Scavenging Capacity of Extracts of Arrabidaea chica Leaves from the Amazonia against ROS and RNS of Physiological and Food Relevance.

Arrabidaea chica, a medicinal plant found in the Amazon rainforest, is a promising source of bioactive compounds which can be used to inhibit oxidative damage in both food and biological systems. In this study, the in vitro scavenging capacity of characterized extracts of A. chica leaves, obtained with green solvents of different polarities [water, ethanol, and ethanol/water (1:1, v/v)] through ultrasound-assisted extraction, was investigated against reactive oxygen (ROS) and nitrogen (RNS) species, namely superoxide anion radicals (O2•-), hydrogen peroxide (H2O2), hypochlorous acid (HOCl), and peroxynitrite anion (ONOO-). The extract obtained with ethanol-water presented about three times more phenolic compound contents (11.8 mg/g) than ethanol and water extracts (3.8 and 3.6 mg/g, respectively), with scutellarein being the major compound (6.76 mg/g). All extracts showed high scavenging efficiency against the tested ROS and RNS, in a concentration-dependent manner with low IC50 values, and the ethanol-water extract was the most effective one. In addition, all the extracts were five times more efficient against ROO• than Trolox. Therefore, the extracts from A. chica leaves exhibited high promising antioxidant potential to be used against oxidative damage in food and physiological systems.

Lactic Acid Bacteria and Bioactive Amines Identified during Manipueira Fermentation for Tucupi Production.

There is scarce information regarding lactic acid bacteria (LAB) and the production of biogenic amines during manipueira fermentation for tucupi. Thus, the objective of this study was to isolate and identify LAB, and to determine their impact on bioactive amine formation. Spontaneous fermentation of manipueira was carried out at laboratory scale and selected LAB colonies were isolated and identified by sequencing techniques and comparison with sequences from a virtual database. Only two LAB species of the genus Lactobacillus were identified during fermentation: Lactobacillus fermentum and Lactobacillus plantarum. L. fermentum was the predominant, whereas L. plantarum was only detected in manipueira prior to fermentation. Spermidine and putrescine were detected throughout fermentation, whereas histamine was produced at the final stage. There was positive correlation between LAB counts and putrescine and histamine levels, suggesting that the identified LAB are responsible for the synthesis of these amines during manipueira fermentation. Genetic assays are needed to verify whether the LAB identified have the genes responsible for decarboxylation of amino acids.

How Climatic Seasons of the Amazon Biome Affect the Aromatic and Bioactive Profiles of Fermented and Dried Cocoa Beans?

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.

Profile of Volatile Compounds of On-Farm Fermented and Dried Cocoa Beans Inoculated with Saccharomyces cerevisiae KY794742 and Pichia kudriavzevii KY794725.

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.

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.

Estabilidade físico-química e microbiológica de farinha de mandioca fermentada comercializada em Belém do Pará / Physicochemical and microbiological stability of fermented manioc flour marketed in Belém do Para

A farinha de mandioca fermentada é um alimento típico da região amazônica brasileira e sua produção ocorre com as seguintes etapas: colheita, descascamento, fermentação (tubérculos são imersos em um tanque com água ou córrego), lavagem, trituração, prensagem, moagem e torrefação. A farinha de mandioca é uma fonte importante de carboidratos na Amazônia, especialmente pelas pessoas de baixa renda. Neste trabalho estudou-se o comportamento físico-químico e microbiológico da farinha de mandioca fermentada comercializada em um mercado de rua e em supermercado. Para tal, 36 quilogramas de farinha de mandioca fermentada foram adquiridos e mantidos sob as mesmas condições ambientais do mercado de rua e do supermercado. Durante dois meses, as amostras foram analisadas quanto à umidade, cinzas acidez total titulável, pH e atividade de água. Os resultados mostraram que o pH e a acidez total titulável foram estáveis, mas a umidade e a atividade de água mudaram e aumentaram significativamente (p>0,05).(AU)