| Berries are favored by consumers for their unique flavor and high nutritional value.However,because berries generally have a short shelf life and are prone to mildew and spoilage,it is necessary to develop deep processing of berries to overcome the problems caused by their short shelf life of waste.There are many common deep processing methods,among which dried fruit is a convenient,low cost and suitable for industrial production deep processing product due to its good taste and good market response.However,during the drying process of the fresh aronia melanocarpa,due to the influence of temperature,polyphenol oxidase and peroxidase during the drying process,nutrients are lost and the product quality is deteriorated.Therefore,in this experiment,electron beam irradiation was performed on fresh aronia melanocarpa before drying and a suitable drying model was established to reduce enzyme activity,reduce the loss of nutrients during drying,and improve product quality.At the same time,traditional preserved fruits have a very high sugar content,which can lead to some modern diseases such as diabetes and obesity.Therefore,in this experiment,healthier natural sweeteners were used to make preserved fruits,in order to adapt to the current people’s healthy eating concept,and at the same time improve the sourness of the original fruit taste.First,in this study,different temperatures(50℃,60℃,70℃,80℃)were selected for hot air drying of aronia melanocarpa.The higher the drying temperature,the shorter the required drying time.The drying rate and heating rate all showed a trend of increasing first and then decreasing;a drying model of aronia melanocarpa was established,of which the Logarithmic model was more relevant and accurate than other mathematical models to describe the drying process of aronia melanocarpa drying process and drying end point of aronia melanocarpa.Secondly,different electron beam irradiation doses(1 k Gy,3 k Gy,5 k Gy)were selected to irradiate aronia melanocarpa and dried at different temperatures(50°C,60°C,70°C,80°C).Through irradiation treatment,the activities of polyphenol oxidase and peroxidase were significantly reduced,but the quality of dried fruit,such as rehydration,color difference and texture,did not change significantly.The content of soluble solids,total phenols,total flavonoids content,anthocyanin content and sensory score were maintained at a high level at 3 k Gy;under different temperature treatments,the soluble solid content,hardness,total phenolic content,total flavonoid content and anthocyanin content were all higher at 70°C,the titrated acid content was the highest at 50℃,and the temperature had no effect on the color difference.The sensory quality of the dried aronia melanocarpa at 60℃ was better,and the microbial content was lower in both irradiation and drying treatments.Again,the effects of different electron beam irradiation doses(1 k Gy,3 k Gy,5k Gy)on the dry quality of aronia melanocarpa during storage were studied.The results of the study showed that irradiation treatment could slow down the deterioration rate of the dried fruit of aronia melanocarpa,the soluble solids,titratable acidity,total phenol content,total flavone content,anthocyanin content and sensory score of the irradiated group stored for 180 days were lower than those of the untreated group,the surface color was maintained better,and the microbial content was lower,indicating that proper electron beam irradiation can better preserve the quality of dried aronia melanocarpa.Finally,based on the production process and formula of the low-sugar aronia melanocarpa preserved fruit,the dried aronia melanocarpa product with uniform color,plump fruit,sweet and sour taste,good chewiness and low sugar content is prepared. |
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