Research Article | OPEN ACCESS
Effects of Synthetic and Natural Extraction Chemicals on Functional Properties, Polyphenol Content and Antioxidant Activity of Soy Protein Isolates Extracted from Full-Fat and Defatted Flours
1, 2Moses Vernonxious Madalitso Chamba, 1Yufei Hua, 1Quirino Dawa, 1Odilon Djakpo and 1Caimeng Zhang
1School of Food Science and Technology, Jiangnan University, 1800 Lihu
Avenue, Wuxi 214122, Jiangsu Province, P.R. China
2Department of Human Ecology, Domasi College of Education, University of Malawi,
P.O. Box 49, Domasi, Zomba, Malawi
Advance Journal of Food Science and Technology 2013 11:1443-1449
Received: June 28, 2013 | Accepted: July 08, 2013 | Published: November 05, 2013
Abstract
The number of consumers preferring natural and organic foods to those that involve synthetic chemicals has recently shown dramatic growth. As such, a native isoelectrically precipitated soy protein isolates (SPIs) were prepared from full-fat and defatted flours using amaranth (Amaranthus tricolor L.) lye (pH>12.5) and lemon extract (pH<2.5) as natural food-plant-based chemicals, replacing the conventional synthetic ones (NaOH and HCl, respectively). Functional properties, total polyphenol content and antioxidant activity of the natural SPIs were compared to those of synthetic ones. All the SPI samples qualified to be soy protein isolates with a minimum protein content of 91.21%. The natural SPI showed significant increase in emulsion stability (p≤0.05). While higher values with narrow margins were shown by the synthetic than the natural SPIs in oil absorption (0.66±0.02, 0.50±0.01%, respectively), emulsion capacity (56.53±0.57, 55.50±0.39%), foam stability (11.33±0.61, 10.40±0.40%). No significant difference was observed in water absorption capacity. The DPPH assay showed increased antioxidant activity in the natural SPI although its total polyphenol content was lower. Thus, SPI with functional properties similar to those of conventional ones can be naturally processed using amaranth ash and lemon extracts as alternative chemicals to addressing the fear of consuming synthetic chemical by health-conscious natural and organic food consumers.
Keywords:
Amaranth ash extract, conventional soy protein isolate, lemon extract, natural chemicals, natural soy protein isolate, synthetic chemicals,
Competing interests
The authors have no competing interests.
Open Access Policy
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Copyright
The authors have no competing interests.
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ISSN (Online): 2042-4876
ISSN (Print): 2042-4868 |
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