Structural Changes and Evolution of Peptides During Chill Storage of Pork

Xiaoyu Zou; Jing He; Di Zhao; Min Zhang; Yunting Xie; Chen Dai; Chong Wang; Chunbao Li

doi:10.3389/fnut.2020.00151

Structural Changes and Evolution of Peptides During Chill Storage of Pork

Front Nutr. 2020 Sep 22:7:151. doi: 10.3389/fnut.2020.00151. eCollection 2020.

Authors

Xiaoyu Zou^{1

2

3}, Jing He^{1

2

3}, Di Zhao^{1

2

3}, Min Zhang^{1

2

3}, Yunting Xie^{1

2

3}, Chen Dai⁴, Chong Wang^{1

2

3}, Chunbao Li^{1

5

6}

Affiliations

¹ Key Laboratory of Meat Processing and Quality Control, Ministry of Education, Nanjing Agricultural University, Nanjing, China.
² Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing, China.
³ Key Laboratory of Meat Processing, Ministry of Agriculture and Rural Affairs, Nanjing Agricultural University, Nanjing, China.
⁴ Experimental Teaching Center of Life Science, Nanjing Agricultural University, Nanjing, China.
⁵ National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing, China.
⁶ Joint International Research Laboratory of Animal Health and Food Safety, Ministry of Education, Nanjing Agricultural University, Nanjing, China.

Abstract

In this work, we investigated changes in protein structures in vacuum-packed pork during chill storage and its impact on the in vitro protein digestion. Longissimus dorsi muscles were vacuum packed and stored at 4°C for 3 days. Samples were subjected to Raman spectroscopy, in vitro digestion and nano LC-MS/MS. The 3 d samples had lower α-helix content, but higher β-sheet, β-turn, and random coil contents than the 0 d samples (P < 0.05). SDS-PAGE revealed significant protein degradation in the 3 d samples and the differences in digested products across the storage time. Proteome analysis indicated that the 3 d samples had the higher susceptibility to digestion. Increasing protein digestibility was mainly attributed to the degradation of myofibrillar proteins. Thus, exposure of more enzymatic sites in loose protein structure during chill storage could increase protein degradation in meat.

Keywords: LC-MS/MS; Raman spectroscopy; chill storage; in vitro digestion; pork.