Study On The Effect Of Browning Control On Stability Of Storage Quality During The Drying Process Of Liguang Apricot

Liguang dried apricots,a fruit specialty of Xinjiang,has been generally loved by consumers for its unique flavor.In recent years,with the growing expansion of the planting area and the steady increase in output,Liguang apricot has drawn more and more attention to its processing.Dried apricots,as one of the most traditional,most popular and most important processed products for Liguang apricots,will still be the leading product in the apricot industry of Xinjiang.However,in the existing processing and storage process of dried apricots,common problems exist such as sulfur dioxide residue,browning,and insects or pests,because of which the quality of dried apricots is degraded.Therefore,taking Liguang apricots as the raw material,the effect of compound sulfur-free color retention agent,combined with traditional open-air drying,on the color(L~*value)of Liguang dried apricots was studied,and the correlation degree of non-enzymatic browning parameters during the drying process was discussed;The impact of plant essential oil fumigation and packaging materials on the storage stability(37?,RH90%)of dried plum apricots was explored as well.The aim is to explore an efficient color retaining and storage technology to provide a theoretical basis for improving the quality of dried apricots,enhancing the economic value of dried apricots,and advancing the development of the distinctive economic forest and fruit industry of Xinjiang.The main research results of this paper are as follows:(1)Optimization of Liguang apricot drying processLiguang apricots were selected as the test material,pretreated with hot water blanching(90?,3 min),and their colors(L~*value)were taken as a reference index to conduct a single factor test and a response surface test.The correlation analysis was employed to explore the correlation degree of non-enzymatic browning parameters during the drying process.The results are as follows:The optimal ratio of the compound sulfur-free color retention agent is:0.60%of citric acid,0.06%of phytic acid,and 0.20%of L-cysteine,Under such conditions,the L~*value of Liguang dried apricots is actually 42.18,with quite good color retention effects;the correlation analysis showed that the order of effects on non-enzymatic browning during the drying process is:reducing sugar>free amino acid>ascorbic acid>total phenols;The compound sulfur-free color retention agent can effectively inhibit Maillard reaction and ascorbic acid oxidation during the drying process of Liguang apricots,and improve the color(L~*value)of the dried apricots.(2)The effect of plant essential oil fumigation on the quality of Liguang dried apricots during storageOn the basis of single factor,orthogonal experiments were conducted to study the effect of fumigation concentration of citrus essential oil,thyme essential oil and tea tree essential oil on the nutrients and sensory scores of Liguang dried apricots during storage.The results are as follows:the optimal ratio of compound essential oils is:0.75 m L/kg of citrus essential oil,0.30 m L/kg of thyme essential oil,and 0.60m L/kg of tea tree essential oil,and in such context the sensory score of Liguang dried apricots is the highest;Compared with the control group,the compound essential oil fumigation treatment can improve the color(L~*value)of dried apricots,effectively prevent them from“moisture regain”,inhibit the growth of microorganisms,and maintain the good texture and flavor of dried apricots.(3)The effect of different packaging materials on the quality of Liguang dried apricots during storageThe Liguang dried apricots,which have been treated with a composite color retention agent,and then fumigated with a composite essential oil,were selected as the test material,and the effects of PE,PVDC and PET/Al/PE packaging materials on the storage stability of Liguang dried apricots were studied.The results showed that:Compared with the control group,PE,PVDC and PET/Al/PE packaging materials can all enhance the quality of dried apricots during storage.Among them,PET/Al/PE packaging bags have the best storage effect.When stored for 60 days,the color(L~*value),reducing sugar,titratable acid,and soluble solids of the dried apricots were 10.41%,5.85%,4.79%and 4.67%higher than those of the control group,respectively,while the moisture content and the total number of colonies were 7.42%and 12.89%lower than those of the control group,respectively.Therefore,the PET/Al/PE packaging treatment can dramatically delay the quality deterioration of Liguang dried apricots and improve the storage stability.