Effects Of Microwave Treatment On The Quality And Freshness Of Fresh Wet Highland Barley Noodles

With the continuous advancement of modern technology and the continuous improvement of people's living standards,the development of the food industry is gradually becoming more convenient and healthy.As a new type of noodle products,fresh and wet noodles are fresh,smooth,chewy and well received.Consumers love it.However,at present,the variety of fresh and wet noodles is single and the nutritional structure is single,which cannot meet the modern needs for nutrition and health;and because of the high moisture content of fresh and wet noodles,microorganisms can easily cause product spoilage and deterioration during storage and affect the circulation of products and sales.Therefore,in order to strengthen the nutrition of fresh and wet noodles,the use of high dietary fiber content highland barley seedlings instead of wheat flour is considered.In order to extend the shelf life of fresh and wet noodles,it is extremely important to explore new sterilization methods of fresh and wet noodles.This project is based on improving the preservation of fresh and wet cereal noodles,and mainly studies the effect of microwave sterilization of different pre-packaging methods on the quality of fresh and wet barley noodles.Under the optimal packaging method,in order to further improve the shelf life of sterilized noodles,combining traditional Water bath sterilization optimizes the combined sterilization process.Finally,the quality change of the combined sterilized noodles during storage is investigated to provide data support and reference for the industrial application of fresh and wet barley noodle sterilization.The main results are as follows:(1)To study the effect of different pre-packaging methods on the quality of microwave sterilized fresh wet highland barley noodles.Compared with traditional water-bath sterilization,microwave treatment increased the temperature,hardness,chew ability,shearing force,and gelatinization of fresh wet barley noodles,and reduced the moisture content,L~*value,enthalpy value,and microbial content.The effect of increasing microwave power is enhanced.The pre-packaging method affects the microwave sterilization effect,and the semi-sealed pre-packaging has the best sterilization effect on microorganisms.Among them,800 W semi-packaged pre-packaged microwave-treated noodles had the lowest total plant count,is 66.67CFU/g,and the shelf life was extended to 60 h at room temperature,which was significantly higher than the shelf life of the untreated blank noodles(p<0.05),which was more effective delay the darkening of the noodles during storage,and have little effect on texture and cooking quality.(2)Study on the optimization of the technological conditions for sterilizing fresh and wet barley noodles with microwave water bath.Using the total number of colonies,moisture content,and color difference as indicators,the effects of microwave power,microwave time,water bath temperature,water bath time,and bagging amount on the sterilization effect of fresh and wet barley noodles combined with microwave water bath were studied through a single factor experiment.The higher the microwave power,the higher the temperature of the water bath,the longer the processing time,the smaller the amount of bagging,and the better the sterilization effect of the sample.Based on the results of the single factor test,an orthogonal test was designed with the total number of colonies and the comprehensive score as the response values.Using the total number of colonies as an index to perform a range analysis,the influence of each factor on the total number of colonies is microwave time>bagging volume>microwave power>water bath time.The optimal level conditions are microwave time 150 s,microwave power500 W,and water bath.The time is 15 minutes and the bagging capacity is 80 g.The range analysis is performed using the comprehensive score as the index.The main and secondary effects of the factors on the comprehensive score are microwave time>bagging amount>microwave power>water bath time.The optimal level is microwave.The time is 90 s,the microwave power is 300 W,the water bath time is 15 min,and the bagging capacity is 80 g.After comprehensive consideration of the total number of colonies and the comprehensive score,the optimal process conditions were obtained,namely,the microwave power was 300 W,the microwave time was 2.5 min,the water bath time was 15 min,and the bagging amount was 80 g.(3)The variation of quality of fresh and wet cereal noodles in storage period was studied.The growth and reproduction of microorganism is the main reason for the quality deterioration of fresh and wet highland barley noodles.The results showed that the shelf life of blank group,low power long term group(300 W?2.5 min)and high power short term group(500 W?1.5 min)was 8 h,3 days and 5 days respectively when stored at 25?.When stored at 4?,the shelf life of noodles in the blank group was 3days,and when stored for 60 days,the total number of colonies in the low-power long-duration group and the high-power short-duration group were 1.5×10~4 CFU/g and8.4×10~3 CFU/g,respectively.The noodles in the two experimental groups maintained good health and safety,and their shelf life exceeded two months,which was at least 20times longer than that in the control group.The high power short time group had better effect on delaying the quality change of fresh and wet highland barley noodles in the storage period.(4)To investigate the quality change of fresh and wet barley noodles with microwave water bath and sterilization under different storage temperature conditions.When stored at 25?and 4?,the quality changes of fresh and wet barley noodles were basically the same,and there was a certain correlation between the indicators.During the storage of noodles,the total number of colonies was consistent with the changes in cooking loss rate,b~*value,acidity and viscosity,and had significant correlations.Generally,the noodles have high moisture content,and it is easy to breed microorganisms during storage,which increases the noodle acidity value and cooking loss rate,and reduces the water absorption rate of cooking.With the increase of storage time,the water content and cooking water absorption rate decrease,the acidity and cooking loss rate increase,the color of the noodles becomes darker,and the overall performance is reduced L~*value and increased b~*value.When stored at room temperature,the hardness,chewiness,and shearing force of the noodles generally increased;when stored at low temperature,the hardness,chew ability,and shearing force of the noodles in the two test groups generally increased first and then decreased,but were still higher than the blank group.However,during the entire storage process,the quality indexes of the high-power short-time microwave group were less than that of the low-power long-time group,indicating that the combined sterilization of the high-power short-time microwave group can more effectively suppress the quality of fresh wet highland barley noodles during storage.In summary,the optimal sterilization process conditions of microwave water bath combined sterilization of fresh and wet barley noodles are microwave power of 500 W,microwave time of 1.5 min,water bath time of 15 min,water bath temperature of 15min,and bagging capacity of 80 g.