Nutritional and Chemical Characterization of Poppy Seeds, Cold-Pressed Oil, and Cake: Poppy Cake as a High-Fibre and High-Protein Ingredient for Novel Food Production

Currently, society demands natural healthy foods with improved nutritional characteristics. Accordingly, poppies (Papaver somniferum) are a traditional crop, cultivated for food and pharmaceutical purposes, whose seeds meet consumers’ preferences, making them a promising candidate for incorporation into the formulation of novel functional foods. This work performed an overall chemical characterization of poppy seeds, cold-pressed oil, and press cake, a by-product of the oil industry. The proximate composition, fatty acids, and vitamin E profiles of the oil fraction were analysed with respect to the whole seeds and the cake. The cold-press oil extracted from the poppy seeds was also characterized. Since poppy cake is a partially defatted product, it has a lower fat content than the seeds, but higher content of the rest of its elements, namely, ash (10%), protein (26%), and fibre (38%). Regarding protein composition, the major amino acid in the cake and seeds was determined to be glutamic acid (59 and 36 mg/g, respectively). All the samples presented α- and γ-tocopherols (>21 and >25 mg/kg, respectively) and the fatty acids profile of the oil fraction was mainly composed of unsaturated fatty acids, where linoleic acid predominates (>50%). The oil’s oxidative stability was low (2.8 h), according to the predominance of unsaturated fatty acids. Thus, poppy cake may be considered as an ingredient with great potential for incorporation into products in the food industry according to its high content in protein and fibre, and the remaining fat content, where polyunsaturated fatty acids predominate.