| Pickle Chicken feet is one of the main varieties of the traditional poultry product which has a vast number of consumers because of its high protein, low fat, low calorie, delicate taste, sour and hot appetizer features. But the market of chicken feet product develops slowly. The key factor which restrict the market development is the microbial contamination, which leads to the instability of product quality, short shelf life, and unsafely for product industrialization development. The microbial contamination mostly happens in the processing, storage, transportation and sales, because the cold chain system is not perfect. This study used vacuum-packed pickle chicken feet as test materials. Sensory quality, pH, TVB-N, TBARS and total bacterial count of chicken feet stored at different storage temperature were detectived. We analyzed the correlation of sensory quality, microbial indictors and physicochemical index. Combining with the regression equation to predict the shelf life of vacuum-packed chicken feet with pickled peppers at different storage temperatures was researched, which will help the product market development of the company. The contents and results are shown as follows:1. Study on quality characteristics of vacuum-packed pickle chicken feet during different temperatures storage.Sensory evaluation, pH, TVB-N, TBARS and total number of bacterial colony count with the storage time were evaluated and undertook correlation analysis. The results revealed that the storage temperature and time had a significant effect (p<0.05) on the quality and shelf life of vacuum-packed pickle chicken feet. With the storage temperature and storage time extension, the product sense appeared as soft tissue of sticky, darken in color dull, with a large amount of sap and undesirable odor; the trend of pH values was decreased with storage time rising, then increased. The higher storage temperature, the more significant changes of pH values; TVB-N and the total number of colonies had continued to rise trend; TBARS value rose in early period of storage, and showed a downward trend at the late period of storage. In addition, storage temperature had an obvious correlation with quality property indexes (p<0.01); the total number of bacterial colony also had an obvious correlation with sensory quality, pH, TVB-N and TBARS (p<0.01). This showed that storage temperature and microorganism were the main factors leading the deterioration of vacuum-packed chicken feet with pickled peppers.2. Research on prediction shelf-life of vacuum-packed chicken feet with pickled peppers at different temperatures.On the basis of storage properties data of chicken feet with pickled peppers at 10℃、 25 ℃、30℃、37℃, using multiple regression equation, we established the products shelf life prediction equation under different temperature. After the residual analysis, modification and verification, prediction equations of the shelf life under different temperature were respectively that Y10℃= 5.570 x TVB-N+234.434 × TBARS+6.194 x TBC-52.737 (R2=0.951); Y25℃= 3.337 × TVB-N+106.333 × TBARS+9.146 x TBC-23.511 (R2 =0.988); Y30℃= 0.823+0.662 x TVB-N+4.225 x TBC (R2=0.955); Y37℃= 9.238+ 0.143 × TVB-N+14.193 × TBARS+1.153 × TBC-2.432 × Sensory evaluation (R2 =0.985). Based on the results of variance analysis to regression equation showed that regression equations have high F value and minimum value (P<0.001), the regression equation of the coefficient of determination R2 were greater than 0.95, which showed that the regression model can well predict the shelf life of the product. Each index limit value into the regression equation, when stored at 10℃, the shelf life was 206d; when stored at 25 ℃, the shelf life was 141d; when stored at 30℃, the shelf life was 35d; when stored at 37 ℃, the shelf life 18d. The experimental results showed the prediction shelf life is similar as practical life. The equation could be used as the actual production theoretical basis. |
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