The aim of this study was to evaluate fermented rice bran phospholipids, lipids and fatty acid content in a fermentation solid system with Rhizopus oryzae fungus. For this, aliquots were withdrawn every 24h over 120 h. The content of phospholipids was determined by colorimetric method. Esterified fatty acids were separated by gas chromatography, then identified and quantified. The total lipids from fermented rice bran (FB) decreased from 20.4% to 11.2% in the range between 0 h and 120 h of fermentation while phospholipid contents were increased up to 2.4 mg P g(lipid)(-1). In fermented bran, oleic, palmitic and linoleic acids prevailed, with a decrease in saturated fatty acids (20%) and increase in the unsaturated ones (5%). This study showed that rice bran fermentation with R. oryzae can be applied to the production of phospholipids altering the saturated to unsaturated fatty acid ratio.

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The aim of this study was to investigate the use of protein-phenolic based coating made from fermented rice bran on cherry tomatoes (Lycopersicum esculentum). Tests were performed with glycerol 3% (v/v), glycerol with protein-phenolic rice bran extract (5%), glycerol with protein-phenolic extract after 96 hours of fermentation (5%), and a control (without coating). The coated cherry tomatoes were kept at room temperature for 28 days. Mass loss, pH and acidity, total soluble solids, and carotenoids were determined every 96 hours. The coating made from the biomass extract reduced the carotenoid and acidity levels in the fruits studied by 17 and 21.1%, respectively, compared to the control. The coating proved an efficient barrier to water vapor with mass loss of 57% less than the control suggesting that it can be used as an alternative for vegetable tissue conservation.

The antifungal and antimycotoxigenic activities of extracts from edible plants were tested by the agar dilution method using the growth diameter of Aspergillus flavus as response and the determination of aflatoxins B1 and B2 in the culture medium. On the 7th incubation day, the greatest fungal inhibitions were reached by the extracts from potato peel; rice and wheat; lemon peel and pulp; eggplant peel; orange peel and pulp; and apple pulp. After the 14-day incubation, the extracts from banana (30 µg phenol/ml agar), eggplant (30 µg phenol/ml agar), and potato (50 and 67 µg phenol/ml agar) pulp reduced the production of aflatoxin B1 by 3.2%/µg phenol/ml agar, 2.9%/µg phenol/ml agar, 1.8%/µg phenol/ml agar and 0.85%/µg phenol/ml agar, respectively, in relation to the control. The extracts from the other vegetables fully inhibited the synthesis of the mycotoxin. These results point to the studied plants and their residues as potential sources of phenolic compounds that may have an inhibitory effect on fungal development and the production of mycotoxins in food.

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Os compostos fenólicos (ferúlico, cinâmico e vanílico) presentes em tecidos vegetais possuem efeitos inibitórios no crescimento de fungos e produção de micotoxinas. Os ácidos ρ-hidroxibenzoico, vanílico e protocatequínico são inibidores somente em concentrações relativamente altas. O metil éster ácido cisferúlico e o metil éster ácido cis-3,4-dimetoxicinâmico, derivados do ácido cinâmico, são inibidores em pequenas concentrações, na faixa de 1 a 10 nM, evidenciando que a atividade inibitória depende não só da concentração, mas também da estrutura do composto (BAKAN et al., 2003;GRIFFIN, 1994;RASOOLI;ABYANEH, 2004). Estas demonstrações sugerem uma perspectiva de substituir aditivos químicos por conservadores naturais obtidos destas estruturas vegetais (BRULL; KLIS, 1999), o que atenderia à atual demanda de produção de alimentos seguros e implementaria o uso de porções vegetais usualmente descartadas (MELO; GUERRA, 2002). Para a extração dos compostos fenólicos de raízes, tubérculos, frutas, espécies dos gêneros de Acácia, Terminália, Copernicia, maçãs, ameixas e outros, vêm sendo usados sistemas aquosos, alcoólicos e acetoetílicos sob diferentes condições de interação (LIMA et al., 2004;SOUSA et al., 2007). A quantificação dos compostos fenólicos totais nos diferentes extratos tem empregado o reagente de Folin-Ciocalteau.Para o contexto da agroindústria da região Sul do Brasil, seria interessante conhecer o potencial de resíduos de cebola e de coprodutos de arroz como fonte de conservadores naturais para extração e utilização na preservação natural de alimentos, pois permitiria a valorização de matérias-primas e coprodutos de baixo valor comercial. No entanto, a atividade antifúngica, que vem sendo atribuída a compostos fenólicos usualmente presentes em tecidos destes vegetais, não tem sido estudada nestes recursos agrícolas.Apesar do conhecimento milenar dos benefícios da cebola, demonstrados em diversos estudos sobre seus efeitos bioativos, algumas regiões produtoras têm dificuldades em comercializar suas safras em condições satisfatórias para consumo in natura ou em formulações industriais, resultando em descarte de material e desestímulo aos produtores (EMATER, 2007). AbstractThe objective of this work was to relate the levels of total phenolic in onion, rice bran, and Chlorella phyrenoidosa with the antifungal activity tested against the fungus Rhyzopus oryzae. The phenolic compounds of onion were extracted in three solvent systems: aqueous, methanolic, and with ethila acetate, whereas the phenolic compounds of rice bran and Chlorella phyrenoidosa were extracted with methanol. The extracts were quantified with the Folin-Ciocalteau reagent. The method to evaluate the antifungal activity employed was the diluted Ágar technique. The Rhyzopus oryzae had its development inhibited in the presence of onion methanolic and aceto-ethylic extracts and rice bran methanolic extracts at the following phenolic concentrations, 86; 2.6, and 46 µg phenolic .mL -1 agar , respectively. The aqueous extracts from onion and the me...

The study evaluated a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method for use with a TLC quantification procedure for deoxynivalenol (DON). It also surveyed DON occurrence in wheat flour from the southern region of Brazil. Forty-eight wheat flour samples were analysed, divided into 2 different harvest lots, each consisting of 24 different brands. The detection and quantification limits of the method were 30 and 100 ng of DON on the TLC plate. The various concentrations of DON presented high linearity (R = 0.99). A negative matrix effect (-28%) of the wheat flour was verified, with suppression of the chromatographic signal of DON, and 80.2-105.4% recovery. The TLC method was reliable for DON evaluation, with a coefficient of variation of less than 10%. High-performance liquid chromatography of lot 2 samples confirmed the presence of DON in all samples identified DON-positive by the TLC technique. Of the 48 wheat flour samples in lots 1 and 2 analysed by TLC, 33.3 and 45.8% of the samples respectively were above the Brazilian legislation limit. Correlations were observed between the water activity and DON content, and between the fungal count and moisture content of the wheat flours.