“酶催化氧化鸡脂-热反应”制备鸡肉香味

Studies on the Preparation of Chicken Flavor from Chicken Fat Oxidized by Enzymatical Catalysis and Thermal Reaction

在脂肪氧合酶催化下氧化鸡脂。从脱脂豆粉中浸提脂肪氧合酶的粗酶液。通过测定鸡脂过氧化值,考察时间、底物(鸡脂)浓度、缓冲液pH值和浓度等因素对鸡脂氧化的影响。由试验确定的较佳氧化工艺是:粗酶液100mL,磷酸盐缓冲溶液30mL(pH9.0,0.05mol/L),鸡脂30g(质量浓度230.7g/L),压缩空气流速0.16m3/h,10℃下搅拌反应5h,此时过氧化值高达108.7mmol/kg鸡脂。将此氧化鸡脂添加到由氨基酸和还原糖组成的热反应体系中,得到鸡肉香味浓郁的热反应产物。用同时蒸馏萃取/气-质联机分析热反应产物的挥发性组成,共鉴定出54种化合物,占总质量分数的62.03%。主要成分(相对峰面积>2%)包括3-甲基-2-噻吩甲醛、己醛、2-乙酰基呋喃、2-甲基-3(2H)-二氢呋喃酮、茴香脑、2-甲硫基噻吩、2,5-二甲基四氢呋喃、4-甲基-5-噻唑乙醇、壬醛。

Chicken fat was oxidized by crude lipoxygenase（LOX）,which was extracted from defatted soybean flour.Indicated by peroxidized value（P.V.）,the influences of time,concentration of chicken fat,pH and concentration of buffer on chicken fat oxidization were investigated.The optimal technology was crude LOX 100 mL,phosphate buffer solution（pH=9.0,M=0.05 mol/L） 30 mL,chicken fat 30 g（in concentration of 230.7g/L）,flux of compressed air 0.16 m3/h,temperature 10 ℃ and stirring time 5 h,in which the P.V.was up to 108.7 mmol/Kg.With the oxidized chicken fat subjected to thermal reaction system containing amino acid and reducing sugar,the product of strong chicken flavor was prepared.Fifty-four volatile compounds representing 62.03% were identified from the product by simultaneous distillation and solvent extraction（SDE） combining with gas chromatography and mass spectrometry.The main components（2%） included 3-methyl-2-thiophenecarboxaldehyde,hexanal,1-（2-furanyl）-ethanone,dihydro-2-methyl-3（2H）-furanone,anethole,2-（methylthio）-thiophene,tetrahydro-2,5-dimethyl furan,4-methyl-5-thiazoleethanol and nonanol.