Study On Processing Technology Of Fresh Squeezed Apricot Juice

Kumat apricot as the experimental object in this research, using different fungicides on apricot fruit surface sterilization, discussed the optimum effective fungicide for surface sterilization of microorganisms. In cellulose and pectinase combination of apricot fruit surface was sterilized juice, explore the optimum parameters double digested. Meanwhile, membrane separation technology for double digested further clarification apricot juice after sterilization. The pore size of the different selection test, membrane sterilization optimized operating conditions. Under different storage conditions on the film after sterilization for storage apricot juice, apricot juice ingredient changes measured at different temperatures and microorganisms. Main conclusions:1.By examining chlorine dioxide and hydrogen peroxide, apricot fruit surface microbial sterilization effect, to determine the chlorine dioxide effective surface disinfectant. In sterilization rate as an indicator, it discusses the chlorine dioxide on the surface of microbes apricot fruit sterilization process, on the basis of single factor test, by L9(33)orthogonal test of chlorine dioxide disinfection process optimization, to determine the best sterilization parameters for the chlorine dioxide concentration 16 mg/L, sterilization time 10 min, sterilization temperature 30℃. Which affect the concentration of chlorine dioxide for sterilizing effect of bacteria, molds and yeasts maximum. Under this condition, the sterilization rate of 91.25% of bacteria, molds and yeasts of the sterilization rate 93.67%.2. In the juice was investigated by single factor experiment, the pectinase, cellulose dosage of apricot puree juice yield enzyme hydrolysis temperature reconciliation time. Analysis optimized by Box-Behnken response surface method can obtain double enzymatic optimum conditions were: cellulose enzyme dosage 2.5 g/Kg, pectinase 1.7 g/Kg, enzymatic time 78.77 min, reaction temperature 40℃, at optimal conditions, apricot fruit juice rate of 88.189%.3.Using micro filtration double digested juice apricot juice can be sterilized after the test, by studying different aperture membrane flux, apricot juice nutrients and aroma components of change before and after sterilization and sterilization efficiency, determining the applicable to the optimal pore size apricot juice sterilization, also discussed the flow rate, pressure and affect the feed temperature on membrane flux, determine the optimal operating conditions of the membrane sterilization. The results showed that: a pore size of 0.45 μm membrane flux was better than 0.10 μm, 0.22 μm pore size of the membrane, but the microbe does not meet the requirements of the national prospective.0.22 μm pore size membrane flux was significantly higher than 0.10 μm membrane and effectively remove microorganisms apricot juice, apricot juice retains most of the nutrients and flavor components. Therefore, the appropriate choice of the optimal filtering membrane pore size of 0.22 μm, the optimum operating conditions: the flow rate of 17 m/s, 0.2 MPa of pressure and operation of the feed temperature 35℃. Under these conditions, having to throw the original apricot juice aroma and flavor, soluble solids content of 10.3%; total phenol content 62.2 mg/100 mL; Flavonoids 61.92 mg /100mL; vitamin C 19 mg/100g; transmittance of 93.7%, yeasts and molds indicators, and total coliform bacteria and other colonies are up to national standards.4.The film after sterilization apricot juice placed 4℃,25℃,37℃storage 120 d at three different temperatures. At 4℃and 25℃conditions observed during the storage period of 120 d of apricot juice in the indicators total number of colonies, color, flavonoids browning, total phenol content of a slight change in the conditions under which the 4℃indexes storage apricot juice is better than 25℃; at 37℃with the extension of storage time, apricot juice color, browning larger changes, total phenol content, flavonoids and other antioxidants larger loss.