Abstract
The effect of cooking time on nutritional characteristics of sesame milk was determined. Sesame milk was cooked at the temperature of 100°C for various duration (0, 15, 30 and 45 min), to produce samples marked as A, B, C and D. The sesame milk products were subjected to physico-chemical and sensory analyses using standard analytical methods. The moisture, protein, crude fat and energy contents decreased significantly (p≤0.05) with increase of cooking time from 89.30 to 87.32%, 2.5 to 2.3%, 5.5 to 4.0% and 54.81 to 49.55 kcal/g respectively; while ash, fiber and carbohydrate contents increased significantly (p≤0.05). Total solids and pH varied from 7.95 to 10.90 and 6.57 to 6.83%, respectively. Calcium was highest (273.44 mg/100 g) followed by phosphorus (196.2 mg/100 g), magnesium (173.5 mg/100 g) and potassium (95.58 mg/100 g) in milk cooked for 45 min when compared with lower values observed at 0, 15 and 30 min. The vitamins (thiamine and riboflavin) significantly reduced in sesame milk after boiling for 45 min. This accounted for a post-boiling decrease of about 76.2 and 64.0% in vitamins B1 and B2, respectively. Duration of cooking was observed to affect the phytate and oxalate concentrations significantly (p≤0.05) in sesame milk with a maximum reduction observed after 45 min. Mean sensory scores for colour and flavour ranged from 6.75 to 7.29 and 7.28 to 7.52, respectively. Sesame milk cooked at 100°C for 30 min (sample C) gave the highest acceptability score of 8.06, followed by samples B, A and D in that order. It was evident that there were varying degrees of changes that occurred in each of the chemical composition of the sesame milk with respect to the different periods of cooking. Processing at 100°C for 30 min gave the product with appreciable nutritional and sensory qualities with tolerable concentration of anti nutrients, and is therefore, recommended for sesame milk processors.
Key words: Chemical composition, cooking, sensory analysis, sesame milk.
