Effect of beetroots substitution and storage on the chemical and sensory properties of wheat noodles
Beetroot consists of betalain, a natural red pigment which has desirable biological activities such as antioxidant, mineral and anti-inflammatory properties. Substitution of wheat flour with beetroot flour could improve the aesthetic and nutritional properties of the product. This study was conducted to determine the effects of beetroots substitution and storage on the chemical and sensory properties of wheat noodles. The noodles were prepared with beetroot powder of 5%, 10%, 15% and 100% wheat flour which serve as the control. Progressive decrease in lightness value was observed from 51.98 to 46.76 with increase in level of beetroot powder. The colour* value of control noodle was 1.13 and those of beetroot powder increased from 5.12 to 9.47, showing more reddish colour than the control. There were increase in redness (a*) value and decrease in lightness (L⃰) value with the increase of colouring pigments. At the third months of storage, the noodles became lighter losing the red colouration. No significant differences (p<0.05) in the protein contents of the noodles. The betalain contents of the noodles increased with beetroot substitution and decreased with storage. Cooking loss and swelling power of the noodles increased with increase in beetroot powder substitution. The antioxidant potential of the noodles increased with increase in beetroot powder with 15% having the highest value (39.22%) while the value decreased with storage. The sensory result showed that the appearance of the control noodles was more preferred and accepted than others.
Keywords: Noodles, Betalain, Storage, Colour, Antioxidant