Nutritional Value and Modelling of Carotenoids Extraction from Pumpkin (Cucurbita Moschata) Peel Flour By-Product

By-products from fruits and vegetables are slices and peels that have been removed or rejected by the food industry and are considered to have low commercial value. Pumpkin peel is a source of carotenoids, minerals, antioxidants and phenolic compounds. This work studied the nutritional value of pumpkin peel flours produced by convective drying (40 degrees C) and milling. Pumpkin peel flours contained high contents of insoluble fibres (24.46 g/100 g), potassium (19.1 g/kg) and iron (152.5 mg/kg). Carotenoids were extracted using hexane at 40 degrees C, and flour particles were classified by 35-, 80- and 100-mesh sieves. The total carotenoids content ranged from 216.9 to 306.8 mu g/g. Fick's second law model computed that 215 min was required to extract 99 % of the total carotenoids. This work evidenced the effects of particle size on carotenoids extraction efficiency and demonstrated that pumpkin by-product flour could be used as a food ingredient or natural dye.