白芝麻蛋白質的萃取與功能特性之探討

在全球環境的變遷及人口快速的增長下，自然資源消耗增加，環境被破壞造成生態的反撲，同時健康意識的抬頭使人們在飲食型態上有所轉變，促使全球素食熱潮的興起，導致素食加工品需求量上升，因此尋找植物蛋白的新來源逐漸受到關注。本研究為萃取白芝麻蛋白質，白芝麻先以不同焙炒溫度（160、180、200℃）及進料速率（20、30、40 g/min）進行機械壓榨脫油，殘存油脂以溶劑萃取方式去除，所得之脫脂芝麻粕再以不同鹽濃度（0.0、0.5、1.0 M）萃取其蛋白質，探討其產率及蛋白質純度並決定最佳蛋白質萃取條件，利用低溫噴霧乾燥法獲得白芝麻蛋白粉，同時完成白芝麻經不同條件的脫脂、蛋白質鹼萃取、pH值及乾燥方法對白芝麻分離蛋白質的萃取率與其功能特性的影響分析。結果顯示，經160℃焙炒後在機械壓榨中進料速率30 g/min時具有最佳的油脂產率為61.57%，且萃取上無損失，以混和溶劑萃取可降低正己烷的操作安全及環境污染並提高乙醇的萃取率；蛋白質純度經焙炒後萃取增加為93.85%，而提高鹽濃度蛋白質萃取率與產率皆具有下降趨勢，因此以鹽濃度0.0M作為低溫噴霧乾燥之條件；在蛋白質的功能特性分析中，溶解性、乳化活性、發泡能力及黏度在pH值、鹽濃度的增加、原料經焙炒萃取與低溫噴霧乾燥後具有上升趨勢，而乳液安定性隨著鹽濃度的增加穩定性上升，發泡穩定性則經低溫噴霧乾燥後增加，但油脂結合能力及保水能力則顯著下降。總和以上結果，白芝麻蛋白的溶解性及發泡性質相似於商業大豆分離蛋白，同時乳化性質甚至顯著較高，但黏度則較低，因此白芝麻蛋白比起作為主原料更適合作為食品添加劑或是副原料，來賦予產品有更好的乳化特性，同時可降低豆類植物蛋白的不良豆腥味，增加消費者的接受度。

關鍵字

白芝麻；蛋白質萃取；功能特性；焙炒；鹽濃度；乾燥方法

並列摘要

With changes in the global environment and rapid population growth, the consumption of natural resources has increased, and the destruction of the environment has caused ecological counterattack. At the same time, the rise of health awareness has led to changes in people's dietary patterns, prompting the rise of a global vegetarian boom, leading to an increase in the demand for vegetarian processed products, so the search for new sources of plant protein has gradually attracted attention. In this study, white sesame protein was extracted. White sesame was deoiled by mechanical pressing at different roasting temperatures (160, 180, 200°C) and feed rates (20, 30, 40 g/min), and the remaining oil was removed by solvent extraction. The obtained defatted sesame meal is then extracted with different salt concentrations (0.0, 0.5, 1.0 M) for protein, the yield and protein purity are discussed, and the best protein extraction conditions are determined. White sesame protein powder is obtained by low-temperature spray drying. At the same time, the effect of degreasing, alkaline extraction of protein, pH value and drying method of white sesame on the extraction rate of white sesame protein and its functional properties was completed. The results show that after roasting at 160°C, the best oil yield is 61.57% when the feed rate is 30 g/min in the mechanical press, and there is no loss in extraction. Extraction with mixed solvents can reduce the operational safety and environmental pollution of n-hexane and increase the extraction rate of ethanol. After roasting, the protein purity was increased to 93.85%, and the protein extraction rate and yield of increased salt concentration had a downward trend. Therefore, the salt concentration of 0.0M was used as the low-temperature spray drying condition. In the analysis of protein functional properties, solubility, emulsifying activity, foam capacity and viscosity have an upward trend with the increase of pH value, salt concentration, raw materials after roasting extraction and low-temperature spray drying. The emulsion stability increases with the increase of the salt concentration, while the foaming stability increases after low-temperature spray drying but water holding capacity and oil binding capacity are significantly reduced. To sum up the above results, the solubility and foaming properties of white sesame protein are similar to those of commercial soy protein isolate, while the emulsifying properties are even significantly higher, but the viscosity is lower. Therefore, white sesame protein is more suitable as a food additive or as a secondary raw material than as the main raw material to give the product better emulsifying properties. At the same time, it can reduce the beany flavor of legume plant protein and increase consumer acceptance.