Abstract
Rice noodle has been commonly and popularly consumed by Asians and Thais. In the noodle factories, noodles are daily and freshly made from rice flour, by pasting, steaming and drying. Before marketing out to customers in the same day, the noodle preparations are traditionally coated with raw peanut oil for the reduction of the stickiness and flavoring of the noodle. Uncooked noodle samples (N=10) from Chiang Mai market were randomly bought and analysed for aflatoxin content by TLC and fluorometry. It was found that aflatoxin B1 (AFB1) content in the samples before and after cooking in boiling water was 20.24±41.16 and 15.75±37.88 ppb, respectively. The effect of heating of oil-coated noodle at 100°C could decrease the AFB1 contamination only about 5%. AFB1 in separated peanut oil, which was contained about 1.8% by wt. in noodle samples, was significantly high averaged 343.35±298.17 ppb. The peanut oil was mainly contaminated with aflatoxin B1. Such aflatoxin contamination in peanut oil and noodle samples was harmful, over the safe level limit (=20 ppb). The noodle-coating peanut oil should be previously detoxified by alkalization. The high-grade peanut oils should be selected for using in order to maximize the health safety of consumers.
