Nanotechnology is important in food packaging because it increases shelf life, enhances food safety, and improves sensory characteristics and nutrient availability. We aimed to review scientific publications on the synthesis of nanoparticles, as well as their properties and applications in the food industry. Research and review articles published from 2020 to 2022 were obtained from the database using the keywords “nanoparticles”, “film”, and “food”. They were on the synthesis of metal and metal oxide nanoparticles and their uses in food films and coatings. We reviewed methods for synthesizing inorganic nanoparticles from metals and their compounds (silver, zinc, iron, etc.), as well as described their antimicrobial action against foodborne pathogens. By incorporating nanoparticles into films, we can create new materials with strong antimicrobial properties in vitro. Nanoparticles can be used to develop both polymer and biopolymer films, as well as their mixtures. Composite coatings can work synergistically with metal nanoparticles to create multifunctional food packaging systems that can act as compatibilizers. Particular attention was paid to metal nanoparticles in food coatings. We found that nanoparticles reduce the rate of microbial spoilage and inhibit lipid oxidation, thereby increasing the shelf life of raw materials and ready-to-eat foods. The safety of using nanoparticles in food coatings is an important concern. Therefore, we also considered the migration of nanoparticles from the coating into the food product. Incorporating nanoparticles into polymer and biopolymer films can create new materials with antimicrobial properties against foodborne pathogens. Such composite films can effectively extend the shelf life of food products. However, the undesirable migration of metal ions into the food product may limit the use of such films.

The interest in berries from food manufacturers is huge, which is explained by good organoleptic characteristics and high biological activity of berries. One way to preserve the properties of berries throughout the year is to obtain extracts. Determining the conditions and type of optimal extraction technology to obtain biologically active substances from plant materials is an important stage in the production of new natural preventive additives. The aim of this work is to study the chemical composition and antioxidant activity of blueberry extracts (Vaccinium myrtillus L.) obtained by various methods: maceration, ultrasonic and microwave extraction. The use of ultrasonic extraction as a method of intensifying the process of extracting biologically active compounds from blueberries is very effective. This proves an almost 2-fold increase in the flavonoid content in the extracts. However, the content of anthocyanins in the extracts of blueberries is not the highest for ultrasonic extraction (a decrease by 3.3 times compared with maceration), in all likelihood due to the instability of this class of compounds in this type of processing. Among the extracts of blueberries obtained by three technologies (maceration, microwave and ultrasound treatment), it is the ultrasound extract that has the highest antioxidant activity (9.5±0.1 mg/cm3, 18.18 mmol±0.24 Fe2+/1 kg, 58.6%), determined by three methods: DPPH method, FRAP method, method for assessing antioxidant properties using a model system with linoleic acid. Ultrasonic extraction was chosen as a technology for obtaining a concentrated blueberry extract.

Extracts and their concentrates can be considered as a source of biologically active ingredients of food products and as food additives to increase the consumption of useful substances of berries. The benefits gained from their use lead to the development of advanced technologies that can allow them to be extracted from the feedstock without significantly compromising the biological activity from the feedstock. In this paper, we studied the content of antioxidants and their activity in concentrated extracts of cranberry (Vaccinium Oxycoccus), sea buckthorn (Hippophae rhamnoides L.), blackberry (Rubus fruticosus), viburnum (Viburnum opulus L.) and mountain ash (Sorbus aucuparia L.) berries. For all extracts, the total content of phenolic compounds, flavonoids and anthocyanins, antioxidant activity according to the DPPH method and iron-reducing antioxidant activity (FRAP) were determined. Concentrated extracts of viburnum contain the largest amount of phenolic compounds (9.3±0.3 mol HA/l), flavonoids (1.96±0.08 mol K/l) and anthocyanins (0.26±0.02 mol CG/l) among the studied extracts. There is also a high total content of phenolic substances and flavonoids in blackberry and rowan extracts (5.7 mol HA/l, 1.33 mol K/l and 4.7 mol HA/l, 192 mol K / l, respectively). The antioxidant activity of the extract of viburnum berries showed a directly proportional dependence on the content of biologically active compounds in it: DPPH-method-2.4 mg / ml; FRAP-method-39.99 mmol Fe2+ / kg. Also, high levels were found in concentrated extracts of blackberries, sea buckthorn and mountain ash. It is the extracts of viburnum, blackberry and mountain ash that are recommended to be used in the production of food products to enrich them with biologically active substances and give them antioxidant properties. Cranberry and sea buckthorn extracts can be used in combination with other extracts.

Plant materials have huge untapped potential in Russia. It has potential antioxidant properties, contains a large number of biologically active substances. As a result of a comparative study of the content of phenols, flavonoids, anti-radical ability according to the method with 2,2'-diphenyl-1-picrylhydrazyl reagent, restoring forces according to FRAP method with 2,4,6-tri (2-pyridyl)-1,3 reagent, 5-triazine in extracts obtained by three different extraction technologies (maceration 37 °C for 2 hours, microwave irradiation 800 W 1 min, ultrasonic treatment 37 °C, 37 kHz 90 min) from plant materials: rosehips (Rosa L.), oak bark (Quercus robur L.), rhubarb root (Rheum officinale), ginseng root (Panax L.), birch buds (Betula L.) on the advantage in the level of the studied indicators for the technology of extracts using innovative effects – ultrasonic irradiation. Extracts of plant materials are potential sources of antioxidant substances and can be used in the pharmaceutical, cosmetic industry and as components of food systems. A general trend is observed, which was observed in the study of various indicators: concentrated extracts, in which phenolic compounds and flavonoids are preserved after concentration (rhubarb root extract and birch bud extract), exhibit the best antiradical activity and restoring power; then, as with their destruction, other indicators fall.

Plant extracts rich in polyphenols can be used in the food industry as natural preservatives, extending the shelf life of prepared and semi-finished foods without chemical preservatives. In this paper, we investigate the polyphenolic composition, antioxidant activity and antibacterial properties of herbal extracts as part of food systems. The research objects were knot grass (Polýgonum aviculáre), marjoram (Oríganum), bur beggar-ticks (Bídenstripartíta), thyme (Thymus), whortleberry leaves (Vaccínium ida vítis), calendula (Calendula), sage (Salvia), chamomile flowers (Matricāriachamomīlla), eucalyptus (Eucalýptus) and bearberry (Arctostáphylosúva-úrsi). We determined the total content of phenolic compounds and flavonoids; the antioxidant activity by DPPH and FRAP methods; variations in the bacterial сontamination of animal raw materials over total bacterial count (TBC), coliform bacteria, yeast/fungi, salmonella and staphylococcus. Extracts of sage (1138±57 mg GA/100 g and 537±25 mg C/100 g), eucalyptus (1073±49 mg GA/100 g and 412±20 mg C/100 g), chamomile flowers (1002±36 mg GA/100 g and 493±22 mg C/100 g) and marjoram (1015±42 mg GA/100 g and 458±21 mg C/100 g) contain the largest amount of biologically active substances (phenols and flavonoids, respectively). Sage, eucalyptus and chamomile extracts demonstrate the highest antioxidant activity among the studied samples. Most of the studied extracts exhibit little or no effect on the organoleptic properties of finished products. In addition, chamomile flower, sage and eucalyptus extracts suppress the growth of pathogenic microorganisms in foods under experimental conditions. The microflora growth is significantly reduced when treating animal raw materials with calendula flowers, marjoram and thyme extracts. Extracts of sage, chamomile flowers, calendula flowers, marjoram and thyme can be recommended as components of food raw materials.