Characteristics of Mulberry Leaf Powder Enriched With γ-Aminobutyric Acid and Its Antioxidant Capacity as a Potential Functional Food Ingredient

Yingchun Jin; Jie Tu; Xinyao Han; Jun Zhuo; Guanhui Liu; Yanhui Han; Hengjun Du; Jun Wang; Hang Xiao

doi:10.3389/fnut.2022.900718

Characteristics of Mulberry Leaf Powder Enriched With γ-Aminobutyric Acid and Its Antioxidant Capacity as a Potential Functional Food Ingredient

Front Nutr. 2022 May 18:9:900718. doi: 10.3389/fnut.2022.900718. eCollection 2022.

Authors

Yingchun Jin¹, Jie Tu^{1

2}, Xinyao Han¹, Jun Zhuo¹, Guanhui Liu^{1

3}, Yanhui Han⁴, Hengjun Du⁴, Jun Wang^{1

2}, Hang Xiao⁴

Affiliations

¹ College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, China.
² Jiangsu Key Laboratory of Sericulture Biology and Biotechnology, Zhenjiang, China.
³ School of Grain Science and Technology, Jiangsu University of Science and Technology, Zhenjiang, China.
⁴ Department of Food Science, University of Massachusetts, Amherst, MA, United States.

Abstract

To improve the functional properties of mulberry leaves, γ-aminobutyric acid (GABA) enrichment treatments were applied. The results showed that the combined treatment of sodium glutamate immersion, cold shock, and anoxic significantly increased the GABA content. HPLC analysis displayed that the quantity of some active phenolics was significantly increased after the treatment. The GABA-enriched mulberry leaf powders were subsequently prepared, and it was found that as the particle size decreased, their water and oil holding capacity and their swelling power decreased, while the angle of repose increased. The dissolution rate of GABA and total phenolics increased as the particle size decreased. Optical observations and SEM results revealed that the fiber structures of the particles were gradually destroyed as the particle size decreased. Further, FTIR analysis showed that the active compounds in the powders were not destroyed. M400 and M140 powder showed the maximum DPPH radical scavenging ability and AGEs inhibition capacity, respectively. Additionally, adding the powders effectively alleviated the staling of bread without any significant effect on taste.

Keywords: AGEs inhibition; DPPH radical scavenging; mulberry leaf; phenolics; γ-aminobutyric acid.