Comparison of microwave and hot-air roasting on microstructure of sesame seed, aroma-active, hazardous components, and sensory perception of sesame oil

Abstract

The unclear effects of microwaves, as a greener alternative to hot air, on sensory perception, aroma, and hazardous components of sesame oil were investigated. Microwaves (900 W, 6–10 min) created more seed porosity and cell destruction and facilitated more γ-tocopherol release in sesame oil (349.30–408.50 mg/kg) than 200 °C, 20 min hot air (304.90 mg/kg). Microwaves (6–10 min) generated more aromatic heterocyclics (42.40–125.12 mg/kg) and aldehydes (5.15–2.08 mg/kg) in sesame oil than hot air (25.59 mg/kg and 1.34 mg/kg). Microwaves (6 min) produced sesame oil with a stronger roasted sesame flavour, and weaker bitter and burnt flavour than hot air. Microwaves reduced harman (≤775.19 ng/g), norharman (≤1,069.99 ng/g), and benzo(a)pyrene (≤1.59 μg/kg) in sesame oil than hot air (1,319.85 ng/g, 1,168.40 ng/g, and 1.83 μg/kg). Appropriate microwave is a promising alternative to hot air in producing sesame oil with a better sensory profile, more bioactive, and less carcinogenic components.