The Occurrence of Ochratoxin A in Hard Wheat and its Products During Milling Processes followed by Certain Mills in Tripoli PDF

Keywords

Contamination, Milling, Ochratoxin A, hard wheat, toxin.

Abstract

This research aimed at detecting the presence of Ochratoxin A (OTA) in local hard wheat and tracking its traces in semolina produce during milling processes followed in some mills in the area of Tripoli. 96 samples of wheat and its derivatives are collected from three mills (32 sample each) at the four stages of the milling process: wheat storage, purification and cleaning, semolina production, and bran separation. A solid phase extraction method is used to obtain the poison (RPSPE 18) and to clean the extract. A high-performance liquid chromatography (HPLC) is employed to detect OTA and estimate its levels. The limits of quantifications were determined to be 0.025 ppb and the recovery rate to be 94%. The results showed that 88% (21/24) of the uncleaned wheat samples are contaminated with OTA, with concentrations ranging from 1.4-11.8 and an average value of 5.9 μg/kg. The percentage of contamination in cleaned wheat reached 79% (19/24), with concentrations ranging from 1.4 to 9.3 μg/ kg and an average concentration of 5.3 μg/kg. Toxin’s presence in semolina decreased by almost 50% (12/24) compared to raw wheat. The concentration observed in semolina ranged between 0.6 and 2.1 μg/kg, with an average of 1.2 μg/kg. On the other hand, the percentage of contaminated bran samples were 83% (20/24), with concentrations varying from 0.7 to 6.9 μg/kg and an average of 4.2 μg/kg. The results showed that 88% of raw wheat samples were of average OTA concentration slightly above the limit of 5 μg/kg as set by the Libyan standard No. 231/2005. On the other hand, the average OTA concentration in all semolina samples was below the limit of 3 μg/kg set for this product in the same standard. Milling processes led to a significant reduction (38%) of the presence of OTA in semolina. The average concentration of the toxin in the semolina also dropped by approximately 80%. The (ANOVA) analysis showed significant variations in OTA presence between each of the raw, cleaned wheat, and semolina/bran (C.L of 99%).