利用豬肉水解產物製備肉類香味料及肉類香氣生成之研究

Abstract

本研究使用五種不同的商用蛋白酶(Bromelain、Flavourzyme、Neutrase、Papain、Alcalase)對碎豬肉進行水解。尋求對豬肉水解效果最佳的酵素，並建立最適的水解條件(溫度、振盪混合速率、水解時間)。結果顯示，以Flavourzyme對碎豬肉進行水解有最好的水解效率。以2% Flavourzyme在40℃、150 rpm下水解10小時為最佳的水解條件，所獲得的水解液之水解率平均為48.8 %。 使用所製備的豬肉蛋白水解液與其它肉香前驅物(胺基酸、還原糖、核苷酸等)進行熱反應來生產肉類香味料。水解液依序添加不同含量的cysteine、glycine、ribose、thiamine 及 IMP和GMP等物質進行熱反應(pH 7，121℃、30分鐘)並進行感官品評，尋求最佳的反應配方及添加量。再使用最佳反應配方在不同pH下(pH 5~9)進行熱反應並進行官能品評，求出最適的反應pH條件。結果顯示，在10 mL水解液中添加0.25 g cysteine、0.15 g glycine、0.5 g ribose、0.15 g thiamine和0.15 g IMP和GMP，在pH 6，121℃下反應30分鐘所生產的肉類香味料，其品評的分數最高(7.33)，具有接受性良好的肉類香味。 在pH 5~9的肉類香味料中一共鑑定出60種的香氣化合物，其中以雜環類化合物的種類(40種)及含量最多。在40種的雜環類化合物中有23種為含硫(S)化物。pH 5的部份產生的風味化合物較少。pH 5~9中，pyrazine的含量有隨著pH的上升而逐漸增加的趨勢。分析中鑑定出含量最多的化合物為4-methyl-5-thiazoleathanol，佔總量的50 %以上。該化合物的閾值偏高，其值為10.8 ppm，並非關鍵的肉類香氣化合物。本實驗只有在pH 6樣品中鑑定到2-methyl-3-furanthiol，其含量約佔總量的0.11 ％，為重要的肉類香味化合物。

In this study, five different commercial proteases (Bromelain, Flavourzyme, Neutrase, Papain and Alcalase) was used to hydrolyze ground prok in order to find the protease which had the highest pork hydrolytic efficiency and established the optimal hydrolytic conditions (temperature, rotate speed and time). The result indicated that utilization of Flavourzyme to hydrolyze pork had the highest hydrolytic efficiency. The optimal hydrolytic condition is using 2 % Flavourzyme to hydrolyze pork for 10 hours at 40℃ and 150 rpm. The degree of hydrolysis of hydrolysate is 48.8 %. Pork protein hydrolysate reacted with meat aroma precursors (amino acids, reducing sugars and nucleotides) to produce meat flavoring by thermal reaction. Hydrolysate reacted (pH 7, 121℃ for 30 min) with different content of cysteine, glycine, ribose, thiamine and IMP&GMP, the samples were tasted and scored by scorer. The best reaction species and contents were found. Reactions were carried out with different pH conditions (pH 5, 6, 7, 8, 9) by thermal reaction. The result showed that 10 mL hydrolysate reacted (pH 6, 121℃ for 30 min) with 0.25 g cysteine、0.15 g glycine、0.5 g ribose、0.15 g thiamine and 0.15 g IMP&GMP to produce the meat flavoring which had the highest score (7.33) and flavorable meat aroma. Sixty compounds were identified from different pH (pH5~9) meat flavoring. There were fourty heterocyclic compounds in total meat flavoring. The content of heterocyclic compounds in meat flavoring was more than other compounds. There were twenty-three sulfides in forty heterocyclic compounds. The pH 5 meat flavoring had fewer flavor compounds. In all pH samples, when pH was increasing, pyrazine content was increasing too. 4-methyl-5-thiazoleathanol was identified from all pH samples which had the highest content (above 50 %). The threshold value of 4-methyl-5-thiazoleathanol is 10.8 ppm. It is not the critical compound of meat aroma. In this study, 2-methyl-3-furanthiol was only identified from pH 6 sample. The content of 2-methyl-3-furanthiol is 0.11 %. It is the important compound of meat aroma.