Effect Of Lactic Acid Bacteria And Yeast Cofermentation On Mutton Sausage Odour Removal And Quality

Mutton is rich in nutrition and is a kind of meat food that can be used both as medicine and food.As a big mutton production country,in recent years,the output of mutton has been increasing continuously,which has a good prospect,but the consumption is not as good as other poultry and poultry,and the sales form is mainly raw meat.However,the consumption is not as large as other livestock and poultry meat,and the sales form mostly stays in the fresh meat stage.There are few enterprises processing mutton on a large scale in China,the degree of standardization is low,the type of mutton processing is single,and the mutton sausage on the market is rare.China’s research on mutton sausage processing is still in the exploratory stage,and it is difficult to achieve large-scale production.In addition to the high price of mutton,this is also closely related to the uncomfortable special smell of mutton itself,which is usually called"mutton smell".The mutton smell will reduce the acceptability of consumers.Therefore,this subject aims to utilize mutton as the research object,and to explore the effect of the synergy of lactic acid bacteria and yeast on the removal of mutton sausage odor and on the quality of final product according to the basic formula of sausage.The main results of this study are as follows:（1）Establishment of the evaluation model of mutton and sausage odor indexThis study utilized sensory evaluation,electronic nose,and free fatty acids to construct an evaluation model for mutton mutton odor intensity index.By mathematically fitting the sensory score,the mutton intensity y value can be obtained as-0.77007+0.77207e^^{（x/9.16271）},with R2=0.99989.Using principal component analysis to analyze the measurement results of electronic nose and free fatty acids,it was found that the calculated value of the mutton flavor intensity evaluation model constructed from free fatty acids was significantly correlated with the sensory evaluation results（P<0.01）,with a correlation coefficient of 0.992.F value of mutton flavor intensity=0.63625F₁+0.28808F₂,where F₁=0.993X₁+0.428X₂+0.983X₃+0.246X₄+0.916X₅+0.901X₆+0.960X₇+0.567X₈,F₂=0.071X₁+0.852X₂-0.133X₃+0.966X₄-0.289X₅-0.394X₆-0.251X₇+0.565X₈。（2）Screening,Identification,and Compounding Study of Strains for Removing Odor in Mutton SausageFive lactic acid bacteria with lipase producing ability and meeting the requirements for fermented meat products were screened from mutton sausages,namely Pediococcus pentose L1,L7,L17,L21,and L211.Five yeast strains with good alcohol production ability and meeting the requirements for fermented meat products,namely Candida parapsilosis Y17,Y21,Y22,Y23,and Y34,all of which do not produce indole harmful substances and do not produce indole harmful substancesα-Hemolysis andβ-Hemolysis is not a hemolytic strain.Among them,combined with the enzyme production ability of lactic acid bacteria,the alcohol production ability of yeast,and their respective growth characteristics,antagonistic and compound experiments were conducted on Pediococcus pentose L7 and Candida parapsilosis Y22.There was no antagonism between the two strains,and the best compound ratio was L7:Y22=2:1.（3）The influence of lactic acid bacteria and yeast inoculation on the odor and quality of mutton sausageBased on the sensory evaluation results of mutton flavor and the F value of mutton flavor intensity,it was found that the combination of inoculation with Pediococcus pentose L7 and Candida parapsilosis Y22 significantly reduced the mutton flavor in mutton sausages（P<0.05）.By reducing the p H value of mutton sausages,finally,it reached 5.33±0.22,the number of microorganisms in the sausages was controlled,the accumulation of histamine and tyramine was reduced,and fat oxidation was also inhibited.The acid value of mutton sausages in the mixed inoculation group was 1.26±0.20 mg/kg,which was significantly lower than that of the blank control group’s 3.17±0.12 mg/kg（P<0.05）,and the peroxide value was only 0.0069±0.0006 g/100g,which was significantly lower than that of Group A’s 0.0095±0.0005 g/100g（P<0.05）,the TBARS value of 0.17±0.01 mg/kg was significantly lower than the 0.22±0.01mg/kg of the blank control group（P<0.05）.In addition,compound inoculation can also improve the sensory quality,texture characteristics,color value,increase the types of volatile substances,and enhance the flavor of mutton sausages.The sensory score of this group of mutton sausages is 88.50±5.28 points,significantly higher than the 69.50±7.83 points of the blank control group（P<0.05）.（4）Storage of fermented mutton sausage inoculated with lactic acid bacteria and yeastAfter inoculating the fermented mutton sausage with the optimal combination ratio of lactic acid bacteria and yeast,it was dried and vacuum packaged at 37℃,room temperature（20℃）,4℃,and-20℃for 28 days.The results showed that on the 28th day,storage at 4℃and-20℃could maintain the sensory quality of the mutton sausage,and the storage effect at-20℃was the best.The sensory score of the mutton sausage stored at 4℃for 28 days was 77.67±2.08 points,and the sensory score of the mutton sausage stored at-20℃was 83.34±1.53 points.Moreover,storing at-20℃for 28 days can maintain the acidity of mutton sausages,with a TBARS value of 0.22±0.01 mg/kg and a TVB-N value of only 13.32±0.86 mg/100g,indicating that the mutton sausages with mixed inoculation and fermentation have good storage performance at-20℃.The results of this study indicate that the use of Pediococcus pentose L7 and Candida parapsilosis Y22 screened from mutton sausages,combined with inoculation of fermented mutton sausages,can reduce the mutton smell of mutton sausages,improve their quality,and provide theoretical support for obtaining mutton sausages with light mutton smell and good edible quality.