Effect Of Preservation Agent And Pasteurized Technology On Shelf-life Of Smoked Ham

How to keep meat fresh? How could meat product be put up longer? These questions have been put on many meat scientists' desk for many years. And they also have been one of the most urgent problems in meat industry. In this thesis, physicochemical and storage properties of smoked ham, which was pasteurized, and effect of preservation agents and temperature of sterilization on shelf life of these ham were studied. Three main parts were included here: first, physicochemical storage properties of smoked ham; Second, effect of preservation agents on shelf life of smoked ham. Six preservatives were applied in smoked ham. And three of them were found out to inhibit microbiology effectively. Accordingly, concentrations of these preservatives were decided; Third, effect of sterilizing temperature on smoked ham was studied.Result of these experiments showed that:1 Storage properties of smoked ham without any preservative was studied. These hams have a low pH (average 5.94) and high water activity (average 0.943). Total colonies of microbiology were 2.5 103at storage time 21 days(0 ~4C storage temperature);and 1.9 104 at 21 days for those stored at 25 C. Shelf life was far shorter at room temperature than at low temperature. pH changed little throughout the storage.2 Orthogonal test was designed for optimal inhibition microbiology agent: acetic acid 2% , sodium lactate 3 % , Vc 1 %, sodium thiosulfate 4%, potassium sorbate 1 % repectively . And three preservatives were selected in three factors quadratic current rotation revolving design. Mathematic model (Regression Equation) of the antisepsis effect was constructed which could show the real prediction. The best combination was Nisin 0.038%; EDTA 2.005%; sodium lactate 2.843% repectively.Result of valedictory experiment showed that total colonies was not more than 104CFU.g-1 at 21 days storage time(0 ~ 4C), which made the shelf life 10 days longer.3 Effect of sterilizing temperature on shelf life of smoked ham was studied. Result (with storage temperature 0~4C or 36C)showed that more microbiology were killed when ham were sterilized at water of 70 ~ 85 C than those sterilized by microwave. And when water temperature was 80 - 85 C,followed by fast chilling could elongate the shelf life.Pasteurized meat product is more excellent than other meat product for high quality, more nutrition and feasible with the development of low temperature chain.