Determination of main lipids and volatile compounds in unconventional cold-pressed seed oils through chromatographic...

The purpose of this study was to characterize unconventional cold-pressed seed oils (rosehip, strawberry, blackcurrant, carrot, plum, pomegranate, radish, and raspberry) as novel alternative edible oil source. A chemical characterization of different lipid components (total fatty acid composition, triacylglycerols, and vitamin E) and volatiles responsible for the particular aroma of these oils was reported. All the oils showed a content of unsaturated fatty acids, mainly oleic, linoleic, and α-linolenic acid, that potentially contribute to the prevention of cardiovascular diseases, in the range of 80%-90%. Moreover, an isomer of α-linolenic acid, namely, punicic acid, was quantified at a level of near to 40% in pomegranate seed oil. Triolein was the most abundant triacylglycerol in most of the analyzed seed oils, with the exception of raspberry and strawberry dominated by trilinolein and pomegranate seed oil, composed for almost 50% of tripunicine. The highest content of vitamin E was found in pomegranate oil (256 mg/100 g), while the lowest amount was found in strawberry (65 mg/100 g). Overall, >300 compounds were identified from volatile profile of oil samples. Among these, aldehydes were the predominant molecule class identified in plum, pomegranate, and strawberry oils, while terpenes were the main volatiles in blackcurrant, carrot, and rosehip oils. Extremely low values were obtained for atherogenicity (0.05-0.10) and thrombogenicity (0.07-0.30) nutritional indices in all the investigated oils. Principal component analysis of the lipid profile was used as strategy to discriminate and classify the samples, highlighting their similarity related to the presence of beneficial compounds. PRACTICAL APPLICATION: Unconventional food products can find wide applicability in both cosmetic and food industry as alternative source that harmonize with consumers' preferences for personal care and nutraceutical purpose. They often address food security, sustainability, and nutritional challenges. Within this context, the chemical characterization of both major (triacylglycerols and total fatty acid composition) and minor components (volatile compounds and vitamin E) was useful to demonstrate that the cold-pressed seed oils here investigated are rich in essential nutrients. Hence, they can cater to specific dietary needs, thus creating new markets in food tech, agriculture, and biotechnology industries.