| Abstract: | 本研究使用兩種酵素（Alcalase和Flavourzyme）分別對三種禽肉（Chicken、Duck和Goose）進行蛋白質水解反應，製備具抗氧化活性之胜?，並探討家禽種類、酵素種類和水解率對禽肉蛋白質水解物抗氧化活性和功能性的影響。 禽肉原料使用異丙醇加熱去脂及風乾後作為實驗之用。首先，進行蛋白?濃度篩選，將禽肉分別以1％、5％、7.5％及10％（w/w of meat protein）的Alcalase和Flavourzyme進行水解，結果顯示，隨著水解時間和酵素濃度增加，水解率均有增加的趨勢，但7.5和10%的水解率增加幅度較小，基於較高水解率與生產成本之考量，選擇以7.5％的Alcalase（pH 8.5, 60℃）和Flavourzyme（pH 7.0, 50℃）水解生產禽肉蛋白質酵素水解物。並分別自預備實驗之水解曲線中挑選四個時間點（Alcalase：0、8、16及360分鐘，Flavourzyme：0、120、240及360分鐘），利用凱氏氮定量法（Micro-Kjeldahl method）測定水解物之總氮含量，禽肉蛋白質水解物之抗氧化活性以α, α-diphenyl-β-picrylhydrazyl（DPPH）自由基清除能力、金屬離子螯合力、氫氧自由基清除能力、還原力及抑制β胡蘿蔔素氧化脫色等五種測定方法進行分析與比較。 由實驗結果得知，不論使用何種酵素和家禽種類，隨著水解時間的增加，水解物之水解率及總氮含量均有增加的趨勢。雞肉、鴨肉及鵝肉的Alcalase和Flavourzyme水解物與Control組比較，均可提昇其DPPH清除能力（≧80%）、還原力及抑制β胡蘿蔔素氧化脫色能力，但不同水解時間之間並無顯著差異。鴨肉和鵝肉的Alcalase和Flavourzyme水解物其氫氧自由基清除能力，隨著水解時間的增加均有增加的趨勢。在金屬離子螯合力方面，則是受家禽、酵素種類及水解時間影響，展現不同的螯合能力。
In this study, three kinds of poultry (chicken, duck and goose) meat were hydrolyzed respectively by Alcalase 2.4L and Flavourzyme 500L for production of hydrolysates with antioxidative activity, Effects of fowl species enzymes and degree of hydrolysis (DH) of hydrolysates on antioxidative activity were also investigated. The poultry raw materials were heated and defatted with isopropanol, then partically dried at room temperature to obtain a defatted poultry meat as starting material. Five different enzyme concentration including 1％, 5％, 7.5％ and 10％ (w/w of meat protein) were employed to hydrolyze defatted poultry meat to produce the protein hydrolysates, individually. The result indicated that the DH would be increased while the hydrolysis time and concentration increasing, but there was no significant different between 7.5％ and 10％ (p<0.05). According to the higher DH and cost, we choose concentration of 7.5% Alcalase (pH 8.5, 60℃) and Flavourzyme (pH 7.0, 50℃) to produce the defatted poultry meat protein hydrolysates. Four periods in the DH v.s. hydrolysis time curve were selected (Alcalase: 0, 8, 16 and 360 minute, Flavourzyme: 0, 120, 240 and 360 minute). Total nitrogen of hydrolysates were determined by Micro-Kjeldahl method. Antioxidative activities of hydrolysates were evaluated using α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, metal chelating activity, hydroxyl radical scavenging activity, and β-carotene bleaching inhibition method. The results showed that DH and total nitrogen content with the increase of hydrolysis time, in spite of poultry species and enzymes. The hydrolysates of poultry protein with Alcalase and Flavourzyme exhibited a stronger DPPH radical scavenging activity, reducing power and β-carotene bleaching inhibition than control, but no significant difference at different hydrolysis time. The hydroxyl radical scavenging activity of both duck and goose hydrolysates increased with the increase of hydrolysis time. For the metal chelating activity, hydrolysates had different activity by poultry species, enzymes and hydrolysing time. |
