application of morphological method for detection of unauthorized tissues in processed meat products

background: nowadays, there is an increase of meat and animal carcass consumption worldwide. due to the economic value of meat, the likelihood of using unauthorized tissue is possible in meat products. based on these observations, the aim of the present study was to apply morphological method for detection of unauthorized tissues in processed meat products.  methods: in this study, a total of 20 samples of different types of processed meat products including kabab loghme (n=5), sausage (n=5), handmade hamburger (n=5) and kabab koobideh (n=5) were randomly collected from restaurants and supermarkets in iran. the samples were divided into three parts and then, one piece was taken from each part for the histological study. the tissues were fixed in 10% neutral-buffered formalin and were dehydrated and embedded in paraffin and routinely processed for light microscopy. the paraffin-embedded blocks were cut into 6 μm sections and stained using hematoxylin and eosin (h&e;) for histological study.  results: the skeletal muscle tissues were visible clearly in all samples. a wide range of unauthorized tissues have been detected including connective tissue (n=20), gizzard (n=2), adipose tissue (n=7), soya (n=11), cartilage (n=5) and ovary (n=1).  conclusion: the present study showed the use of unauthorized tissues in iranian processed meat products which were detectable by histological method. therefore, histological technique may be a simple and economic tool for evaluation of the meat adulteration and to improve hygiene and meat quality.