Study On Quality Changes And Browning Mechanism Of Hami Melon Air-dried Sheets During Storage

Cantaloupe air-dried sheets is a common product about cantaloupe.The cantaloupe air-dried sheets processed at low temperature has golden color and good quality.But its color is prone to changes during storage and transportation,which affects the value of the product.This paper studied the influence factors of cantaloupe air-dried sheets' quality including color change in the process of storage and transportation.The influence factors are radiation sterilization,packaging methods and temperature.In order to monitor the uneven color of the cantaloupe air-dried sheets,this paper also studied the application of image analysis in determining the color of cantaloupe air-dried sheets,by using RGB and HSV colors space.And then a color evaluation and ranking method were proposed.It provides theoretical support for the qualitatively change of cantaloupe air-dried sheets.It is of great significance to keep quality and increase market value of cantaloupe air-dried sheets.It would promote the development of cantaloupe processing industry.The main conclusions of this article:1.The treatment of 10 kGy irradiation for 8 h can effectively keep the quality of cantaloupe air-dried sheets.Excessive microbial and highly active peroxidase content in the cantaloupe air-dried sheets,resulting in reduction of amino acids,sugars and phenols.After irradiation treatment,the total number of colonies was less than 10 cfu/g,and the number of E.coli was less than 30 MPN/100 g.Also enzymatic are inactivation.Irradiation treatment can stable content of various substances and inhibit browning,to protect the quality of cantaloupe air-dried sheets.2.The packaging method has minimal impact on the color and composition of cantaloupe air-dried sheets.However,vacuum packaging is likely to cause sugar crystals on the surface of cantaloupe air-dried sheets not only affect the appearance of food,but also affect image collection.It is inconvenience.Non-vacuum packaging is recommended.3.The temperature of 30°C and below is suitable for storage of cantaloupe air-dried sheets.When cantaloupe air-dried sheets were stored at 35°C and above.Ascorbic acid,total sugar and total phenolic were significantly reduced.Remarkable browning occurred within 7 days.At 30°C and below,the content and color of cantaloupe air-dried sheets in the storage period remained relatively stable.4.The main cause of cantaloupe air-dried sheets' browning is the temperature.The free amino acid content is stable.And no 5-hydroxymethylfurfural content can be detected.Which shows that the caramelization and Maillard are not the main reactions.The mechanism may be the combined action of ascorbic acid oxidation,phenol oxidation and complex carbohydrate reactions.5.Using the GB color space can accurately evaluate the color change of cantaloupe air-dried sheets.The results showed that the fit between browning degree and gray value of cantaloupe air-dried sheets can be as high as 0.99.At the same time,in the RGB color space,the pixels of the image can be divided by color.And the rating standard can be established according to the division ratio.At present,there are many researches on the craft of cantaloupe,but most of them are difficult to implement in factory.Therefore,the research in this paper provides an effective theoretical basis for the storage and transportation from the production to the shelf.And it also proposes the use of image processing technology to monitor the quality,create rating system of cantaloupe air-dried sheets.Which make cantaloupe air-dried sheets detection closer to automation,,easier to implement and lower cost.