NUTRITIVE AND ANTIOXIDATIVE POTENTIALS OF BEVERAGE BLENDS FROM ACHA (DIGITARIA EXILIS),TIGERNUT (CYPERUS ESCULENTUS), AND GINGER (ZINGIBER OFFICINALE) EXTRACTS

Abstract

The global increase in the occurrence of degenerative diseases has been linked to the world’s changing lifestyle and the importance of bioactive compounds in plant foods in correcting the menace cannot be over emphasized. Acha and tigernut provides health benefits aside their nutritive value. Beverages were produced from roasted acha malt and tigernut extracts in varying proportions and spiced with ginger. The nutritive and anti-oxidative potentials of the blends were evaluated and the phenolic profiles of the beverages were determined using a high-performance liquid chromatography separation method with diode array detector (HPLC-DAD). The physicochemical properties showed that the pH ranged from (4.75-5.85). The brix and total soluble solids increases as the addition of tigernut extract increases. The beverages contain vitamin A ranging from (0.17- 0.26 mg/ml); vitamin B1 (10.84-12.59 mg/ml); vitamin C (2.25-7.51 mg/ml) and vitamin E (0.01-0.02 mg/ml). The ferric reducing property and ABTS scavenging ability decreases as the percentage of tigernut extract increases while DPPH increases in similar trend. Total flavonoid and total phenolic content ranged from 0.07 to 0.48 mg rutin Eqv/ml and 0.06 to 0.43 mg gallic acid Eqv/mls respectively. The soluble, insoluble and total dietary fiber of the beverages ranged from respectively. As the level of tigernut increases, extractable phenolic content increases and there was no significant difference in hydrolysable phenolic content of the blends. The blend with equal proportion of acha and tigernut had the highest value of condensed tannin (0.23 mg/g). Four phenolic acids (gallic acid, chlorogenic acid, ellagic acid and caffeic acid) and four flavonoids (quercetin, kaempferol, quercitrin and rutin) were identified by HPLC-DAD. Quercetin, the dominant phenolic compound in plant foods was detected in high quantity in all the beverages. The beverage blend containing the highest proportion of tigernut extract had the highest overall acceptability score (7.47)on a 9-