Studies On The Shelf Life Of The Packed Dried Bean Curd

The dried bean curd which has a long history, high nutrition value, good tasting and easy to carry about, is loved by most of people. They are the maximum batches of the bean products in the market. Bt there is not system research in pertinent shelf life at present. With the material of packed dried bean curd, this research study on shelf life estimating. Try to ascertain that the qualitative change mechanism of packed dried bean curd through storage, and constitute the shelf life estimating method and modeling quality loss of the dried bean curd or the correlative products.Through storage the physicochemical, microbiological, and sensory changes of the packed dried bean curd have been investigated in this research at first. Then the key indices could be ascertained. And the influence of the texture which is the most important factor of the key indices to the shelf life has been analyzed.The shelf life of samples stored at 15℃,25℃,35℃could be estimated by the indices. At last, the influence of temperature to the shelf life has been discussed. The conclusions as follows:1. According to the investigation of the process of dried bean curd, and the hygienic standard for non-fermented bean products and gluten (GB2711) , the indices which is likely to touch the shelf life of the dried bean curd need to be measured has been established. The physicochemical indices are water content, protein content and texture. And the microbiological indices are aerobic bacterial count and Coliform bacteria. The sensory indices are texture, flavor, odor and appearance.2. Under the situation of not controlling the temperature and the relative humidity (simulating sample laid in home), samples have been storied for 40 days. To the physicochemical indices, Water content and protein content had changed a little. The changes of texture parameters had no obvious rules. To the microbiological indices, aerobic bacterial count had some changes, Coliform bacteria never changed, but both aerobic bacterial count and Coliform bacteria were in the range set by the hygienic standard for non-fermented bean products and gluten (GB2711—2003) . The sensory indices were the primary indices to the shelf life, especially texture. So texture were the limiting factor of the sensory indices. Therefore, the sensory indices were ascertained to be used to estimated the shelf life of the packed dried bean curd.3. The texture of samples were mensurated by Texture Analyzer. According to the results of sensory evaluation, it is found that the most important texture parameter were the hardness, cohesiveness and chewiness. And the fracturability, adhesiveness, springiness and resilience had little influence to the acceptance of texture. When hardness was about 1500 or cohesiveness was about 0.7, it had a lower acceptance of texture. When chewiness was within 600～800, it had a higher acceptance of texture.4. The end point of shelf life was ascertained by sensory indices. The consumer' s acceptance to the sensory indices that are the overall liking , texture, flavor, odor and appearance were testing using Weibull model experiment designed. The shelf life of samples stored at 15℃,25℃,35℃respectively were 70.55,57.62,31.69 estimated by the overall liking of the consumer's acceptance. It is found that texture were the key factor of consumer's acceptance by the consumer's acceptance results analysis.5. The influence of temperature to the shelf life of the packed dried bean curd has been studied. At last the equation of the shelf life of the samples to the temperature was educed:t=7.625×10⁶e^-0.04T...