Enhancing nutritional value and flavor profiles of whey powder through fungal fermentation with <i>Aspergillus oryzae</i> and <i>Neurospora intermedia</i>

Investigation of the nutritional properties, biological activities, volatile compounds and sensory properties of fungal biomass and supernatants obtained from cheese whey powder fermented with <i>Aspergillus oryzae</i> and <i>Neurospora intermedia</i> was aimed in this study. The biomass produced by <i>A. oryzae</i> exhibited higher total lipid (118.54 g/kg) and total essential amino acid (62.05 g/kg) contents improve in comparison to <i>N. intermedia</i>. In contrast, the <i>N. intermedia</i> biomass showed superior bioactive properties, with the highest levels of total phenolics (4.72 mg gallic acid/g dry basis), total flavonoids, (23.85 mg quercetin/dry basis), and antioxidant activities (221.49 mg Trolox/g dry basis). Furthermore, the <i>A. oryzae</i> biomass derived from whey powder significantly enhanced the concentration of 1-octen-3-ol from 15.64 to 129.35 µg/kg, indicating its potential for improving the flavor profiles of food products with a natural mushroom-like aroma. Whey powder fermented with <i>A. oryzae</i> and <i>N. intermedia</i> contained significant amounts of calcium, sodium, and magnesium. The dominant mineral in the supernatant was Mg (7.40-7.90 mg/L) and a distinct fruity aroma was observed especially in the <i>N. intermedia</i> supernatant. These findings highlight the potential of fungal fermentation to convert dairy industry byproducts into nutrient-dense, flavor-enhancing alternatives.