Fungal Population and Aflatoxin Contamination on Stored Gamma-Irradiated Nutmeg (Myristica fragrans) Kernels

Abstract

800x600 A study on the effectiveness of gamma irradiation at dose s of 5 and 10 kGy on fungal population, Aspergillus flavus strains , and aflatoxin B 1 contamination on stored nutmeg kernels was conducted. The kernels were collect ed from seed s in a period of one week from the ground at North Sulawesi Province, Indonesia . D ried shelled kernels with ± 10 % moisture content , packed in polyethylene bag s at 2.1 kg/bag, were irradiated at 5 and 10 kGy and stored at ambient temperature (28 ° C) for 2 and 4 months. Kernel moisture content, fungal population, and aflatoxin B 1 were determined before and after irradiation, and after 2 and 4 months of storage . Results showed that fungal population was reduced with the increasing irradiation dose. Five species of fungi were isolated , i.e. , Aspergillus flavus , A. niger , Cladosporium cladosporioides , Eurotium chevalieri , a nd Penicillium citrinum . A total of twelv e A. flavus strains were isolated, five strains from unirradiated kernels and five and two strains from irradiated kernels at doses 5 and 10 kGy , respectively. Among these strains , 58 % were capable of producing L sclerotia and 25 % were identified as toxigenic. Kernel moisture during storage was 7.3 % and no aflatoxin B 1 was detected before and after irradiation , and after 2 and 4 months of storage duration. Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:Table Normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Times New Roman,serif;}