Chitosan Activated with Genipin: A Nontoxic Natural Carrier for Tannase Immobilization and Its Application in Enhancing Biological Activities of Tea Extract

Abstract

In this work, a non-toxic chitosan-based carrier was constructed via genipin activation and applied for the immobilization of tannase. The immobilization carriers and immobilized tannase were characterized using Fourier transform infrared spectroscopy and thermogravimetric analysis. Activation conditions (genipin concentration, activation temperature, activation pH and activation time) and immobilizations conditions (enzyme amount, immobilization time, immobilization temperature, immobilization pH, and shaking speed) were optimized. The activity and activity recovery rate of the immobilized tannase prepared using optimal activation and immobilization conditions reached 29.2 U/g and 53.6%, respectively. The immobilized tannase exhibited better environmental adaptability and stability. The immobilized tannase retained 20.1% of the initial activity after 12 cycles and retained 81.12% of residual activity after 30 days storage. The catechins composition analysis of tea extract indicated that the concentration of non-ester-type catechins, EGC and EC, were increased by 1758% and 807% after enzymatic treatment. Biological activity studies of tea extract revealed that tea extract treated with the immobilized tannase possessed higher antioxidant activity, higher inhibitory effect on α-amylase, and lower inhibitory effect on α-glucosidase. Our results demonstrate that chitosan activated with genipin could be an effective non-toxic carrier for tannase immobilization and enhancing biological activities of tea extract.

Pruned tea biomass plays a significant role in functional food production: A review on characterization and comprehensive utilization of abandon‐plucked fresh tea leaves

“…It is shown that tannase treatment increases the polyphenols recovery rate in the extraction process due to the hydrolysis of ferulic acid dimers in the plant cell wall (Shao et al., 2020). In addition, the biological activities of tannase‐treated tea extracts, such as antioxidant activity and inhibitory effect on digestive enzymes (α‐amylase), also increase (Wang, Chen, et al., 2021). Increasing the content of GA by tannase‐treated green tea extract improves the free radical scavenging activity (Baik et al., 2015).…”

Evaluation of Antioxidant, Cytotoxic, Mutagenic and Other Inhibitory Potentials of Green Synthesized Chitosan Nanoparticles

“…The α-glucosidase had a more substantial inhibitory effect than αamylase [46]. The apparent variation in the inhibition effect of α-amylase and α-glucosidase might lead to undigested sugars reaching the colon, resulting in intestinal microbial digestion and successive intestinal illnesses, including abdominal discomfort, constipation, and diarrhea [47]. The bioactive compounds coated over the surface of MAL-CNPs are thought to be promising and efficient inhibitors of α-amylase as well as α-glucosidase.…”

Construction of a Tannase-Immobilized Magnetic Graphene Oxide/Polymer Nanobiocatalyst with Enhanced Enzyme Stability for High-Efficiency Transformation of Tannins

“…Despite the previously mentioned benefits, the enzyme-catalyzed transformation of tannin using tannase still faces several key challenges. For example, the complicated purification process, high production cost, insufficient enzyme stability, limited enzyme selectivity or specificity, low tolerance in the presence of inhibitors, finite application conditions, and inability to recycle after every use of free forms make this approach unsustainable for the long-term usage in industrial applications. , In this situation, immobilization of enzymes on a solid support is regarded as an effective strategy to overcome the above-mentioned limitations. − Stable supports for tannase immobilization include calcium alginate beads, − chitosan, manganese nanoparticles, magnetic nanoparticles, multiwalled carbon nanotubes, and silica oxide nanoparticles . The immobilization yield and reusability have been improved to a certain extent, but some major drawbacks remain.…”

“…1,3 In this situation, immobilization of enzymes on a solid support is regarded as an effective strategy to overcome the above-mentioned limitations. 20−22 Stable supports for tannase immobilization include calcium alginate beads, 23−25 chitosan, 26 manganese nanoparticles, 27 magnetic nanoparticles, 28 multiwalled carbon nanotubes, 29 and silica oxide nanoparticles. 30 The immobilization yield and reusability have been improved to a certain extent, but some major drawbacks remain.…”