ABSTRACT
The use of rapid steam distillation followed by redox iodine titration provides a rapid and accurate determination of total sufite residual in shrimp. Values obtained for sulfite-treated shrimp using the rapid distillation method gave comparable results to those of the officially recognized Monier-Williams method. Values for the rapid distillation method ranged from 6 to 212 ppm while those of the Monier-Williams procedure ranged from 6 to 241 ppm for untreated and treated shrimps, respectively. Statistical analysis using two-sample Student's t-test indicated that there were no significant differences (p>0.05) for residual levels below 100 ppm but the values obtained by the rapid distillation method and the Monier-Williams procedure were significantly different (p<0.05) at concentrations near and above 100 ppm.
ABSTRACT
Effects of culture media, near-ultraviolet exposure time, and temperature on sporulation of Alternaria alternata were investigated. Strains RL 671-2 and ATCC 36068 were cultivated on Potato Dextrose Agar (PDA), V8 Juice Agar (V8 Agar) and Mycological Agar (MA). The best culture medium for sporulation of strain RL 671-2 was PDA, followed by V8 agar, with only negligible numbers of spores appearing on MA. Near-UV exposure significantly increased sporulation in strain RL 671-2 on PDA and V8 agar. Significantly higher (P<0.01) spore counts were found in PDA cultures of this strain exposed to near-UV at 35 than at 20°C. On V8 agar significantly more spores were observed at 20 than at 35°C. MA was not a satisfactory medium for sporulation of ATCC 36068. Both PDA and V8 agar equally supported sporulation for this strain (ATCC 36068) at all exposure times.
