Ratchada Tangwongchai, Khanittha Lerkchaiyaphum, Kasame Nantachai, and Thanakorn Rojanakorn.

pp. 1351 - 1363

Abstract

Screening experiments using 2^5-1 fractional factorial design showed that pH, temperature, and extracting time were the main factors affecting the amount and quality of extracted pectin from Citrus medica Linn. Optimum condition of pectin extraction was studied using central composite design (CCD). Mathematical models relating pH, temperature and extracted time to amount of extracted pectin, equivalent weight, methyl content and anhydrogalacturonic acid content were established. Based on the mathematics
models, the condition of pH 2, 100ºC and 105 min was found to be the optimum conditions for pectin extraction from Citrus medica Linn. Mathematical and experimental results were verified. The use of extracted pectin as a gelling agent in pineapple jam revealed no significant difference in gel consistency compared to that of commercial pectin grade 150 (p>0.05). However, the commercial pectin had a higher liking score on the spreadability, texture and overall liking. As a stabilizer in chocolate pasteurised milk,
0.2% of the extracted pectin was required to prevent precipitation of chocolate powder with the similar viscosity obtained from 0.06% κ-carageenan