Search

Thua-Nao , a traditional fermented soybean product in Thailand, is susceptible to contamination with biogenic amines (BAs), thus increasing the risk to human health. The present study evaluated the contamination, formation, and risk assessments of BAs in two types of Thua-Nao. The elution conditions were optimized and used to analyze thua nao BAs with good correlation coefficients and high recovery. The average total BA content in dried Thua-Nao (D-TN; 342 mg/kg) was greater than that in fresh Thua-Nao (F-TN; 239 mg/kg), but the difference was not significant. Tyramine (TYM) was the dominant BA in thua nao , accounting for more than half of the total BAs in the majority of the samples, and it also exhibited a significant positive correlation with soluble protein and total BAs. The calculated highest estimated daily intake (EDI) and index of food safety (IFS) of TYM were 1.51 μg/kg/day and 0.008, respectively, among the age groups who consumed thua nao , indicating a low risk to human health. However, the acute risk index of TYM in F-TN and D-TN among patients taking monoamine oxidase inhibitors (MAOIs) was greater than 80 %. Thus, these results suggested that an adverse health effect is unlikely for the general population after excessive consumption of TYM-contaminated Thua-Nao , but it may have serious health implications for patients taking MAOIs. • The contamination of biogenic amines in thua nao were analyzed through the optimized HPLC. • Tyramine was the dominant BAs in thua nao correlating with soluble protein and total BAs. • BAs wouldn't formed during thua nao drying and storage period. • BAs exposure from thua nao would be of low potential health concern for the health population. • A relatively high health risk of TYM dietary was observed in MAOI patients. [ABSTRACT FROM AUTHOR]

Chlorpyrifos is an organophosphate pesticide that is wildly used among farmers for crop protection. However, there are concerns regarding its contamination in the environment and food chain. In the present study, an in-house indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) specific for detecting chlorpyrifos is developed and validated against gas chromatography-flame photometric detection (GC-FPD) as the conventional method. The developed ic-ELISA was used for detecting chlorpyrifos residue in vegetable samples. The developed ic-ELISA showed good sensitivity to chlorpyrifos at an IC 50 of 0.80 µg/kg, with low cross-reactivity to other organophosphate pesticides. The 160 samples were collected from local markets located in the Chiang Rai, Chiang Mai, and Nan provinces in northern Thailand. The positive rate of chlorpyrifos residues in the vegetable samples was 33.8%, with the highest levels found in cucumbers, coriander, and morning glory, at 275, 145, and 35.3 µg/kg, respectively. The highest median levels of chlorpyrifos found in the detected samples were Chinese cabbage (332 μg/kg), cucumber (146.3 μg/kg) and Chinese Kale (26.95 μg/kg). The developed ic-ELISA is suitable for the rapid quantitation of chlorpyrifos residues.