Abstract:
In this study, xylan from some agricultural wastes (corn cobs, rice straw, rice husk, bagasse and peanut shells) were extracted and used as bases for film formation and applied for antioxidation in pork jerky. The highest hemicellulose content at 43.42±1.21% (w/w) was found in the corncob while the highest amount of extracted xylan (12.00 ±0.006% (w/w)) was obtained from rice husk. Functional modification of the extracted xylans with citric acid at the different ratios of 1:1 1:3 and 1:5 was performed and their structures were analyzed by fourier transform infrared spectroscopy. These xylans and modified xylans in each type of agricultural wastes were casted into films together with 3% (w/v) CMC and glycerol at the different concentrations of 0.5, 1.0 and 1.5% (v/v). The thickness of films was not significantly different in all treatments while film casted from modified rice husk-xylan (M-XRH) in all ratios with 0.5% (v/v) glycerol presented the significantly higher values of tensile strength (54.71-58.84 MPa) than those from other modified xylans. Therefore, these M-XRH films were selected to analyze other physical properties. The highest degree of substitution at 0.84±0.03 was obtained from M-XRH film at the ratio of 1:5 while the highest oxygen permeability (41.6 cm3/m2.day.bar) and water vapor permeability (4.17±0.01 (x10-6) g/m.s.Pa) were found in M-XRH film at the ratio of 1:3. The peroxide values measured from oxidation of lipid in pork jerky trend to be slower when the pork jerky were covered with M-XRH films in all ratios comparing with the control without film covering. Therefore, the M-XRH films were found to be suitable for applying on meat products.