Abstract:
In order to evaluate the quality changes of embryo rice during storage, the embryo rice with vacuum packaging of two kinds of materials was stored at 25 and 4 ℃ for 300 d and the changes in the fatty acid value, taste, texture, and other indexes were analyzed. A quality evaluation model was constructed based on principal component analysis and entropy weight method. The volatile compounds were determined using Headspace-Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) to further explore the correlation between the indexes. The results showed that with prolonged storage time, fatty acid value, hardness, and chewiness increased significantly (
P<0.05), springiness and taste value decreased significantly (
P<0.05), and lipase and malondialdehyde (MDA) first increased and then decreased. A quality evaluation model of embryo rice was established based on seven core indexes: Y=0.0803×chewability+0.1170
×springiness+0.1221×flavor+0.1182×taste value comprehensive score+0.2215×malondialdehyde+0.2234×lipase activity+0.1175×fatty acid value. According to the comprehensive scores obtained by the model, the quality of the embryo rice at different storage periods was classified as grade I after 0 d of storage, grade II after 60 d of storage, grade III after 120 d of storage, and grade IV after 180 d of storage. A total of 53 volatile compounds were detected, among which aldehydes, ketones, acids, and other compounds appeared in large quantities after 300 d of storage. There was a significant negative correlation between 2,2,6-trimethyloctane and fatty acid value, lipase, malondialdehyde, hardness, chewability,
b*, or
∆E (
P<0.05) and a significant positive correlation between the taste value and quality evaluation comprehensive score (
P<0.05), followed by 2-n-propyl furan and 3-methylundecane. These results provide a theoretical basis for quality evaluation and storage method selection of embryo rice.