Use of hull-less pumpkin (Cucurbita pepo L.) seed oil press-cake in gluten-free cookies: Nutritional and mineral profile
Hull-less pumpkin seed oil press-cake flour), as a by-product and functional ingredient, was incorporated into gluten-free cookies with the aim to improve their nutritional quality. Nutritional characteristics of the cookies were assessed and compared to brown rice and whole-wheat flour cookies. All samples with added pumpkin seed oil press-cake flour had much better nutritional qualities than the brown rice and whole-wheat flour cookies in terms of significantly higher micro- and macronutrients, monounsaturated fatty acids and polyunsaturated fatty acids (contents. Both, the monounsaturated fatty acids and the polyunsaturated fatty acids contents were the highest in samples no. 3 (30% of added hull-less pumpkin seed oil press-cake flour) and 4 (40% of added hull-less pumpkin seed oil press-cake flour), while the omega-6 essential fatty acid content was much higher in samples with addition of hull-less pumpkin seed oil press-cake flour than in the control sample, whereas it was not detected in whole-wheat cookies. All cookies with added hull-less pumpkin seed oil press-cake flour had significantly lower carbohydrate contents, than the brown rice and whole-wheat flour cookies (9.5-36.8%). Due to addition of hull-less pumpkin seed oil press-cake flour , protein content significantly increased in samples no. 1-4 (10-40% of added PCF). Samples no. 2 (with 20% hull-less pumpkin seed oil press-cake flour enrichment) and no. 3 (with 30% hull-less pumpkin seed oil press-cake flour enrichment) had the best nutritional profiles. These formulations have demonstrated potential application in the baking industry by marketing these gluten-free cookies as a value-added functional product.
The food processing industry is producing millions of tons of by-products that are regarded as waste and disposed into landfills. These by-products could be potentially used as innovative ingredients for the nutritional enhancement of existing foods or as raw materials for new product development (1). The use of these waste by-products as food additives or supplements with high nutritional value have gained increasing interest because they have high nutritive value and their recovery may be economically attractive (2). Different food industry by-products, such as mango peel powder used in biscuits (3) and wet okara in a coconut-based soft snack (4), have been utilized in the past.
Oil cakes/oil meals are one of the reusable by-products category. They are obtained after pressing or solvent extraction from the oil seeds, which could be edible or non edible. Being rich in protein (15-50%), some of these have also been considered ideal for food supplementation (5). Edible oil press-cakes have been incorporated in various food products: hemp press-cake in gluten-free crackers (6), flax oil cake in bread (7), and hull-less pumpkin seed oil press- ...