Development of soy whey fortified orange juice beverages: their physicochemical, rheological, antioxidant, and sensory properties

Abstract

Aim: Soy whey is a byproduct of tofu production and is being discarded after tofu preparation. However, soy whey is a rich source of phytochemicals, minerals, and protein. The present study was conducted to utilize soy whey for the development of nutraceutical-rich orange juice beverages. Methods: The soy whey and orange juice were produced and beverage samples were developed from them. The samples were evaluated for physicochemical, rheological, antioxidant, and sensory properties to evaluate the optimum percentage of soy whey that can be utilized for beverage development. Results: The protein content increased from 0.45% to 1.65% with an increase in soy whey from 0% to 50%. The pH of the beverage samples was in the range of 4.27–4.77 with the total soluble solids (TSSs) of 5.75–6.0 for various beverage samples. The lightness (L*), redness (+a*), and yellowness (+b*) of beverage samples range between 31.57–49.04, 1.21–0.54, and 25.37–39.63 respectively. The vitamin C content of the beverage samples was 56.30 mg/L, 52.75 mg/L, 36.97 mg/L, 26.35 mg/L, and 22.87 mg/L for A, B, C, D, and E beverages respectively. The 1, 1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), reducing power ranges of beverage samples range between 91.2–96.23%, 0.521–0.994%, and 0.204–0.859% respectively, and total phenolic content (TPC) ranges between 112 mg gallic acid equivalents (GAE)/100 mL and 181 mg GAE/100 mL of beverage samples. The beverage samples presented a shear thinning property with a flow index (n) ranging between 0.2371–0.8214. The consistency coefficient of the beverage samples ranges between 0.0405 Pa∙Sn and 0.0041 Pa∙Sn. The control, 20%, and 30% soy whey-containing beverage samples showed higher sensory properties. Conclusions: The beverage samples with 0%, 20%, and 30% showed improved DPPH and FRAP percent activity and higher overall acceptability compared to 40% and 50% soy whey-containing beverage samples.