Sensory and Physicochemical Properties of Pasteurized Coconut Water from Two Varieties of Coconut

Abstract

Coconut water is traditionally consumed fresh and is widely patronized by all and sundry. Storage of coconut water has however become a challenge due to it susceptibility to microbial attack coupled with several biochemical changes that takes place to alter it properties. Pasteurization is a mild thermal process used for fruit juice and beverage preservation. The objective of this study was to investigate the effects of pasteurization on the qualities of coconut water. Coconut water was extracted from two varieties, Malayan Green and Malayan Yellow and each variety was pasteurized at 90^oC for 5 minutes, 80^oC for 15 minutes and 70^oC for 25 minutes. Sensory evaluation was conducted and the most preferred pasteurized sample for each variety was selected. Total soluble sugars (TSS), pH, titratable acidity (TA), total phenols and vitamin C of the most preferred pasteurized sample and the control for each variety were determined. Findings from the study revealed that, panellists mostly preferred the Malayan Green and Malayan Yellow samples pasteurized at 90^oC for 5 minutes and 80^oC for 15 minutes respectively. A higher TSS of 5.8 ^oBrix and pH of 4.78 were recorded for unpasteurized Malayan Yellow sample. The Malayan Green recorded higher values in all the other physicochemical properties analyzed. It recorded 0.14% of TA, 95.15 mg/L for total phenols and 30.18 μg/mL for vitamin C content. Reduction in the properties occurred in pasteurized samples of both varieties. This indicates that pasteurization had a reducing effect on microbes, sensory and nutritional value of coconut water. However, the Malayan Green variety was found to be more stable to pasteurization conditions compared to the Malayan Yellow variety.

Keywords: Malayan Yellow coconut, Malayan Green coconut, pasteurized coconut water, sensory evaluation, physicochemical properties