Flavor Improvement Of Potato Juice Based On Maillard Reaction And Its Application In Salad Dressing Production

Potato flour is an important material for potato staple food production,but it has high energy consumption in the production process and price,whice limits of popularize and sale.The freeze-thaw method is a new drying pretreatment process for potato flour,which can reduce the drying time,save energy,reduce costs,and make low cell-breaking.However,there will be about 30%of potato juice by-products,limits its popularize and application.Thus,it is urgent for research on key technologies of potato juice by-products by this process.This study aimed at poor flavor potato juice by-products,improved the flavor through the Maillard reaction,and carried out the key technology research of salad dressing,then finded out a new method to reprocess with potato juice by-products.The results as follows:1.Improved the flavor through the Maillard reaction.The optimal reaction conditions were:xylose:fructose=1:3,addition amount 3.0%,reaction temperature 110℃,reaction time 50 min,reaction p H 6.0.2.Analysis of flavor substances in Maillard reaction juice.GC-MS analysis showed,there were 27new aroma substances,including 5 key aroma substances:nonanal,2-methylbutanal,benzaldehyde,phenylacetaldehyde,beta-ionone(ROAV≥1.0),1 retouch aroma substances:benzyl alcohol(0.1≤ROAV<1.0),and pyridine and pyrazine,etc.They give Maillard reaction juice roasted,nutty,and barbecued flavor.The analysis results of amino acid composition and content showed,the umami,sweet and bitter amino acids content decreased significantly in MPRs,the free amino acid content decreased by 22.52%,the proportion of different taste amino acids in the total free amino acids changed significantly,the umami,sweet amino acids content increased by 2.88%and 0.85%,when the bitter amino acids decreased by3.72%,then potato juice by-products’flavor had improved.At the same time,the 0.3-3 k Da peptides,5’-guanylic acid,glutamic acid,aspartic acid and other umami amino acids contained in MPRs contribute strong umami and aftertaste,it enhances the salty and fresh flavor,and masks the original bitterness and astringency.The results of antioxidant activity in vitro showed that the antioxidant activity in vitro of potato Maillard reaction juice was significantly enhanced,the total reducing power had increased by 3.35times,DPPH and ABTS cation radical scavenging had increased by 55.82%and 33.12%。3.Salad dressing recipe optimization experiment.The results showed that the best formula was:potato Maillard reaction liquid 36 g,soybean oil 24 g,cooked mashed potato 16 g,egg yolk 14 g,white sugar 10 g,white vinegar 2 g,milk powder 1.6 g,edible salt 0.6 g,lemon juice 0.6 g,monosodium glutamate 0.2 g.4.Study on stability of salad dressing.The best stabilizer was xanthan gum and sodium alginate,xanthan gum:sodium alginate=5:5,addition 0.8%.5.Irradiation sterilization dose optimization of salad dressing.Through 6 k Gy electron beam irradiation by 10 Me V electron accelerator,the salad dressing had good sensory and flavor,and with no total bacterial count,mold and yeast.6.Analysis of the storage quality of salad dressing and prediction of shelf life.Measured the sensory score,acid value,peroxide value and total bacterial count during storage at 15,25,35,and 45℃after sterilization,the shelf life model was established by the first-order chemical reaction kinetic model combined with the Arrhenius equation.The results showed that with the prolongation of storage time,the sensory quality of salad dressing decreased gradually,the acid value,peroxide value and total number of colonies gradually increased,and the change rate of each quality evaluation index accelerated with the increase of storage temperature;The first-order chemical reaction can better reflect the changes of each index during the storage period.Taking sensory score,acid value,peroxide value and total number of colonies as indicators,the prediction model of shelf life established by the first-order chemical reaction kinetic model has better fitting accuracy,and the coefficient of determination R~2 was 0.9980、0.9851、0.9930、0.9848,respectively.The relative error between the measured value and the predicted value of shelf life was within 10%,and the shelf life was 153 days under the storage condition of 25℃.