本试验旨在研究一种以乳酸菌为主要成份的复合生物保鲜剂对龙眼果实的保鲜作用，复合保鲜剂配方为8.6×106 CFU/mL dgnkzx002+1%曲酸+1%乳酸钠。以“东丰”龙眼（Dimocarpus longan Lour. cv. Dongfeng）果实为试材，研究肠膜明串珠菌复合保鲜剂在冷藏（4 ℃）条件下龙眼果实品质的影响及其在龙眼保鲜中的应用。结果显示，经复合生物保鲜剂处理的龙眼果实在4 ℃冷藏30 d后的可滴定酸(TA)、可溶性固形物(TSS)和维生素C(Vc)含量分别为清水处理对照组的190.90%、123.19%和147.79%，而商品率与失重率分别为192.31%和73.9%，说明保鲜剂处理不仅抑制了贮藏期间龙眼果实的呼吸作用，延缓了果实营养成分的下降，还能有效减少果实水分损失、显著提高果实的商品率。此外，复合保鲜剂还在一定程度上抑制多酚氧化酶(PPO)和过氧化物酶(POD)的活性，保持超氧化物歧化酶(SOD)的活性。采用肠膜明串珠菌复合保鲜剂处理可较好地保持冷藏条件下龙眼果实的品质，减缓酶促褐变过程，在龙眼生物保鲜上具有较好的应用前景。

The paper studied the preservation effect of lactic acid bacteria on fresh longan fruits and developed a composite bio-preservative agent with lactic acid bacteria as the main component. The formula of bio-preservative agents is 8.6×106 CFU/mL dgnkzx002, 1% kojic acid and 1% sodium lactate. Taking longan fruits (Dimocarpus longan Lour. cv. Dongfeng) as test materials, the influence of composite biological preservative of Leuconostoc mesenteroides on fruit quality and effect on fresh-keeping of longan fruits were evaluated during storage at 4 ℃. The results showed that titratable acidity (TA), soluble solids (TSS) and vitamin C (Vc) content of longan fruit treated by the composite biological preservative were 90.90%, 23.19% and 47.79%, respectively, higher than those by the water control group. The commodity rate and weight loss rates were 192.31% and 73.9%, respectively. This showed that the composite biological preservative could delay the decrease of total soluble solids (TSS), titrable acid (TA), vitamin C, reducing sugar and total sugar, reduce weight loss rate, and slow down the commodity rate of decline and inhibit polyphenol oxidase (PPO) activity, peroxidase (POD) activity, thus maintaining the activity of superoxide dismutase (SOD). Therefore, composite biological preservative treatment effectively maintained the quality of longan fruits and slowed down the process of enzymatic browning. The composite biological preservative of Leuconostoc mesenteroides showed great potential in longan biological preservation.

东莞市高等院校科研机构科技计划项目（NO.2011108101008）