Preparation Of Sorbic Acid Nanoparticle And Its Application On Keeping Pork Fresh

Nowadays， nanotechnology has been widly applied in food industry. Preparingnanoparticles contain vitamin, antioxidants or presrevatives through encapsulating can deliverthe functional components targetedly, besides, it can improve the solubility and thermostablityof the material. Sorbic acid is a widely used food preservative, non toxic, no side effects, butbecause of its poor solubility in water, its application is restricted. In order to expand itsapplication range, increasing its effiency of useage, and provide new methods for keepingmeat fresh.In this paper, we used chitosan as a carrier, though ionic gelation to prepare sorbicacid nanoparticle. Then did single factor esperiments and orthogonal design experiments tofind the best process, then vetify it. After that, we applied the sorbic acid nanoparticle onkeeping chilled pork fresh and making Chinese sausage, we took the samples at regular time,then measured the physicochemical and microbiological indexes. Upon the above results toresearch the preservative and bacteriostatic effect of sorbic acid nanoparticle. The mainlyobtained results were listed as the following:(1) The best process to prepare the sorbic acid nanoparticle: we mainly did single factorand orthogonal design experiments to optimize the process of synthesize the nanoparticle, theresults demonstrated that the best process for preparing sorbic acid nanoparticle is:CSconcentration:1mg/mL,TPPconcentration:1mg/mL, the contact time between CS andTPP:30min, sorbic acid concentration:0.5mg/mL,the diameter is327.6nm, EE is68.9%. Afterthat, we characterized the particle by transmission electron microscopy(TEM), FTIRspectrogram and DLS. They all confirmed the encapsulation of sorbic acid, the observationshowed sorbic acid nanoparticle had a spherical shape, Furthermore, it had certain releaseprofiles.(2)Sorbic acid nanoparticle applied on chilled pork: Firstly, the sorbic acid nanoparticlecould inhibit the bacterial counts and yeast and mould counts on the surface of the chilledpork. During the whole storage time,the total bacterial counts of chilled pork treated by sorbicacid nanoparticle is significantly lower than the controlled group(p<0.05), at10d and13d, thetotal bacterial counts of chilled pork treated by sorbic acid nanoparticle is4.76and 6.39logcfu/g respectively, which is significantly lower than other groups. At day7, the totalbacterial counts of chilled pork in controlled group is6.46logcfu/g, At day13, the totalbacterial counts of chilled pork treated by sorbic acid nanoparticle is6.39logcfu/g. Socompared with the blank controlled group, the sorbic acid nanoparticle could prolong theshelf life of chilled pork for5days. At the same time, the sorbic acid nanoparticle couldprotect the redness of the meat sample.(3)The antioxidant and bacteriostatic ability of sorbic acid nanoparticle on traditionalChinese style sausage: First, we made the Chinese style sausage upon the traditionalprocessing method, and air dried the sausage in room temperature for20d. Second, wemeasured the index at regular time interval. During the50days storage after the sausage hadbeen air dried for20d, the index of sausage samples treated with different preservatives werebetter than the blank controlled samples.Compared with the sample treatd by blank nanoparticle, the molds and yeast counts ofsausage samples treated with sorbic acid nanoparticle is singnificantly lower(p<0.05) from36d to52d of the whole storge time, it shows that the sobic acid nanoparticle can inhit thebacterial directly and its release profiles also expressed properly. Besides, its TBA value issignificantly lower (p<0.05) than the controlled group during the whole storage time, its acidvalue (3.98mgKOH/glipid) is significantly lower than the controlled group in the11th day ofthe storge time,showing that the sorbic acid nanoparticle could low down the oxidantionspeed of lipid.The above results showed sorbic acid in nanoparticle form can inhibit the growth ofbacterical to a certain degree, All of the above results indicated that: Preparing sorbic acidnanoparticle using ionic gelation, then apply the sorbic acid nanoparticle on keeping meatfresh in order to prolong the shelf life of chilled pork and improving the flavor of Chinesestyle sausage. We achieved our orginal aims and the research methods we used are feasible.