Abstract:
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% N
2, 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% N
2 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% N
2 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% N
2 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% N
2 treatment group during storage, respectively. Ninety percent of N
2 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% N
2 treatment group was 41.27% and 415.23% of those in CK treatment group, respectively. In addition, 90% N
2 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% N
2 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% N
2 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.