Long-term storage of Pink Lady apples modifies volatile-involved enzyme activities: consequences on production of volatile esters.
Long-term storage of Pink Lady apples modifies volatile-involved enzyme activities: consequences on production of volatile esters.
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DOI：
10.1021/jf801098b
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发表时间：
2008-09
影响因子：
6.1
通讯作者：
C. Villatoro;G. Echeverría;J. Graell;M. López;I. Lara
中科院分区：
文献类型：
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作者：
C. Villatoro;G. Echeverría;J. Graell;M. López;I. Lara
在商品成熟期采收粉红女士苹果，在1 ℃和92%相对湿度下，在空气或气调条件（2kPa O2：2kPa CO2和1 kPa O2：1 kPa CO2）下贮藏27周。在随后的20摄氏度的保质期内，获得了皮肤和肉组织中挥发性化合物排放和一些相关酶活性的数据。贮藏气氛和贮藏后的时间对挥发性酯及其前体物的释放有重要影响。挥发性酯的产生的变化，部分是由于醇O-酰基转移酶的活性的改变，但具体的酯由水果储存后排放也主要是由于在相应的基板供应的修改。在空气中储存的样品的特点是乙醛的可用性较高，而那些存储在CA下显示出增强排放的醇前体乙醇和1-己醇（2 kPa O 2）和1-丁醇（1 kPa O 2），相应地更高的生产乙基，己基，和丁基酯。多变量分析表明，所观察到的前体可用性差异的很大一部分来自所考虑的酶活性的修改。空气储存的水果中较高的丙酮酸脱羧酶活性可能是这些样品中较高的乙醛水平的原因，而在1 kPa O2下储存导致脂氧合酶活性显着降低，从而减少了1-己醇和己酯的产生。低乙醛的可用性，以及增强氢过氧化物裂解酶和乙醇脱氢酶水平在这些水果中的建议，导致较高的排放1-丁醇和丁酯。
Pink Lady apples were harvested at commercial maturity and stored at 1 degrees C and 92% relative humidity under either air or controlled atmosphere conditions (2 kPa O 2:2 kPa CO 2 and 1 kPa O 2:1 kPa CO 2) for 27 weeks. Data on the emission of volatile compounds and on the activity of some related enzymes in both skin and flesh tissues were obtained during subsequent shelf life at 20 degrees C. Major effects of storage atmosphere and poststorage period were observed on the emission of volatile esters and their precursors. Changes in the production of volatile esters were partly due to alterations in the activity of alcohol o-acyltransferase, but the specific esters emitted by fruit after storage also resulted largely from modifications in the supply of the corresponding substrates. Samples stored under air were characterized by higher availability of acetaldehyde, whereas those stored under CA showed enhanced emission of the alcohol precursors ethanol and 1-hexanol (2 kPa O 2) and 1-butanol (1 kPa O 2), with accordingly higher production of ethyl, hexyl, and butyl esters. Multivariate analysis revealed that a large part of the observed differences in precursor availability arose from modifications in the activity of the enzymes considered. Higher pyruvate decarboxylase activity in air-stored fruit possibly accounted for higher acetaldehyde levels in these samples, while storage under 1 kPa O 2 led to significantly decreased lipoxygenase activity and thus to lessened production of 1-hexanol and hexyl esters. Low acetaldehyde availability together with enhanced hydroperoxide lyase and alcohol dehydrogenase levels in these fruits are suggested to have led to higher emission of 1-butanol and butyl esters.