Effect of gamma irradiation and water activity on mycotoxin production of Alternaria in tomato paste and juice.
Gamma-irradiation, water activity (aw) and incubation temperature were found to affect the production of tenuazonic acid (TZA) by Alternaria alternata in tomato paste and juice. By increasing the irradiation doses, the dry weight as well as TZA decreased greatly until complete inhibition at 4 kGy. Greatest production of TZA occurred at 0.98 aw (57.5 micrograms/g and 26.3 micrograms/g) for both tomato paste and juice, respectively, at 25 degrees C. Changing temperature and aw altered the relative amounts of TZA produced in tomato paste und juice by unirradiated and irradiated conidia of A. alternata. Only trace amount of TZA was detected at 0.98 aw (1.50 micrograms/g) by 3 kGy-irradiated conidia in tomato paste, while it was inhibited completely in juice. Increasing gamma-irradiation doses and decreasing water activities decreased greatly or inhibited TZA production in both tomato paste and juice.
National Center for Radiation Research and Technology, A.E.A., Nasr City, Cairo, Egypt.
N H
NH
Aziz
S
S
Farag
M A
MA
Hassanin
D000528:Alternaria / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D001628:Beverages; D002957:Citrus / Q000528:radiation effects*; D005514:Food Irradiation; D005516:Food Microbiology; D005720:Gamma Rays; D013696:Temperature; D013720:Tenuazonic Acid / Q000096:biosynthesis*; D014867:Water / Q000378:metabolism
D014867:Water; D013720:Tenuazonic Acid