Effects Of Rosemary And Star Anise Extract On The Quality Of Pork Patties

In recent years,low temperature and prepared meat products has developed rapidly.Especially for prepared meat products,it has the advantage of convenience,easy and high nutrition which meets the requirement of high rythym of China society.However,the quality of prepared meat products could be influenced easily by lipid and protein oxidation and microbial contamination during storage.Currently,the most common method to solve the above problems is to add synthetic antioxidants and preservatives,such as dibutylhydroxytoluene(butylated hydroxytoluene,BHT),butylated hydroxy aniisole(butylated hydroxy anisole,BHA),potassium sorbate and others.Synthetic antioxidants have strong antibacterial and antioxidaive abilities.However,using synthetic antioxidants and preservatives are no longer the best option to improve food storage stability because consumers become increasingly concerned about their safety issues.Therefore,exploring natural antioxidants and preservatives becomes a hot research topic.This thesis explores the effects of rosemary and star anise extract on the quality of pork patties.The main contents are as follows:1.Component analysis of rosemary and star anise extractRosemary and star anise were extracted by 70%ethanol.The total phenol content was determined by Folin-Ciocalteu method.The volatile components of these two extract were analyzed by Gas Chromatography-Mass Spectrometer(GC-MS)method.High performance liquid chromatography(HPLC)method was used to determine the main functional components in rosemary extract.The result showed that the total phenol content of 70%ethanol extract for rosemary and star anise were 643,41 mg/g and 105,64 mg/g,respectively.Thirty-six compounds were detected in rosemary extract by the GC-MS method.The major compunds were 4,6,6-trimethyl-bicyclo[3.1.1]hept-3-en-2-one(27.302%),anethole(8.499%)and 2-borneol(7.131%).Thirteen compounds were detected in star anise extract by the GC-MS method and the major compunds were anethole(34.896%),lignocerane(3.016%)and anisic aldehyde(2.335%).The contents of rosmarinic acid,carnosol and carnosic acid were 5.5%、3.3%and 5.3%,respectively.2.Effects of rosemary extract on the quality of raw pork patties during refrigerated storageThe effect of different amounts of rosemary extract(0%,0.01%,0.02%and 0.03%)on the quality of raw ground pork patties during 10 d of chilled storage was assessed.The results showed that lipid oxidation was reduced significantly by rosemary extract.The patties with 0.03%rosemary extract showed lower levels of lipid oxidation at 10 d compared with samples with 0.02%butylated hydroxytoluene(BHT).In the first 7 d of storage,the cooking yield and antibacterial ability of patties with rosemary extract were improved.In addition,rosemary extract could stabilize and improve the patty color.Based on the color and the special taste of reosemary extract,the supplementation level should not be higher than 0.02%.3.Effects of star anise extract on the quality of raw pork patties during refrigerated storageThe effect of different amounts of star anise extract(0%,0.03%,0.06%and 0.09%)on the quality of raw ground pork patties during 10 d of chilled storage was assessed.The results showed that star anise extract could not only inhibite lipid and protein oxidation,but also had effective antibacterial ability.Addition of 0.09%star anise extract showed similar activity of antibacterial activity with 0.02%BHT.In addition,star anise extract could stabilize the color and improve textural characteristics and sensory attributes of cooked pork patties under vacuum package.4.Effects of rosemary extract on the quality of vacuum-packaged cooked pork patties during refrigerated storageThe effect of different amounts of rosemary extract(0%,0.01%,0.02%and 0.03%)on the quality of vacuum-packaged cooked pork patties during 10 d of chilled storage were assessed.The results showed that rosemary extract could reduce the extent of lipid oxidation of vacuum-packaged cooked pork patties.The antioxidant effect of the 0.03%rosemary extract was similar to 0.02%butylated hydroxytoluene(BHT)at 1d.In addition,rosemary extract had great antibacterial activities and could improve the color and textural characteristics of cooked pork patties under vacuum package.