No abstract

Starch is the major component of cereal, pulses, and root crops. Starch consists of two kinds of glucose polymers, amylose and amylopectin. Waxy starch—with 99–100% amylopectin—has distinctive properties, which define its functionality in many food applications. In this research, a novel material was prepared through the cryogelification of waxy starch (WS) using four cycles of freezing and thawing in indirect contact with liquid nitrogen at −150 °C. Polyvinyl alcohol (PVA) was used as a reference. The cryogels were characterized using several validation methodologies: modulated differential scanning calorimetry (MDSC), scanning electron microscopy (SEM), rheology, and Fourier transform infrared (FTIR) spectroscopy with diffuse reflectance (DR). Based on the number of freeze–thaw cycles, significant changes were found (P < 0.05) showing important structural modifications as well as reorganization of the polymeric matrix. Two cryogelification cycles of the WS were enough to obtain the best structural and functional characteristics, similar to those of PVA, which has already been tested as a cryogel. From these results, it is concluded that WS has potential as a cryogel for application in food processing.

No abstract

The aims of this work were to evaluate the effect of Ultrasound- Assisted Extraction (UAE) in oil yield, as well as in the physicochemical and chemical characteristics of Chia seed oil. The seeds were cryo ground before extraction; ultrasonic bath at 40 kHz was used during 90 min extraction process. The UEA resulted in intensification of the extraction, with 79.3% oil yield, while 69.2% were for stirring extraction. Diffusion coefficient´s values were 1.04x10^-11 m²s^-1 and 9.16x10^-12m²s^-1, respectively. From thermal analysis, made with MDSC, the main triacylglycerols (TAG´s) transitions were obtained. By ATR-FTIR, changes in the 987 and 968 cm^-1 wave numbers, corresponding to the outside plane deformation of C-H bonds in unsaturated fatty acids, were obtained . The UEA could change the material properties by cavitation that enhances the mass transfer, but no oil composition.