Tinctorial properties of a non-meat proteins

The article discusses the identification of vegetable protein additives used in the meat industry using histological methods. The supplements tested were Soy Protein Isolate Powder 90%, Pea Protein Powder 80%, and Rice Protein Powder 80%, which were provided by Summit Ingredients Co., Ltd. (China). Samples of minced chicken breast were prepared; 0.2 g of dry additive was added to 10 g of minced meat. Histological samples were prepared using standard methods. Staining was carried out with different groups of dyes specified in regulatory documents. Each sample was stained with the following dyes: hematoxylin-eosin; hematoxylin-eosin with additional Sudan III staining; hematoxylin and Sudan III. As a result, a catalog of microphotographs of these additives was compiled. Rice protein fragments have the shape of polygonal lumps with a heterogeneous structure without holes. They stain only oxyphilically with eosin. Soy isolate fragments have a variety of shapes with rounded outlines with a hole inside. They perceive hematoxylin and stain basophilic. Pea protein fragments are characterized by more rounded shapes, also with a hole inside. They perceive hematoxylin and turn purple. In this work, we encountered a discrepancy between the tinctorial properties of soy isolate and pea protein and regulatory documents, which makes further research on these additives relevant. Soybean and pea food additives, which belong to the same family, demonstrate similar morphological and tinctorial properties, which complicates their histological identification and requires additional genetic research methods. This makes it possible for unscrupulous manufacturers to use pea protein as a counterfeit additive, since PCR studies most often examine soybean DNA.