The Nutritional, ACE Inhibition, and Antioxidant Properties of Hydrolysate Powders Derived from Different Stages of Thai Silkworm (Bombyx mori)

This study evaluated the bioactive potential of Thai silkworms (<i>Bombyx mori</i>) at three developmental stages-mature silkworm (MS), A-silking silkworm (AS), and pupae (PP)-as alternative protein sources for functional hydrolysates. Silkworm powders were hydrolyzed with Alcalase^® (5% <i>w</i>/<i>w</i>, 1 h, 60 °C) to obtain MS hydrolysate powder (MSHP), AS hydrolysate powder (ASHP), and PP hydrolysate powder (PPHP). AS contained the highest protein content (72.13%), followed by MS (70.20%) and PP (56.70%). Amino acid profiling revealed stage-specific and hydrolysis-dependent variations, MS was enriched in phenylalanine and histidine, AS in threonine, valine, and tyrosine, and PP in lysine, leucine, and arginine. Hydrolysates showed markedly increased amino acid levels across all samples, indicating enhanced peptide release and improved nutritional quality. The hydrolysates achieved yields of 61-64% and protein recoveries of approximately 46%. MSHP and ASHP exhibited higher degrees of hydrolysis than PPHP. Among the biological activities, MSHP demonstrated the strongest angiotensin-converting enzyme (ACE) inhibition (88.46%), whereas PPHP exhibited the greatest antioxidant capacity (DPPH, ABTS, FRAP). Overall, Alcalase^® hydrolysis effectively enhanced silkworm bioactivity, supporting their potential as multifunctional ingredients for functional foods and nutraceuticals targeting cardiovascular and oxidative stress-related disorders.