postharvest application of calcium carbonate nanoparticles on enzyme activity and some attributes quality in fresh cut apples varieties golden delicious

introduction: nowadays, due to mechanization of life, consumers need of food which they spent little time for preparation, so fresh cut industry is growing rapidly in the world. these products had strong growth since 1940, and in 2013, most sales of fresh cut fruit related to apples, against 21.8 percent. minimal processing operations include grading, washing, sorting, slicing, chopping and then packaging of fruit or vegetables. since these operations result in quality loss, due to water loss, softening, microbial contamination, increased respiration, ethylene and tissue browning. to extend the shelf life of fresh cut fruit, some effective techniques including, low temperature, modified atmosphere packaging, nanotechnology and coating have been applied. nowadays, edible coatings are used for fresh cut fruits to reduce respiration and control physiological changes. nano-scale ingredients lead to increase surface to volume ratio so increases the activity of the particles and their impact, the other hand use of calcium compounds in the fruit can be caused strength of the cell wall and bridges between pectin polymers in cell wall and cell membrane so the activity of digestive enzymes decreases. materials and methods: golden delicious apples were selected for uniform size and appearance in a commercial orchard in urmia. fruit disinfected with disinfectant solutions for 10 min. half of the apples in the laboratory before cutting were immersed in nano calcium carbonate solution at concentrations of 0, 0.1, 0.2, and 0.4 % for 4 min and the other half of the fruit after cutting treated with the same concentrations of nano calcium carbonate for 2 minutes. control fruit were treated with distilled water. fresh cut were dried at 20 ᵒc for 15 minutes and placed in plastic containers (8 slices per a dish), in refrigerator equipment at 1±0.5ᵒc and relative humidity 90-95% for 20 days. results and discussion: fresh cut apples coated with nano calcium carbonate reduced the enzyme activities. so that in treated samples compared to control samples polyphenol oxidase activity was reduced. also, antioxidant activity and catalase levels were higher than the treated fruit during storage. as a result, fresh cut apples coated with nano calcium carbonate can be used as an easy way to increase the shelf life of apples in cold storage.