Enhancing flavor and oxidation stability of roasted peanut oil via germination pretreatment

This study investigated the effects of short-term peanut germination (0-48 h, 25 °C, 85% relative humidity) prior to microwave roasting (540 W, 8 min) on the flavor and oxidation stability of hydraulic-extracted peanut oil. Extended germination enhanced activities of endogenous enzymes (amylase, lipase, proteases), and increased free amino acids (5.34 → 11.75 mg/g) and soluble sugars (4.69 → 6.12 g/100 g) in peanuts (p < 0.05). Increasing germination time increased α- and β-tocopherols, and extended oxidation induction time (9.81 h → 14.89 h) (p < 0.05). Increasing germination time increased the relative concentrations of total pyrazines and total phenols, while reducing total aldehydes, leading to enhanced nutty, roasted, butter, and sweet aromas in peanut oil (p < 0.05). However, over-germination (48 h) induced undesirable burnt and smoky notes. Appropriate short-term germination can serve as a mild pretreatment to modulate the flavor profile and oxidative stability of roasted peanut oil.