Chitosan is a biopolymer with high added value, and its properties are related to its molecular weight. Thus, high molecular weight values provide low solubility of chitosan, presenting limitations in its use. Based on this, several studies have developed different hydrolysis methods to reduce the molecular weight of chitosan. Acid hydrolysis is still the most used method to obtain low molecular weight chitosan and chitooligosaccharides. However, the use of acids can generate environmental impacts. When different methods are combined, gamma radiation and microwave power intensity are the variables that most influence acid hydrolysis. Otherwise, in oxidative hydrolysis with hydrogen peroxide, a long time is the limiting factor. Thus, it was observed that the most efficient method is the association between the different hydrolysis methods mentioned. However, this alternative can increase the cost of the process. Enzymatic hydrolysis is the most studied method due to its environmental advantages and high specificity. However, hydrolysis time and process cost are factors that still limit industrial application. In addition, the enzymatic method has a limited association with other hydrolysis methods due to the sensitivity of the enzymes. Therefore, this article seeks to extensively review the variables that influence the main methods of hydrolysis: acid concentration, radiation intensity, potency, time, temperature, pH, and enzyme/substrate ratio, observing their influence on molecular weight, yield, and characteristic of the product.

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This graphical abstract reports quickly, the process of cocoa processing, from its harvest to the drying process. Also, linked to each stage, the main characteristics reported in each one.

This study aimed to identify the volatile compounds in the fermented and dried cocoa beans conducted with three distinct inoculants of yeast species due to their high fermentative capacity: Saccharomyces cerevisiae, Pichia kudriavzevii, the mixture in equal proportions 1:1 of both species, and a control fermentation (with no inoculum application). Three starter cultures of yeasts, previously isolated and identified in cocoa fermentation in the municipality of Tomé-Açu, Pará state, Brazil. The seeds with pulp were removed manually and placed in wooden boxes for the fermentation process that lasted from 6 to 7 days. On the last day of fermentation, the almonds were packaged properly and placed to dry (36 °C), followed by preparation for the analysis of volatile compounds by GC-MS technique. In addition to the control fermentation, a high capacity for the formation of desirable compounds in chocolate by the inoculants with P. kudriavzevii was observed, which was confirmed through multivariate analyses, classifying these almonds with the highest content of aldehydes, esters, ketones and alcohols and low concentration of off-flavours. We conclude that the addition of mixed culture starter can be an excellent alternative for cocoa producers, suggesting obtaining cocoa beans with desirable characteristics for chocolate production, as well as creating a product identity for the producing region.

A rapid molecular identification technique was applied on microbial microflora isolated from Brazilian cassava roots given a yeast profile presented in the samples analyzed. A total of 24 strain isolated from cassava were initially grouped and identified in five groups using restriction-fragment length polymorphism (RFLPs) of 5.8S-ITS rDNA region. Sequencing analysis of the domains D1 and D2 of the 26S rRNA gene or 5.8S rRNA-ITS region were used to identify different groups of yeasts. Representative colonies of yeasts of each group were isolated and identified as Debaromyces hansenii, Kodamaea ohmeri, Candida glabrata, C. haemulonii, and Pichia gullhermondii. It is hoped that these results will contribute toward selecting yeast from this microflora capable to degrade cassava starch in the near future.

Purpose The purpose of this study was to investigate the diversity of filamentous fungi and the hydrolytic potential of their enzymes for a future understanding of the influence of these factors on the sensory characteristics of the cocoa beans used to obtain chocolate. Methods Filamentous fungi were isolated from the natural cocoa fermentation boxes in the municipality of Tucuman, Pará, Brazil, and evaluated for the potential production of amylases, cellulases, pectinases, and xylanases. The fermentation was monitored by analyzing the pH and temperature. The strains were identified by sequencing the ITS1/ITS4 section of the 5.8S rDNA and partially sequencing the 18S and 28S regions, and the molecular identification was confirmed by phylogenetic reconstruction. Result The fungi isolated were comprised of three classes from the Ascomycota phylum and one class from the Basidiomycota phylum. There were found 19 different species, of this amount 16 had never been previously reported in cocoa fermentation. This fact characterizes the fermentation occurring in this municipality as having wide fungal diversity. Most of the strains isolated had the ability to secrete enzymes of interest. Cladosporium cladosporioides, Fomitopsis subtropical, Aspergillus versicolor, Penicillium pimiteouiense, Phanerochaete australis, Neonothopanus nambi, and Aspergillus parasiticus were the strains that excelled in the secretion of the following enzymes: amylase, pectinase, cellulase, and xylanase. Conclusion The presence of 16 species not yet reported in cocoa seed fermentations and their potential hydrolytic activities show a diversity of filamentous fungi in this microbial biome that needs to be better understood.

In addition to the vast diversity of fauna and flora, the Brazilian Amazon has different climatic periods characterized by periods with greater and lesser rainfall. The main objective of this research was to verify the influence of climatic seasons in the Brazilian Amazon (northeast of Pará state) concerning the aromatic and bioactive profiles of fermented and dried cocoa seeds. About 200 kg of seeds was fermented using specific protocols of local producers. Physicochemical analyzes (total titratable acidity, pH, total phenolic compounds, quantification of monomeric phenolics and methylxanthines) and volatile compounds by GC-MS were carried out. We observed that: in the summer, the highest levels of aldehydes were identified, such as benzaldehyde (6.34%) and phenylacetaldehyde (36.73%), related to the fermented cocoa and honey aromas, respectively; and a total of 27.89% of this same class was identified during winter. There were significant differences (p ≤ 0.05, Tukey test) in the profile of bioactive compounds (catechin, epicatechin, caffeine, and theobromine), being higher in fermented almonds in winter. This study indicates that the climatic seasons in the Amazon affect the aromatic and bioactive profiles and could produce a new identity standard (summer and winter Amazon) for the cocoa almonds and their products.

In this paper, natural deep eutectic solvents (NADESs) with lactic acid, glycine, ammonium acetate, sodium acetate, and choline chloride were prepared with and without the addition of water. NADES formation was evaluated using FTIR and Raman, where hydrogen bonds were identified between the hydroxyl group of lactic acid and the amino and carboxyl groups of glycine. Acetate and ammonium ions were also identified as forming bonds with lactic acid. The addition of water did not cause changes in the vibrational modes of the FTIR and Raman spectra but contributed to a reduction in NADES viscosity and density. Viscosity ranged from 0.335 to 0.017 Pa s−1, and density ranged from 1.159 to 0.785 g mL−1. The best results for the extraction of phenolic compounds from pitaya (dragon fruit) were achieved with an organic solvent (450. 41 mg 100 g−1 dry bases-db) in comparison to NADESs lactic acid:glycine (193.18 mg 100 g−1 db) and lactic acid:ammonium acetate (186.08 mg 100 g−1 db). The antioxidant activity of the extracts obtained with the NADESs was not statistically different from that of the extract obtained with organic solvents.