氮气气调条件下鲜食花生中挥发性物质的变化及其与脂肪酸的相关性

Changes of volatile compounds in fresh edible peanuts under nitrogen modified atmosphere and their correlation with fatty acids

研究氮气气调条件下鲜食花生储藏期间挥发性物质的变化,以期为科学评价氮气气调对鲜食花生风味品质的影响,加快其在鲜食花生保鲜领域的应用提供理论依据。采用90%N2对鲜食花生进行气调包装处理,以空气包装的鲜食花生为对照(CK),置于低温(4℃)储藏30 d,定期取样并对鲜食花生的挥发性物质和脂肪酸相对含量进行测定与分析。结果表明:90%N2处理有效抑制了亚油酸和亚麻酸的氧化,储藏30 d, 90%N2处理组中亚油酸和亚麻酸的相对含量分别是CK组的1.190倍和1.178倍;主成分分析表明,CK组和90%N2处理组样品的挥发性物质在整个储藏过程中均存在明显差异;具体而言,在整个储藏过程中,烃类和醛类分别是CK组和90%N2处理组中相对含量最高的挥发性物质,90%N2处理能有效抑制鲜食花生储藏过程中烃类的升高、醛类的降低;储藏30 d后,90%N2处理组中烃类和醛类物质的相对含量分别为CK组的41.27%和415.23%;在储藏过程中,90%N2处理有利于保持醇类物质相对含量的稳定,但对酯类和杂环类物质影响较小;LEfSe分析表明,2,2,4,6,6-五甲基庚烷和正癸烷是CK组中的特征性挥发性物质,而90%N2处理组中的特征性挥发性物质为邻苯二甲酸二丁酯、桉叶油醇、反,反-2,4-壬二烯醛、反-2-壬烯醛和壬醛;相关性分析表明,硬脂酸、花生酸、山嵛酸和花生五烯酸主要与少数烃类和醇类物质相关,棕榈酸和花生四烯酸主要与少数醇类和醛类物质相关,亚油酸主要与醛类物质相关,油酸和亚麻酸主要与醇类、醛类和酯类物质相关。90%N2处理有效抑制了鲜食花生储藏过程中风味的变化,脂肪酸是鲜食花生挥发性物质合成过程中重要的前体物质。

This study was aimed to explore the influence of nitrogen modified atmosphere on volatile substances of fresh edible peanuts during storage,and to provide theoretical basis for scientifically evaluating the influence of nitrogen modified atmosphere on flavor and quality of fresh edible peanuts and speeding up its application in the field of fresh edible peanuts preservation.Fresh edible peanuts were treated by modified atmosphere packaging with 90%N2,stored at low temperature(4℃)for 30 days,and controlled by air packaging treatment(CK)under the same conditions.The volatile substances and fatty acids of fresh edible peanuts were determined and analyzed regularly.The results showed that 90%N2 treatment effectively inhibited the oxidation of linoleic acid and linolenic acid.After storage for 30 days,the relative content of linoleic acid and linolenic acid in 90%N2 treatment group were 1.190-fold and 1.178-fold of those in CK treatment group,respectively.The results of principal component analysis showed that there were significant differences in volatile substances between CK group and 90%N2 treatment group during the whole storage time.Specifically,hydrocarbons and aldehydes were the volatile substances with the highest relative content in CK group and 90%N2 treatment group during storage,respectively.Ninety percent of N2 treatment could effectively inhibit the increase of hydrocarbons and the decrease of aldehydes in fresh edible peanuts during storage.After 30 days of storage,the relative content of hydrocarbons and aldehydes in 90%N2 treatment group was 41.27%and 415.23%of those in CK treatment group,respectively.In addition,90%N2 treatment was beneficial to keep the relative content of alcohols stable,but had little effect on esters and heterocyclic compounds during storage.LEfSe analysis showed that 2,2,4,6,6-tetramethyloctane and n-decane were the characteristic volatile substances in CK group,while the characteristic volatile substances in 90%N2 treatment group were dibutyl phthalate,eucalyptol,trans-2,4-nonadienal,trans-2-nonenal,and nonanal.Correlation analysis showed that stearic acid,arachidonic acid,behenic acid,and arachidonic acid were mainly related to a few hydrocarbons and alcohols,palmitic acid,and arachidonic acid were mainly related to a few alcohols and aldehydes,linoleic acid was mainly related to aldehydes,and oleic acid and linolenic acid were mainly related to alcohols,aldehydes,and esters.In a word,90%N2 treatment effectively inhibited the flavor changes of fresh edible peanuts during storage,and fatty acids were the important precursor in the synthesis of volatile substances in fresh edible peanuts.