a survey of cyanide metabolism in two apple cultivars fuji and abbasi mashhad

abstract cyanide is a colorless, harmful, and dangerous substance with a smell similar to bitter almond. cyanide forms a stable compound with iron and magnesium and interferes with cell activity by interfering with respiration, carbon stabilization and nitrate revival. in order to evaluate cyanide metabolism in fuji and abassi mashhad apples, a factorial experiment was conducted as split plot based on a complete randomized block design in 4 replications. the fruits were randomly divided into four separate parts and were stored at four different temperatures (-2, 0, 2, and 4c) in a normal cold storage (under refrigerator conditions), with a relative humidity of 85%±2 for a period of four months. the cyanide accumulation amount and beta-cas enzyme activity analysis were evaluated after removal of the samples from the storage for a period of thirteen days. beta-cas enzyme activity was assessed using colorimetric method based on the production of h2s. the result showed that the highest cyanide accumulation was at -2c and the lowest was at 4c in both cultivars. it seems that higher temperatures were more effective in the decomposition and metabolization of cyanide. beta-cas enzyme activity in abassi mashhad cultivar was more than fuji cultivar and different storage temperatures, had different effects on the enzyme's activity. activity of the enzyme increased daily up to 12 days but decreased on day 13.