【作者】 黄明泉；

【导师】 孙宝国；

【作者基本信息】 陕西科技大学 ， 应用化学， 2012， 博士

【摘要】 氯丙醇是国际公认的食品污染物，具有肾脏毒性、肝脏毒性及致癌作用，其中以氯丙醇(3-chloropropandiol，3-MCPD)含量及毒性最大。对热反应肉味香精中的氯丙醇进行研究对肉味香精行业的健康发展和人民的身体健康具有重要的意义。本论文主要通过一系列模型热反应，对肉味香精中3-MCPD的形成机理和影响因素进行了研究。对竹荪的挥发性成分进行了分析，并以竹荪为原料对肉味香精的制备进行了研究。主要内容概括如下。(1)参照文献，建立了3-MCPD的检测方法，并对5个不同厂家生产的HVP液和2个厂家的20种肉味香精中的3-MCPD进行了检测分析，结果表明：不同地区HVP液中的3-MCPD含量差距较大，含量最高为0.5887mg/kg，最低的0.0050mg/kg；在20种肉味香精的检测中，十九种都含有3-MCPD，总体上差别也较大，含量最高达0.5087mg/kg。(2)通过三油酸甘油酯、三硬脂酸甘油酯分别与NaCl进行模型热反应，对NaCl用量、甘油三酯用量、反应温度和时间进行了研究，结果表明：温度升高和甘油三酯浓度增大都会促进3-MCPD的生成，而高浓度NaCl则可使3-MCPD含量降低；反应时间对3-MCPD生成的影响较复杂，不同的甘油酯差别较大。(3)通过牛脂与NaCl的热反应模型，考察了原料用量、反应温度和时间对3-MCPD生成的影响，结果表明：温度对3-MCPD的生成产生影响较大，当高于140℃时可以极大地促进3-MCPD的生成；高浓度NaCl也会使3-MCPD含量降低；随牛脂用量增加，3-MCPD含量的增加；随着反应时间延长，3-MCPD含量先下降后上升。(4)以牛脂的模型反应为例，还考察了还原糖和氨基酸的种类、用量对3-MCPD的影响，结果表明：葡萄糖能增加3-MCPD含量，核糖和木糖有轻微降低作用，半乳糖、甘露糖、果糖有显著的降低作用，且随用量的增加降低作用增强；赖氨酸、脯氨酸及苏氨酸对3-MCPD的生成有明显的促进作用，而谷氨酸、半胱氨酸、丙氨酸、色氨酸对3-MCPD的有显著的降低作用，且随氨基酸用量的增加，脯氨酸的促进作用较大，谷氨酸、色氨酸及半胱氨酸用量足够大时检测不到3-MCPD。(5)通过“葡萄糖+NaCl”的模型热反应研究，可知四个因素对3-MCPD含量影响大小的次序为：温度＞氯化钠用量＞时间＞葡萄糖用量；随着氯化钠用量的增加，模型反应产物中3-MCPD的含量是先下降，后上升；随着温度的上升和反应时间的延长，模型反应产物中3-MCPD的含量不断增加；葡萄糖用量基本上没有影响。通过“葡萄糖+NaCl+氨基酸”模型反应研究，发现不同氨基酸由于酸碱性的不同对葡萄糖裂解产生3-MCPD的影响不同，基本上酸性氨基酸可降低3-MCPD的含量，碱性氨基酸增加3-MCPD的含量，中性氨基酸对3-MCPD的形成没有影响。通过“单糖+NaCl”模型热反应研究，发现六种单糖都能裂解后与氯化钠反应生成氯丙醇，其中以核糖和木糖生成量最多，产生3-MCPD量的高低顺序依次为核糖>木糖>>半乳糖>甘露糖>葡萄糖>果糖。结合上述三种模型，对糖裂解生成3-MCPD的机理进行了推导。(6)通过对肉味香精原料各个原料中3-MCPD的检测分析，以及对“油脂+氯化钠”和“单糖+氯化钠”两种模型中3-MCPD的研究，可知肉味香精中3-MCPD的来源主要有三个方面：一是由原料引入，如辛香料、酵母抽提物等；二是由油脂的水解产物与氯化钠反应生成；三是由单糖的降解产物与氯化钠反应生成。(7)通过对热反应牛肉香精中各种原料和反应条件的研究，可知牛骨素、甘氨酸、丙氨酸、酵母抽提物(酵母浸膏)、半胱氨酸、辛香料和葡萄糖等对牛肉香精中3-MCPD含量的影响较小或基本不影响；牛肉酶解物、HVP液、谷氨酸和木糖对香精中3-MCPD含量的影响比较复杂，为降低3-MCPD的含量，在香精配方中较佳的用量依次为牛肉酶解物30%~55%、HVP液10%~15%、谷氨酸0.20%、木糖0.50%；VB1、NaCl和牛油会促进3-MCPD的生成，尽可能少用；反应温度对香精中3-MCPD的影响很大，时间次之，pH值较小，合适的反应温度是110℃以下，时间小于2h，pH值以香精的风味来选择。(8)采用同时蒸馏萃取，结合气质联机对短裙竹荪、长裙竹荪、红托竹荪、棘托竹荪以及棘托竹荪蛋的挥发性成分进行了研究。结果表明，从短裙竹荪中共计鉴定出139种挥发性成分，其中含量较大的成分有十四碳内酯、Albaflavenone，等；从长裙竹荪中共鉴定出116种挥发性成分，其中含量较大的成分有Albaflavenone、雪松烯、亚油酸，等；从棘托竹荪中共鉴定出67种挥发性成分，其中含量较大的成分有十四碳内酯、苯乙醛等；从红托竹荪和棘托竹荪蛋中分别共鉴定出108和97种挥发性成分，其中主要成分都是长链脂肪酸。(9)采用AEDA法，用嗅闻仪GC-O，对红托竹荪和棘托竹荪蛋的特征香味成分进行了分析。红托竹荪中共有22种活性香味成分被鉴定出来，芳香稀释因子在1-27之间，其中有7种特征香成分，其FD值在3-27之间，分别是2,3-戊二酮(FD27),乙酸(FD27),2-甲基丁酸(FD27),(E)-2-辛烯醛(FD9),2-苯基-2-丁烯醛(FD9),苯甲醛(FD3),3,5-乙基-2-甲基吡嗪(FD3)。从棘托竹荪蛋的挥发性成分中鉴定出12种稀释系数(FD)在1-27之间的活性香成分，其中有6种FD值为27的特征香成分，分别是3-甲基丁醛、己醛、1-辛烯-3-酮、糠醛、5-甲基糠醛、2,4-癸二烯醛。(10)通过柱层析，从长裙竹荪中分离具有抗菌活性的酮类化合物Albaflavenone，从棘托竹荪中分离出具有麝香味的十四碳内酯，并通过MS、NMR等手段进行了结构鉴定。通过定量分析可知，长裙竹荪中Albaflavenone含量为0.0063%，棘托竹荪中十四碳内酯的质量百分含量为0.091%。(11)通过在热反应香精配方中添加竹荪和硫化铵，通过单因素实验对新型牛肉香精进行了开发，得到两种肉香味浓郁、特征香明显和口感好的两种牛肉香精。更多还原

【Abstract】 The chloropropanols are internationally recognized food contaminants andhave kidney toxicity, liver toxicity, and can cause cancer, but among them thetoxicity of3-MCPD is the largest. Studies on chloropropanols in meat flavorproduced by the thermal reaction is of great significance to the healthydevelopment of meat flavor industry and the health of the people.In this paper, the mechanism of formation and influencing factors of3-MCPD in meat flavor were studied by a series of model reactions. At the sametime, volatile compounds of Dictyophora indusiata were analyzed by gaschromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O), and two new meat flavors were developed when takingDictyophora indusiata as the raw material. The main contents of the paper wereas followings.The method for the determination of3-MCPD is established based onliteratures. By the established method,3-MCPD was tested in HVP from fivedifferent factories and20meat flavors from two factories, the results showed thatthe gaps of3-MCPD among different HVP were large, and the highest contentwas0.5887mg/kg, the lowest0.0050mg/kg. In20meat flavors, nineteen meatflavors contained3-MCPD, and in whole, the difference is also large, the highestcontent was0.5087mg/kg. Besides3-MCPD pollution in paste flavor is moreserious than in the form of powder.The formation of3-MCPD was studied in thermo-reaction models consistedof sodium chloride with triolein, or tristearin. The influences of various factorswere researched on the formation of3-MCPD, such as material amounts,reaction temperature and reaction time. The outcomes indicated that theincreases of temperature and the glyceride concentration would promote thegeneration of3-MCPD, but the high concentration of NaCl decreased the contents of3-MCPD. The influences of the reaction time were relativelycomplicated, having some differences between the two glycerides.The formation of3-MCPD in thermal-reaction models consisted of sodiumchloride and tallow was also investigated. The effects of four factors wereresearched on the formation of3-MCPD, such as material amounts, reactiontemperature and reaction time. The results displayed that the influence oftemperature on the3-MCPD was bigger than others, and could greatly promotethe formation of3-MCPD, especially when more than140℃. High concentrationof NaCl decreased the content of3-MCPD. The amounts of3-MCPD were raisedwith the enhancement of tallow amount. As reaction time was enhanced, the3-MCPD concentration was increased after being decreased.Taking thermal-reaction models of tallow as an example, the influences ofreducing sugars and amino acids to3-MCPD were studied. The results showedthat galactose, mannose, fructose had the significant declining effect for theconcentration of3-MCPD, and the same was also for reducing sugars, but thechanges were lesser relatively. Lysine, proline and threonine had significantpromoting function to the generation of3-MCPD, and the promoting action ofproline was the biggest.3-MCPD could not be detected when the amounts ofglutamic acid, tryptophan, and cysteine were large enough.Through the study of thermal reaction model of glucose with NaCl, theresults revealed that the influences of four factors on3-MCPD content in theproducts of model reaction followed the order, temperature, NaCl amount, time,glucose amount. With the amounts of NaCl increasing, the3-MCPD content wasdecreased and then increased. With the temperature and reaction time increased,the3-MCPD content was gradually increased. The contents of glucose had littleinfluence on3-MCPD amounts. In the reaction model of glucose with NaCl andamino acid, the results showed the effects of different amino acids on3-MCPDformation was different. Basically, The formation of3-MCPD could bedeclineed by the acidic amino acid, and promoted by the basic amino acid, butcould not be affected by the neutral amino acid. In the reaction model ofmonosaccharide with NaCl, the pyrolysis of six monosaccharides could allgenerate3-MCPD with NaCl, which the highest amounts was generated by themodel of the ribose and xylose with NaCl. The3-MCPD amounts generated from monosaccharides followed the order, ribose> xylose>> galactose>mannose> glucose> fructose. From the above reaction models, the formationmechanism of3-MCPD from glucose with sodium chloride was deduced.By analyzing contents of3-MCPD from raw materials of meat flavours, themodels of fat and sodium chloride, and the models of sugars with sodiumchloride, the results showed that there were three sources for3-MCPD in meatflavours, which were materials, the formations by the reaction of grease withNaCl, and sugars with NaCl.With the research of raw materials and reaction conditions in the beefflavoring of thermal reaction, the results showed that the raw materials, such asprime bovine bone, glycine, alanine, yeast extract, cysteine, glucose and spices,had small or no effects on the3-MCPD formation. Effects of beef hydrolysates,HVP, glutamic acid and xylose on3-MCPD formation were more complex. Inorder to decrease the3-MCPD content, the better usage of raw materials in theflavoring formula was followed by beef hydrolysates (30%-55%), HVP (10%-15%), glutamic acid (0.20%), xylose (0.50%). VB1, NaCl and tallow couldpromote the formation of3-MCPD, and used as small as possible. The reactiontemperature had a great function on3-MCPD formation in the meat flavor, thereaction time came second, and pH values had a little, so the appropriateconditions were that the reaction temperature was below110oC, the reactiontime less than2h, and the pH values were chosen by according to the flavor ofmeat flvourings.The volatile components from Dictyophora duplicate,Dictyophora indusiata Fisch, Dictyophora rubrovolota, Dictyophoraechinovolvata, embryo of Dictyophora echinovolvata, were extracted bysimultaneous distillation and extraction (SDE) and analyzed by gaschromatography-mass spectrometry (GC-MS). Total139compounds wereidendified from Dictyophora duplicate, and the major compounds wereoxacyclopentadecan-2-one, albaflavenone, and so on.116compounds wereidentified from Dictyophora indusiata Fisch, and the prominent compoundswere albaflavenone, cedrene,(Z, Z)-linoleic acid, etc. Total69volatilecompounds were identified from Dictyophora echinovolvata, where the maincomponents were oxacyclopentadecan-2-one, benzeneacetaldehyde, etc.108 volatile components from Dictyophora rubrovolota and97volatiles fromembryo of Dictyophora echinovolvata were identified, where long-chain fattyacids were the major compounds.The aroma-active volatiles were identified by aroma extract dilutionanalysis (AEDA) method with gas chromatography-olfactometry (GC-O). ByGC-O analysis,22aroma-active compounds were identified from the volatiles ofDictyophora rubrovolota, among which seven key flavor volatiles with highflavour dilution factor (FD) ranging from27to3included2,3-pentanedione (FD27), acetic acid (FD27),2-methylbutanoic acid (FD27),(E)-2-octenal (FD9),2-phenyl-2-butenal (FD9), benzaldehyde (FD3),3,5-diethyl-2-methyl-pyrazine(FD3). From embryo of Dictyophora echinovolvata,12odor-active compoundswere identified, showing a flavor dilution (FD) factor in the range of1-27,among which six key aromatic volatiles with the highest FD factor27included3-methyl butanal, hexanal,1-octen-3-one, furfural,5-methylfurfural,2,4-decadienal.(9) By solvent extraction and column Chromatography, the sesquiterpeneantibiotic albaflavenone was isolated from dried fruiting body ofDictyophora indusiata (Vent:Pers.) Fischer, and the macrocyclic lactoneoxacyclopentadecan-2-one isolated from Dictyophora Echinovolvata, which hasa soft musk-like odor. Their chemical structures were identified by FTIR, GC-MS, HR-FIMS and NMR spectra. Quantified by GC through an externalstandard method, the content of albaflavenone in dried fruiting body ofDictyophora indusiata Fischer (the content of water was15.63%) was about0.0063%, and the content of oxacyclopentadecan-2-one in dried fruiting body ofDictyophora Echinovolvata (the content of water was14%) was about0.091%.(10) By single factor experiments, new type beef flavoring was developedwith Dictyophora indusiata and (NH4)2S as raw materials in the flavoringformula of thermal reaction, and two beef flavoring of Dictyophora indusiatawere produced. They smelt strong meat flavor, obvious characteristics of beef,and had good taste.更多还原