| Braised pork sauce is one of the classic traditional Chinese dishes.It is made by combining the main and auxiliary ingredients and adding seasoning,combining the aroma of scallion and meat.The phenomenon of water dissolving and poor sensory quality often occur in the processing of braised pork sauce,which affects its nutritional and edible value.It was found that adding starch,hydrophilic colloid and other substances in the processing of meat products can improve the water holding capacity,gel quality and sensory quality of meat products.In view of the problems existing in the quality and flavor substances of braised pork sauce products at present,this topic takes braised pork sauce with hydrophilic colloid(carrageenan,xanthan gum,curdlan)as the research object,and studies the changes of hardness,viscoelasticity,water migration and other quality characteristics by means of texture detection and low-field nuclear magnetic resonance detection.The nutritional quality and flavor were analyzed by free amino acid determination and gas chromatography-ion migration spectrometry(GC-IMS).The optimal concentration of hydrophilic colloid was optimized and determined,and the effects of different storage time and thawing methods on the quality and flavor of braised pork sauce products were further studied,in order to provide a scientific basis for the quality optimization of braised pork sauce products.The main research contents and results of this paper are as follows:(1)Study on the effect of carrageenan on the quality and flavor of braised pork sauceThe effects of different concentrations of carrageenan(0.1%,0.2%,0.3%,0.4%,0.5%)on the quality and flavor of braised pork sauce were studied.In this paper,the quality and flavor of traditional braised pork sauce were studied by means of mass texture analyzer,low field nuclear magnetic resonance,determination of free amino acids and gas chromatography-ion migration spectrometry(GC-IMS).The results showed that adding carrageenan could improve the texture quality(hardness,elasticity,chewability,etc.),strengthen the binding of bound water,and improve the water holding capacity of the product.The sample quality of 0.2%carrageenan group was better.The results of flavor substance study showed that the quantity of flavored amino acids in braised pork sauce added 0.1%and 0.2%carrageenan groups was the largest.The richness and content of volatile flavor compounds increased with the increase of carrageenan concentration,and the contents of aldehydes,alcohols and esters were significantly increased after adding carrageenan(P<0.05).In conclusion,the addition of 0.2%carrageenan can improve the texture characteristics,enhance the product retention and enrich the product flavor.(2)Study on the effect of xanthan gum on the quality and flavor of braised pork sauceThe effects of xanthan gum on the quality and flavor of braised pork sauce were compared.The quality and flavor of braised pork sauce with 0%,0.2%,0.4%,0.6%,0.8%and 1.0%xanthan gum were compared and analyzed by means of texture analyzer,low field nuclear magnetic resonance,determination of free amino acid and gas chromatography-ion migration spectrometry(GC-IMS).The results showed that adding xanthan gum could effectively improve the hardness and chewability of braised pork sauce and make the meat more elastic.Water that is not easy to flow is the most important water state in the gravy system.Adding xanthan gum can better bind the bound water in the system and reduce the fluidity of fat.A total of 21 amino acids were found in the samples with xanthan gum added,and their contents showed a significant increase trend(P<0.05),which could enhance the umami and sweet taste,and cover up some bitter taste.The difference and fingerprint of GC-IMS showed that the amount of volatile flavor substances increased with the increase of xanthan gum concentration,and the main flavor components changed from aldehydes and ketones to aldehydes and alcohols after xanthan gum was added.Therefore,the addition of xanthan gum has great significance to improve the texture quality and water retention of marinated meat sauce,and can improve the flavor of the product.(3)Study on the effect of curdlan on the quality and flavor of braised pork sauceThe effects of different concentrations of curdlan(0%,0.6%,0.7%,0.8%,0.9%,1.0%)on the quality and flavor of braised pork sauce were studied and analyzed.In this paper,the quality and flavor of braised pork sauce with curdlan were compared and analyzed by means of texture analyzer,low field nuclear magnetic resonance,determination of free amino acids and gas chromatography-ion migration spectrometry(GCIMS).The results showed that adding curdlan could significantly improve the adhesion,cohesibility and adhesibility of braised pork sauce(P<0.05),and the texture properties of braised pork sauce adding 0.7%curdlan were better.The binding ability of the system to the bound water increases with the increase of the concentration of curdlan.The amino acid content of braised pork sauce with 0.7%curdlan was the highest,which was sweet amino acid>umami amino acid>bitter amino acid.The richness and content of volatile flavor substances increased with the increase of the concentration of curdlan.The main flavor components of the braised pork sauce after adding curdlan were aldehydes and alcohols.In conclusion,the texture and water retention of braised pork sauce can be improved by adding 0.7%curdlan,and the product flavor can be enriched.(4)Study on the effect of different storage time on the quality and flavor of braised pork sauceConsidering the research results of the first three chapters,the braised pork sauce with 0.7%curdlan added has the best texture and flavor quality.Therefore,the following research takes braised pork sauce with 0.7%curdlan added as the test object.The samples stored for 0,7,30,90 and 180 days were compared and analyzed by means of texture analyzer,low field nuclear magnetic resonance,determination of free amino acids and gas chromatography-ion migration spectrometry(GC-IMS).The results showed that the texture quality of braised pork sauce was better after 30 days of storage.With the extension of storage time,the fluidity of bound water and free water increases,but the migration of difficult flowing water is not obvious.The total amount of free amino acids and the contents of flavored amino acids increased first and then decreased with the extension of storage time.The total amount of free amino acids reached the maximum at 30 days of storage time,and the contents were significantly decreased after 30 days of storage time(P<0.05).When the storage time is 30 days,the total amount of volatile substances is the highest.Therefore,the quality of braised pork sauce is maintained well within 30 days of storage,but it declines after 30 days.(5)Study on the effect of different thawing methods on the quality and flavor of braised pork sauceBased on the research in the previous chapter,the samples of three thawing methods(water bath thawing,microwave thawing and ultrasonic thawing)were compared and analyzed by means of texture analyzer,low field nuclear magnetic resonance,free amino acid determination and gas chromatogram-ion migration spectrometry(GC-IMS).The change of its quality and flavor substance was studied.The results showed that ultrasonic thawing could significantly improve the hardness,adhesion and adhesiveness of the brine paste(P<0.05),reduce the fluidity of the bound water in the system,and improve the water holding capacity of the product.Compared with water bath thawing,microwave thawing and ultrasonic thawing could significantly increase the total amount of free amino acids and all kinds of flavorful amino acids(P<0.05),and the content of free amino acids was the highest under microwave thawing.The quantity of volatile flavor compounds in the braised pork sauce was significantly increased after thawing by ultrasonic(P<0.05),while the ketones,alcohols and esters in the braised pork sauce were significantly decreased after thawing by microwave(P<0.05).In conclusion,compared with water bath thawing and microwave thawing,ultrasonic thawing can improve the quality of braised pork sauce.Based on the above research results,three different hydrophilic colloid can improve the quality and flavor of braised pork sauce.Among them,the quality and flavor of braised pork sauce with 0.7%curdlan were the best.Through the study of different storage time and thawing methods on the quality and flavor of braised pork sauce products,the best storage time of braised pork sauce products is within 30 days,ultrasonic thawing can improve the quality of braised pork sauce products. |
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