A method for improving the color of dried daylily products by ultrasonic-assisted blanching combined with series drying

Abstract

The invention relates to a method for improving the color of a dried day lily product by combining ultrasonic-assisted blanching with cascade drying, belonging to the technical field of agricultural product deep processing. The method takes fresh day lily as raw material, and comprises the steps of classifying the day lily, cleaning, removing stems, carrying out ultrasonic-assisted blanching, carrying out hot air-combined vacuum microwave drying and packaging. The method combines ultrasonic pretreatment with combined drying, and can change the color of the dried day lily product by controlling enzymatic browning and non-enzymatic browning; the time of heat treatment is shortened by ultrasonic waves to the utmost extent, so that the aim of controlling enzymatic browning by enzyme deactivation is achieved, and the loss of heat-sensitive nutrients such as total phenols and vitamin C is reduced; the drying time is shortened by hot air-combined vacuum microwave combination drying in stages, so that the phenomenon of uneven temperature distribution is avoided in a drying process, and non-enzymatic browning is effectively controlled. The produced dried day lily product is good in color, high in nutritional quality and good in rehydration characteristic.

Description

technical field [0001] The invention relates to a method for improving the color of dried daylily products by ultrasonic-assisted blanching combined with serial drying, and belongs to the technical field of deep processing of agricultural products. Background technique [0002] Day lily (Hemerocallis citrina Baroni), also known as day lily, belongs to the genus Hemerocallis of the family Hemerocallis. It is a perennial herbaceous plant. Hematemesis, blood in the stool, difficulty urinating, insomnia, breast milk retention, etc. have curative effects. The flowering period of day lily has a short storage period. If it is not handled in time after picking, it will easily change color and rot. Dehydration and drying is a common processing method for day lily storage. Color is the main index to evaluate the quality of dehydrated day lily, and the main influencing factors are enzymatic browning and non-enzymatic browning. [0003] Fixing is one of the primary processes of day li...

AI Technical Summary

Problems solved by technology

Sulfur dioxide and sulfite treatment is one of the more commonly used methods in the processing of dried daylily products at present. It can process raw materials in large quantities and consumes less energy. However, sulfur dioxide residues are easily produced during processing. The content of sodium metabisulfite exceeds the standard

Compared with a single drying method, combined drying can effectively improve the color of dried products. At present, there are many reports on improving the color quality of dried products through combined drying. However, the combination of ultrasonic pretreatment and combined drying can control enzymatic browning and non-toxic. Enzymatic browning to improve the color of dried fruit and vegetable products has not been reported