Enhanced antioxidant activity of Chenopodium formosanum Koidz. by lactic acid bacteria: Optimization of fermentation conditions

Hsing-Chun Kuo; Ho Ki Kwong; Hung-Yueh Chen; Hsien-Yi Hsu; Shu-Han Yu; Chang-Wei Hsieh; Hui-Wen Lin; Yung-Lin Chu; Kuan-Chen Cheng

doi:10.1371/journal.pone.0249250

Enhanced antioxidant activity of Chenopodium formosanum Koidz. by lactic acid bacteria: Optimization of fermentation conditions

PLoS One. 2021 May 11;16(5):e0249250. doi: 10.1371/journal.pone.0249250. eCollection 2021.

Authors

Hsing-Chun Kuo^{1

2

3

4}, Ho Ki Kwong⁵, Hung-Yueh Chen⁶, Hsien-Yi Hsu^{7

8}, Shu-Han Yu⁵, Chang-Wei Hsieh⁹, Hui-Wen Lin¹⁰, Yung-Lin Chu¹¹, Kuan-Chen Cheng^{5

6

10

12}

Affiliations

¹ Division of Basic Medical Sciences, Department of Nursing, Chang Gung University of Science and Technology, Chiayi, Taiwan.
² Chang Gung Memorial Hospital, Chiayi, Taiwan.
³ Research Center for Industry of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan.
⁴ Chronic Diseases and Health Promotion Research Center, CGUST, Chiayi, Taiwan.
⁵ Institute of Biotechnology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan.
⁶ Institute of Food Science and Technology, College of Bioresources and Agriculture, National Taiwan University, Taipei, Taiwan.
⁷ Department of Materials Science and Engineering, School of Energy and Environment, City University of Hong Kong, Kowloon Tong, Hong Kong, China.
⁸ Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China.
⁹ Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan.
¹⁰ Department of Optometry, Asia University, Wufeng, Taichung, Taiwan.
¹¹ Department of Food Science, College of Agriculture, National Pingtung University of Science and Technology, Pingtung, Taiwan.
¹² Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan.

Abstract

In this study, different probiotics commonly used to produce fermented dairy products were inoculated independently for Chenopodium formosanum Koidz. fermentation. The strain with the highest level of antioxidant activity was selected and the fermentation process was further optimized via response surface methodology (RSM). Lactobacillus plantarum BCRC 11697 was chosen because, compared to other lactic acid bacteria, it exhibits increased free radical scavenging ability and can produce more phenolic compounds, DPPH (from 72.6% to 93.2%), and ABTS (from 64.2% to 76.9%). Using RSM, we further optimize the fermentation protocol of BCRC 11697 by adjusting the initial fermentation pH, agitation speed, and temperature to reach the highest level of antioxidant activity (73.5% of DPPH and 93.8% of ABTS). The optimal protocol (pH 5.55, 104 rpm, and 24.4°C) resulted in a significant increase in the amount of phenolic compounds as well as the DPPH and ABTS free radical scavenging ability of BCRC 11697 products. The IC50 of the DPPH and ABTS free radical scavenging ability were 0.33 and 2.35 mg/mL, respectively, and both protease and tannase activity increased after RSM. An increase in lower molecular weight (<24 kDa) protein hydrolysates was also observed. Results indicated that djulis fermented by L. plantarum can be a powerful source of natural antioxidants for preventing free radical-initiated diseases.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Antioxidants / chemistry*
Antioxidants / metabolism
Batch Cell Culture Techniques / methods*
Carboxylic Ester Hydrolases / metabolism
Chenopodium / chemistry*
Chenopodium / metabolism
Hydrogen-Ion Concentration
Lactobacillus plantarum / growth & development*
Peptide Hydrolases / metabolism
Phenols / chemistry
Phenols / metabolism
Protein Hydrolysates / metabolism

Substances

Antioxidants
Phenols
Protein Hydrolysates
Carboxylic Ester Hydrolases
tannase
Peptide Hydrolases

Grants and funding

This project was funded by the Ministry of Science and Technology, Taiwan (MOST 109-2628-E-002-007-MY3 and MOST 107-2320-B-255-001-MY3). HC Kuo received grant of MOST 107-2320-B-255-001-MY3. KC Cheng received grant of MOST 109-2628-E-002-007-MY3. URL: https://www.most.gov.tw/?l=en. HC Kuo also received funding grant of BMRPD42 for this study was also provided in part by research grants from the Chang Gung Memorial Hospital, Chiayi, Taiwan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.