Berry Seeds—A By-Product of the Fruit Industry as a Source of Oils with Beneficial Nutritional Characteristics

Abstract

Proper management of waste is one of the major challenges for the food industry. Fruit seeds are an example of by-products that are rich in bioactive substances and generated in significant amounts during fruit processing. Oils, including those obtained from seeds, should meet certain requirements to be allowed for human consumption. The aim of this study was to determine the quality of oils from black currant, strawberry and cranberry seeds by determining the following parameters: fatty acid composition by gas chromatography, distribution of fatty acids between sn-2 and sn-1,3 positions of triacylglycerols by partial enzymatic hydrolysis, oxidative stability by pressure differential scanning calorimetry and melting characteristics by differential scanning calorimetry. Additionally, health indices of atherogenicity (IA), thrombogenicity (IT) and hypocholesterolemic/hypercholesterolemic (HH) ratio were calculated. It was found that the oils studied were a rich source of unsaturated fatty acids. Linoleic acid was found to occupy the internal position of triacylglycerols in the highest proportion. Black currant and strawberry seed oils were of lower oxidative stability and, in the case of cranberry seed oil, high oxidative stability was determined. The shape of melting curves for black currant and strawberry seed oils indicated the presence of low-melting fractions of triacylglycerols containing polyunsaturated fatty acids. It can be concluded that cranberry seed oil, with low values of IA and IT, high values of HH index and the highest oxidative stability, can be considered the most favorable from a nutritional point of view concerning human health.