【作者】 徐伟；

【导师】 薛长湖；

【作者基本信息】 中国海洋大学 ， 食品科学， 2008， 博士

【摘要】 本文针对鱿鱼加工废弃物量逐年增加且得不到有效地利用,传统鱼酱油食盐含量较高、发酵周期长等问题,对利用鱿鱼加工废弃物制备低盐鱼酱油的速酿工艺及生化特性进行了研究,具体研究内容如下:1.研究了鱿鱼加工废弃物的自溶水解工艺,建立了自溶水解的数学模型方程。单因素试验的结果表明48h是鱿鱼加工废弃物自溶水解的最佳时间。正交试验的结果表明温度、初始pH、加水比三因素对α-氨基氮含量的影响均显著;通过回归分析建立了能较好地预测鱿鱼加工废弃物自溶水解的数学模型方程,根据模型方程得到了自溶水解的最佳条件:温度45.49℃,加水比0.277:1,初始pH6.42。响应面分析的结果表明温度、加水比和初始pH三因素对响应值的影响存在交互作用。模型的验证试验结果表明鱿鱼加工废弃物自溶水解离心清液中的氨基氮含量达到0.42±0.02g/100ml,和模型的预测值(0.43g/100mL)有较好的拟和性。说明所建的模型方程能较好的预测鱿鱼加工废弃物的自溶水解结果。通过对最佳条件下自溶水解过程中主要生化变化的研究,表明离心清液中α-氨基态氮、可溶性总氮、TVB-N含量及蛋白水解度随着自溶水解的进行而逐渐增加,48h自溶水解的离心清液中α-氨基态氮、可溶性总氮、游离氨基酸总量分别达到0.42±0.02g/100ml、1.29±0.03g/100ml、4.378g/100ml,蛋白质水解度达到26.2±0.64%,TVB-N含量为63.68±2.39mg/100ml,表明鱿鱼加工废弃物内源蛋白酶可以催化自身蛋白水解生成肽、氨基酸,且在48h的自溶水解过程中没有腐败现象发生。2.探索了三种制备工艺所得低盐鱼酱油中的α-氨基态氮含量、总可溶性氮含量、pH、TVB-N含量、蛋白质回收率、细菌总数等的变化,并结合三种鱼酱油中的游离氨基酸含量及其感官评价分析,得到了较好的低盐鱼酱油制备工艺,即鱿鱼加工废弃物先经自溶水解,然后再进行加曲发酵。采用单因素试验和二次回归正交旋转组合设计对发酵的主要影响因素进行了研究,采用回馈消除回归分析法建立了能较好地预测鱿鱼加工废弃物低盐鱼酱油发酵的数学模型方程。单因素试验结果表明30天是最佳发酵时间,回归正交试验结果表明加水比、加盐量、加曲量、发酵温度四个因素对α-氨基氮含量的影响显著;根据模型方程得到的最佳发酵工艺条件为:发酵温度:50.99?C;加曲量:30%;加盐量的9.32%;加水比:0.2:1;初始pH7.28。模型方程的F检验结果表明线性项系数(X1、X2、X3、X4)、交叉项系数(X25)及二次项系数(X11、X33、X44、X55)都显著。ANOVA结果表明,回归模型的F值(26.63834)较高,显著性Prob.>F(<0.0002),同时模型的试验验证结果表明鱿鱼加工废弃物低盐鱼酱油中的氨基氮含量达到1.36±0.04g/100ml,与模型预测值(1.40g/100ml)有较好的一致性,说明该模型可以较好地对发酵结果进行预测。3.研究了最佳发酵条件下鱿鱼加工废弃物低盐鱼酱油的质量指标及微生物变化。质量指标的研究结果表明,低盐鱼酱油中α-氨基态氮、可溶性总氮、TVB-N、无盐固形物、食盐等含量随发酵的进行不断增加,发酵30天后各项指标分别达到1.37±0.04g/100ml、2.24±0.04g/100ml、157.18±4.02mg/100ml、19.35±0.57g/100ml、10.16±0.23g/100ml,均符合或优于鱼酱油的国家标准,并且原料蛋白的利用率较高。生物胺的分析结果表明,酪胺、腐胺、组胺在发酵过程中增加较多,其他四种生物胺变化较小,发酵结束时得到的低盐鱼酱油中酪胺、腐胺、尸胺、组胺、胍丁胺、精胺、亚精胺七种生物胺含量分别为20.753±0.838mg/l, 8.946±0.547mg/l, 0.321±0.072mg/l, 3.366±0.268mg/l, 0.143±0.014mg/l, 0.674±0.016mg/l, 0.689±0.034 mg/l,均远远低于市售传统鱼酱油。微生物的归类分析及鱼酱油产品的感官评价结果表明,发酵过程中的主要微生物是细菌、乳酸菌、酵母和霉菌,主要来自于所添加的酱油曲发酵剂,它们随着发酵的进行而逐渐减少;感官评价结果表明产品在鲜味、咸味、腥味、苦味等方面都有较好的可接受性。4.研究了离子色谱法分析检测鱼酱油中有机酸的方法。结果表明,在试验所得的洗脱条件下,鱼酱油样品中的有机酸得到较好的分离,加标回收率在93.6%-104.33%之间。鱿鱼加工废弃物低盐鱼酱油中各种有机酸含量分别为:L-乳酸:14.480±0.151g/l;乙酸:0.794±0.017g/l;甲酸:0.035±0.001g/l;丙酮酸:0.002±0.001g/l;苹果酸:1.598±0.015g/l;酒石酸:0.280±0.003g/l;α-酮戊二酸:0.594±0.005g/l;草酸:0.367±0.005g/l;柠檬酸:1.071±0.018g/l。有机酸总量为19.274±0.202g/l,比日本、韩国及中国传统鱼酱油的有机酸含量稍高,L-乳酸为其主要有机酸。SPME和GC-MS的挥发性风味成分分析结果表明,低盐鱿鱼废弃物鱼酱油的主要挥发性成分有95种,包括7种酸、5种醇类化合物、26种羰基化合物、4种酯类化合物、18种含氮化合物、14种含硫化合物、5种呋喃类化合物、5种酚类化合物、7种碳氢类化合物及未确定化合物,共同构成了鱼酱油的特殊风味,其中苯基乙醇、2-甲基丁醛、苯甲醛、苯乙醛、安息香酸乙酯、2-二甲氧基-苯酚、2-甲氧基-4-乙烯基苯酚、2-乙基呋喃、二甲基三硫化物、二甲基二硫化物、3-苯基呋喃、2-乙基-6-甲基吡嗪等是鱿鱼加工废弃物低盐鱼酱油的主要挥发性风味化合物。更多还原

【Abstract】 The quantity of squid processing wastes was increased with years and there was not good method of utilizing squid processing wastes effectively at present. The concentration of salt was bigger in traditional fish sauce and the fermentation period was longer. The research was done for solving the above questions. The accelerated fermentation technology was studied for low salt fish sauce from squid processing wastes. The changes of biochemistry characteristics were also investigated during production. The details of the paper were as follows.1. The technology of autohydrolysis was investigated about squid processing wastes. The mathematical model was eastablished for autohydrolysis of squid processing squid. The results of single factor experiment suggested that 48 hours was optimum hydrolysis time. The result of the orthogonal experiment suggested that the effect from three factors (temperature, initial pH and water addition ratio) was prominent on the content ofα-amino nitrogen in supernatant. The process of autohydrolysis could be predicated well and truly by the mathematical model. The optimum conditions on autohydrolysis were as follows, temperature (45.49oC), water addition ratio (0.277:1), initial pH (6.42). The results of analyzing the response surfaces showed that the effect from three factors (temperature, initial pH and water addition ratio) had interaction on response value each other. The result of verification test demonstrated that the content ofα-amino nitrogen in autohydrolysis supernatant attained to 0.42±0.02g/100ml. The predicted value of the equation was 0.43g/100ml. The good coherence lied in between them. The result of autohydrolysis could be predicted well and truly by the mathematical model.The result on the change of biochemistry index proveded thatα-amino nitrogen content, solubility total nitrogen content, free amino acid content, etc. in supernatant and the degree of protein hydrolyze were increased gradually during the course of hydrolyzation. The final value of TVB-N content was 63.68±2.39mg/100g and showed that the obvious rotten phenomenon did not happen in 48 hours hydrolysis.2. The changes of important indexes, which consitist ofα-amino nitrogen content, total solutable nitrogen content, pH, TVB-N content, the recovery rate of protein, the content of free amino acids and the total number of bacteria in fish sauce, were explored in three processes. The sense quality of fish sauces was scored by the sense estimate group. The optimum technology for low salt fish sauce was found by virtue of comparison between them. The best technology was as follows, the hydrolyte was fermented by adding salt and koji after squid processing wastes was hydrolyzed by endogenesis proteases.The main factors of fermentation were investigated by single factor test and the quadratic regression orthogonal rotational combing design. The mathematical model was eastablished for predicting the result of fermentation by regressional analysis methods.The result of single factor experiment showed that 30 days was the optimum fermentation time. The result from quadratic regression orthogonal rotational combing design and response surface analysis demonstrated that the effect on response value from four factors (temperature, quantity of salt, quantity of koji, water addition ratio) was prominent. The optimum conditions on the fermentation were as follows, temperature (50.99oC), quantity of salt (9.32%), quantity of koji (30%), water addition ratio (0.20:1) and initial pH (7.28). The result of F-test suggested that the significance effect factors on response value were linearity coefficient: X1 (temperature), X2(quantity of koji), X3(quantity of salt) and X4 (water addition ratio), cross factors coefficient X25(quantity of koji and initial pH), quadratic factors coefficient X11(temperature), X33(quantity of salt), X44(water addition ratio), X55(initial pH). The result from ANOVA showed that the F-value was higher in regression equation. The result of verification test demonstrated that the content ofα-amino nitrogen in fish sauce attained to 1.36±0.04g/100ml. The predicted value of the equation was 1.40g/100ml. The good coherence was present in them. Theα-amino nitrogen content in fish sauce could be predicted well and truly during fermentation.3. The changes of main indexes of quality and microorganism were studied under optimum fermentation condition of fish sauce from squid processing wastes. The results of quality indexes demonstrated thatα-amino nitrogen content, soluble total nitrogen content, TVB-N content, water-soluble solid without salt, salt content in fish sauce were increased gradually with fermentation and were 1.37±0.04g/100ml, 2.24±0.04g/100ml, 157.18±4.02mg/100ml, 19.35±0.57g/100ml, 10.16±0.23g/100ml separately at the end of 30 days fermentation. These index values were superior to the ones in the nation standard of fish sauce. And the recovery of protein was higher under optimum technological condition. The analysis result of biogenic amine suggested that the content of tyramine, putrescine, histamine increased much and other biogenic amine increased little. The content of tyramine, putrescine, cadaverine, histamine, spermine, spermidine, agmatine were 20.753±0.838mg/L, 8.946±0.547mg/L, 0.321±0.072mg/L, 3.366±0.268mg/L, 0.143±0.014mg/L, 0.674±0.016mg/L, 0.689±0.034mg/L separately and was low relative to the ones of fish sauce on sale. The result of microbial classify analyze indicated that the main microorganism was include in bacterium, lactobacillus yeast and mould and these microorganism come from koji. The number of all microprganism decreased gradually with the development of fermentation. The result of sense score suggested that fish sauce from squid processing wastes had better acceptability in umami, salty, fishy, bitter and so on.4. The method was investigated by ion chromatography for analyzing organic acids in fish sauce and the content of organic acids were detected in different fish sauce. The result of experiment suggested that different organic acids were separated well in fish sauce and the recovery of standard addition ranged from 93.6% to 104.33%. The content of L-lactate, acetate, formate, pyruvate, malate, tartrate,α-ketoglutarate, oxalate, fumarate, citrate in low salt fish sauce from squid processing wastes were 14.480±0.151g/l, 0.794±0.017g/l, 0.035±0.001g/l, 0.002±0.001g/l, 1.598±0.015g/l, 0.280±0.003g/l, 0.594±0.005g/l, 0.367±0.005g/l, 1.071±0.018g/l separately. The total content of organic acid in low salt fish sauce was 19.274±0.202g/l, which was higher than traditional fish sauces in Japan, korea, China. And L-lactate was the main organic acid in low salt fish sauce. The volatile flavor compounds were extracted by SPME and were detected by GC-MS in low salt fish sauce from squid processing wastes. The detection results demonstrated that main volatile compounds were 95 compounds and consist of 7 acid compounds, 5 alcohol compounds, 26 carbonyl compounds, 4 ester compounds, 18 nitrogen compounds, 14 sulphocompounds, 5 furan compounds, 5 phenol compounds, 7 hydrocarbons and undetermined compounds. These compounds are thought to be major contributors to low salt fish sauce odor. The major volatile compounds involved of phenylethyl alcohol, 2-methyl-butanal, benzaldehyde, benzeneacetaldehyde, benzoic acid ethyl ester, 2-methoxy-4-vinylphenol, 2-methoxy-phenol, 2-ethyl-furan, dimethyl trisulfide, dimethyl disulfide, 3-phenyl-furan, 2-ethyl-5-methyl-pyrazine and so on.更多还原