ANTIMICROBIAL BIODEGRADABLE PACKAGING FOR SLICED BAKERY

In the modern minds of the advanced ecology and safety of food products control, it is relevant the development of antimicrobial biodegradable packaging. The article presents the results of the antagonistic action of nanodispersed titanium dioxide powder (TiO2) at the warehouse of biodegradable packaging for bakery products on the living of microorganisms (Escherichia сoli, Bacillus subtilis, Candida albicans, Aspergillus niger). It is known there are developments on the use of antimicrobial substances of both organic and inorganic origin, the microbiological action of the substances used have an effect on pathogenic, opportunistic, fungi, gram-negative and gram-positive bacteria. We found that the introduction of 1% TiO2 r into the molding solution allows to give the package antibacterial properties, as it inhibits the development of Escherichia coli and Bacillus subtilis, as there is a delay in the growth of their colonies compared to the sample without packaging with TiO2. According to the results of provocative testing, biodegradable packaging with a content of 1% TiO2 has an inhibitory effect on Bacillus subtilis. In addition to antimicrobial properties, the package under study must also have barrier properties, so the vapor permeability of the presented package was determined. The study results show that the addition of 1% TiO2 slightly reduces the vapor permeability, but the increase in the concentration 2–5% of TiO2 causes an increase in vapor permeability from 4.7 to 5.2 mg / (m∙h∙kPa). The vapor permeability of the presented biodegradable antimicrobial packaging is due to the presence of pores, the number and size of which were determined experimentally. Thus, nanodispersed TiO2 in the amount of 1% in the molding solution of the biodegradable coating is an effective antimicrobial component for antimicrobial coatings, which does not impair their barrier properties.

Nanocellulose as Modifier for Hollow Fiber Ultrafiltration PSF Membranes

In the present work, a study was conducted for the first time on the modification of hollow fiber UF PSF membranes by cellulose nanofibrils. Two approaches to membrane modification were analyzed: 1) introduction of CNF into the molding solution; 2) additions of CNF to the internal coagulant. Analysis of the transport properties of the investigated membranes showed that the first approach allows increasing the porosity of hollow fiber PSF membranes, due to which the permeability increases from 82 to 287 l / m2 h bar compared to the original membranes. Rejection of dye Blue Dextran (MM = 69 kg / mole) is reduced by 20%. The addition of CNF to the outside coagulant led to the formation of not only the inside selective layer, but also the outer one, while the permeability increases 1.5 times, and the rejection of the dye also increases from 96 to 99%.