- 學位論文
多孔性微晶纖維素的製備及其特性
Preparation of porous microcrystalline cellulose and its properties
摘要
研究顯示，鈉攝取量與發生高血壓以及心臟病的風險呈正相關性。美國心臟協會在2010年提出減少食品中鈉含量10-40%的建議，足見發展減鹽食品是市場的趨勢。本研究可分為兩部分，第一部分利用酵素進行水解，製造具較大比表面積的多孔性纖維素，第二部份將多孔性纖維素與幾丁聚醣結合，並以其做為氯化鈉的載體，期望藉由纖維素的多孔性結構及與幾丁聚醣結合後產生的功能特性，達到延長氯化鈉溶解釋放的時間，當味覺較持久即可望減少食鹽的攝取量。由實驗結果發現，在酵素與基質重量比例為0.025的條件下進行水解4小時可使大部份纖維素表面出現多孔性結構，其比表面積、孔體積與保水力分別增加為原料的2.6、3.4及1.4倍。當纖維素懸浮液與0.3 %幾丁聚醣溶液以1:1 (V/ V)比例於160 rpm混合6小時，每克纖維素原料可結合的幾丁聚醣達最大值4.88毫克 (mg chitosan/ g cellulose)。經酵素處理3、4、5小時的纖維素與幾丁聚醣結合的能力則分別提昇為5.5、6.1、6.0 (mg chitosan/ g cellulose)。其中，水解4小時的纖維素結合幾丁聚醣，界面電位由-16 mV上昇為31.43 mV，代表幾丁聚醣可包覆在纖維素表面並改變其介面電位特性。以RC_Chi (纖維素-幾丁聚醣複合物)及HC_Chi (水解4小時纖維素-幾丁聚醣複合物)做為氯化鈉的載體，於添加3%食鹽水組可分別使NaCl達釋放終點時間延長為對照組(等量的氯化鈉直接在水中溶解釋放的組別)的1.4與8.1倍；於添加31.28%食鹽水組則分別延長為對照組的1.3與6.5倍。顯示俱多孔性結構的HC_Chi比RC_Chi更可顯著降低NaCl於水中溶解釋放的速度。
並列摘要
According to the study daily sodium intake has a positive correlation with risk of hypertension and cardiovascular disease. In 2010, American Heart Association suggested the food producer to reduce 10-40% sodium content of their products. Obviously, development of salt reduction products is a current trend. This study was divided into two parts. In the first part, the preparation of porous cellulosic materials was employed by enzymatic hydrolysis. In the other part, combination of porous cellulosic material and chitosan was tested to create a complex material to be a carrier of sodium chloride for the purpose of prolongation of sodium chloride dissolution. The longer the salty taste is maintained, the less intake of salt is approached. The result denoted that the porous cellulosic material was successfully prepared by enzymatic hydrolysis for 4 hours and E/S 0.025. Their specific surface area, pore volume and water holding capacity, in comparison to the raw cellulose, were improved to be 2.6, 3.4 and 1.4 times, respectively. The maximum binding capacity of raw cellulose to chitosan was 4.88 (mg chitosan/g cellulose) in the mixture (1:1 V/V) of cello-dispersion and 0.3% chitosan solution with 6 hours and 160 rpm agitation. Cellulose hydrolyzed 3, 4 and 5 hours can be respective promoted their binding ability to chitosan to 5.5, 6.1 and 6.0 (mg chitosan/g cellulose). The binding of chitosan onto porous cellulosic material varied the zeta potential of the cellulose from -16 mV to 31.43 mV, which changed the charge property of cellulose interfaces. The steady state duration of the NaCl dissolution could be postponed to 1.4 and 8.1 times for the samples of RC_Chi (raw cellulose-chitosan complex) and HC_Chi (hydrolysis cellulose-chitosan complex) for the 3% NaCl test, as compared to the raw cellulose, and they were 1.3 and 6.5 times for the 31.28% NaCl test. It proved that the porous cellulose/chitosan complex significantly retarded the desorption of NaCl than did the un-hydrolyzed one.