The effects of single and dual heat-moisture treatment (HMT) of rice, cassava and pinhão starches at 100 °C and 120 °C were investigated. The starches were adjusted to 22% w.b. moisture content and subjected to single HMT (autoclaved for 2 h) or dual HMT (after being autoclaved for 1 h, the material was allowed to stand for 24 h and was autoclaved again for more 1 h). Starch crystallinity, solubility, swelling power, thermal properties, pasting properties, and gel hardness were evaluated. The temperature variation affected more the starch properties than the single or dual HMT. The starch subjected to single HMT at 120 °C was the most applicable to food applications, where low swelling power, low viscosity and high thermal stability are necessary.

No abstract

No abstract

No abstract

The objectives of this study were to characterize zein fibers and capsules prepared by electrospinning and electrospraying techniques, respectively, and then use them to encapsulate folic acid. Folic acid containing fibers and capsules (0.5, 1.0, and 1.5%, w/v) were submitted to thermal treatment (100, 140, and 180°C) and ultraviolet A light (UVA) irradiation to evaluate the resistance of folic acid. Zein fibers and capsules containing folic acid showed high encapsulation efficiency (> 80%). Unencapsulated folic acid showed a reduction in folic acid content from 17.17 μg/mL to 5.44 μg/mL (approximately 70%) when exposed to 180°C. Photodegradation of unencapsulated folic acid lowered its concentration from 17.17 μg/mL to 12.58 μg/mL (~26% of reduction), when exposed for 1 h to UVA irradiation. However, folic acid concentration when encapsulated in fibers (1.5%) was maintained or only slightly reduced from 9.73 μg/mg to 8.88 μg/mg after thermal treatment at 180°C. The capsules containing 1.5% of folic acid also presented a slight reduction in folic acid concentration from 8.84 μg/ mg to 7.88 μg/mg when exposed to 24 h of UVA irradiation. Zein fibers and capsules containing folic acid present promising characteristics for application in foods that require thermal processing or exposure to irradiation.

The mechanical, barrier, solubility, and thermal properties are factors which direct the type of the film application in packaging for food products. The films elaborated with acetylated starches of low degree of substitution were not effective in a reduction of the water vapor permeability. The addition of the cellulose fiber in acetylated and native starches films can contribute to the development of more resistant films to be applied in food systems that need to maintain their integrity. © 2016 Society of Chemical Industry.

The objective of this work was to study the effect of enzymatic hydrolysis of black bean protein concentrate using different enzymes. Bean proteins were extracted and hydrolyzed over a period of 120 min using the enzymes pepsin or alcalase. The protein hydrolysates' molecular weight was assayed by electrophoresis and the antioxidant activity was evaluated by the capturing methods of free radicals ABTS•+ and DPPH. Electrophoretic results showed that the bands above 50 kDa disappeared, when the beans protein was subjected to hydrolysis with pepsin. The bean protein hydrolysate obtained by hydrolysis with alcalase enzyme, showed higher antioxidant activity for inhibition of the radical ABTS•+ . However, the hydrolysates obtained by hydrolysis with pepsin had higher antioxidant activity for inhibition of the radical DPPH. The use of pepsin and alcalase enzymes, under the same reaction time, produced black bean protein hydrolysates with different molecular weight profiles and superior antioxidant activity than the native bean protein.

The aim of this study was to develop and evaluate films produced from potato and cassava starches, reinforced with cellulose fibers and/or nanoclay. The films were elaborated with 4% starch, 30% glycerol, 20% cellulose fiber, and/or 5.0% nanoclay. The films were evaluated by physical, mechanical, and water vapor barriers, and morphological properties. The addition of nanoclay and cellulose simultaneously increased the tensile strength from 12.03 to 17.75 MPa and decreased the elongation from 13.81 to 0.94% of the potato starch films when compared to films without addition of these reinforcements. The addition of cellulose fibers and/or nanoclay increased the tensile strength of the cassava starch films. The water vapor permeability (WVP) of the films decreased with the addition of reinforcing agents, and the lowest WVP values were presented when cellulose and nanoclay were added simultaneously to the starch films. A synergistic effect between the cellulose and the nanoclay in the constitution of the film promoted a lower WVP value. The addition of cellulose increased the water solubility from 14.7 to 19.6% of the potato starch films. The addition of reinforcement agents in potato starch films produced more resistant films with a moderate solubility, thus can be used as a biodegradable sachet to release systems.