Study On The Ultra-high Pressure Processing Of Health Porridge

At present, our diet is more sophisticated, coupled with increased intake of animal fats and other reasons, the rich diseases have high incidence, such as high blood pressure, cardiovascular disease, diabetes and so on. Cereals are rich in dietary fiber, vitamins and minerals, and have very high value of nutrition and health function, but have poor palatability and digestion. Making cereals into porridge can obtain higher sensory evaluation, and have a broad market prospect. Another problem, is that retrogradation of convenient cereal products is inevitable in the process of storage, it will lead to poor eating quality and changing of texture properties. There is no way to solve this problem now, people mainly ues additives to play a slow retrogradation and/or improve flavor. So, we used ultra-high pressure technology in the production, in order to get porridge with excellent eating quality, safety without any additives and low degree of retrogradation. Our experiment results shown that:1. Studied the initial production process of the porridge and determined the technological factors: the porridge formula was brown rice: oat: big shelled corn: kidney bean: small shelled corn: millet: red bean: mung bean =3:1:1:1:0.5:0.5:0.5:0.5 (g/g), packing materials was aluminum hollowing out bags, solid-liquid ratio was 1:6.5 (g/mL), soaking condition was at the temperature 50°C for 30 minutes, steam cooking condition was at the temperature 120°C for 30 minutes. The processings were as follow: weighting of raw materials, washing and draining, soaked at 50°C for 30 minutes in 6.5 times water, ultra-high pressure processing, cooked at 120°C for 30 minutes.2. In the process of storage, texture characteristics changed accompanied by retrogradation, including the increase of hardness, gumminess, adhesiveness, resilience and the decrease of cohesiveness. We found that the hardness, gumminess and adhesiveness of different cereal in porridge were decreased by ultra-high pressure processing, this effect was not abvious in the early storage, but apparent in the later. The ultra-high pressure processing can significantly reduce the extent of the retrogradation of porridge, the optimum conditions of ultra-high pressure was at 200MPa for 5 minutes and at 300MPa for 5 minutes.3. In the storage, texture characteristics of the porridge were determined by TPA with a single material changed accompanied by retrogradation, including the increase of hardness and gumminess. The influence of ultra-high pressure processing on each material was different. Ultra-high pressure can reduce the hardness and increase the cohesiveness of the big shelled corn, this was clearly in the early storage. The crackle ratio of red bean was reduced by high pressure treatment, it shown that high pressure has a protective effect on the shape of the red bean. Ultra-high pressure processing also can reduce the hardness, springiness and the growth rate of gumminess of the red bean. The effect of high pressure on the hardness of oatmeal occurred mainly in the later storage, and the growth rate of hardness of oatmeal can also be reduced. Kidney beans are more sensitive to pressure, the reduction of hardness was obvious at the early storage. Increase the pressure or extend the treatment time can decrease the hardness of brown rice porridge, the impact on gumminess and adhesiveness was not obviously in the early storage.4. Sensory evaluation of porridge with different processing were determined, the evaluation terms are color, smell, form, palatability and taste. Each term was divided into three grades to make judges easy to grasp the score scale. We found that there was a significant difference between samples of different production processes, the sample with 200MPa for 2min and 200MPa for 5min got the highest score, followed by 300MPa for 2min, all of these three were significantly better than 300MPa for 5min and the contrast sample (no ultra-high pressure treatment). The final process of the porridge was as follows: weighting raw materials, washing and draining, soaked at 50°C for 30 minutes in 6.5 times water, 200MPa treatment for 5 minutes and cooked at 120°C for 30 minutes.5. The physical and chemical properties of the porridge were tested. The protein content of the porridge was 3.045% and same as raw material. And all the products were meet with the criterion requirements of food hygiene-examination of commercial sterilization of canned food.