热处理复合香茅精油处理对番木瓜保鲜效果及软化相关酶活性的影响

Effects of Heat Combined Citronella Essential Oil Treatment on the Preservation and Softening Related Enzymes of Papaya

本文以‘美中红’番木瓜为试材,研究了热处理复合香茅精油处理对番木瓜果实采后保鲜效果及软化相关酶的影响,测定了贮藏过程中果实失重率、硬度、颜色、可溶性固形物(TSS)、可滴定酸(TA)、维生素C(Vc)和呼吸速率,还测定了多聚半乳糖醛酸酶(PG)、果胶甲酯酶(PE)、纤维素酶(CL)和β-半乳糖苷酶(β-GAL)等软化相关酶的活性。结果表明:热处理复合香茅精油处理可显著降低番木瓜果实病情指数和失重率,延缓果实硬度下降和颜色的转黄,提高果实中的TSS和Vc含量和果实固酸比,降低果实呼吸速率,延迟呼吸高峰的出现;复合处理可降低果实PG酶、PE酶和β-GAL酶活性,延迟PE酶峰值的出现,对CL酶活性影响不显著。可见,复合处理对番木瓜果实有较好的保鲜效果,复合处理延缓果实硬度下降与降低呼吸速率以及降低PG酶、PE酶和β-GAL酶活性密切相关。

In this paper,the effects of heat combined citronella essential oil treatment on the preservation and activity of softening related enzymes were studied by using‘Meizhonghong’papaya as the test materials,and the fruit weight loss rate,hardness,color,titratable acid(TA),vitamin C(Vc),galacturonic acid polymer(PG),cellulase enzyme(CL),β-galactose glucoside enzyme(β-GAL)and methyl pectin enzyme(PE)activities were determined in the process of storage.Heat combined citronella essential oil treatment could improve the preserving quality by significantly reducing the disease index of papaya fruit,weight loss rate,decrease of firmness and yellow rate,and increasing the content of TSS and VC and TSS/TA ratio,slowing down the respiration rate and delaying the occurrence of respiration peak,meanwhile the activity of PG,PE andβ-GAL enzymes,involved in the degradation of cell wall were significantly reduced by the combined treatment except the activity of CL enzyme which was not significantly influenced.In conclusion,heat combined citronella essential oil treatment showed good preservation effect on papaya fruit,delaying the decrease of fruit firmness,reducing the respiration rate and the activity of PG enzyme,PE enzyme andβ-GAL enzyme.