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This research evaluated the antioxidant, antimicrobial and toxicity potential of the leaf extract of Croton blanchetianus Baill (ExCb) and its effect on the conservation of lamb ribs. The ExCb (control treatment) revealed higher concentration of 2,5-dihydroxybenzoic acid (190.10 mg/g), catechin (84.10 mg/g), rosmarinic acid (56.01 mg/g), 4-hydroxybenzoic acid (52.05 mg/g) and myricetin (40.00 mg/g). And it showed high phenolic content (204.05 mg GAE/g), antioxidant potential (11.78 µg/mL by DPPH and 140.40 mmol Sulf Fer/g by FRAP) and antimicrobial activity with inhibition for Staphylococcus aureus, Listeria innocua, Salmonella enterica, Escherichia coli and Aspergillus flavus. However, it showed toxicity against brine shrimp (Artemia Salina) (LD50 of 66.26 µg/mL). The 2,5-dihydroxybenzoic acid was indicated as the main compound responsible for the toxicity of ExCb. After treatment in an oven at 110 °C for 15 min, the toxicity of ExCb was reduced by over 7 times, the compound 2,5-dihydroxybenzoic acid was not identified, and still maintained the phenolic compounds content of 94.35% and antioxidant activity compared to the control (without thermal treatment). The application of absorbent containing 50 mg/mL of ExCb added to the packaging maintained the quality and prevented the lipid oxidation of lamb ribs during 10 days of refrigerated storage.

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Properties of modified starch and its interaction with functional raw materials are of great interest to the food industry. Thus, this study aimed to evaluate the rheological and technological characterization of starches modified by the action of the enzymes α-amylase and amyloglucosidase and their mixtures with jaboticaba peel powder. The parameters of firmness, gumminess, and final viscosity of starches paste increased, and the tendency to setback was reduced with the addition of jaboticaba peel powder. Starches and mixtures presented shear-thinning behavior. The addition of jaboticaba peel powder to starches increased water, oil, and milk absorption capacity, while syneresis remained stable over the storage period. The addition of jaboticaba peel powder had a positive effect on native and modified starches' rheological and technological properties, qualifying it as an alternative for developing new functional food products.

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Starch is a technologically challenging polysaccharide that arouses the global interest in its modification to increase its applicability. Thus, the objective of the present work was to study the influence of enzymatic modification on the properties of red rice starch. The enzymatic modification was performed sequentially through the actions of α-amylase enzymes and amyloglucosidase using a design of experiments where several process conditions were used at sub-gelatinization temperatures. Then the native and modified starches were characterized for its physicochemical, physical, centesimal, phytochemical, morphological, and thermal properties. The enzymatic hydrolysis of the starch granules with α-amylase resulted in 4.46% hydrolysis and more 8.63% after the action amyloglucosidase. Results revealed that surface adsorption is more limiting than diffusion. The enzymatic hydrolysis process resulted in a reduction of the amylase and amylopectin content, as well as on all phytochemicals. After hydrolysis, granules starches presented surface alterations and tendency to become spherical. Small differences on crystallinity revealed that the enzymes had more influence on the amorphous fractions of the starch granules.

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Grain corn is predisposed to fungal growth and biosynthesis of aflatoxins. This research has the objective of evaluating the quality of grain corns used as raw material to make corn powder, regarding the presence of fungi and aflatoxins. The achieved results were compared to humidity level and water activity. The grain corn samples were analyzed from July 2004 to July 2005. The macrobiotic research of fungi was carried out via the macro and micromorphological identification and via the aflatoxins research, using the Thin Layer Chromatography Technique (TLC) as well as Bright Greenish Yellow Fluorescence (BGYF). In order to evaluate the humidity level and the water activity (Aw), the standard greenhouse method and the static method with the NOVASINA equipment were respectively used. The 40 samples analyzed did not present the aflatoxins B1, B2, G1 or G2. Eight samples presented number of fluorescent points when the BGYF technique was used. The humidity did not exceed the limit allowed by the Brazilian legislation – 14.50 per cent. There was growth of Aspergillus sppin 100 per cent of the samples; and there was growth of A. flavus in 22.5 per cent of the samples analyzed. The grain corns analyzed follow the rules of the Brazilian legislation.

O milho é um grão susceptível ao desenvolvimento fúngico e à biossíntese das aflatoxinas. A presente pesquisa teve como objetivo avaliar a qualidade dos grãos de milho utilizados como matéria-prima para fabricação de farinha de milho, quanto à presença de fungos e aflatoxinas. Os resultados obtidos foram comparados com o teor de umidade e a atividade de água. As amostras foram analisadas no período de julho de 2004 a julho de 2005. A pesquisa da macrobiota fúngica realizou-se através de identificação macro e micromorfológica e a pesquisa de aflatoxinas empregando-se atécnica de Cromatografia em Camada Delgada (CCD) e Brigth Greenish Yellow Fluorescence (BGYF). Para a avaliação do teor de umidade e a atividade de água (Aw), utilizou-se o método padrão de estufa e o método estático com aparelho NOVASINA, respectivamente. Nas 40 amostras analisadas não foi detectada a presença das aflatoxinas B1, B2, G1 e G2. Pela técnica BGYF, 8 amostras apresentaram número de pontos fluorescentes. A umidade não excedeu o limite permitido pela legislação brasileira – 14,50 por cento. Em 100 por cento das amostras houve crescimento de Aspergillus spp.; em 22,5 por cento das amostras analisadas houve crescimento de A. flavus. Os grãos de milho analisados estão de acordo com a legislação vigente do país.

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