (TBARS)], Fourier transform infrared (FTIR), and differential scanning colorimetry (DSC) analysis of both cocoa beans and chocolate samples were analyzed. According to the results, the TPC of URB (24.96 mg gallic acid equivalent (GAE)/g sample) was higher than roasted beans (21.32 mg GAE/g sample). Similar results were also seen in the TPC of chocolate samples. Although roasting did not affect the DPPH scavenging activity and caffeine content of cocoa beans, it decreased FRAP and CUPRAC values. (-)-Epicatechin and chlorogenic acid values were higher in unroasted bean and chocolate samples, but the amount of gallic acid increased with the roasting process. Free fatty acid, peroxide, conjugated dienes, conjugated trienes, and TBARS results of unroasted samples were lower than roasted ones, indicating better oxidative stability. The melting temperatures of cocoa beans changed with roasting while it was similar between chocolate samples. Composition of the beans and the chocolate samples were qualitatively determined with FTIR.

Metabolite profiling identifies chemical markers associated with the cytotoxic properties of roasted fermented avocado seeds

Studies have demonstrated avocado seeds are a good source of bioactive compounds. This study investigated the effects of roasting on the metabolites and anticancer activities of fermented avocado seeds. All three anti-cancer activities of fermented avocado seeds were higher at lower roasting temperature and time. The best inhibition effect was found against Hep G2 followed by the MDA-MB-231 and MCF-7 cancer cell lines. Untargeted metabolite profiling using gas chromatography-mass spectrometry resulted in identification of 208 metabolites. In total, 41 metabolites identified had VIP values more than 1 using PLS-R that were related to anticancer activities. All amino acids and most sugars were higher at lower roasting temperature and positively correlated to anticancer activity. The roasting conditions for optimal antioxidant and anticancer activities were determined to be 121 °C for 9 min. Findings showed that fermented avocado seed powder has the potential to become a functional food ingredient with beneficial bioctive properties.

Changes of polyphenols and antioxidants of arabica coffee varieties during roasting

Coffee is the most consumed beverage in the world after water. Multiple benefits are attributed to it in human health due to the presence of antioxidant compounds, whose content depends, among other factors, on the processing conditions of the coffee bean. The objective of this study was to determine the kinetics of polyphenols and antioxidants during the roasting of three varieties of arabica coffee. For this, we worked with varieties of coffee, Catimor, Caturra, and Bourbon, from the province of La Convencion, Cuzco, Peru. The samples were roasted in an automatic induction roaster, and 12 samples were taken during roasting (at 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, and 21 min of roasting) in triplicate. For green coffee beans, titratable acidity, total soluble solids, moisture and apparent density were determined. The change in polyphenol content was determined using the Folin-Ciocalteu method, and antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis- (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS⁺) free radical capture technique during roasting. Polyphenol and antioxidant contents increased until minute 5 of roasting and then decreased until minute 20, and in some cases, there were slight increases in the last minute. The model that best described the changes in these bioactive compounds was the cubic model (R ² 0.634 and 0.921), and the best fits were found for the Bourbon variety, whose green grain had more homogeneous characteristics. The changes in the relative abundances of nine phenolic compounds were determined using high-performance liquid chromatography (HPLC). In conclusion, roasting modifies phenolic compounds and antioxidants differently in the coffee varieties studied. The content of some phenols increases, and in other cases, it decreases as the roasting time increases. The roasting process negatively affects the bioactive compounds and increases the fracturability of Arabica coffee beans, elements that should be taken into account at the moment of developing roasting models in the industry.

Influence of Freeze-Dried Phenolic-Rich Plant Powders on the Bioactive Compounds Profile, Antioxidant Activity and Aroma of Different Types of Chocolates

In this study, the blueberries (BLUB), raspberries (RASB), blackberries (BLCB), pomegranates pomace (POME) and beetroots (BEET) freeze-dried powders were used as the sources of phenolic compounds to enrich different types of chocolates, substituting a part of the sweetener. It was found that 1% addition of fruit or vegetable powders to chocolates increased the content of total phenolic compounds (flavan-3-ols, phenolic acids and anthocyanins) of enriched dark and milk chocolates compared to the control ones dependent on the powder used. Among the enriched chocolates, the chocolates with the addition of BLUB powder were characterized by the highest total polyphenol content. The highest percentage increase (approximately 80%) in the total polyphenol content was observed in MCH chocolate enriched with BLUB powder. Chocolates incorporated with BLUB, RASB, BLCB and POME powders presented a richer phenolic compound profile than control counterparts. The highest DPPH radical-scavenging capacity was exhibited by the DCH98S chocolate enriched with BEET powder. However, the DCH98ESt chocolates enriched with POME and BEET powders demonstrated the highest FRAP values. An electronic nose analysis confirmed the existence of differences between the profiles of volatile compounds of various types of chocolates enriched with fruit or vegetable powders. Thus, the enrichment of dark and milk chocolates with BLUB, RASB, BLCB, POME and BEET powders seemed to be an interesting approach to enhance bioactivity and to enrich the sensory features of various chocolate types.

From Plantation to Cup: Changes in Bioactive Compounds during Coffee Processing

Coffee is consumed not just for its flavor, but also for its health advantages. The quality of coffee beverages is affected by a number of elements and a series of processes, including: the environment, cultivation, post-harvest, fermentation, storage, roasting, and brewing to produce a cup of coffee. The chemical components of coffee beans alter throughout this procedure. The purpose of this article is to present information about changes in chemical components and bioactive compounds in coffee during preharvest and postharvest. The selection of the appropriate cherry maturity level is the first step in the coffee manufacturing process. The coffee cherry has specific flavor-precursor components and other chemical components that become raw materials in the fermentation process. During the fermentation process, there are not many changes in the phenolic or other bioactive components of coffee. Metabolites fermented by microbes diffuse into the seeds, which improves their quality. A germination process occurs during wet processing, which increases the quantity of amino acids, while the dry process induces an increase in non-protein amino acid γ-aminobutyric acid (GABA). In the roasting process, there is a change in the aroma precursors from the phenolic compounds, especially chlorogenic acid, amino acids, and sugars found in coffee beans, to produce a distinctive coffee taste.

Effect of roasting conditions on cocoa bioactivity and gut microbiota modulation

Cocoa is a highly consumed food with beneficial effects on human health. Cocoa roasting has an important influence on its sensory and nutritional characteristics; therefore, roasting could also play a role in cocoa bioactivity. Thus, the aim of this paper is to unravel the effect of cocoa roasting conditions on its antioxidant capacity and modifications of gut microbiota after in vitro digestion-fermentation. HMF and furfural, chemical markers of non-enzymatic browning, were analyzed in unroasted and roasted cocoa powder at different temperatures, as well as different chocolates. The antioxidant capacity decreased with roasting, most probably due to the loss of phenolic compounds during heating. In the case of the evaluated chocolates, the antioxidant capacity was 2-3 times higher in the fermented fraction. On the other hand, HMF and furfural content increased during roasting due to increasing temperatures. Moreover, unroasted and roasted cocoa powder have different effects on gut microbial communities. Roasted cocoa favored butyrate production, whereas unroasted cocoa favored acetate and propionate production in a significant manner. In addition, unroasted and roasted cocoa produced significantly different gut microbial communities in terms of composition. Although many bacteria were affected, Veillonella and Faecalibacterium were some of the most discriminant ones; whereas the former is a propionate producer, the latter is a butyrate producer that has also been linked to positive effects on the inflammatory health of the gut and the immune system. Therefore, unroasted and roasted cocoa (regardless of the roasting temperature) promote different bacteria and a different SCFA production.

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.

Kinetics Drying of Blackberry Bagasse and Degradation of Anthocyanins and Bioactive Properties

The process of drying food is necessary to preserve it; however, some bioactive compounds can be degraded during drying process. In this work, the convective drying process of Peruvian blackberry bagasse and the degradation of anthocyanins, total phenolic content (TPC), and antioxidant capacity (AC) were studied. The logarithmic model fitted well to the data and could predict the process, showing that 6 h of drying at 90 °C is enough to reach equilibrium moisture. Anthocyanin degradation followed a first-order kinetic model with reaction rate constant between 5.45 × 10^-2 ± 4.68 × 10^-3 and 1.21 × 10^-1 ± 2.31 × 10^-2 h^-1, and activation energy of 25.11 kJ/mol. The highest retention (84.38%) of anthocyanins was obtained in 1 h at 50 °C and the highest degradation (68.54%) in 6 h at 90 °C. The TPC and AC increased with the drying time and temperature due to the increased water evaporation.

Rheological, bioactive properties and sensory preferences of dark chocolates with partial incorporation of Sacha Inchi (Plukenetia volubilis L.) oil

We studied the effect of substituting partially, cocoa butter (CB) with Sacha Inchi (Plukenetia volubilis L.) oil (SIO) on rheology, bioactive properties, and sensory preferences in potentially functional chocolate. For this 70% dark chocolates were prepared and the CB was substituted with 1.5%, 3%, and 4.5% of SIO. Hardness and viscosity of the SIO-chocolates were significantly reduced compared to the control (5451 ± 658 g; 17.01 ± 0.94 Pa s, respectively). Total phenolic content remained constant while the antioxidant capacity increased up to IC₅₀ of 2.48 ± 0.10 as the content of SIO increased. The Casson yield stress and Casson plastic viscosity decreased as the amount of SIO increased. Chocolates with 4.5% SIO had a similar color, better glossiness, preferable snap attributes, and were more accepted (7.50 ± 0.08) compared to the control (p < 0.05), measured with a hedonic scale. Then, SIO can improve the bioactive properties of dark chocolates obtaining a potentially functional food with acceptable physicochemical characteristics. SIO can be considered as a new cocoa butter equivalent.

An overview of conventional and emerging techniques of roasting: Effect on food bioactive signatures

Roasting is a food processingtechnique that employs the principle of heating to cook the product evenly and enhance the digestibility, palatability and sensory aspects of foods with desirable structural modifications of the food matrix. With the burgeoning demand for fortified roasted products along with the concern for food hygiene and the effects of harmful compounds, novel roasting techniques, and equipment to overcome the limitations of conventional operations are indispensable. Roasting techniques employing microwave, infrared hot-air, superheated steam, Revtech roaster, and Forced Convection Continuous Tumble (FCCT) roasting have been figuratively emerging to prominence for effectively roasting different foods without compromising the nutritional quality. The present review critically appraises various conventional and emerging roasting techniques, their advantages and limitations, and their effect on different food matrix components, functional properties, structural attributes, and sensory aspects for a wide range of products. It was seen that thermal processing at high temperatures for increased durations affected both the physicochemical and structural properties of food. Nevertheless, novel techniques caused minimum destructive impacts as compared to the traditional processes. However, further studies applying novel roasting techniques with a wide range of operating conditions on different types of products are crucial to establish the potential of these techniques in obtaining safe, quality foods.

Antioxidants in Cocoa

Cocoa beans are the seeds of the tropical tree Theobroma cacao L [...].

Food-Safe Process for High Recovery of Flavonoids from Cocoa Beans: Antioxidant and HPLC-DAD-ESI-MS/MS Analysis

Considering the increasing interest in the incorporation of natural antioxidants in enriched foods, this work aimed to establish a food-grade and suitable procedure for the recovery of polyphenols from cocoa beans avoiding the degreasing process. The results showed that ultrasound for 30 min with particle sample size < 0.18 mm changed the microstructure of the cell, thus increasing the diffusion pathway of polyphenols and avoiding the degreasing process. The effect of temperature, pH, and concentration of ethanol and solute on the extraction of polyphenols was evaluated. Through a 24 full factorial design, a maximum recovery of 122.34 ± 2.35 mg GAE /g, 88.87 ± 0.78 mg ECE /g, and 62.57 ± 3.37 mg ECE /g cocoa beans, for total concentration of polyphenols (TP), flavonoids (TF), and flavan-3-ols (TF3), respectively, was obtained. Based on mathematical models, the kinetics of the solid-liquid extraction process indicates a maximum equilibrium time of 45 min. Analysis by HPLC-DAD-ESI-MS/MS showed that our process allowed a high amount of methylxanthines (10.43 mg /g), catechins (7.92 mg /g), and procyanidins (34.0 mg /g) with a degree of polymerization >7, as well as high antioxidant activity determined by Oxygen Radical Absorbance Capacity (1149.85 ± 25.10 µMTrolox eq /g) and radical scavenging activity (DPPH•, 120.60 ± 0.50 µM Trolox eq /g). Overall, the recovery method made possible increases of 59.7% and 12.8% in cocoa polyphenols content and extraction yield, respectively. This study showed an effective, suitable and cost-effective process for the extraction of bioactive compounds from cocoa beans without degreasing.