Preparation of high‐quality concentrated fragrance flaxseed oil by steam explosion pretreatment technology

In this study, flaxseed was pretreated by steam explosion technology and subsequently pressed to prepare flaxseed oil. GC, UPLC, HPLC, and GC‐MS techniques were used to analyze the quality characteristics of the prepared flaxseed oil. These included the food safety risk indices, micronutrient components, and oxidative stability. The effects of different steam explosion pressures on the quality characteristics and relative volatile components of flaxseed oil were also investigated. The results revealed that steam explosion pretreatment technology could significantly increase the oil yield, improve micronutrient content, and strengthen the oxidation stability of the product. Moreover, the food safety risk indices (e.g., benzopyrene) were controlled within a reasonable range, while the fatty acid content remained almost unchanged. Notably, the relative pyrazine content in the total volatile components of flaxseed oil was 68.25% when the steam explosion pressure reached 1.2 MPa. This was considered as the main factor that contributed to the unique concentrated fragrance of the produced flaxseed oil. To prove the superiority of the steam explosion pretreatment, we compared this technique with traditional high‐temperature roasting and popular microwave pretreatment techniques. The results revealed that flaxseed oil prepared by steam explosion pretreatment displayed the best quality characteristics and most concentrated fragrance. Thus, steam explosion technology shows great potential for application to produce high‐quality concentrated fragrance flaxseed oil. This study provides significant reference and guidance for the preparation process of flaxseed oil. The objective of the present study was to carry out different steam explosion experiments on flaxseed, compared the lipid characteristics (physicochemical parameters, fatty acid composition, phytochemicals (tocopherols, phytosterols, polyphenols, flavonoids), oxidation induction time (OIT), and relative volatile components. The results of this study will not only help factories produce high‐quality and concentrated fragrance pressed flaxseed oil, but also have important reference significance for the development of oil crop preparation process.