Microwave pretreatment of hemp seeds changes the flavor and quality of hemp seed oil

Hemp seed is becoming increasingly popular around the world. Hemp seed oil is nutritious and rich in essential fatty acids, including omega-6 and omega-3. Microwave heating is considered a relatively new and effective technology for the preparation of high-quality oils, which is receiving more and more attention. When heated for 2 min at a microwave temperature of 40 °C and a microwave power of 850 W, the oil yield of hemp seed became higher, the acid value increased, and the OSI value also increased. In this study, a metabolomics approach based on the combination of GC TOF-MS technology and chemometrics was established to identify the quality changes of hemp seed oil before and after microwaving. A total of 390 metabolites were detected in the hemp seed oil, from which 91 differential metabolites were screened to evaluate the effect of microwave on the oil quality, and a total of 105 Vocs were detected, and the analysis of Vocs was beneficial to identify the characteristics of hemp seed oil. The results showed that microwave pretreatment improved the quality characteristics of hemp seed oil and affected the flavour of hemp seed oil, while metabolomics approaches have great potential for the authentication of hemp seed oil.