[Review of the possible impact of 100% juices on nutritional quality, risk of obesity and type 2 diabetes mellitus].

Studies show that fruit juices are a source of macro- and micronutrients. Despite the fact that modern technologies for the industrial processing of fruits into juice are aimed at preserving the bioactive compounds of the original raw materials, juices are the subject of controversy due to the presence of free sugars and less dietary fiber than in fresh fruits. The purpose of the work was to systematize the available studies on the effect of 100% juices on nutrition quality, obesity and type 2 diabetes mellitus. Material and methods. Systematic search in PubMed, Google Scholar, eLIBRARY databases in accordance with the inclusion criteria: the study examined 100% fruit or vegetable juices, the article was in Russian or English in a peer-reviewed journal, the subjects (in the case of clinical studies) were people aged 1 to 18 years and older. 98 sources were analyzed based on the title of the article, of which 35 did not relate to juices. 63 sources were analyzed based on their abstracts, of which 28 were included in the main study. Results. According to the results of the literature analysis, it follows that moderate consumption of 100% juices not only does not have negative effects on human health, but, on the contrary improve the health of the organism. In particular, its intake helps lower blood pressure and the content of highly sensitive C-reactive protein, thereby reducing the risk of cardiovascular diseases. Juices enrich the daily diet due to the macro- and micronutrients they contain, which improves the quality of nutrition in general. Researches prove that there is no correlation between moderate juice consumption and type 2 diabetes onset. The glycemic index of the juices is low or medium, which distinguishes them from standard soft drinks containing sugar. The consumption of juices (100-500 ml/day) does not increase the risk of obesity in adults and children. Conclusion. Negative effects, such as weight gain and an increased risk of diabetic diseases, can only be observed with excessive consumption of juices.

[Comparative analysis of the total content of polyphenols in some types of industrial juice products].

Fruits are the most important source of polyphenols, substances that have a positive effect on human health. Modern technologies for the industrial processing of fruits into juice are aimed at preserving the useful components of the raw material in it. The issue of the content of polyphenols in industrial juice products, and, especially, changes in their concentration over time, is important for understanding the nutritional value of juice products and requires further study. The purpose of the work is to study the total content of polyphenols depending on the type of juice products and the time elapsed since the product was manufactured. Material and methods. The total content of polyphenols in terms of gallic acid was determined by the Folin-Ciocalteu method in four popular types of juice products (orange, grapefruit and apple juice, cherry nectar), various brands and with different production dates. The results of the determination in 60 product samples selected from Russian retail chains were analyzed. Results. Polyphenols are found in all types of products in significant amounts: in orange juices from 678 to 870 mg/kg, in grapefruit juices from 447 to 798 mg/kg, in apple juices from 264 to 1320 mg/kg, in cherry nectars from 696 to 1090 mg/kg. The highest average content was found in cherry nectars (859±106 mg/kg), followed by orange (781±54 mg/kg) and grapefruit juices (634±91 mg/kg). In apple juices, there is a significant variation in the content of polyphenols depending on the method of juice production - the highest content of polyphenols was found in straight-pressed apple juices (1119±124 mg/kg). The content of polyphenols in products stored for six months or more does not show any significant differences from the content in fresher products, which suggests a consistently high content of polyphenols in juice products throughout the entire shelf life. Conclusion. The study showed the presence of high concentrations of common polyphenols in juice products. The dependence of total polyphenol content on the time elapsed since the production of juice product was not found. Juice products of industrial production can make a significant contribution to the intake of polyphenols in the human body.