Comparison of liquid chromatography and high performance thin layer chromatography for determination of aflatoxin in peanut products.

Recent research studies concerning aflatoxin in peanut products have involved the use of new instrumental methods for greater detection sensitivity. A comparison of 2 such techniques, liquid chromatography (LC) and high performance thin layer chromatography (HPTLC), is reported here. With respect to precision, accuracy, sensitivity, recovery, and linearity of response, HPTLC appears to be equivalent to LC. These points illustrate the viability of HPTLC as an alternative technique in the determination of aflatoxin.

Instrumental determination of flavor stability of fatty foods and its correlation with sensory flavor responses.

The evaluation of flavor and the flavor stability of vegetable oils and products made from them has evolved from the purely subjective to the objective through the use of instrumental measurement techniques. An attempt has been made in this report to catalogue this evolution and put in perspective the advantages and limitations of both the sensory and the instrumental techniques. Multi-laboratory collaborative studies have shown the viability of the instrumental approach and the utility of a number of methods for research and quality control. While the benchmark of consumer acceptance remains anchored in the subjective sensory responses, the instrumental objective methods are beginning to replace these for application to product and process evaluation. They have also provided insight into the identity of the flavor bearing components and their changes with time and temperature abuse. Recent utilization of mass spectrometry for analysis of the flavor components from vegetable oil containing products has provided greater assurance of the validity of the instrumental approaches.

Sampling and preparation of samples of peanut butter for aflatoxin analysis.

Procedures are discussed for sampling peanut butter and preparing those samples for alatoxin analysis. Special emphasis is placed on sampling the product from shipping pallets and comminuting chunk stype peanut butter in order to reduce the variability in the analysis associated with the nonuniform distribution of aflatoxin in the product. The slurry method of preparation is a convenient means of obtaining a sample which is representative of a nonhomogeneous product.

Evaluation of rapid polarographic method for determining tocopherols in vegetable oils and oil-based products.

A polarographic procedure for the determination of the tocopherols in vegetable oils was compared to a conventional gas-liquid chromatographic procedure. The polarographic method is 2-3 times more precise and more rapid, which is an important advantage for monitoring the nutritional value of processing conditions of vegetable oil-based products. Attempts to establish the validity of apparently slightly higher values for alpha- and gamma-tocopherols obtained by polarography has implicated the gas chromatography or derivative formation rather than the extensive prior manipulation of the sample for chromatography as the source of error. Essentially the same results were obtained for alpha-tocopherol, regardless of the technique used. However, more variable results which were product dependent were obtained for gamma- and delta-tocopherols when gas-liquid chromatography was used.