Quality evaluation of biscuits produced from composite blends of pumpkin seed oil press cake and wheat flour

Pumpkin seed oil press cake (PSOPC) is a by-product of pumpkin oil production, and after cold pressing, a significant amount of oil still remains in the press cake. The aim of this study was to investigate the possible use of PSOPC flour as a substitute for wheat flour in biscuit production and, consequently, for reducing shortening usage. Biscuits have been produced from composite blends of plain white flour and PSOPC flour in ratios 100:0, 80:20, 60:40 and 40:60, respectively. Shortening addition was gradually reduced depending on the PSOPC flour addition. Biscuit baking quality was determined by width, thickness, spread factor, volume and textural properties. Computer vision was used to evaluate biscuit colour, and sensory evaluation was conducted for colour, taste, texture and overall acceptance. Results showed that PSOPC flour decreased biscuit diameter, height and volume and also caused a softer texture of biscuit. PSOPC flour contributed to the greenish colour of biscuits and the pleasant taste of roasted pumpkin seed. PSOPC flour can be successfully used as a functional and nutritionally valuable substitute for wheat flour and shortening, even in quantities up to 60%, without significant deterioration of the technological quality of biscuits.