采后菠萝果实品质及果胶分解酶活性的变化

目的]研究采后后熟软化过程中菠萝贮藏品质及果胶酶活性的变化,探讨菠萝果实成熟软化的原因.方法]试验以菠萝为原料,测定常温贮藏过程中菠萝果实的色差、硬度、呼吸强度、可滴定酸（TA）、抗坏血酸（VC）、可溶性固形物（TSS）等品质指标,同时分析多聚半乳糖醛酸酶（PG）、果胶甲酯酶（PME）、β-半乳糖苷酶（β-Gal）3种果胶酶活性的变化.结果]试验表明,菠萝果实的后熟软化是一个渐变的过程,随着果实成熟度的提高,其果肉硬度逐渐降低,呼吸强度、TSS及TA含量逐渐增强,VC含量先上升后下降.PG等果胶酶的活性先升后降,且与菠萝果肉硬度呈显著负相关,说明3种酶参与了菠萝果实的后熟软化.结论]研究可为菠萝果实贮藏保鲜提供理论依据.

Changes on Quality and the Activities of Pectin Decomposition Enzymes of Postharvest Pineapple Fruit during Storage

Objective ] To study change of pineapple storage quality and pcctinase activity in ripening and softening process. Method ] Used pineapple as experimental materials, the color difference, hardness, respiration intensity and TA, Vc , TSS of different maturity of pineapple in normal temperature storage were determined, and the activity of 3 kinds of pectin decomposition enzyme,including polygalacturonase （PG） and pectin methyl esterase （PME）, β-galactosidase （β-Gal） were measured and analyzed. Result] The results showed that the ripening and softening of pineapple was a gradual process, as the fruit matarity from low to high, its hardness gradually reduced, breathing intensity, TSS, TA increased, the content of Vc increased firstly and then decreased. The activities of pectin decomposition enzymes increased firstly and then decreased, and they had significant negative correlation with pineapple pulp hardness, showed that the three enzymes involved in the softening of the pineapple fruit. Conclusion ] The study can provide theoretical basis for pineapple storage.