Study On Vacuum Freeze-drying Technology And Storage And Packaging Of Garlic Slices

In this paper,the garlic was used as the experimental material.This experiment uses freeze-drying technology to dry the fresh garlic slices.By changing the single-factor environment variable,the different freeze-drying conditions are compared and studied for various kinds of finished products.The influence of the index,and then through orthogonal experiments to screen out the optimal conditions for garlic freeze-drying.After determining the best process parameters of vacuum freeze-drying,by using the content of allicin,ascorbic acid,reducing sugar,titratable acid and color of the products to study the quality changes of freeze-dried garlic slices and the best process was further verified.Finally,study on storage and packaging of dry products.The main findings are as follows:1.Optimization of freeze drying process:On the basis of single factor experimental study,four factors with significant influence on freeze-drying were selected to set up orthogonal optimization experiment,Taking the content,rehydration and L value of allicin after freeze-drying as reference indexes to evaluate the process of freeze-drying,the optimal technology of garlic slice vacuum freeze-drying is as follows: slice thickness is 2 mm,drying and heating temperature is 35℃,pre freezing time is 270 min,sublimation temperature is-30℃,sublimation drying time is 270 min,vacuum degree is 200 MT.2.Study on the quality of freeze-dried garlic slices:The effect of the best processing technology on the quality of garlic slice was evaluated by the quality index of garlic slice after freeze-drying(allicin content,ascorbic acid content,reducing sugar content,titratable acid content).The results showed that different drying conditions affect the quality of garlic slices.The thickness of slice was 2 mm,the pre-freezing time was 270 min,the sublimation drying temperature was-30℃,and the sublimation drying time was 270 min Under the condition of min,the retention rate of each nutrient component of garlic slice is higher and the quality of the product is better.3.Study on storage and packaging of dried garlic slices:In this experiment,three packing materials(PE self sealing bag,PA/PE and composite packing)and two packing methods(ordinary packing and vacuum packing)were selected to pack the dried garlic slices,and the effects of different packing and storage methods on the quality and antioxidant activity of garlic slices were compared.Finally,it is concluded that the best packaging storage method for maintaining the quality of garlic slices under long time is vacuuming storage with aluminum foil composite packaging.