Study On Flavor Change Mechanism Of Anchor Processed Cheese And Preparation Of Tomato And Cod Seed Cheese

Processed cheese is made from natural cheese,which cannot be accepted by some Chinese people because of its flavor.Processed cheese can add various flavor materials to enrich the taste of products.In this paper,anchor cheese as the main raw material,the mechanism of flavor change of reprocessed cheese was researched,mainly focusing on the selection of emulsified salt type and the determination of the amount of compound,as well as the determination of the enzymatic hydrolysis conditions of flavor protease and lipase.Under different enzymatic hydrolysis conditions,the flavor,texture,and rheological characteristics of processed cheese were analyzed,and a better enzymatic hydrolysis process was selected.On this basis,tomato and cod seeds were added to improve the bioactive components and antioxidant levels of reprocessed cheese,then improve the flavor and texture of processed cheese.The main findings and results of this paper are as follows:(1)Sodium pyrophosphate enhances the elasticity of processed cheese,reduces the hardness,disperses the protein more evenly,and has a good emulsification effect.The chewiness,adhesiveness and hardness of processed cheese made with sodium polyphosphate were obviously higher than those made with sodium pyrophosphate and sodium citrate,while the processed cheese made with sodium hexametaphosphate had the worst melting and elasticity.The reprocessed casein with disodium phosphate was not evenly dispersed and the emulsifying effect was poor compared with other emulsifying salts.Therefore,the emulsifying capacity of the five emulsifying salts is sodium pyrophosphate > sodium polyphosphate > sodium citrate > sodium hexametaphosphate > disodium hydrogen phosphate.The results showed that the processed cheese with 1.5% sodium pyrophosphate and 1.5% sodium polyphosphate were heated and stirred in water bath at 50℃ for 4h and then cooled at 4℃,which had better appearance and flavor.(2)The key parameters of flavor proteolysis and lipolytic enzyme were further determined.The flavor protease content was 0.02%,enzymolysis temperature was 55℃,enzymolysis time was 4 h;Lipase content was 0.4%,enzymolysis temperature was50℃,enzymolysis time was 4 h.The hardness of Ep was significantly affected by enzymolysis temperature,enzymolysis time and enzymolysis amount(p < 0.05).The hardness,elasticity,adhesiveness and cohesion of processed cheese(El)with lipase were significantly different at different enzymolysis temperature and time(p < 0.05).Under all processing conditions,the processed cheese showed weak gelation properties.The bitterness and astringency of Ep and El decreased compared with the control.All the flavor substances of reprocessed cheese mainly include acids,ketones,alcohols,esters,aldehydes and hydrocarbons.Among them,acid compounds have the highest content,followed by ketones.In all processed cheeses,glutamate had the highest content and proline the second.Compared with the control,lactic acid and tartaric acid contents of all the processed cheeses with added enzymes were decreased.Tartaric acid,lactic acid and acetic acid in Ep were significantly higher than those in El.Citric acid,tartaric acid,acetic acid and lactic acid were all detected in El.With the increase of enzyme content,the content of citric acid increased and the content of tartaric acid decreased,while the content of acetic acid and lactic acid had no effect.(3)The study found that the reprocessed cheese with tomato and cod seeds had a lower p H,making the whole network more compact.During storage,the brightness of tomato processed cheese increased,while the greenness and yellowness decreased slightly.Electronic tongue analysis showed that the bitterness and astringency were significantly different with the addition of tomato and cod seeds,but the bitterness and astringency were improved with the addition of flavor protease or lipase.GC-MS analysis of flavor compounds showed that there were more acid compounds and new flavor compounds were detected,which helped to maintain the typical flavor of cheese.The tomato and cod seed reprocessed cheeses showed elastic properties,and the reprocessed cheeses showed weak gel properties through rheological properties and microstructure observation.The processed cheese with cod seed and lipase had the highest storage modulus and formed a strong gel structure.