Study On Technology Of Anti-browning And Preservation Of Fresh-cut Apple

Fresh-cut fruits and vegetables become more and more popular by consumers because of their convenient to eat. But series of physiological changes after cutting affect seriously the shelf life, which also restrict the scale production of fresh-cut fruits and vegetables. In this research, apple was used to investigate the characteristics of different varieties of fresh-cut apples to determine the appropriate fresh-cut apple variety. Then we explored the anti-browning effect of different color protecting agent on fresh-cut apples and effects of the different packaging methods, different storage temperature and high oxygen treatments on storage quality of fresh-cut apples to determine the anti-browning and preservation comprehensive control technology of fresh-cut apples. The conclusions were as follows:Fresh-cut characteristics of Fuji, Jonagold, Golden delicious and Green apple were studied. The color and firmness of four fresh-cut apples showed declining trend during storage and firmness and color of Fuji decreased more slowly. L* and firmness values of Fuji were 69.78 and 8.21 kg/cm2 at 15 d; Golden delicious and Jonagold firmness decreased rapidly, while the green apple had serious browning at the end of storage. SSC, total phenolic content and PPO activity of four varieties of fresh-cut apples were increased at first and then decreased. Fuji was suitable for fresh-cut material.The effects of 0.7% NaCl,0.5% CaCl2,1.5% Vc and 1% CA on anti-browning and keeping firmness of fresh-cut apples were best among the single browning inhibitors. Through response surface experiments, the optimum combination treatment was that 1.53% VC+1.10% CA+0.51% CaCl2, and the optimum soaking time for the fresh-cut apple was 15.91 min. The optimum coating combination was 0.5% CMC+0.01% Natamycin+0.015% Nisin. Fresh-cut apples with these treatments had good sensory quality.Different packaging methods resulted in the different storage quality. Vacuum packaging was the most appropriate packing method because its obvious effect of inhibiting browning, delaying the senescence and keeping the sensory quality on fresh-cut apples.Fresh-cut apples storaged at-2℃ appeared to physiological metabolic disorder so that it accelerated browning and decaying. The best storage temperature for apple was 0℃, which can effectively inhibit browning and PPO activity and keep quality.High oxygen treatment could inhibit browning of fresh-cut apples and maintain the apple quality. Fresh-cut apples treated by 100% O2 for 4h could keep the best quality during storage. Fresh-cut apples by color protection and coating, combined with 100% O2 for 4h, vacuum packaging and storage at 0℃, can storage 90 d. Fresh-cut apples had good quality.