การยืดอายุการเก็บรักษาไข่ไก่โดยเคลือบด้วยไคโตซานที่เตรียม จากการฉายรังสีแกมมา / สุกัญญา ยาเสร็จ = Prolonging shelf life of hen eggs by coating with chitosan prepared from gamma irradiation / Sukanya Yaset
Chitosan is a biopolymer derivative of chitin prepared from deacetylation of chitin from shrimp shells, crab shells, squid pens and cell walls of certain fungi. In this study, chitosan powder was degraded by gamma irradiation in the range of 10 to 100 kGy in order to obtain an appropriate molecular size. Gamma irradiation of chitosan in the solid state is easy, convenient and fast, and does not alter the molecular structure of chitosan. Irradiated chitosan was subsequently dissolved in 2 % (v/v) acetic acid to obtain 1 % (wt/v) final concentration. The pH of the solution was then adjusted to 5.6 using 6 N NaOH. The final product was applied to coat hen eggs by dipping each egg in the solution for 5 seconds. Coatings of 1, 2 and 3 layers were studied. Egg quality stored at room temperature (30 °C) for 0 to 8 weeks in terms of pH of albumin, weight loss, haugh unit, separation of albumin and yolk, and weights of albumin and yolk of was evaluated. Results indicated that chitosan irradiated at 10 kGy with the molecular weight of 492 kDa was most suitable to coat hen eggs, as the shelf life of chitosan-coated eggs increased to 6 weeks compared with only 2 weeks for uncoated eggs. This technique can be applied to other kinds of eggs as well as scaling-up for commercial applications in egg processing industry.