Fruits and vegetables are most often consumed without being thoroughly processed before consumption. Some plant foods are vacuum-packed to ensure long shelf life as well as preserving the quality and safety of the product. Fruits and vegetables carry naturally occurring non-pathogenic epiphytic microflora on their surfaces. During growth, harvesting, transport and further handling they can be repeatedly contaminated by pathogens from human or animal sources. Fresh fruit crops have been implicated in a number of documented foodborne disease outbreaks. Outbreaks of diseases caused by bacteria, viruses and parasites have been epidemiologically linked to the consumption of a wide range of fruits and vegetables. The aim of our study is to assess the risk of contamination in fruit and berry crops and how to address this long-standing problem, namely, contamination of fruit and vegetables with unnatural pathogenic microflora. The following fruit and berry crops common in Turkestan region were chosen for the experiment: Apple variety Suislepskoe (stolovka) , peach variety Nectarine and grape variety Kishmish. Bacteriological inoculation was carried out by membrane filtration of used sterile water to obtain flushes from the surface of fruit crops. All work was carried out under full aseptic conditions. The utensils, water and other equipment used in the work were sterilised in advance. The data obtained during the experiment shows that there is a potential for widespread contamination of uncharacteristic microflora of plant products. Based on the results of the study it can be concluded that there are yeasts and acetic acid bacteria on the surface of all three samples of fruit and berry crops, which can be universally contaminated food and are not the natural microflora for the above mentioned crops. Specifically, fruits and vegetables can be contaminated with various bacterial pathogens, including Salmonella, Shigella, E. Coli O157:H7, Listeria monocytogenes and Campylobacter.

The article is devoted to the study of the main types of retort packaging, as well as polymer and combined materials used for its manufacture. The authors have compiled a classification of retort packaging presented on the modern market, investigated the technological properties of packaging materials, and also determined the requirements for modern retort packaging: resistance to sterilization at a temperature of at least 120°C, steam and moisture resistance, chemical inertia to canned products, tightness, low gas permeability. It has been established that in order to give the retort packaging the required properties, it is made of multilayer polymer or combined materials, each of the layers of which performs certain functions. It is determined that due to the barrier properties of polymer and combined materials with respect to oxygen, retort packaging provides shelf life of canned products up to 5 years, which allows the use of retort packaging made of polymer and combined materials as an alternative to glass and metal packaging. In experimental studies, the composition of the outer layers of modern retort packaging was analyzed and it was concluded that polypropylene or polyethylene terephthalate are most often used, since these polymer materials are thermally and chemically resistant, vapor- and moisture-proof. It is established that materials that are barriers to gases are used as the middle layer – aluminum foil, metallized films, ethylene vinyl alcohol, polyamide. It is proved that polymer co-extrusion, multilayer injection molding or lamination is used for the manufacture of such materials and packaging. The data obtained indicate the high barrier properties of combined packaging materials, therefore, the thermal and chemical stability of the polymer and combined materials used makes it possible to use retort packaging for packing almost all groups of canned products.