Preparation, characterization and evaluation of L-theanine - zinc chelate: increasing stability, antioxidant, and antidiabetic activity

IF 2.9 3区农林科学 Q2 FOOD SCIENCE & TECHNOLOGY

Journal of Food Measurement and Characterization Pub Date : 2025-01-17 DOI:10.1007/s11694-025-03104-0

Xiaoya Pan, Hongyue Wang, Keshuang Guo, Tong Zhang, Xinnan Li, Xiangrong Zhang

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引用次数: 0

Abstract

The study aimed to prepare the chelate of L-theanine (LT) with zinc (Zn) and evaluate its stability, antioxidant and antidiabetic activity. The chelation mechanism between Zn²⁺ and LT was investigated by ultraviolet-visible, Fourier transform infrared, scanning electron microscopy/energy dispersive spectrometer and ¹H nuclear magnetic resonance spectroscopy. L-theanine-Zn chelate (LT-Zn) was obtained using LT to Zn citrate in a mass ratio of 3:1 at pH 6 and 70 °C for 180 min with the chelation efficiency of 61.86 ± 1.26%. The results revealed the amino nitrogen atoms and carboxyl oxygen atoms in LT chelated with Zn ions, and the mass of the chelate was confirmed by liquid chromatography with tandem mass spectrometry. Scanning electron microscopy with the element analyzed by energy dispersive spectroscopy showed that the morphology of LT-Zn consisted of irregular granular particles with rough surface. The LT-Zn exhibited higher solubility and improved stability under 100 °C, various pH condition and different concentrations of glucose and NaCl (p < 0.05) than that of sulfate Zn and Zn gluconate. Compared to sulfate Zn and Zn gluconate, the LT-Zn showed better stability during simulated gastrointestinal digestion. The chelate also exhibited antioxidant activity, as well as an inhibitory effect on α-glucosidase and α-amylase. Overall, the study provided a novel approach to prepare Zn nutraceuticals with antioxidant and antidiabetic properties.

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来源期刊

Journal of Food Measurement and Characterization Agricultural and Biological Sciences-Food Science

CiteScore

6.00

自引率

11.80%

发文量

425

期刊介绍： This interdisciplinary journal publishes new measurement results, characteristic properties, differentiating patterns, measurement methods and procedures for such purposes as food process innovation, product development, quality control, and safety assurance. The journal encompasses all topics related to food property measurement and characterization, including all types of measured properties of food and food materials, features and patterns, measurement principles and techniques, development and evaluation of technologies, novel uses and applications, and industrial implementation of systems and procedures.