quality and microbial changes of four dried sour cherry by osmosis process through one year storage

sour cherry is one of the most important horticultural products in iran that consumes as fresh and dried fruit. in this research the effect of osmotic pretreatment on physicochemical, antioxiative and microbial characteristics of 4 cultivars of sour cherry: early jibilium, butermo, sigany and local were investigated. the samples were placed in different osmotic solution, dried and vacuum packed in polyamide pouches the physicochemical tests (ph, bx, titrable acidity, moisture content, color, anthocyanin and phenolc compounds and antioxidative activities) and microbial tests were carried out after 6 and 12 months. the results showed that sour cherry butermo var. had the most bx, ph, acidity. local and early jibelium var. had the least bx and ph. the amount of moisture of early jibelium and local var. were the most and the least, respectively. the chroma of local var. was the most and had the more red purity than other varieties. butermo and local var. with 28.8 and 23.35 mg cyanidin 3 glychoside had the most and the least anthocyanins respectively. the amount of total phenolic compounds in butermo var. was significantly more than other varieties. the reducing power of early jibelium var. was the more significantly than other varieties. osmosis process had no effect on the moicrobial growth, anthocyanins and phenolic compounds and antioxidative activities. one year storage significantly increased moisture, color, microbial growth, phenolic compounds and radical scavenging power of dried cherries but had no effect on other factors. the microbial conditions of samples were on the standard limits.