Detection of adulteration in locally marketed retail meat products: Combined histological and chemical analyses

Abstract

Species authentication in food of animal origin is an urgent necessity for food control since food adulteration is relevant to religious, economic, and public health concerns. This study was conducted to apply histological and chemical means of identification to detect commercial fraud in different meat products. To achieve this aim, about 60 samples including, 20 samples each of minced meat, luncheon meat, and sausage were collected from various markets in Beni-Suef, Egypt. All samples were examined histologically using hematoxylin and eosin stains for the detection of foreign tissue. The examination was confirmed with acid-chiffon blue and Masson's trichrome stain. Additionally, meat product samples were chemically examined for determination of fat, protein, starch, and nitrite. The results revealed that the examined minced meat, luncheon, and sausage samples were adulterated by different tissues including elastic artery, spongy bone, skin, fibrous connective tissue, visceral muscles, visceral organs, cartilage, tendon, secretory gland, and plant tissue. The percentages of fat accounted for 17.75 ± 0.9, 13.97 ± 0.40, and 11.23± 0.5 %, while the percentages of protein were 19.47 ± 0.6, 15.99 ± 0.3 and 16.67 ± 0.7 % in minced meat, luncheon meat, and sausage samples, respectively. Sodium nitrite was below the detection limit in all minced meat samples and 40% of luncheon samples, nonetheless, 60% of luncheon samples and all sausage samples contained detectable levels of sodium nitrite. Furthermore, starch was undetectable in all minced meat samples and 40% of sausage samples, on the other hand, all examined luncheon samples and 60% of examined sausage samples contained detectable starch levels. In conclusion, the histological and chemical examination could be valuable methods to detect adulteration in meat products.