Studying the effects of nucleating agents on texture modification of puffed corn-fish snack

Delayed Quality Deterioration of Low-Moisture Cereal-Based Snack by Storing in an Active Filler-Embedded LDPE Zipper Bag

This study focused on controlling the vapor permeability of an active zipper bag and preserving the quality of cereal-based snacks during the storage period at home. The active zipper bag was prepared by extruding low-density polyethylene with active fillers obtained from natural mineral materials. The active zipper bag showed the same transparent appearance as the existing one but showed 21% lower water vapor capability. As a result, during a 20-day storage period, three types of grain-based snacks (biscuits, shortbread cookies, and puffed snacks) showed delayed increases in weight, moisture content, and moisture activity when stored in an active zipper bag. In addition, this also affected the texture of the biscuits and shortbread cookies, in which the area under the curve was reduced significantly after appearing at a peak during the hardness measurement. On the other hand, the decrease in the number of air cell fracture events in puffed snacks was remarkable. This result suggests that the inner microstructure is preserved better when stored in an active zipper bag. In conclusion, the active zipper bag showed poor water vapor permeability, suggesting that the prepared zipper bag can be developed as snack packaging.

Interaction of Squid (Dosidicus giga) Mantle Protein with a Mixtures of Potato and Corn Starch in an Extruded Snack, as Characterized by FTIR and DSC

The majority of snacks expanded by extrusion (SEE) are made with vegetable sources, to improve their nutritional content; it has been proposed to incorporate squid (Dosidicus gigas), due to its high protein content, low price and high availability. However, the interaction of proteins of animal origin with starch during extrusion causes negative effects on the sensory properties of SEE, so it is necessary to know the type of protein-carbohydrate interactions and their effect on these properties. The objective of this research was to study the interaction of proteins and carbohydrates of SEE elaborated with squid mantle, potato and corn. The nutritional composition and protein digestibility were evaluated, Fourier transform infrared (FTIR) and Differential Scanning Calorimetry (DSC) were used to study the formation of protein-starch complexes and the possible regions responsible for their interactions. The SEE had a high protein content (40-85%) and biological value (>93%). The melting temperature (Tm) was found between 145 and 225 °C; the Tm values in extruded samples are directly proportional to the squid content. The extrusion process reduced the amine groups I and II responsible for the protein-protein interaction and increased the O-glucosidic bonds, so these bonds could be responsible for the protein-carbohydrate interactions.

Phagocyte NADPH oxidase, chronic granulomatous disease and mycobacterial infections

Infection of humans with Mycobacterium tuberculosis remains frequent and may still lead to death. After primary infection, the immune system is often able to control M. tuberculosis infection over a prolonged latency period, but a decrease in immune function (from HIV to immunosenescence) leads to active disease. Available vaccines against tuberculosis are restricted to BCG, a live vaccine with an attenuated strain of M. bovis. Immunodeficiency may not only be associated with an increased risk of tuberculosis, but also with local or disseminated BCG infection. Genetic deficiency in the reactive oxygen species (ROS)-producing phagocyte NADPH oxidase NOX2 is called chronic granulomatous disease (CGD). CGD is among the most common primary immune deficiencies. Here we review our knowledge on the importance of NOX2-derived ROS in mycobacterial infection. A literature review suggests that human CGD patient frequently have an increased susceptibility to BCG and to M. tuberculosis. In vitro studies and experiments with CGD mice are incomplete and yielded - at least in part - contradictory results. Thus, although observations in human CGD patients leave little doubt about the role of NOX2 in the control of mycobacteria, further studies will be necessary to unequivocally define and understand the role of ROS.