a b s t r a c tThe effects of processing for two types of Asian noodles production (yellow alkaline and instant) on DON levels were investigated. Deoxynivalenol (DON) level at each step of processing was determined using high performance liquid chromatography (HPLC) with a PDA (photodiode array) detector at 218 nm. An acetonitrile: water (17:83 v/v) mixture was used as mobile phase and a MycosepTM #225 column as clean-up method. Significant reductions of the initial DON levels were found, 43.2% and 66.6% in yellow alkaline and instant noodles, respectively. The presence of alkaline salt as an ingredient appeared to be the primary factor influencing the extent of reduction in the two types of noodles. The data indicated that significant reduction of DON have occurred during cooking and frying of both yellow alkaline and instant noodles, respectively. The mechanism of reduction due to cooking is probably a leaching of DON out of the noodle into the cooking medium.

The tocopherol and tocotrienol compositions of the genuine cocoa butter (CB) and palm mid-fraction (PMF) were investigated to introduce a more reliable indicator in detecting PMF in CB. The results suggested that the a-tocotrienol data presented could be utilised for the detection of the PMF admixture to CB. The PMF was added to CB at different levels. HPLC was used to detect the presence of PMF admixture to CB using a-tocotrienol as an indicator. The results derived from the model system indicated that increasing the PMF amount at 0-15% to CB resulted in an increase in the concentration of the a-tocotrienol significantly (P < 0.05). The addition of PMF amount more than 15% did not have any effect on the a-tocotrienol concentration. A linear plot with a high correlation of 0.9967 was obtained with SE of 1.527. The high correlation obtained indicated good accuracy, reflecting a close relationship between experimental and theoretical predicted value.

Following model studies, the detection of palm mid-fraction (PMF) added to cocoa butter (CB) in chocolate formulations was investigated. Different levels of PMF (0-25%, CB basis) were added to CB in chocolate. High performance liquid chromatography was then used to detect the presence of PMF in chocolate using α-tocotrienol as an indicator. The results, in line with the model studying indicated that increasing the amount of PMF added to CB resulted in a significant (P < 0.05) increase in the concentration of α-tocotrienol in chocolate; a linear plot (R 2 = 0.9837) was obtained with standard error of 1.986. A validation test was conducted to verify the equation obtained from the regression analysis. The high R 2-value obtained indicated a good accuracy, reflecting a close relationship between experimental and theoretically predicted values. The applied indicator performed well beyond the level of the statutory limit of 5% PMF addition on a chocolate basis that verified the previously studied model.