Chayote seeds possess high-quality protein and beneficial biological properties but remain underutilized as a protein source for producing protein hydrolysates [1]. Subcritical Water Hydrolysis (SWH) has emerged as an advantageous method for generating protein hydrolysates due to its affordability, safety, environmental friendliness, high yields, and low energy consumption [2].

This study investigates SWH to produce chayote seed protein hydrolysates with potential antioxidant and anti-diabetic properties. Experiments were conducted at different temperatures (160 ºC, 190 ºC) and with various gas atmospheres (N₂, CO₂, and 0.05 M HCl modifier), maintaining the same pressure (15 bar), frequency (3 Hz), solid-to-solvent ratio (1:30 g/mL), and reaction time (60 minutes). The resulting protein hydrolysates were analyzed for their chemical and nutritional properties, and detailed amino acid and phenolic profiles were obtained through chromatographic analysis. Additionally, the protein hydrolysates were assessed for their antioxidant potential and α-amylase inhibition activity.

The results indicated that the highest degree of hydrolysis was achieved at 190 ºC in a CO₂ atmosphere, while the lowest value was found in a N2 atmosphere with pure water at 160 ºC. Despite this, protein content was similar in both CO₂ and N₂ atmospheres when a HCl modifier was used. All extracts showed high levels of essential amino acids (334.13 mg/g of protein) and improved protein digestibility (83.1 ± 5.0%). Furthermore, the chayote protein hydrolysate produced in a CO₂ atmosphere exhibited the highest phenolic content (8.90 mg GAE/g dw), antioxidant capacity, and α-amylase inhibition (85% at 100 μg/mL concentration).

SWH significantly enhances the production of bioactive protein hydrolysates from chayote seeds. These protein hydrolysates hold promising potential for applications in food systems, enhancing both their nutritional and commercial value.