Study On Pasteurization Efficacy And Technology Of Seed-used Melon Juice Treated By Radio Frequency

Seed-used melon is a cucurbitaceous crop with rich nutritional value.It is widely planted in Northwest of my country and is one of the important economic crops.seed-used melon juice is a kind of low-acid and heat-sensitive fruit juice.In the traditional high-temperature heat sterilization process,it cannot effectively inhibit the production and volatilization of alcohol and aldehyde compounds related to the juice aroma,resulting in thermal peculiar smell,resulting in different taste and flavor of seed-used melon juice Degree of deterioration.Choosing and using appropriate sterilization technology is the key to solving the heat sensitivity problem of seed-used melon juice and realizing its industrial production.As a new type of sterilization technology,radio frequency sterilization technology is widely used in the fruit and vegetable juice sterilization industry due to its advantages of low heating temperature,fast sterilization rate,good heating uniformity,and good product quality.In order to study the effect of radio frequency treatment on the sterilization effect and quality and flavor of seed-used melon juice,this article systematically studied seed-used-used melon juice from the aspects of radio frequency sterilization mechanism,radio frequency heating uniformity research,and radio frequency heat sterilization effect.The main research contents and results are as follows:In order to study the effect of radio frequency treatment on the sterilization effect and quality and flavor of seed-used melon juice,this article systematically studied seed-used melon juice from the aspects of radio frequency sterilization mechanism,radio frequency heating uniformity research,and radio frequency heat sterilization effect.The main research contents and results are as follows;(1)In order to study the effect of radio frequency heating on the microbial sterilization effect of materials,according to the principle of absorption of radio frequency waves by polar media,the principle of radio frequency energy conversion,and the mechanism of radio frequency sterilization,this paper establishes the absorption equation and The heat equation generated by the action of radio frequency on the material theoretically explains the absorption and conversion of radio frequency energy by seed-used melon juice.At the same time,it compares and analyzes the change law of the material temperature when the radio frequency processes different materials,discusses and explains the existence and influence of the non-thermal effect of radio frequency sterilization.(2)Select Jingyuan No.1 freshly squeezed seed-used melon juice as the research object,and study the heating uniformity and heating rate of seed-used melon juice during the radio frequency treatment with the experimental factors of the distance between the plates,the volume of the juice and the solid content of the juice.The research results show that the distance between the plates has a significant effect on the heating uniformity and heating rate of the seed-used melon juice.When the distance between the plates is130 mm,the maximum temperature of the seed-used melon juice reaches 85?;when the distance between the plates is 120 mm,the temperature of the seed-used melon juice is relatively 62?.The juice has good heating uniformity;The juice volume and the solid content of the juice have no significant effect on the heating uniformity and heating rate of the seed-used melon juice.With the increase of the processing time,the temperature difference of the seed-used melon juice is in the range of 10±3?.(3)The effect of radio frequency heating sterilization technology on the sterilization effect and physical and chemical characteristics of seed-used melon juice was studied by taking the distance between the plates,the radio frequency treatment time,the volume of the juice,and the solid content of the juice as the test factors.Experiments show that when the electrode plate spacing is 120?140mm,the radio frequency treatment time is 200?300s,the juice volume is 30?40ml,and the juice solid content is 2.55?2.40%,the temperature of seed-used melon juice varies from 45 to 90?,and the logarithm of the total number of bacteria is less than 2(Total number of bacteria <100 CFU/m L).At the same time,the minimum retention rate of total sugar is 89.6%;the maximum increase of total acid content is 24%;the minimum retention rate of Vc content is 59.7%;the p H value has a small range of change,which can better retain the acidity and alkalinity of the juice.The sensory evaluation score of seed-used melon juice ranges from 114 to 132,which can retain the flavor and quality of the original juice to a greater extent.(4)On the basis of the single factor test,the distance between the plates,the volume of the juice and the radio frequency treatment time are used as the test factors,and the logarithmic value of the total number of bacteria,temperature and sensory evaluation scores are the test indicators.The radio frequency heating sterilization process of the seed-used melon juice is carried out.Optimization and comparison of the sterilization effect and physical and chemical properties of seed-used melon juice obtained by different sterilization methods.The optimal combination of process parameters for radio frequency heating sterilization of seed-used melon juice is: the plate spacing is 125.75 mm,the radio frequency heating treatment time is 300 s,the juice volume is 30 m L,which can reduce the logarithm of the total number of colonies in the juice to 1.828,the temperature is52.17 ?,and the sensory evaluation score Value 126;comparing the sterilization effect,physicochemical properties and flavor quality of seed-used melon juice treated with different sterilization methods,it is found that it takes less time for the seed-used melon juice to reach the logarithm value of the total number of bacteria of 2 after the radio frequency sterilization treatment,and the effect on the physical and chemical properties and flavor of seed-used melon juice is excellent.For water bath and high temperature and high pressure treatment.