Effect of functional sugar replacer on the thermal gelation of high methoxyl pectin

• Main Authors: Shieh, Shuenn-Jye, 謝順吉
• Other Authors: V. An-Erl King
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/83125064988393477728

碩士 === 國立中興大學 === 食品科學系 === 85 === Large amounts (at least 55%) of sugar (sucrose) are required as the cosolute for gelation of high methoxyl pectin (HMP). The effective replacement of sucrose by other low-calorie replacers would be significantly favorable to human health. However, besides gelation, sucrose also provides sweetness, shelf life, and improves a number of properties such as bulking and lowering water activity in the gelled product. Therefore, several sugar replacers with similar functional properties were selected to replace sucrose in this study. The samples were formed by thermal gelation and the substitute effects of individual sugar replacers were evaluated by physical measurements including gel strength, Hunter L, a, b values, and Instron texture profile analysis (TPA). The results indicated that among the sugar bulking agents tested, sorbitol and xylitol possessed more effects on HMP gelation and significantly lowered the water activity. In addition, there were higher lightness and no browning reaction in the gels formed by sorbitol and xylitol. Response surface methodology (RSM) and a three-variable and three-level design were then used to determine the optimum processing conditions of the HMP gelled products based on the responses of physical measurements and sensory evaluation. The optimum processing condition was found to be citric acid 0.0025 M, sorbitol 28.6 %, and xylitol 32.5 %. After storage at 4℃for three months, it was also found that there was no significant change in water activity and appearance except slight increases of hardness and springiness values, and the products became more acceptable to the mass panel.