When buying dumplings carefully inspect the package. It must be sealed, marked the date of production and shelf life of the product. Note the presence of address of the manufacturer, barcode, composition and category of dumplings. Often important information is on the back of the packaging.
Look at the composition of frozen dumplings. A quality product should consist of meat (beef, pork, chicken, etc), onions, water, dough and spices. Permitted eggs or clear powder, garlic. Vegetable protein (soy, for example) affect the taste of the dumplings.
If the packaging is transparent, look at the integrity of the dumplings - they should be without faults and cracks. Should not be sticky dumplings.
Please pay special attention on the category of dumplings. There are five categories of meat and meat-containing semi-finished products. Category "a" means that the dumplings at least 80 percent of the meat. Dumplings category "B" contain from 60 to 80 percent of the meat in the stuffing. Products category contain from 40 to 60 percent of the meat. In the category "G" from 20 to 40 percent, and in category "D" meat at least 20 percent.