Study On Quality Characteristics Of Traditional Air-Dried Sausage Of Ningxiang Pork Meat And Related Influence By Inoculating Of Starter Cultures

Ningxiang pig,also known as Native Ningxiang pig,is a local pig variety in Ningxiang county,Hunan province.From consumer's perspective,Ningxiang pork meat is still a highly valued meat variety worth for new product development.This paper studied the quality properties of the traditional air-dried sausage made of Ningxiang pork meat and the effects of certain kinds of starter culture application on these properties during air-dried sausage making.The main results and conclusions were as follows:1.Regarding to the physicochemical properties,the traditional air-dried sausage made of Ningxiang pork meat possessed relative superior physicochemical properties,however,there were some differences among products made of different parts of Ningxiang pork meat,for instance,the red value of air-dried sausage made of hind legs is significantly higher than that made of other parts.From nutritional point of view,the amino acid composition of air-dried sausage made of Ningxiang pork meat were in consistent with the ideal model of protein recommended by FAO/WHO.Among them,the essential amino acids/total amino acids(EAA/TAA)ratio of the air-dried sausages processed in streaky pork,foreleg meat,hind legs and tenderloin of Ningxiang pork meat were 38.80%,40.22%,40.12%and 42.29%.The essential amino acids/nonessential amino acids(EAA/NEAA)values were 75.62%,77.19%,77.49%and 85.57%,respectively.In addition,it is also rich in fatty acids.The contents of the monounsaturated fatty acids(MUFA)of these air-dried sausage were as high as 45%,43.27%,43.78%and 44.77%,respectively.And the contents of the polyunsaturated fatty acids(PUFA)were 12.32%,12.38%,14.17%and 12.95%respectively.2.The aroma characteristic of the traditional air-dried sausage made of Ningxiang pork meat were identified and analyzed by HS-SPME-GC/MS.35 volatile compounds from air-dried sausage made of different parts of Ningxiang pork meat were identified,including alcohols,aldehydes,esters,hydrocarbons and other compounds.Some 12,23,27 and 13different kinds of volatile compounds were correspondingly detected from the air-dried sausages made of belly,shoulder meat,hind legs and tenderloin.Of all these different kinds of volatile substances aldehydes and esters were the major contributors to the characteristic flavor of the products.3.Inoculating of compound Starter Cultures made up of Pediococcus pentosaceus&Staphylococcus xylosus(both 10~7 CFU/g).At the end of fermentation phase,the product pH dropped to below 5.3&was significantly lower than the control group.The pH value of product reached pH 5.55 in final product.The effect of the starter culture on the moisture content of the product is minor,but has dramatic impact on color,texture,fatty acids composition and flavor.At the end of drying and aging process,some of related color,texture parameters of inoculated group were significantly higher to that of the control group.Furthermore,the content of saturated fatty acids(SFA)in inoculated group was reduced to4.20%,and the relative contents of unsaturated fatty acids(UFA)such as trans-9-octadecenoic acid,linoleic acid and linolenic acid increased to 71.24%,13.61%and0.99%,respectively.In addition,at the end of the air-drying and aging process,25 and 26different kinds of aroma substances have been detected in inoculated group,which were significantly higher than these of the control group(14,22).