Abstract Resistant starch (RS) has gained interesting because of its health benefits as the control of diseases, such as diabetes. Modifications in starches have been applied in order to increase RS content and consequently the range of industrial food applications. The heat-moisture treatment (HMT) combined with the addition of organic acids was the aim of this study, and also to evaluate the in vitro digestibility and other properties of corn starches. In both botanical sources, the RS content increased significantly, for the normal type and the waxy. Among organic acids used, citric, followed by lactic and acetic acid, promoted the most evident alterations and showed promising results in the increasing of RS. The results obtained by this combined method open opportunities for further applications in functional foods as well as starch based encapsulation process.

Abstract Starch is an important energy reserve polysaccharide for vegetables, found in large quantities in nature. From a renewable and low-cost source, it is considered an excellent raw material for the production of biopolymers. Biodegradable films can be obtained from different starch sources and can be an alternative to the damages caused by petroleum products, since they have the properties of conventional plastics and are easily degraded in the environment. However, starch-based films have limitations such as poor mechanical properties. To overcome this weakness, the addition of secondary additives is used to improve its resistance. This review highlights how different materials used in the production of biodegradable polymers, the importance of incorporating reinforcement content in the polymer matrix and as the main characterization techniques of bio composites.

Abstract Biodegradable films were prepared using regular and waxy starch and reinforced with cellulose nanofibers (CNF) from eucalyptus. Both films were characterized by their optical, structural, barrier, thermal and mechanical properties. The films presented a homogeneous, smooth surface without bubbles or cracks and good handling characteristics. Both films showed a mixture of B and V-type diffraction patterns. The water solubility of the samples decreased after the incorporation of nanocellulose. The water vapor permeability for both sources significantly reduced after incorporating nanocellulose at 0.5% and 1%. It is possible to observe that the addition of CNF increased the thermal stability of the starch films. On the other hand, the incorporation of nanocellulose improved either the mechanical resistance of the starch films.

Abstract The effects of gamma radiation (0, 1, 2 and 3 kGy) were used to evaluate the stability and thermal degradation kinetics of anthocyanins, as well as the stability of total phenolic compounds (TPC) and antioxidant activity at different temperatures (4, 25, 35 and 45 °C) during the storage (0, 30, 60, 90 and 120 days) of black rice flour. This flour can be used as ingredient for gluten-free cereal products with higher nutritional value. For this it is necessary to preserve the anthocyanin content during thermal processing and shelf-life periods. At time 0, the dose of 3 kGy provided all of the most available bioactive compounds, raising their antioxidant potential, except for TPC. During the storage at different temperatures up to 120 days, gradual losses occurred in all the analysed parameters. Regarding the total anthocyanin content and TPC, the sample irradiated with a 1 kGy dose remained most stable. The analysis of kinetic data indicated a first-order reaction for the degradation of anthocyanins. The combination of irradiation with different temperatures may improve the shelf-life of black rice flour.