| Salt-soluble Meat Protein (SSMP) can dissolve in the salt brine and which refers to a compound protein system composed by the myosin, actin, actomyosin, propomyosin and the globulin. SSMP have the influential role for meat product forming the gelatin. Chitosan (CTS) are the only natural alkalinity polysaccharide which function had been proven that it can extends product shelf life and enhances the moisture-holding capacity in the meat product.This research extracted SSMP from longest muscle on Changbai pig back, and then added water-soluble CTS to produces blending gel by heating. It takes moisture-holding capacity and hardness as evaluating indicator to studies the effects on the pH value, NaCl concentration, CTS concentration, heating temperature and time of blending gel.The results showed that gel quality influence by pH value remarkablely. when pH lower than 6.0, CTS had not enhance gel characteristic; under alkalinity condition, the blending gel had the best quality. Compared with SSMP gel, at pH8.5, the water hold capacity of CTS-SSMP gel was increased 21.21%, hardness was increased 4.23kpa. When the NaCl concentration is 0.75M, moisture-holding capacity reached the highest value on SSMP gel and CTS-SSMP gel. Compared with SSMP gel, at 0.75M NaCl concentration, the water hold capacity of CTS-SSMP gel was incredsed 8.33%, hardness was increased 2.95kpa. Along with the NaCl concentration rising, moisture-holding capacity present decline tendency, but hardness had maintained the increasing tendency on CTS-SSMP gel.CTS had not affected SSMP gel pH, the ionic strength dependent characteristic. CTS recruitment and gel moisture-holding capacity assume the linear relationship: y = 16.141x + 50.868 (R~2 = 0.9683) and CTS recruitment and the gel hardness' linear equation is: y = 2.3906x + 3.6628 (R~2 = 0.9870). Heating temperature and time also have influence to the gel quality. Although high temperature and the long time heating may enhance the hardness of gel, the gel moisture-holding capacity destruction seriously.CTS will lose moisture-holding capacity in the high temperature situation; therefore, CTS should be used in low temperature meat product. Results showed that protein plays the mainly role on CTS-SSMP gel gelling during forming process and CTS had the auxiliaries function by infrared spectrum and the scanning electron microscope. Moreover, CTS combined the protein union by static electricity action and the hydrogen bonds, which become gel binding belt in continual SSMP network, thus enhanced gel characteristic.To understand the changing of essential flavor compounds in low temperature smoking pork by GC/MS, results showed that there are 11 phenol, 8 carbonyl compound, 19 hydrocarbon, 25 ester, 8 ether and 3 free fatty acids, 17 others.In which essential flavor compound including of phenol, 3-meyhyl, 4- meyhyl-2 methoxy phenol, 4-ethyl-2-methoxy phenol, eugenol, isoeugenol, 2,4-decadienal, benzaldehyde, hexanal, 2-cyclohexen-1-one, 3-methyl-6-(1-methylethylidene)-(cas), 2-pentadecanone(cas) , octadecanal , trans-ocimene, limonene, beta-myrcene, gamma-terpinene; 2,7-octadiene-1,6-diol,2,6-dimethyl-,(Z), linalool, 4-terpineol,α-terpineol, linalyl acetate, terpinyl acetate and geranyl acetate, hexadecanoic acid, oleic acid and stearic acid.The change rule of essential flavor compound on low temperature smoking pork during processing is that the quantity and content of phenol, carbonyl compound, and hydrocarbon were increase obviously in processing and alcohol compound increased in the earlier processing period and then reduced; change of ester compound was not obviously; free fatty acids content increases in the processing process. Flavor of meat product influenced by smoking materials.Protein is limited to food contribution, but has important effect on the flavor compounds retention in food. This research studied the effect of SSMP concentration (2.1,4.2, 6.3, 8.4mg/ml), pH (5.0, 7.0, 9.0) , NaCl concentration (0.25,0.5,0.75, 1.0M) on the binding volatile compounds ability using dynamic headspace sampling (DHS) and GC-MS analysis. SSMP has the binding ability to the aldehyde and ketone class, phenol and ester volatile compound, but diversity in different compounds.The protein concentration influence binding ability of flavor compound. In certain concentration scope, as protein concentration increasing the binding ability strengthened, but the concentration further rose, binding ability had drop tendency, the possibly reason is that protein concentration increased which can provide more adsorption spots and as the protein concentration further rose, interaction among protein molecular strengthened, the fluidity was weaken, thus affected combine degree between flavor compound.There are difference between different compounds on binding ability. At SSMP concertation was 8.4mg/ml, the strength of binding carbonyl compounds was hexanal> 2-pentanone> decanal> 2-me-butanal>3-me-butanal, isoeugenol> phenol> eugenol >4-me-guaiacol > Guaiacol; Ethyl hexanoate > Ethyl butyrate >octyl acetate >2-me-hexyl butyrate> ethyl acetate.pH influence SSMP binding ability. when pH value increased, binding ability of SSMP rised to aldehyde and ketones compound and the ester compound, the reason is that high pH caused electric repel affect stronger than electrostatic attraction function and weakened protein intermolecular action and increased solubility which can provide more adsorption spot; however, increasing pH value reduce binding ability to phenol compound which might that phenol hydroxyl was easier to combined with protein under low pH value condition, thus formed phenol - protein networking which enhanced binding ability of SSMP to the volatile compound.NaCl reduce binding ability of SSMP to the aldehyde and ketone class, the ester and phenol volatile compound, its reason possibly was that salt caused protein denatured and changed protein interaction, thus affected binding ability to the flavor compound.The multi-carbohydrate compound had been proven which has the binding ability to the volatile compound. In this experiment we studied CTS binding ability to flavor compound. The result indicated that CTS had obvious binding ability to the majority of aldehyde and ketones class, ester and phenol flavor compounds, however, bindings ability was differ.Binding ability of CTS to the volatile compound increased as CTS concentration rose to certain extent; however, it has decreased when CTS concentration rose further. the reason is that which can provide more adsorption spot while as CTS concentration increased, When CTS concentration rises, the huge CTS molecular volume hindered the volatile compound free migration in medium and enhanced CTS molecule action and reduced adsorption probability between CTS and volatile compound.CTS binding ability is higher under low pH value. The reason is those CTS molecules unfold bigger at this condition which can provide more union position spot for the adsorption. As pH value increased, CTS binding ability to flavor compound drops. The reason is possibly that CTS solubility reduces and fluidity weakened which reduced contact probability between CTS and the volatile compound under the high pH value condition.Besides above reason, it also related to Schiff's bases regarding to aldehydecompounds. Binding ability of CTS-SSMP system was more strengthen than CTS or SSMP which might as a result of CTS own had binding ability to some extent, thus strengthened binding ability to volatile compound. |
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