Phenolic Antioxidant Enrichment of Soy Flour-Supplemented Guava Waste by Rhizopus Oligosporus-Mediated Solid-State Bioprocessing

Abstract

In this paper, we investigated the potential for Rhizopus oligosporus to produce enhanced levels of free phenolics from guava residue mixed with soy flour as the nitrogen source. b -glucosidase activity and antioxidant activity in crude extracts were evaluated. Two substrates were studied based on carbon and nitrogen ratios: A, 90% guava residue : 10% soy flour (G9) and B, 50% guava residue : 50% soy flour (G5). Bioprocessing increased water extractable phenolics 12.9% with G9 substrate and 98.6% with G5 substrate. For both substrates, antioxidant activity increased during early stages of fungal growth but decreased thereafter. Phenolic antioxidant mobilization during bioprocessing was associated with b -glucosidase activity and hypothesized to involve the mobilization of polymeric phenolics. The bioconversion of soy flour-supplemented guava residue by R. oligosporus represents a novel strategy for the enhancement of phenolic antioxidant content and potential commercial value of guava wastes.

Revealing the Power of the Natural Red Pigment Lycopene

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Use of Amazon Fruits Barks as Source of Nutrients

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Biotechnological Reuse of Fruit Residues as a Rational Strategy for Agro-industrial Resources

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