Enhancement of Nutritional Quality and Antioxidant Activity Through Fermentation and Reduction of Antinutritional Compounds in Peanuts (Arachis hypogaea L.)

¹ Department of Food Science and Biotechnology, Faculty of Agroindustrial and Biosystem Technology, Brawijaya University, Malang, 65145, Indonesia
² Food Technology Study Program, Faculty of Agriculture, Universitas Muhammadiyah Gresik, Gresik 61121, Indonesia

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Peanuts are a nutrient-dense food with considerable potential for further utilisation. However, their nutritional value may be limited by antinutritional compounds, particularly phytic acid and tannins, which can interfere with nutrient absorption. This study investigated the effects of fermentation time on the nutritional composition, antioxidant capacity, and antinutritional content of peanut flour. Fermentation was performed with Rhizopus oligosporus at 1% (w/w). A completely randomised design was applied with three treatments: unfermented peanuts (0 h) and peanuts fermented for 48 and 72 h, with each treatment conducted in triplicate. The findings demonstrated that fermentation significantly improved the nutritional and functional properties of peanut flour. Protein content increased from 25.26% to 30.46%, while total phenolic content rose from 3.61 to 7.38 mg GAE/g. Antioxidant activity also improved, as reflected by the reduction in IC₅₀ value from 184.81 to 96.82 ppm. In contrast, phytic acid content declined from 0.81% to 0.33%, and tannin content decreased from 2.21 to 0.87 mg TAE/g. In conclusion, 72-hour fermentation was identified as the optimal condition for improving both nutritional quality and functional properties. Further studies on bioavailability and industrial application are recommended.