Enzymatic protein hydrolysis is a well-established method for improving the quality of dietary proteins, including edible insects. Finding effective enzymes from natural sources is becoming increasingly important. This study used nuruk extract concentrate (NEC), an enzyme-rich fermentation starter, to produce protein hydrolysate from defatted Tenebrio molitor (also called mealworm, MW). The nutritional, functional, and sensorial properties of the hydrolysate were then compared to those obtained using commercial proteases (alcalase and flavourzyme). The protease activities of the crude nuruk extract (CNE), NEC, alcalase, and flavourzyme were 6.78, 12.71, 11.07, and 12.45 units/mL, respectively. The degree of hydrolysis and yield of MW hydrolysis by NEC were 15.10 and 35.92% (w/w), respectively. MW hydrolysate was obtained using NEC and had a significantly higher free amino acid content (90.37 mg/g) than alcalase (53.01 mg/g) and flavourzyme (79.64 mg/g) hydrolysates. Furthermore, the NEC hydrolysis of MW increased the antioxidant and angiotensin-converting enzyme inhibitory activity, with IC₅₀ values of 3.07 and 0.15 mg/mL, respectively. The enzymatic hydrolysis also improved sensory properties, including umaminess, sweetness, and saltiness. Overall, this study found that the NEC hydrolysis of MW outperformed commercial proteases regarding nutritional quality, sensory attributes, and biological activity. Therefore, nuruk could potentially replace commercial proteases, lowering the cost of enzymatic protein hydrolysis.

This study evaluated the physical and rheological properties of whole rice flour treated for different sonication times (0-15 min). Ultrasonication reduces the particle size of rice flour and improves its solubility. Viscosity tests using RVA and steady shear showed a notable decrease in the viscosity of the rehydrated pregelatinized rice flour. Although no unusual patterns were observed in the XRD analysis, the FT-IR and microstructure morphology findings suggest that ultrasonication led to structural changes in the rice flour. Overall, the study indicates that ultrasonication is a practical and clean method for producing plant-based drinks from rice flour, which could expand its limited applications in the beverage industry.

Yeast, crucial in beer production, holds great potential owing to its ability to transform into a valuable by-product resource, known as brewer’s spent yeast (BSY), with potentially beneficial physiological effects. This study aimed to compare the composition and soluble polysaccharide content of Brewer’s spent yeast with those of cultured yeast strains, namely Saccharomyces cerevisiae (SC) and S. boulardii (SB), to facilitate the utilization of BSY as an alternative source of functional polysaccharides. BSY exhibited significantly higher carbohydrate content and lower crude protein content than SC and SB cells. The residues recovered through autolysis were 53.11%, 43.83%, and 44.99% for BSY, SC, and SB, respectively. Notably, the polysaccharide content of the BSY residue (641.90 μg/mg) was higher than that of SC (553.52 μg/mg) and SB (591.56 μg/mg). The yields of alkali-extracted water-soluble polysaccharides were 33.62%, 40.76%, and 42.97% for BSY, SC, and SB, respectively, with BSY comprising a comparable proportion of water-soluble saccharides made with SC and SB, including 49.31% mannan and 20.18% β-glucan. Furthermore, BSY demonstrated antioxidant activities, including superoxide dismutase (SOD), ABTS, and DPPH scavenging potential, suggesting its ability to mitigate oxidative stress. BSY also exhibited a significantly higher total phenolic compound content, indicating its potential to act as an effective functional food material.