Effects of Blanching on Physicochemical Properties of Chantenay Carrots Juice and Assessing the Qualities of Formulated Carrot-MD2 Pineapple Juice Blends

摘要

This study was carried out to determine the effects of three blanching methods on carrots and also to assess the physico-chemical and sensory properties of formulated Chantenay carrot-MD2 pineapple juice blend. Hot water, steam and microwave blanching were the methods used and the respective blanching temperatures were 98, 105 and 75 °C for 10 minutes each. Physicochemical properties determined on the juices extracted by gravity from blanched carrots were yield, pH, total soluble sugars, total solids, ash and vitamin C. There were significant differences (p<0.05) in the yield, vitamin C and total solids of the blanched and unblanched carrots. Steam blanching method was chosen for the formulation of the carrot-pineapple juice blend due to its high yield and ash content of 76.65 and 0.66% respectively. The carrot juice from the steam blanching process was formulated with MD2 pineapple juice into various ratios of 50:50, 60:40, 70:30 and 100:0 with the carrot juice being the major component. A preference ranking test carried out on the formulated carrot-pineapple juices indicated that the 50 untrained panellists mostly preferred the 50:50 formulated juice. Proximate and physicochemical analyses were conducted on the 50:50 formulated carrot-pineapple juice and had the following compositions: fat (0.25%), ash (0.25%), protein (0.78%), crude fibre (2.68%), carbohydrates (23.47%), moisture (72.57%), vitamin C (12.40 mg/100 g), β-carotene (955.71 μg/100 g), pH (4.45), total soluble sugars (14.87%) and titratable acidity (1.50%). In conclusion, development of this product will enhance the utilization of carrot not solely for stews and salads but also as a juice blend with the potential to compete with the local and foreign fruit juices on the market. Consumption of the product will help address the resurgence of nutrition-related chronic diseases due to its appreciable content of β-carotene which are potent free radical scavengers in humans.