川南晚熟荔枝保鲜过程中防止褐变的研究

Research on preventing browning in the process of preserving late-ripening litchi in south of Sichuan

荔枝保鲜是荔枝产业发展的技术瓶颈之一,是制约荔枝产业发展的主要因素。川南晚熟合江荔枝成熟在每年7、8月,正值夏季,四川盆地天气炎热,荔枝极易发生褐变、腐败。因此,防止或延缓荔枝果皮发生褐变是荔枝保鲜必须解决的问题。试验发现,通过瞬间漂烫、速冻、定温解冻及颜色复原技术组合,可获得良好的荔枝保鲜结果。试验结果表明:荔枝冷冻保鲜最佳条件为:荔枝在100℃沸水中漂烫10s,捞出冷却至室温后,放入速冻冷柜,3h内将荔枝温度降至-16℃。定温解冻最佳温度为3℃,解冻时间为3h。正交试验结果表明,颜色复原最佳组合:以10%柠檬酸+2%维生素C为颜色复原剂,浸泡时间20min,浸泡温度1℃。该保鲜方法30d内荔枝完好率最高可达100%,货架期2-3d,并且口感良好。

Litchi preservation is one of the technical bottlenecks in the development of litchi industry and the main factor restricting the development of litchi industry. The Hejiang litchi in Sichuan matures in July or August. It is so hot in the Sichuan Basin that litchi is prone to browning and corruption. Therefore,preventing or delaying the browning of litchi must be solved for litchi preservation. It has been found that a good preservation result can be obtained by instantaneous blanching, quick freezing, constant temperature thawing, and color recovery using organic acids and vitamins. The test results showed that the litchi was blanched in boiling water at 100 ℃ for 10 s,and then cooled to indoor temperature,then placed in a quick-freeze freezer, and the temperature of the litchi was lowered to -16 ℃ within 3 h. The optimum temperature for thawing at constant temperature is 3 ℃,and the thawing time is 3 h. The results of orthogonal test showed that the best combination of color recovery:citric acid + vitamin C,20 min,1 ℃. The rate of litchi freshness can be up to 100% within 30 days,the shelf life is 2-3 days.