Enhancement of functional ingredients in fermented <i>Moringa oleifera</i> seeds using <i>Rhizopus</i> species (<i>Moringa</i> tempe) by additional anaerobic treatment

We developed new fermented foods —Moringa tempe Rm and Rs—from Moringa seeds fermented under aerobic conditions with Rhizopus oligosporus and Rhizopus stolonifer, respectively. In this study, Moringa tempe Rm and Rs were treated under additional anaerobic conditions to enhance their functional ingredients. The amounts of essential amino acids, branched-chain amino acids, and gamma-aminobutyric acid in the free amino acids of anaerobically treated Moringa tempe Rm were approximately five, seven, and eight times higher than those in samples maintained under aerobic conditions, respectively. Similarly, the anaerobically treated Moringa tempe Rs exhibited approximately six, eight, and six times higher levels of these compounds, respectively. Additionally, the total polyphenol contents of both anaerobically treated Moringa tempe Rm and Rs increased significantly. However, the antioxidant activities of both tempes did not differ significantly between aerobic or anaerobic conditions. Altogether, our results demonstrate that anaerobic fermentation effectively improves the nutritional quality.