study of effect of 4 hexylresorcinol antioxidant on blackspot of cultured shrimp (litopenaeus vannamei) in freezing

this project was carried out in order to study of possibity of uses from 4 hexyresorcinol for prevention of melanosis in cultured shrimp.treatments including of samples processed with 0.15% concentration of 4 hexylresorcinol and control samples. the samples were kept at -18oc. bacterial, chemical and sensory examinations were carried out for a period of six months. statistically significant difference was observed in peroxide value, free faty acids, thiobarbotouric acid and trimethylamin in test samples compared with the control samples during storage period (p<0.05). no statistically significant difference was observed in and ph, tvn, protease and total bacterial counts in test and control samples during storage period(p<0.05). in sensory parameters including melanosis (colour), meat, eyes, cephalotrax, odour, logs, skins and antennae were observed meaningful different in test samples compared with control group (p<0.05). test samples had better quality compared with the control samples. the test samples had a favorable quality until the end of storage period. but, the control samples had a favorable quality for a period of lower of one month.