壳聚糖涂膜对鸡蛋品质的影响

通过对新鲜鸡蛋涂擦不同质量浓度的壳聚糖溶液，旨在研究壳聚糖对鸡蛋品质的影响。试验将300 枚新鲜鸡蛋随机分成6 组，分别涂上0、0.5、1.0、1.5、2.0g/100mL 和2.5g/100mL 壳聚糖溶液，25℃条件下贮存5周。每周从每个处理中取10 枚鸡蛋测定鸡蛋失重率、哈夫单位、蛋黄指数和蛋清pH 值。结果表明，第5 周与第1 周相比，不涂壳聚糖的鸡蛋失重率和蛋清pH 值显著升高(P ＜ 0.05)、哈夫单位和蛋黄指数显著低(P ＜ 0.05) 。5 周时，与不涂壳聚糖的鸡蛋相比，所有涂壳聚糖的鸡蛋失重率显著降低(P ＜ 0.05)，蛋黄指数显著升高(P ＜ 0.05)；涂1.0、1.5、2.0g/100mL 和2.5g/100mL 壳聚糖的鸡蛋哈夫单位显著升高(P ＜ 0.05)，蛋清pH 值显著降低(P ＜ 0.05)；涂1.5、2.0g/100mL 和2.5g/100mL 壳聚糖的鸡蛋间比较，蛋质量损失率、哈夫单位、蛋黄指数和蛋清pH 值差异均不显著(P ＞ 0.05)。用0.5g/100mL 壳聚糖涂擦的鸡蛋5 周时降到C 级，相当于不涂壳聚糖的鸡蛋3 周时的级别；用1.0、1.5、2.0g/100mL 和2.5g/100mL 壳聚糖处理的鸡蛋5 周时降到B 级，相当于不用壳聚糖处理的鸡蛋2 周时的级别。该实验证明壳聚糖能够延长鸡蛋货架期。

Effect of Chitosan-coating on Egg Quality

A total of 300 fresh eggs were randomly allocated into 6 treatment groups, and coated with 0, 0.5, 1.0, 1.5, 2.0 g/100 mL and 2.5 g/100 mL of chitosan. Then the eggs were stored at 25 ℃ for 5 weeks. Ten eggs were chosen from every treatment per week for determination of the weight loss ratio, Haugh unit, yolk index and albumen pH. The result showed that after 5 weeks storage, the weight loss ratio and albumen pH were significantly increased (P＜0.05), meanwhile, the Haugh unit and yolk index of the eggs significantly decreased (P＜0.05) in non-chitosan coated egg group. At 5 wk, compared with the eggs nocoated with chitosan, the weight loss ratio of all the eggs coated with chitosan was significantly decreased (P＜0.05) and yolk index was significantly increased (P＜0.05). The Haugh unit of the eggs coated with 1.0, 1.5, 2.0 g/100 mL and 2.5 g/100 mL chitosan was significantly increased (P＜0.05) and albumen pH was significantly decreased (P＜0.05). It had no significant difference on the weight loss ratio, Haugh unit, yolk index and albumen pH among the eggs coated with 1.5, 2.0 and 2.5% of chitosan(P＞0.05). The grade of the eggs coated with 0.5 g/100 mL chitosan at 5 wk was C , which was equal to the grade of the eggs nocoated at 3 wk. The grade of the eggs coated with 1.0, 1.5, 2.0 g/100 mL and 2.5 g/100 mL chitosan at 5 wk was B , which was equal to the grade of the eggs nocoated at 2 wk. The shelf life of eggs were prolonged significantly by coating of chitosan.