Research On The Technologies Of Cold Chain And Hot Chain In Central Kitchen

Several kinds of typical Chinese food were studied in this paper. The technology of vacuum cooling was applied and possible temperature fluctuation and time changes were simulated from factory to supermarket during circulation. The quality and safety of the chilled cooked rice were studied too. In the way of the quality, changes of texture, color and microorganism after different temperature fluctuation were determined. Compared with the control, the quality of the vacuum cooled samples at fluctuant temperature was estimated. Then effects of temperature on growth of total bacteria were discussed.The main results of this research can be concluded as follows:1) Under the condition of vacuum cooling, results showed that to cool the same cooked food products from 70℃to 10℃, the vacuum-cooling rate was 36 times quicker than the slow air-cooling, which made the products chilled quickly to the safe temperature. But compared with traditional ways, this technology induced higher weight loss. It was effective and necessary to add water before vacuum cooling with the purpose of compensating the water loss.2)It was found that the cooling speed and the texture change were inversely proportional to water loss .The texture and sensory qualities reduced obviously after stored 2 hours in 65℃,so we should keep time in 2 hours.3) The result showed that colors have no notable difference during the treatment.4) The result showed that the samples chilled by vacuum-cooling had significantly effects on restraining the growth of microorganism than by air-cooling. Higher waiting temperature (20℃), longer storage and higher distribution temperature increased the probability of microorganism growth.