Study On Processing Technology And Quality Change Of Garlic Puree During Storage

Garlic is rich in nutrients and has both medicinal and food functions.At present,garlic is processed into garlic puree and garlic powder.However,in the process of processing,garlic is prone to greening,which not only affects the appearance quality of the product,but also hinders the further processing of garlic.In addition,garlic has a short resting period.Garlic is susceptible to mildew and cannot be stored for a long time.Therefore,it is necessary to explore methods to control the greening of garlic and its mechanism.At the same time,it is necessary to develop garlic products that can be preserved for a long time,which provides new processes and formulas for garlic processing and production,and provides reference and basis for garlic processing and production.In this paper,the method of blanching was used to protect garlic color.The parameters of blanching were optimized by response surface methodology,and the best color protection solution that can inhibit garlic greening and maximize the preservation of allicin was determined.The influences of blanching process on the activity of enzymes(γ-glutamyl transpeptidase(GGT)and alliinase)and garlic color were investigated,and dynamic models of color change and enzyme inactivation was established.At the same time,the degradation of allicin during blanching and the changes in the antioxidant capacity of garlic were investigated.Secondly,the garlic puree obtained from the best blanching process was used as main raw material,and garlic products are made by adding edible oil,xanthan gum,citric acid,salt and other auxiliary materials.The response surface method was used to optimize the optimum formulation parameters of garlic products.Finally,a quality analysis and evaluation method for garlic products was established,and a series of quality indicators and rheological properties were measured,and the shelf life of the garlic products was determined through the storage period test.The followings are results:1.The optimization of color protection process:According to response surface tests,the blanching temperature,blanching time,and liquid-to-material ratio were used as independent variables,and a*value and allicin were used as response values.The best color protection process is as follows:blanching temperature 81°C,blanching time 4 min,liquid material ratio 10:1.2.In the process of blanching,the inactivation process of alliinase andγ-glutamyl transpeptidase followed the first-order kinetics model,with R~2 values ranging from 0.925 to0.970 and 0.920 to 0.973,respectively.The activation energies of alliinase andγ-glutamyl transpeptidase were 59.414 KJ/mol and 35.430 KJ/mol,respectively.The first-order kinetic model can also describe the green degradation process of garlic,with R~2 value ranging from 0.929 to 0.966 and the activation energy is 67.70 KJ/mol.Correlation analysis showed that there was a significant positive correlation between enzyme activity and green degradation(p<0.05),indicating that blanching can inhibit greening by inhibiting enzyme activity.3.In the process of blanching,the degradation process of allicin can also be described by a first-order kinetic model,with R~2 value ranging from 0.954 to 0.995 and the activation energy is 14.54 KJ/mol.With the increase of blanching temperature and blanching time,the antioxidant capacity of garlic decreased significantly(p<0.05).4.The optimization of garlic product formula.Taking oil quantity,oil temperature,xanthan gum,and citric acid as independent variables and sensory evaluation scores as response values,the optimum formulation parameters of garlic products were optimized by response surface methodology:oil content 16%,oil temperature 50℃,xanthan gum 0.6%,citric acid 0.3%.The garlic product under this formula was named"aqueous"garlic puree;on the basis of"aqueous"garlic formula,the amount of oil was increased to 50%to obtain"oily"garlic puree.5.In the senses,"aqueous"garlic products are white,with a strong garlic flavor,coordinated salty and spicy,delicate the sauce body,moderate stickiness;"oily"garlic products are white,the oil is light yellow,with a strong garlic flavor,coordinated salty and spicy,delicate the sauce body,good fluidity and even distribution.The allicin contents of“aqueous”and“oily”garlic were 0.73 mg/g,0.41 mg/g.The total number of colonies was≦300 cfu/g,and the total number of moulds was≦50 cfu/g,and there was none of pathogenic bacteria.Rheological tests have shown that both"aqueous"and"oily"garlic mud are pseudoplastic fluids.The order of chew viscosity is:commercial garlic>"aqueous"garlic>"oily"garlic.In dynamic rheological measurements,both"aqueous"and"oily"garlic puree exhibited a solid-like structure.6.The quality change of the garlic product during storage and the determination of the shelf life.With the prolongation of storage time,the acid value and peroxide value both increased.During the storage,the acid value and peroxide value of corn oil in the product were in line with the standard of the fourth grade corn oil in GB 19111-2003;The allicin content of two kinds of garlic products continued to decline,and the garlic taste gradually disappeared;the total sugar content gradually decreased,the 5-HMF content gradually increased,and the garlic products gradually browned.It was finally determined that the shelf life of garlic products was 150d.