Development of a Hull‐Less Pumpkin ( Cucurbita pepo L.) Seed Oil Press‐Cake Spread

  A stable, oil‐based spread rich in the omega‐3 (ω‐3) and omega‐6 (ω‐6) fatty acids was developed using a hull‐less pumpkin seed (C ucurbita pepo L.) oil press‐cake, a by‐product of the pumpkin oil pressing process, along with cold‐pressed hemp oil. Response surface methodology (RSM) was applied to investigate the effects of two factors, as the formulation's compositional variables: a commercial stabilizer (X 1 ) and cold‐pressed hemp oil (X 2 ) added to the pumpkin seed oil press‐cake in the spread formulations. A central composite, 2‐factorial experimental design on 5 levels was used to optimize the spreads where model responses were ω‐3 fatty acids content, spreadability (hardness), oil separation, and sensory evaluation. The selected responses were significantly affected by both variables ( P < 0.05). The spreads resembled commercial peanut butter, both in appearance, texture and spreadability; were a source of ω‐3 fatty acids and with no visual oil separation after 1 mo of storage. An optimum spread was produced using 1.25% (w/w) of stabilizer and 80% of hemp oil (w/w, of the total added oil) which had 0.97 g of ω‐3 fatty acids per serving size; penetration depth of 68.4 mm; oil separation of 9.2% after 3 mo of storage; and a sensory score of 17.5. Practical Application:  A use of by‐products generated from different food processing technologies, where the edible waste is successfully incorporated as a value‐added ingredient, has become a very important area of research to support global sustainability efforts. This study contributes to the knowledge of a product design process for oil‐based spread development, where oil press‐cake, a by‐product of the oil pressing process of the naked pumpkin seeds, was used and where results have demonstrated that a new product can be successfully developed and potentially manufactured as a functional food.