•  
  •  
 

Abstract

Walnut kernel was used to research the influence of temperature and vacuum degree on its protein structure and function properties. The results showed that the quality of walnut kernel protein was significantly affected by factors of temperature and vacuum, and the influence degree of these factors was valued as: temperature > vacuum, constant temperature (35 ℃) > room temperature (25 ℃)> refrigeration (4 ℃). Moreover, with the extension of storage time, the content of sulfhydryl groups in walnut kernel protein decreased, and the content of disulfide bonds and carbonyl compounds increased. The results obtained from electrophoresis and infrared analyses indicated that the protein aggregation phenomenon occurred, and the ratio of β-sheet and random coils in the secondary structure increased, with the decrease of the ratio of α-helix to β-turn. In terms of functional properties, the surface hydrophobicity of walnut kernel protein increased, and solubility decreased, as well as its digestive properties significantly changed.

Publication Date

4-28-2021

First Page

143

Last Page

149

DOI

10.13652/j.issn.1003-5788.2021.04.027

References

[1] Food and Agriculture Organization. FAOSTAT data . [2020-11-03]. http://www.fao.org/faostat/en/#data/QC.
[2] GAO Pan, LIU Rui-jie, JIN Qing-zhe, et al. Comparison of solvents for extraction of walnut oils: Lipid yield, lipid composi-tions, minor-component content, and antioxidant capacity[J]. LWT-Food Science and Technology, 2019, 110: 346-352.
[3] GAO Pan, LIU Rui-jie, JIN Qing-zhe, et al. Comparative study of chemical compositions and antioxidant capacities of oils obtained from two species of walnut: Juglans regia and Juglans sigillata[J]. Food Chemistry, 2019, 279: 279-287.
[4] GAO Pan, LIU Rui-jie, JIN Qing-zhe, et al. Comparison of different processing methods of Iron walnut oils (Juglans sigillata): Lipid yield, lipid compositions, minor components, and antioxidant capacity[J]. European Journal of Lipid Science and Technology, 2018, 120: 1-9.
[5] GAO Pan, JIN Jun, LIU Rui-jie, et al. Chemical compositions of walnut (Juglans regia L.) oils from different cultivated regions in China[J]. Journal of the American Oil Chemists' Society (JAOCS), 2018, 95(7): 825-834.
[6] SERRANO A, COFRADES S, RUIZ-CAPILLAS C, et al. Nutritional profile of restructured beef steak with added walnuts[J]. Meat Science, 2005, 70(4): 647-654.
[7] LV Ying, WEI Kai-hua, MENG Xiao-guang, et al. Separation and identification of iron chelating peptides from defatted walnut flake by nanoLC-ESI-MS/MS and de novo sequencing[J]. Process Biochemistry, 2017, 59: 223-228.
[8] 姜莉. 核桃渣制备核桃蛋白和多肽的研究[D]. 咸阳: 西北农林科技大学, 2007: 18-19.
[9] 曹灿. 不同处理条件对核桃蛋白特性的影响[D]. 西安: 陕西科技大学, 2018: 17-18.
[10] LIU Feng-lan, WANG Xian-chang, ZHAO Xiao-yan, et al. Surface properties of walnut protein from AOT reverse micelles[J]. International Journal of Food Science and Technology, 2014, 49(2): 626-633.
[11] LASS M, DEB-CHOUDHURY S, HAINES S, et al. The impact of pH, salt concentration and heat on digestibility and amino acid modification in egg white protein[J]. Journal of Food Composition and Analysis, 2015, 38: 42-48.
[12] ZHAO Xiao-yan, LIU Hong-kai, ZHANG Xiao-wei, et al. Comparison of structures of walnut protein fractions obtained through reverse micelles and alkaline extraction with isoelectric precipitation[J]. International Journal of Biological Macromolecules, 2019, 125: 1 214-1 220.
[13] SHI Jia-yi, WU Mei-dan, QUAN Meng-meng. Effects of protein oxidation on gelatinization characteristics during rice storage[J]. Journal of Cereal Science, 2017, 75: 228-233.
[14] QU Wen-juan, ZHANG Xin-xin, HAN Xiao, et al. Structure and functional characteristics of rapeseed protein isolate-dextran conjugates[J]. Food Hydrocolloids, 2018, 82: 329-337.
[15] HOU Fu-rong, DING Wen-hui, QU Wen-juan, et al. Alkali solution extraction of rice residue protein isolates: Influence of alkali concentration on protein functional, structural properties and lysinoalanine formation[J]. Food Chemistry, 2017, 218: 207-215.
[16] ORSINI DELGADO M C, NARDO A, PAVLOVLE M. Identification and characterization of antioxidant peptides obtained by gastrointestinal digestion of amaranth proteins[J]. Food Chemistry, 2016, 197: 1 160-1 167.
[17] CHANG Cui-hua, LI Xin, LI Jun-hua, et al. Effect of enzymatic hydrolysis on characteristics and synergistic efficiency of pectin on emulsifying properties of egg white protein[J]. Food Hydrocolloids, 2017, 65: 87-95.
[18] LI Chun-qiang, XIONG You-ling L, CHEN Jie. Oxidation-induced unfolding facilitates Myosin cross-linking in myofibrillar protein by microbial transglutaminase[J]. Journal of Agricul-tural and Food Chemistry, 2012, 60(32): 8 020-8 027.
[19] LADJAL-ETTOUMI Y, BOUDRIES H, CHIBANE M, et al. Pea, chickpea and lentil protein isolates: Physicochemical characterization and emulsifying properties[J]. Food Biophy-sics, 2016, 11(1): 43-51.
[20] DAMODARA N, PARKIN K L, FENNEMA O R. Food chemistry[M]. 4th ed. New York: CRC Press, 2008, 146-149.
[21] WANG Pei, TAO Han, WU Feng-feng, et al. Effect of frozen storage on the foaming properties of wheat gliadin[J]. Food Chemistry, 2014, 164: 44-49.
[22] CHEN Nan-nan, ZHAO Mou-ming, SUN Wei-zheng. Effect of protein oxidation on the in vitro digestibility of soy protein isolate[J]. Food Chemistry, 2013, 141(3): 3 224-3 229.
[23] CARBONARO M, MASELLI P, NUCARA A. Structural aspects of legume proteins and nutraceutical properties[J]. Food Research International, 2015, 76: 19-30.
[24] YANG Yong, WANG Zhong-jiang, WANG Rui, et al. Secondary structure and subunit composition of soy protein in vitro digested by pepsin and its relation with digestibility[J]. Biomed Research International, 2016, 54: 1-11.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.