Application of Optical Quality Control Technologies in the Dairy Industry: An Overview

Quantification of Lactobacillus reuteri ProTectis in MRS Broth Using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) Spectroscopy and Chemometrics

There is an increasing global demand for probiotics because of their numerous health benefits. However, a significant percentage of commercially available probiotic products have microbial quantities that are not in accordance with their product labels. In quantifying bacteria, the viable plate count is the standard method but is considered laborious and time-consuming. We demonstrate the use of an attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy coupled with chemometrics to quantify a pure culture of Lactobacillus reuteri (L. reuteri) ProTectis grown in deMan, Rogosa, and Sharpe broth. The chemometric partial least-squares model generated was able to accurately quantify viable plate count (VPC) (root-mean-square error of cross-validation (RMSECV) = 0.115 log CFU mL-1, root-mean-square error of prediction (RMSEP) = 0.145 log CFU mL-1, R2 = 0.982). These results provide proof of concept for this quantification technique and can potentially be developed and applied for the quantification of L. reuteri ProTectis in food products.

A Monoblock Light-Scattering Milk Fat Percentage and Somatic Cell Count Sensor for Use in Milking Systems

A monoblock light-scattering sensor, which is capable of measuring the fat content of milk and indicating the excess by which the somatic cell count (SCC) is over the permissible level, has been developed for installation in dairy systems. In order for the sensor to perform measurements when the milking machine is working in the "milk plug" mode, a flow-through unit is designed in the form of a pipe with a lateral cylindrical branch, in which milk accumulates so as to eliminate large bubbles and achieve continuity of the milk flow. The operation of the sensor is based on the registration of the angular intensity distribution of light scattered in the transparent cylindrical segment of the tube branch. A semiconductor laser with a wavelength of 650 nm is used as a light source for determining scattering in milk. The angular distribution of the scattered light intensity (scattering indicatrix) is recorded using an axial photodiode array. The fat content is determined by the average slope of the measured scattering indicatrix in the range of scattering angles 72-162°. The SCC level is estimated from the relative deviation of the forward scatter intensity normalized to the backscatter intensity with respect to uninfected milk. The sensor has been tested on a Yolochka-type milking machine.

Activation of Tomato Growth Under Photoconversion Coatings with Nanoluminophor Sr0.76Ba0.20Yb0.02Er0.02F2.04

The effect of coatings containing upconversion luminescent nanoparticles on the cultivation of Solanum lycopersicum has been studied. Sr0.76Ba0.20Yb0.02Er0.02F2.04 particles capable of converting infrared radiation into visible light (λem = 660 nm, 545 nm, and 525 nm) were used as the phosphor. It was shown that the cultivation of tomatoes under photoconversion coatings accelerated the adaptation of plants to ultraviolet radiation. A more efficient distribution of the energy of absorbed light between the processes of photosynthesis and thermal dissipation under upconversion coatings was revealed. As a result, plants grown under photoconversion coatings increased the number and total leaf area, stem length, and leaf chlorophyll content.

Interaction of Nd:YAG Laser Radiation with Bovine Serum Albumin Solution

In this paper, the effect of Nd:YAG laser radiation on the properties of the BSA protein is investigated. A solution with a protein concentration of 5 mg/ml was irradiated for 30 minutes. After a 5-minute and 30-minute exposure, absorption spectra were taken, the particle size in the solution was determined by dynamic light scattering (DLS), the refractive index was determined, and fluorescent maps were taken. Raman spectroscopy of proteins was also performed. The results showed that after irradiation, the absorption of the protein solution decreases in the spectral range corresponding to amino acid residues. In DLS experiments, it was shown that the peak corresponding to protein molecules decreases, and the peaks corresponding to large aggregates (>100 nm) grow. Raman spectroscopy has shown that there is a decrease in intensity at a wavelength of 1570 cm-1. There were no significant changes in the refractive indices and the shape of the fluorescent maps. The data suggest that partial denaturation of proteins took place.

Composite Coating for the Food Industry Based on Fluoroplast and ZnO-NPs: Physical and Chemical Properties, Antibacterial and Antibiofilm Activity, Cytotoxicity

Bacterial contamination of meat products during its preparation at the enterprise is an important problem for the global food industry. Cutting boards are one of the main sources of infection. In order to solve this problem, the creation of mechanically stable coatings with antibacterial activity is one of the most promising strategies. For such a coating, we developed a composite material based on "liquid" Teflon and zinc oxide nanoparticles (ZnO-NPs). The nanoparticles obtained with laser ablation had a rod-like morphology, an average size of ~60 nm, and a ζ-potential of +30 mV. The polymer composite material was obtained by adding the ZnO-NPs to the polymer matrix at a concentration of 0.001-0.1% using the low-temperature technology developed by the research team. When applying a composite material to a surface with damage, the elimination of defects on a micrometer scale was observed. The effect of the composite material on the generation of reactive oxygen species (H₂O₂, •OH), 8-oxoguanine in DNA in vitro, and long-lived reactive protein species (LRPS) was evaluated. The composite coating increased the generation of all of the studied compounds by 50-200%. The effect depended on the concentration of added ZnO-NPs. The antibacterial and antibiofilm effects of the Teflon/ZnO NP coating against L. monocytogenes, S. aureus, P. aeruginosa, and S. typhimurium, as well as cytotoxicity against the primary culture of mouse fibroblasts, were studied. The conducted microbiological study showed that the fluoroplast/ZnO-NPs coating has a strong bacteriostatic effect against both Gram-positive and Gram-negative bacteria. In addition, the fluoroplast/ZnO-NPs composite material only showed potential cytotoxicity against primary mammalian cell culture at a concentration of 0.1%. Thus, a composite material has been obtained, the use of which may be promising for the creation of antibacterial coatings in the meat processing industry.

Development of an Environmentally Friendly Technology for the Treatment of Aqueous Solutions with High-Purity Plasma for the Cultivation of Cotton, Wheat and Strawberries

The microwave setup for obtaining plasma-activated water (PAW) has been created. PAW contains significant concentrations of H2O2 and NO3−, has a reduced content of O2, high conductivity, a high redox potential and low pH. Likewise, the specific electrical conductivity and concentration of H2O2 and NO3− linearly depend on the treatment time. These parameters are simple and convenient markers for controlling the preparation of PAW. It has been established that PAW solutions with a concentration of 0.5–1.0% increase the germination energy, protect against fusarium and hyperthermia in cotton, wheat and strawberry seeds. In addition, PAWs have a positive effect on the growth rate of plants in the early stages of development. The use of PAW provides significant benefits over the chemical preparations Dalbron and Bakhor, so-called seed germination stimulators (SDS).

Development of an Algorithm for Rapid Herd Evaluation and Predicting Milk Yield of Mastitis Cows Based on Infrared Thermography

The aim of this study was to explore the possibility of assessing the health status of a cow’s udder using infrared thermography. We studied the effect of mastitis on cow milk yield, the effect of mastitis on udder surface skin temperature, and the dependence between severity of mastitis and udder temperature. We determined the presence of a significant relationship between the udder surface skin temperature and the milk yield of mastitis cows (Coefficient of determination = 0.886, linear Pearson correlation coefficient = −0.96), as well as the absence of a significant relationship between the udder surface skin temperature and the milk yield of healthy cows (Coefficient of determination = 0.029, linear Pearson correlation coefficient = 0.16). We substantiated the temperature ranges of the udder surface of healthy cows [32–35.9 °C] and mastitis [36.1–39 °C]. The obtained data made it possible to form an algorithm that allows a quick assessment of the herd for the presence of udder disease, using infrared images of the udder surface skin temperature.