Contamination of poultry products with Listeria monocytogenes at poultry processing plants.

This study aimed to confirm that poultry products packed at poultry processing plants have already been contaminated with Listeria monocytogenes and that poultry products contaminated with L. monocytogenes are derived from broiler flocks infected with L. monocytogenes. L. monocytogenes was isolated from 16.8% (58/345) of chicken breast products and 2.3% (8/345) of chicken liver products. In contrast, L. monocytogenes was isolated from the pooled cecal content sample from only 1 (4%) of 25 flocks and was never isolated from any pooled dropping samples collected from 25 farms. The results of our study indicate that cecal content does not seem to be an important source of L. monocytogenes in poultry products.

A method for the determination of acrylamide in a broad variety of processed foods by GC-MS using xanthydrol derivatization.

A novel GC-MS method was developed for the determination of acrylamide, which is applicable to a variety of processed foods, including potato snacks, corn snacks, biscuits, instant noodles, coffee, soy sauces and miso (fermented soy bean paste). The method involves the derivatization of acrylamide with xanthydrol instead of a bromine compound. Isotopically labelled acrylamide (d3-acrylamide) was used as the internal standard. The aqueous extract from samples was purified using Sep-Pak™ C18 and Sep-Pak™ AC-2 columns. For amino acid-rich samples, such as miso or soy sauce, an Extrelut™ column was used for purification or extraction. After reaction with xanthydrol, the resultant N-xanthyl acrylamide was determined by GC-MS. The method was validated for various food matrices and showed good linearity, precision and trueness. The limit of detection and limit of quantification ranged 0.5-5 and 5-20 µg kg⁻¹), respectively. The developed method was applied as an exploratory survey of acrylamide in Japanese foods and the method was shown to be applicable for all samples tested.