Study Of The Key Technology For High Quality Carrot Juice Concentrate Processing

The carrot juice concentrate is one of the most important parts of international vegetable juice trade. But some major technical problems in the processing of carrot juice concentrate has restriceted the trade of our country; include low concentrated multiple, poor carotent content, bad quality stability in storage and the white precipitation formed. Against these peoblems, a suitable enzyme was selected for carrot juice concentrate processing in this research, and the processing parameter was been determined after single factor experiments and experiments of central composite rottable design (CCRD); Effects of the storage conditions on the quality of carrot juice concentrate and reconstituted carrot juice was investigated, and effect of unit operations in the reconstituted carrot juice processing was investigated too; At last, the white precipitation formed during the storage in carrot juice has been preliminarily analysised, and a settlement programmer was given.The results were summarized as follow:Effect of enzyme preparations was studied on the carrot juice yield, carotenoid content, TSS, viscosity, and turbidity, then the enzyme Pectinex Smash XXL has been regarded as the most suitable enzyme for cloudy carrot juice producing. The suitable maceration condition was: temperature 45 ℃, enzyme concentration 127.5mL/t, incubation time 74 min, carrot juice produced under such condition has yield about 64.4%, that increase about 23.54% than the contrast;carotene content about 56.88mg/kg , which increase26.13mg/kg than contrast;and viscosity about 2.1 mPa · S ,which decreased about 0.4 mPa ? S than the contrast,but the juice still has good cloudy stability. Pectinex Smash XXL could destructe the carrot cell wall, after enzyme maceration treatment, the soluble pectin in carrot juice was increased while insoluble pectin decreased, it could be one of the main reasons that wiry carrot juice produced by enzyme maceration has a better cloudy stability.Carrot juice concentrate produced after enzyme maceration has TSS about 60° Brix, and the carotene content was 568mg/kg, while the contrast one just has TSS about 40° Brix,and carotene content was 380mg/kg . 4 ℃ is better than 25 ℃ for the cloudy stability and (3-carotene keeping in both reconstituted carrot juice and carrot juice concentrate in the storage. Carotene content and turbidity in the reconstituted carrot juice was significantly reduced by homogenization and pasteurization can significantly reduced the carotene content too.The white precipitation, which was formed during the storage of carrot juice, is mixture with some organic calcium, magnesium, ferrum salt in it, but the addition of phosphate and phytic acid can resolve its occurence.