Study On Chloropropandiol Formation In Thermo-reaction Meat Flavours And Development Of New Meat Flavours

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.