Role of endoxylanase and its concentrations in enhancing the nutraceutical components and bioactivities of red rice bran

• Published in: Food science & technology Vol. 147; p. 111675
• Main Authors: Sapna, I., Jayadeep, A.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2021
• Subjects: Antioxidant activity; LDL-Cholesterol oxidation inhibition; Phenolics; Tocopherols and tocotrienols; γ-oryzanol; Tocopherols and tocotrienols; γ-oryzanol; Phenolics; Antioxidant activity; LDL-Cholesterol oxidation inhibition
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2021.111675

Enzyme type and concentration are crucial factors in improving the release of bioactive compounds entrapped in rice bran's complex cell wall matrix. This work investigates the effect of various concentrations (2–20-units/2 g) of endoxylanase from bacterial (EXB) and fungal (EXF) origin in enhancing the content of phenolics, tocopherols, tocotrienols, and γ-oryzanol, and boosting the bioactivities of red rice bran compared to non-enzyme treated bran (control). At specific concentrations, EXF increased caffeic (503%) vanillic (354%) and ferulic acid (186%) in soluble phenolics, along with cycloartenyl ferulate (35%), β-sitosteryl ferulate (33%) and δ, γ, α-tocopherols (24%–210%) and tocotrienols (50%–182%). Whereas EXB enhanced catechin (267%) and p-coumaric acid (269%) in bound phenolics along with 24-methylenecycloartenyl ferulate (48%) and campesteryl ferulate (97%). The bioactivity assays and correlation study showed that EXF treated bran exhibited scavenging activities against, superoxide anion (76%), and inhibition of human LDL oxidation (93%) with caffeic acid and α-tocotrienol exhibiting positive correlation. While EXB treated bran exhibited reducing power (109%), DPPH• (60%), and hydroxyl (25%) radical scavenging activities, with β-sitosteryl ferulate, and soluble phenolics demonstrating positive correlation. Thus, endoxylanase treatment is a potential approach for processing the rice bran into a functional food ingredient having higher bioactivities. •Endoxylanase greatly enhances phenolics, tocols, γ-oryzanol from red rice bran.•Bacillus endoxylanase enhances p-coumaric, γ-tocotrienol and γ-oryzanol fractions.•Trichoderma endoxylanase increases ferulic acid, γ-tocopherol and cycloartenyl ferulate.•Phenolics, β-sitosteryl ferulate and α-tocopherol correlated with antioxidant potential.•Enzyme concentration has no direct relation with quantity of released nutraceuticals.