贮藏对半干型荔枝干非酶褐变的影响(英文)

Effect of Storage on Non-enzymatic Browning of Hemi-dried Litchi Fruit

研究了半干型荔枝干在-20、3、40℃贮藏11周中的非酶褐变动力学,利用褐变指数和CIE-Lab色泽系统测定贮藏期间的色泽变化,用真空包装与非真空包装的半干型荔枝干贮藏在不同温度下,其褐变符合零级反应动力学,反应活化能分别是54.51J/mol和52.17J/mol;色泽的形成也符合零级反应动力学,反应活化能分别是38.49J/mol和38.41J/mol。依不同贮藏温度,半干型荔枝干中5-HMF的浓度从78.63到2050.49μg/5g。真空包装与否不是影响色泽变化与5-HMF积累的主要因素。在常温下贮藏超过4月,从色泽考虑,半干型荔枝干的商品价值降低。

Kinetics of non-enzymatic browning in hemi-dried litchi fruits during 11 weeks were investigated. Hemi-dried litchi fruits were stored at -20℃, 3℃ or 40℃. Color changes were assayed by browning index （A280nm, A420nm） and the CIE-Lab color system. Browning level of hemi-dried litchi fruits stored at different temperatures with vacuum and no-vacuum packages increased according to a zero-order reaction kinetic. Activation energy for it was 54.51 J/mol and 52.17 J/mol, respectively. And color formation（ΔE） followed zero-order reaction kinetic, too. Activation energy was 38.49 J/mol and 38.41J/mol, respectively. 5-（hydroxymethyl）-2-furfural（5-HMF） concentration, in hemi-dried litchi fruits ranged from 78.63 to 2050.49μg/5 g according to storage temperature changes. Package form was not the main factor of affecting color formation and 5-HMF accumulation during storage period of hemi-dried litchi fruits. Evaluated from the color of products, the hemi-dried litchi fruits would lose their commercial value when they are stored for over 4 weeks at room temperature.