A Kinetic analysis of changes in sweetness and acidity of sliced pineapples during ultrasonication

Sweetness and acidity changes in pineapple

Abstract

Changes in sweetness and acidity of sliced pineapples during ultrasonication was carried out by determining the rate of changes in total sugar content and pH. Half and fully ripe sliced pineapples were prepared and exposed to ultrasonic waves at the frequency of 40kHz for 0, 5, 10, 15, 20, 25, 30, 35, and 40 minutes. Total sugar content, pH, and order of reaction during ultrasonication were analyzed. Sonication of half-ripe pineapples for 40 minutes resulted in the lowest total sugar content (9.53% Brix), whereas the same treatment on fully ripe pineapples resulted in the highest pH (4.73). The reduction of total sugar content in half and fully ripe pineapples followed a first-order reaction with rate of constants (k) of  -0.450 and -0.612 per hour, respectively. The kinetic changes in pH during ultrasonication showed that half and fully ripe of pineapples followed a first-order reaction with rate of constants (k) of  0.222 and 0.216 per hour, respectively.