Development of Fortified Biscuit with Acid and Sweet Whey Proteins and Its Effects on Body Weight, Indices of Body Composition and Antioxidant Capacity in Rats

The effect of sweet (SW) and acid whey (AW) proteins on body weight (BW) and composition (BC), and antioxidant capacity (AC) is uncertain. We dehydrated SW and AW proteins obtained from local white cheese and labneh production lines, developed biscuits containing these protein powders and evaluated biscuits' sensory attributes and proximate nutrient contents, and investigated their effects on BW, indices of BC, and AC in rats. Four types of biscuit were prepared: plain (PB), albumin (ALB), SWB, and AWB. Five isocaloric and isonitrogenous diets containing Albumin (control), PB, ALB, SWB, and AWB were used.  Sixty adult male Sprague-Dawley rats were used, 10 were sacrificed at the start, and the remainder were randomly assigned to the five diet groups (10 rats/ group) and fed for four weeks. BW, food (FI) and water (WI) intake, food efficiency ratio (FER), serum AC, liver weight (LW), Lee index (LI), body mass index (BMI), length, and abdomen (AS) and chest (CC) circumferences were measured following standard protocols. AW was higher in ash and fat whereas lower in carbohydrates but similar to SW in protein and moisture contents. ALB had the highest protein content, AWB had the most increased fat and ash contents, and SWB had the highest moisture content. PB had the highest carbohydrates and the lowest ash contents among the other biscuits. PB and SWB were the best in all sensory attributes tested and the overall acceptability compared to other biscuits. The four biscuit diets kept similar BW, whereas the control diet kept the highest BMI, LI, and LW, which was also not significantly different from the initial group. Animals fed the PB diet had the most increased length, abdomen, AS, and CC, whereas these measurements were lowest in animals fed SWB and AWB diets which were not different from the control. Animals fed the AWB diet had the highest WI, but all other diets were not significantly different from the control diet in FI and FER. Serum AC was the highest in animals fed SWB and AWB diets that were insignificantly different from the initial group, whereas it was the lowest in PB and AWB diets. Given their sensory attributes and effects on AC and BW status, SW and AW may be used as protein substitutes in bakery products; however, further studies are warranted. Keywords: Body weight, Sweet whey, Acidic whey, Proximate nutrients, Body composition, Antioxidant capacity, Rat.