Oxidation of potato starch with different sodium hypochlorite concentrations and its effect on biodegradable films

AbstractThe objective of this study was to evaluate the effects of oxidation with sodium hypochlorite at different concentrations of active chlorine (0.5, 1.0 and 1.5 g/100 g) on the physicochemical, morphological, pasting, thermal and gel texture properties of potato starch. The native and oxidized starches were used in different concentrations (3.0, 4.0 and 5.0 g starch/100 mL) for the preparation of biodegradable films using glycerol as plasticizer. The films were evaluated for their mechanical properties, color, water solubility and permeability of water vapor. The degree of oxidation potato starches was more intense as there was an increased concentration of active chlorine in the reaction. Films made with oxidized starch with the highest level of active chlorine had lower tensile strength when compared to native starch films. Also, these films had a lower water solubility and water vapor permeability as compared to the native starch films

Níveis de deoxinivalenol, compostos fenólicos e atividade antioxidante de farinha de trigo após processo de polimento

The objective of this work was to evaluate the effect of the debranning process on the deoxynivalenol (DON) content, phenolic compounds, and antioxidant activity of wheat flours, in order to determine which milling technology provides the safest and most nutritional wheat products. Grain samples from the BRS Marcante, BRS Reponte, and BRS 374 wheat (Triticum aestivum) cultivars were used to obtain both whole-wheat and white flours. For whole-wheat, grains were debranned at different times (20 and 40 s). The debranning process significantly reduced the DON content in the whole-wheat flours from all cultivars. The DON concentration decreased 22 and 28% in the 20 and 40 s debranning treatments, respectively, when compared with the treatment without debranning. In addition, phenolic compound content and antioxidant capacity are significantly higher in the whole-wheat flours. The debranning process contributes to the production of safer and healthier foods, by reducing DON content and retaining phenolic compounds and antioxidant activity in whole-wheat flours.O objetivo deste trabalho foi avaliar o efeito do processo de polimento nos níveis de deoxinivalenol (DON), nos compostos fenólicos e na atividade antioxidante de farinhas de trigo, para determinar a tecnologia de moagem que fornece os produtos de trigo mais seguros e nutritivos. Amostras de grãos das cultivares de trigo (Triticum aestivum) BRS Marcante, BRS Reponte e BRS 374 foram utilizadas para obter farinhas de trigo integral e branca. Para a farinha integral, os grãos foram submetidos a diferentes períodos (20 e 40 s) de polimento. O processo de polimento reduziu significativamente o teor de DON nas farinhas de trigo integral de todas as cultivares. A concentração de DON diminuiu 22 e 28% nos tratamentos polimento por 20 e 40 s, respectivamente, quando comparada à do tratamento sem polimento. Além disso, os níveis de compostos fenólicos e a capacidade antioxidante são significativamente maiores nas farinhas de trigo integral. O processo de polimento contribui para a produção de alimentos mais seguros e saudáveis, ao reduzir o teor de DON e conservar os compostos fenólicos e a atividade antioxidante na farinha de trigo integral

Structural, morphological, and physicochemical properties of acetylated high-, medium-, and low-amylose rice starches

AbstractThe high-, medium-, and low-amylose rice starches were isolated by the alkaline method and acetylated by using acetic anhydride for 10, 30, and 90min of reaction. The degree of substitution (DS), the Fourier-transformed infrared spectroscopy (FTIR), the X-ray diffractograms, the thermal, morphological, and pasting properties, and the swelling power and solubility of native and acetylated starches were evaluated. The DS of the low-amylose rice starch was higher than the DS of the medium- and the high-amylose rice starches. The introduction of acetyl groups was confirmed by FTIR spectroscopy. The acetylation treatment reduced the crystallinity, the viscosity, the swelling power, and the solubility of rice starch; however, there was an increase in the thermal stability of rice starch modified by acetylation

Funcionalidade de hidrolisados proteicos de cabrinha (Prionotus punctatus) obtidos a partir de diferentes proteases microbianas

The objective of this work was to study the influence of enzymes Alcalase, Flavourzyme and Novozym in the functional properties of hydrolysates of Bluewing searobin (Prionotus punctatus) minced. The hydrolysates of Bluewing searobin were evaluated for the chemical composition and the functional properties. The Novozym enzyme presented greater specific activity differing significantly from the enzymes Alcalase and Flavourzyme. The hydrolysates of Bluewing searobin presented protein content above of 87% and excellent solubility, capacity of water retention, capacity of oil retention and emulsifying capacity