Adding sorbitol improves the thermostability of α‐l‐rhamnosidase from Aspergillus niger and increases the conversion of hesperidin. Issue 2 (30th December 2021)

• Record Type: Journal Article
• Authors: Sun, Jiang; Li, Wenjing; Liao, Hui; Li, Lijun; Ni, Hui; Chen, Feng; Li, Qingbiao
• Is Part Of: Journal of food biochemistry. Volume 46:Issue 2(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-30
• Subjects: conversion -- hesperidin -- sorbitol -- thermostability -- α‐l‐rhamnosidase; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; Biochemistry -- Periodicals; 664.024
• DOI: 10.1111/jfbc.14055
• Languages: English
• ISSNs: 0145-8884

Abstract

Abstract: In this study, we found the addition of sorbitol could improve the thermostability of α‐l ‐rhamnosidase from Aspergillus niger . When α‐l ‐rhamnosidase with sorbitol was heat‐treated at 60°C, 65°C, and 70°C, the half‐life t 1/2 increased by 28‐, 18‐, and 9‐fold, respectively. Inactivation thermodynamic analysis showed that both E a and Δ G ≠ of α‐l ‐rhamnosidase increased. Through the response surface methodology (RSM) analysis, the higher hesperidin conversion (63.26%) by α‐l ‐rhamnosidase was attained with 0.7 M sorbitol at 60°C and pH 4.5 for 10 min. Furthermore, hesperidin could be completely hydrolyzed after 10 hr of reaction. Overall, the results indicated that the addition of sorbitol improved the thermostability of α‐l ‐rhamnosidase and increased the enzymatic conversion of hesperidin to hesperetin‐7‐O‐glucoside (HMG). It also provided a simple and efficient way to increase enzymatic conversion of other valuable flavonoid monomers due to the broad substrate specificities of α‐l ‐rhamnosidase from A. niger . Practical applications: Hesperetin‐7‐ O ‐glucoside (HMG), a derhamnosylation product of hesperidin, is considered as a synthetic precursor for novel and efficient sweeteners and is important in food, functional food, and nutraceutical industries. Compared to chemical hydrolysis methods, the enzymatic conversion of hesperidin is milder and has the advantages of high specificity. Adding sorbitol can improve the thermostability of α‐l ‐rhamnosidase and increase the enzyme efficacy against hesperidin. This study gave more evidence that adding sorbitol could improve the thermostability of enzymes and provide a better choice for improving biotransformation potency of enzymes. Abstract : Addition of sorbitol can improve the thermostability of α‐L‐rhamnosidase from Aspergillus niger. Inactivation thermodynamic analysis showed that both Ea and ΔG≠ of α‐L‐rhamnosidase increased. The optimum conditions for the conversion of hesperidin by α‐L‐rhamnosidase were determined by response surface methodology (RSM) analysis and hesperidin could be completely hydrolyzed after 10 h of reaction.