Development of flavored amaranth juice

Abstract

Red amaranth is a crop with a rich nutritional profile. It is rich in vitamin C, proteins, iron, folic acid and polyphenols that possess antioxidant activity. Red amaranth plays a big role in preventing cardiovascular diseases, various cancers, iron deficient anemia and also lowers the blood cholesterol levels. However present studies indicate that red amaranth is faced with high postharvest losses (>30%) during the peak season and this is basically attributed to the perishable nature of the crop. The major objective of this study was to develop a vegetable juice from red amaranth. Four products with different flavors were developed namely: unflavored amaranth juice, ginger flavored amaranth juice, vanilla flavored amaranth juice and strawberry amaranth juice. The samples were evaluated for overall consumer acceptability using untrained panelists (n = 40). The nutritional quality (protein, fiber, iron) and antioxidant activity of the most acceptable formulation and that of the control sample were determined using standard methods. Shelf stability was also determined by evaluating changes in sensory acceptability, titratable acidity, pH, color and vitamin C of samples stored at 4 0C for 2 weeks. Ginger flavored amaranth juice was the most liked with an overall acceptability of 7.5 while the unflavored flavored amaranth juice was the least liked with an overall acceptability of 5.4 on a nine point hedonic scale. However, since the overall acceptability of the juices was above 5 (neither like nor dislike) they were both acceptable. The protein, fiber, iron and antioxidant capacity of the amaranth juice ranged between 0.96-1.20%, 1.25-1.37%, 0.19-0.27 mg/100 ml and 44.61-37.61mg/100ml equivalent vitamin C, respectively. Ginger flavored amaranth juice had a significantly (p<0.05) higher antioxidant activity. Ginger flavored amaranth juice had higher total titratable acid (TTA) and pH (0.35%, 4.12) compared to the unflavored amaranth juice (0.25%, 4.14).The vitamin C content (10.32mg/100ml) was the same for both the ginger flavored and unflavored amaranth juice while the colour intensity absorbance varied between 6.32-6.09nm at 538nm reading. There were no significant changes in pH, acidity and color of the juice stored for two weeks and both samples received acceptability scores greater than 5 (neither like nor dislike). It is therefore possible to produce an acceptable antioxidant rich ginger flavored amaranth juice.