Preparation and stabilization of low-caffeine and high-catechin tea extract: Combing enzymatic treatment, macroporous resin adsorption, and microencapsulation

Abstract

Tea products with low caffeine and high catechins can strengthen the health benefits of tea while avoiding its potential risks. This study integrated enzymatic treatment, macroporous resin adsorption, and microencapsulation to achieve green preparation and quality improvement of low-caffeine and high-catechin tea extracts. Under the optimal enzymatic condition with cellulase and pectinase, the total catechin content in the tea infusion increased from 50.51 mg/g to 68.08 mg/g. Furthermore, LX-8 was screened from five resins for separating catechins from caffeine, and the adsorption of catechins fitted with the pseudo-second-order kinetic model and Langmuir model. With the integration of enzymatic extraction and macroporous resin adsorption, the obtained tea extract achieved a total catechin content of 91.29 % and the caffeine content of 0.09 %. The low-caffeine and high-catechin tea extract was encapsulated with maltodextrin and gum Arabic, achieving optimal encapsulation and loading efficiencies of 98.09 ± 0.08 % and 32.70 ± 0.03 %, respectively, exhibiting a better storage stability and achieving the sustained release in small intestinal phase. Moreover, the microcapsules retained the original aroma with more floral and sweet odor. This study establishes an integrated enzymatic-macroporous resin-microencapsulation strategy to prepare low-caffeine and high-catechin tea extract products, providing an insight into valorizing underutilized summer-autumn tea into high-value functional ingredients.