A new method for the specific and sensitive detection of soya (Glycine max) in processed meat products has been developed using polymerase chain reaction (PCR) technology. The presence of soya deoxyribonucleic acid (DNA) from several soya protein concentrates was determined with two pairs of specific oligonucleotides yielding a 414-bp (bp = base pair) fragment and an internal 118-bp fragment amplified from the soya lectin Le1 gene. The test detected DNA from textured soya protein concentrates in meat products at a level of 1% and was confirmed by a commercially available enzyme-linked immunosorbent assay (ELISA).

The polymerase chain reaction (PCR) technique was applied to meat species identification in marinated and heat-treated or fermented products and to the differentiation of closely related species. DNA was isolated from meat samples by using a DNA-binding resin and was subjected to PCR analysis. Primers used were complementary to conserved areas of the vertebrate mitochondrial cytochrome b (cytb) gene and yielded a 359 base-pair (bp) fragment, including a variable 307 bp region. Restriction endonuclease analysis based on sequence data of those fragments was used for diffferentiation among species. Restriction fragment length polymorphisms (RFLPs) were detected when pig, cattle, wild boar, buffalo, sheep, goat, horse, chicken, and turkey amplicons were cut with Alul, Rsal, Taql, and Hinfl. Analysis of sausages indicates the applicability of this approach to food products containing meat from 3 different species. The PCR–RFLP analytical method detected pork in heated meat mixtures with beef at levels below 1%, and the method was confirmed with porcine- and bovine-specific PCR assays by amplifying fragments of their growth hormone genes. Inter- and intraspecific differences of more than 22 animal species with nearly unknown cytb DNA sequences, including hoofed mammals (ungulates), and poultry were determined with PCR–RFLP typing by using 20 different endonucleases. This typing method allowed the discrimination of game meats, including stag, roe deer, chamois, moose, reindeer, kangaroo, springbok, and other antelopes in marinated and heat-treated products.

No abstract

No abstract

No abstract

No abstract

A rapid, sensitive and specific analysis of food samples determining wheat contamination was established using polymerase chain reaction (PCR) technology. First, primers specific for highly conserved eukaryote DNA sequences were used to prove isolated nucleic acid substrate accessibility to PCR amplification. Subsequently, a highly repetitive and specific genomic wheat DNA segment was amplified by PCR for wheat detection. This assay was tested with 35 different food samples ranging from bakery additives to heated and processed food samples. In addition, the PCR method was compared to an immunochemical assay that detected the wheat protein component gliadin. Combination of both assays allowed a detailed characterization of wheat contamination. Hence, wheat flour contamination could be distinguished from gliadin used as a carrier for spices as well as from wheat starch addition.

No abstract