Physicochemical, Nutritional, and Functional Characteristics of Seeds, Peel and Pulp of Grewia tenax (Forssk) Fiori Fruits

Purpose: To determine the physicochemical, nutritional, and functional characteristics of the seeds, peel, and pulp of Grewia tenax (Forssk.) Fiori fruits.Methods: The whole fruit was flooded with ionized water for 6 h, and the seeds manually separated from the peel and pulp. The mineral content was determined by atomic absorption spectroscopy while the amino acids were separated and quantified by injecting 50 μL into an amino acid analyzer (Hitachi 835-50). Gas chromatography–mass spectrometry (GC/MS) was used to separate and determine the volatile compounds, whereas color was measured with a digital colorimeter.Results: Protein, fat and ash contents were higher in the seeds than in the peel and pulp. Carbohydrate content was higher in the pulp (87.09 %) than in the seeds and peel (59.56 and 70.74 %), respectively. The peel, seeds, and pulp had Na concentration of 19.3, 5.8 and 11.5 mg/100 g, respectively; and for potassium (K), 502.5, 400 and 300 mg/100 g, respectively. The pulp contained the following essential amino acids: histidine, thereonine, valine, isoleucine and lysine at levels of 4.3, 6.4, 9.7, 9.5, and 6.4 g/100 g, respectively. The pulp had the highest water absorption capacity (WAC, 3.3 ml/g), whereas oil absorption capacity was 3.6 ml/g in the peel. Foaming capacity (FC) was 8.6 % in the seed. The bulk density (BD) of seeds, peel, and pulp were 0.5, 0.6, and 0.9 g/mL, respectively. The concentration of the volatile components of seeds, peel, and pulp of the fruits was 42.1, 97.9, and 71.4 %, respectively.Conclusion: Grewia tenax fruits are a good source of nutritional components and essential nutrients, including minerals and amino acids, and have functional properties, which, if properly utilized, can improve human nutrition and health.Keywords: Grewia tenax, Physicochemical, Amino acids, Nutrition, Functional properties, Minerals, Volatile compound