利用研磨與食用膠對乾燥粉圓的膨潤速度和咀嚼度維持性的影響

Effects of grinding and edible gels on dried pearl swelling rate and chewiness duration

張家豪(Jia-Hao Zhang)

指導教授 ： 林昭任

國立中正大學/工學院/化學工程學系/碩士(2015年)

摘要

珍珠奶茶是台灣著名的食品，甚至也風行至歐美各國，但因食用前須烹煮與澱粉老化無法長期保存等缺點，因此若能開發一快速食用且可長久保存的珍珠粉圓對消費市場是一重大貢獻。本研究藉由澱粉與食用膠共研磨來改善粉圓膨潤特性，之後採隔水加熱法糊化澱粉，再經40℃乾燥6小時後製作成沖泡型粉圓。結果顯示，研磨澱粉能破壞其內部之結晶結構，增加溶水性，使粉圓之膨潤速率提升。當食用膠與澱粉共研磨時，雖然食用膠可阻礙澱粉的blocklet的再結合，使得水分子易於進入blocklet中加速粉圓的膨潤速率，但也無法維持粉圓的彈性時間(5分鐘)。然而將0.5wt%的海藻酸鈉與關華豆膠以8:2比例混合，加入15wt%木薯澱粉和10wt%砂糖在10℃下共研磨2小時，顯示8分鐘即可膨潤至可食用咀嚼性區間(200-300g/10mm2)，且彈性持續時間可達50分鐘，其可能原因為關華豆膠鏈上羥基可與海藻酸鈉以氫鍵結合，形成一個保水結構阻礙膨潤速度，但砂糖溶解形成的孔隙可增加水於粉圓內部的質傳速率，使得粉圓彈性時間延長。此結果證明共研磨食用膠與澱粉來製作快速食用與長久保存的粉圓方法是可行的。

關鍵字

食用膠 ； 機械性質 ； 研磨 ； 澱粉

並列摘要

Pearl milk tea is a famous food in Taiwan, even so popular in the world. Because of requiring cooking prior eating and difficult preservation due to the retrogradation influence, it would be connvenient to consumers to develop an instant eadible pearl with capable long-term storage. Hence, a manufacture process was proposed in this study: fisrt, co-grinding starch and edible gum to enhance the swelling rate, thent double-boiling the co-grinded starch for gelatinization, finally drying the instant pearl at 40℃ for 6 h. The results showed that grinding can destory the starch internal crystalline structure to cause the increase of water solubility, leading to the swelling rate of the pearl. When starch and edible glue were grinde together, the molecule of glue can hinder the starch blocklet to reform again. Although the hinder effect can bring water easily entering to the blocklet to accelerate the pearl swelling rate, this result also decrease the chewiness duration with only 5 min. However, the case of adding 0.5wt% of sodium alginate and guar gum in 8: 2 ratio into the mixture 15wt% starch and 10wt% sugar for co-griding 2 h at 10℃ showed that it only takes 8 min swelling to reach the edible chewiness duration region (200-300g/10mm2) and the chewiness duration time can last to 50 min. The reason could be attributed to hydroxyl groups on guar gum to form hydrogen bonding with sodium alginate, which becomes a water retention structure to retain the swelling rate. Neverless, the water mass transfer rate can be improved via the pores generated by dissolving sugar from the pearl. Compensating both effects, the pearl possess a better swelling rate with longer chewiness duration time. Hence, the proposed method proved that it is practicable to manufacture an instant eadible pearl with capable long-term storage.

並列關鍵字

edible gum ； mechanical properties ； grinding ； starch

參考文獻

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