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.
