天然保鲜剂对蟠龙菜贮藏特性的影响OA北大核心CSTPCD

To improve the storage quality and to study the changes in storage characteristics of Panlongcai,the bacteriostatic effects of rosemary extract,tea polyphenols,carvacrol,ε-poly-L-lysine(ε-PL)and nisin on spoilage bacteria isolated from Panlongcai were tested by the Oxford cup method.Panlongcai added with the preservatives with good bacteriostatic activity were stored at 4℃and evaluated for microbiological,organoleptic,physicochemical and flavor qualities after 0,5,10,15,20 and 25 days.The results showed that ε-PL,nisin and carvacrol had good inhibitory effects on the dominant spoilage bacteria in Panlongcai.During the storage process,the pH decrease was smaller in the carvacrol and ε-PL addition groups,0.11 and 0.06,respectively.Carvacrol and nisin effectively inhibited lipid oxidation as assessed by thiobarbituric acid reactive substances(TBARS)value and total volatile basic nitrogen(TVB-N)generation.The total bacterial count(TBC),pH,TBARS and TVB-N data were analyzed by the combined use of partial least squares regression(PLSR),entropy weighting method and weighted grey correlation,and it was found that the highest weighted grey correlation occurred upon the addition of nisin(0.405 9)and carvacrol(0.387 6)after 25 days of storage,which indicates that the addition of nisin and carvacrol could effectively improve the microbiological and physicochemical qualities of Panlongcai during the storage process.Both nisin and carvacrol groups exhibited a less porous and denser microstructure.Electronic nose analysis showed a greater difference in the flavor of Panlongcai with the addition of carvacrol compared to the control group.Sensory evaluation showed that the addition of carvacrol significantly reduced the flavor and acceptability of Panlongcai(P＜0.05).In conclusion,the addition of nisin could effectively inhibit the growth and reproduction of microorganisms and reduce the changes of physicochemical indexes during cold storage without altering the flavor of Panlongcai,and improve its storage quality.