Nutritional and phytochemical screening of high altitude grown beans of Nepal

Abstract

Phaseolus sp. are considered to be a good source of carbohydrate, protein, dietary fiber and other nutritional components. Besides, they are rich in a variety of bioactive compounds and thus possess health promoting effects in relation to prevention of chronic diseases including cancers, cardiovascular diseases, obesity and diabetes. This investigation provides analyses of nutrients and screening of bioactive compounds present in the common bean species which are cultivated in high altitude of Nepal. Eighteen varieties of bean commonly grown in high altitude of Nepal were analyzed. The proximate values range from 6.49-8.84% moisture, 61.94-67.35% carbohydrate, 19.40-24.55% crude protein, 1.98- 3.58% crude fat, 3.61-4.91% total ash and 4.02-4.96% crude fiber. The mineral content in the ash were determined and found to be ranged from 843.86-2763.62 mg/kg, 1540.63- 2083.52 mg/kg, 38.93-73.69 mg/kg, 205.91-695.81 mg/kg, 13560.21- 16957.05 mg/kg, 2.72-8.77 mg/kg and 19.80-31.00 mg/kg dry weight for calcium, magnesium, iron, sodium, potassium, copper and zinc respectively. Besides nutrients, the presence of various bioactive compounds-alkaloids, flavonoids, phenolics, tannins, saponins, were screened and quantified in all eighteen samples. Higher concentration (more than 5 mg GAE/g) of phenolics were observed in four beans samples whereas eight samples ranged from 4-7 mg GAE/g and less than 4 mg GAE/g was observed in six samples. Similarly, higher concentration (more than 2 mg QE/g) of flavonoids were observed in five samples and less than 2 mg QE/g was observed in thirteen beans samples. The composite flour of wheat (lacks lysine) and pulses (lacks s-amino acids) fulfills each other’s deficiencies including amino acids and other nutritional and anti- nutritional components that are required for better health. Key words: Common beans, high altitude, proximate composition, phytochemicals.