The production of hydrolysates from industrially defatted rice bran and its surface image changes during extraction

Kaewjumpol, G., Oruna-Concha, M. J. ORCID: https://orcid.org/0000-0001-7916-1592, Niranjan, K. ORCID: https://orcid.org/0000-0002-6525-1543 and Thawornchinsombut, S. (2018) The production of hydrolysates from industrially defatted rice bran and its surface image changes during extraction. Journal of the Science of Food and Agriculture, 98 (9). pp. 3290-3298. ISSN 0022-5142 doi: 10.1002/jsfa.8832

Abstract/Summary

BACKGROUND This research employed mild-subcritical alkaline water extraction (SAW) technique to overcome the difficulty of active compounds extractability from an industrially defatted rice bran (IDRB). Mild-SAW (pH 9.5, 130 °C, 120 min) treatment, followed by enzymatic hydrolysis (Protease G6) were applied to produce rice bran hydrolysate (RBH). Response surface methodology was used to identify proteolysis conditions for maximizing protein content and ABTS radical scavenging activity (ABTS-RSA). The microstructural changes during the extraction occurring in the IDRB were monitored. The selected RBH was characterised for protein recovery, yield, antioxidant activities, phenolic profile and hydroxymethylfufural (HMF) content. RESULTS Optimal proteolysis conditions were at 20 mL kg-1 IDRB (E/S) for 6 h. Under these conditions, the yield, ABTS-RSA, Ferric reducing antioxidant power and the total phenolic content of the RBH were 46.1%, 294.22 μmol trolox g-1, 57.72 μmol FeSO4 g-1, and 22.73 mg gallic acid g-1, respectively, with relatively low HMF level (0.21 mg g-1). The protein recovery was 4.8 times greater than the recovery obtained by conventional alkaline extraction. Its major phenolic compounds were p-coumaric and ferulic acids. The microstructural changes of IDRB confirmed that the mild-SAW/Protease G6 process enhanced the release of active compounds. CONCLUSION The process of mild-SAW followed by proteolysis promotes the release of active compounds from IDRB.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/74513
Identification Number/DOI	10.1002/jsfa.8832
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences > Food Research Group
Uncontrolled Keywords	Biotechnology, Agronomy and Crop Science, Food Science, Nutrition and Dietetics
Publisher	Wiley
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