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The addition of microbial transglutaminase (MTGase) generally increased the gel strength of lizardfish (Saurida spp.) scale gelatin gels (P≤0.05) with an increase in gel strength with the addition of MTGase up to 0.5% (w/v). The texture profile analysis compression tests of lizardfish scale gelatin gel with and without MTGase were studied to determine their effects on gel characteristics. MTGase added to the gels decreased the band intensity of the β- and α-components with increasing concentrations of enzyme. Gel microstructures with various concentration of MTGase showed denser strands in the gels with enzyme compared with the looser stands in non-enzyme-treated gel samples. Films cast from lizardfish scale gelatin with and without 0.5% MTGase and bovine gelatin films were transparent and flexible. The lizardfish gelatin films were all slightly yellowish while the bovine gelatin films were clearer. The L value of bovine gelatin films had the highest value (P≤0.05) whereas lizardfish scale gelatin films with and without enzyme were not significantly different (P>0.05) for L, a, and b values and ΔE. The film's mechanical properties included tensile strength (TS) and elongation at break (E) were not significantly different (P > 0.05) for E and the films of lizardfish scale gelatin showed higher TS than the films without enzyme added (P ≤ 0.05). The water vapor permeability of films from lizardfish scale gelatin with and without 0.5% MTGase and bovine gelatin films were 21.0 ± 0.17, 26.3 ± 0.79, and 25.8 ± 0.09 g·mm/m(2)·d·kPa, respectively, while the oxygen transmission rate of all 3 types of films were less than 50 cc O(2)/m(2)·d.

Purple glutinous rice bran (Kum Doi Saket rice (KUM)) contains high content of edible polysaccharides and anthocyanins and has an excellent antioxidant activity. This research aimed to optimize the extraction of crude polysaccharides from defatted purple glutinous rice bran using an ultrasonic-assisted extraction (UAE) and compared with a hot water extraction (HWE). Results showed that optimal extraction condition was as follows: a defatted rice bran to water ratio of 1:20 w/v, extraction temperature and time of 70 °C for 20 min. Under the optimal extraction condition, the yield of polysaccharide of UAE (4%) was significantly higher than that obtained from the HWE (0.8%). Additionally, antioxidant activities of extracted polysaccharide including IC50 value DPPH, IC50 value ABTS, and FRAP value were 1.09 mg/mL, 2.80 mg/mL and 197 µM Fe2+/g, respectively. It is suggested that the UAE process is promising method to decrease the processing time and to enhance extracted polysaccharide yields by 4 times.