以氯化銘沉澱法從西番果果皮回收果膠質之研究

Studies on Preparation of Pectin from Passion Fruit Rinds with Aluminum Precipitation Method

紫色種西番果果皮中含有利用價值的果膠質，為試驗檢討氯化鋁沉澱法對於所回收果膠質品質和回收率的影響，果皮以4倍量0.02N鹽酸和氯化鋁抽取果膠質時，回收率隨處理溫度和時間而異；即100°C處理者多於80°C，而100分鐘者優於50分鐘。果皮經乾燥後貯藏二個月，所抽取果膠質品質和回收率並不受影響，果膠質沉澱物中所含總灰分及鋁量分別為10.27〜12.12%和2.25〜2.61%，經含鹽酸酒精洗滌後各降低為1.31〜1.43%和0.19〜0.22%，水溶性和六偏磷酸納可溶性部分隨成熟度而有增加現象，鹽酸可溶性部分則反之。自果皮可檢出Pectinesterase活性，卻未能檢出Polygalactuironase之存在，以80°C殺菁5分鐘可使上述酵素完全失去活性。

1. The conditions affecting the recovery of pectin from purple passion fruit rinds with aluminum chloride precipitation method were investigated. Recovery of alumium pectin precipitate extracted with four times 0.02N HC1 of rind weight was varied with temperature and extraction time. The recovery rate at 100°C for both 50 and 100 minutes was higher than corresponding batches at 80°C. and longer extraction timer (100 minutes) resulted in higher yield. Storage of dry rinds for two monthes did not significantly affect the yield and quality of pectin. Therefore during the peak season, the rinds could be dried with advantage and utilized later for pectin recovery during off-season. Total ash and aluminum contents of aluminum pectin precipitate were 10.27〜12.12% and 2.25〜2.61% respectively. Washing the wet aluminum pectin precipitate with acidified alcohol reduced the total ash and aluminum contents to 1.31〜1.43% and 0.19〜0.22% respectively. When such purified pectin was added into foods, the aluminum content in foods was not considered high. Yield and quality of pectin in the A1C1₃ precipitation method was only slightlyi inferor to that prepared with the alcohol precipitation method. Pectin prepared from passion fruit rinds with both A1C1₃ and alcohol precipitation method were in good quality. 2. Studies on the fractionation of pectic substances from rinds at the two stages of maturity revealed that at the partially purple stage the water- soluble (pectin) and sodium hexametaphosphate-soluble fractions (pectic acid) were much less than tlife acid-soluble fraction (protopectin). With the ripening of the passion fruit there was an increase in the water-soluble and sodium hexametaphosphate-soluble fractions with a corresponding decrease in the acid-solublefraction. 3. The pectinesterase in pulp and sliced rinds of passion fruit was inactivated at 80°C. for five minutes. No polygalacturonase could be detected. It is necessary to take five minutes blanching at 80°C. for the complete inactivation of pectin enzynis before extraction of pectic substance.