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

Abstract

A study on the effectiveness of gamma irradiation at doses of 5 and 10 kGy on fungal population, Aspergillus flavus strains, and aflatoxin B1 contamination on stored nutmeg kernels was conducted. The kernels were collected from seeds in a period of one week from the ground at North Sulawesi Province, Indonesia. Dried shelled kernels with ± 10 % moisture content, packed in polyethylene bags 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 B1 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, and Penicillium citrinum. A total of twelve 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 B1 was detected before and after irradiation, and after 2 and 4 months of storage duration.

Effects of gamma irradiation dose and short‐term storage on phytochemicals, antioxidants, and textural properties of boiled ‘Tainan 9’ peanuts

“…Al-Bachir (2016) stated that microbial load in irradiated peanuts significantly decreased when applied with gamma irradiation, resulting in enhanced safety of the product. Nurtjahja et al (2018) reported that irradiated nutmeg at 5-10 kGy reduced the fungal population and no aflatoxin B1 that could be stored up to 4 months at ambient temperature (28 °C). Moreover, thermal processing methods including boiling may affect the quality of cooked products.…”

“…Nurtjahja et al . (2018) reported that irradiated nutmeg at 5–10 kGy reduced the fungal population and no aflatoxin B1 that could be stored up to 4 months at ambient temperature (28 °C). Moreover, thermal processing methods including boiling may affect the quality of cooked products.…”

Government Policy and Regulation to Support the International Trade of Maluku High-Grade Nutmeg Commodity in Spatial Perspective Overview

“…As for other cases of rejection, they occur due to the lack of health certificate in the product's reason (Badan Karantina Pertanian, 2016). The rejection of Indonesian nutmeg has an impact on the economy which also directly affects the welfare of farmers and is detrimental to the image of Indonesia as the producer of nutmegs with the best quality in the world (Nurtjahja, et al, 2018;Wang & Lee, 2017). The low quality of the nutmeg is caused by several factors including lack of maintenance, low productivity because half of the plants are old or not productive and have not used high-quality seeds, farmer institutions that are still weak, and low production quality.…”