Meat adulteration constitutes an important problem in Egypt especially with the low income to make meat products of lower prices. Adulteration may occur by substitution of low priced or even banned meat species for that high priced one as well as by addition of non meat protein as soybean. This adulteration causes many diseases as infection with bacteria or virus as Bovine Spongiform Encephalopathy (BSE) and scrapie especially with addition of infected parts. Moreover consumers suffer from allergy to some proteins which may be added but not labeled. It is reported that genetically modified organisms may cause allergy and antibiotic resistance.
Therefore, in this study AGID and PCR techniques were applied for detection of meat and soybean adulteration. Firstly for application of AGID technique meat extract from beef, chicken, pork and donkey as well as saline extract from heated and raw soybeans were prepared. Hyper immune sera were prepared in rabbits by subcutaneous injection of meat extracts and soybean extracts. Then rabbits were bled and blood collected to get the specific antisera. Positive results indicated by appearance of clear precipitation line between the antibody and the corresponding antigen with assurance that no cross reaction occurred between species.
Two hundred samples from beef meat products (50 minced meats, 50 raw kofta, 50 sausages and 50 beef burger) were subjected to analysis by AGID technique. The incidence of adulteration of minced meat with each of chicken and pork were 6%. The rate of adulteration was 34% and 26% in raw kofta, 32% and 14% in sausage and 32% and 2% in beef burger, respectively. Donkey was detected only in beef burger at rate of 2%.
The adulteration rates with heated and raw soybeans were 8% and 4% in raw kofta, 28% and 2% in sausage and 18% and 2% in beef burger, respectively. Heated and raw soybean failed to be detected in minced meat.
For application of PCR technique specific primers for chicken, pork, donkey meat species, native and modified soybean were prepared, there molecular weights were 420, 343, 350, 118 and 172 bp, respectively. Deoxyribonucleic acid (DNA) was extracted from tested samples for detection of the previous species in these tested samples.
Out of suspected and negative adulterated samples examined by AGID technique, fifty samples were reanalyzed by PCR technique. By using PCR technique the adulteration rates with chicken were 57%, 63.7%, 66.7% and 69% in minced meat, raw kofta, sausages and beef burger, respectively. The adulteration rates with pork were 35.7%, 45.5%, 41.7% and 23% in minced meat, raw kofta, sausages and beef burger, respectively. The adulteration rates with donkey were 7%, 18%, 8% and 7.7% in minced meat, raw kofta, sausages and beef burger, respectively. The adulteration rates with native soybean were 50%, 72.7%, 75% and 100% in minced meat, raw kofta, sausages and beef burger, respectively. The adulteration rates with modified soybean were 28.6%, 45.5%, 50% and 69% in minced meat, raw kofta, sausages and beef burger, respectively. It is noticed that about 57%, 62.5%, 66.7 % and 69% from native soybean were modified in minced meat, raw kofta, sausages and beef burger, respectively. Totally it was 65% form native soybean was modified.