Nutritional Profiling, Phytochemical Composition, and Glycemic Benefits of Indigenous Plant-based Powdered Beverages

Plant-based foods and beverages are culturally adaptable; they offer healthier dietary options and have the potential to regulate blood glucose response. Existing research has largely focused on liquid plant-based beverages, with minimal attention to solid forms. This study aims to fill this gap by determining the nutritional profile and phytochemical compositions of powdered plant-based beverages, and their effects on blood glucose response. Soybean, the primary component of the beverage, was processed by two separate methods (toasted and fermented-boiled). Samples included four blends (TS1, TS2, FBS1, and FBS2) of ginger, tiger nuts, dates, and soybean. The proximate, micronutrients, amino acid profile, phytochemical compositions and fungal count of the beverages were determined using standard methods. Consumer acceptability of eight beverages, obtained from 20g and 50g dilutions of each sample in 250ml of water, as well as the glycemic index (GI) and glycemic load (GL), were analyzed. Data obtained were subjected to statistical analysis. The study observed high protein (41.3-46.2%) and fiber (19.22-26.05%) contents, with significantly high protein levels (p<0.05) in beverages with toasted soybean (TS1 and TS2). The beverages had relatively low levels of moisture (1.29-2.09%) and fungal counts (6-10 log10 sfu/g). High amounts of vitamins C and E were found compared to iron, zinc, and calcium levels. The beverages contained varying amounts of amino acids, with highest compositions found in TS1 (5g-Ginger:25g-Tiger nuts: 10g-Dates:60g -Soyabean). Phytochemical composition of the drinks ranged as follows: saponin (5.59-9.99g/100g), alkaloids (5.26-7.52g/100g), tannin (1.65-2.72g/100g), phytates (1.65-2.62g/100g), flavonoids (2.95-4.96g/100g), and carotenoids (2.39-4.47g/100g). With the exceptions of sample TS2-1 (4.47) and FBS2-2 (4.27), the beverages were generally liked by the test panel members. The blend with 60% fermented-boiled soybean at 50g dilution concentration (FBS1-2) had the highest score, though not significantly different (p>0.05) from TS1-1, TS1-2, FBS1-1, FBS2-1, and TS2-1 samples. The glycemic index (20.04-31.52mmol/L) and glycemic load (10.02-15.76) of the beverages were relatively low. Our study shows that the formulated powdered plant-based beverages, can be a valuable addition to the diet of Nigerians, offering not only nutritional benefits but also a low glycemic index and load.