Impact of roasting on nutritional quality, bioactive retention, and oxidative stability of sacha inchi (Plukenetia volubilis L.) seeds

Sacha inchi (Plukenetia volubilis L.) seeds are rich in protein and α-linolenic acid (omega-3) and have gained recognition as a plant-based functional food ingredient. Their quality is strongly influenced by roasting, which can modify nutritional composition and bioactive attributes. This study examined the effects of oven and pan roasting at 100, 125, and 150 °C for 5, 10, and 15 min on the physicochemical, bioactive, antioxidant, and oxidative properties of sacha inchi seeds. Raw seeds contained 27.9 g/100 g protein, 47.6 g/100 g fat, and 16.0 g/100 g α-linolenic acid, confirming their nutritional value. Roasting reduced moisture and water activity, decreased hardness, and modified seed color. Phenolic and flavonoid contents, as well as individual phenolics, declined with increasing severity (p < 0.05), whereas antioxidant activity improved under moderate conditions (p < 0.05). Pan roasting at 125 °C for 10 min resulted in the highest enhancement. Hydroxymethylfurfural content increased with roasting, reflecting Maillard reactions, while lipid oxidation indices (p-anisidine and thiobarbituric acid) also rose with increasing temperature and time (p < 0.05). Overall, roasting enhanced product stability and antioxidant functionality under moderate conditions, whereas excessive heat promoted quality deterioration. Pan roasting at 125 °C for 10 min was identified as optimal, balancing bioactive retention, oxidative stability, and nutritional quality, thereby supporting roasted sacha inchi seeds as sustainable functional food ingredients.