The saponification value of fats and oils is one of the most common quality indices, reflecting the mean molecular weight of the constituting triacylglycerols. Proton nuclear magnetic resonance (1H-NMR) spectra of fats and oils display specific resonances for the protons from the structural patterns of the triacylglycerols (i.e., the glycerol backbone), methylene (-CH2-) groups, double bonds (-CH=CH-) and the terminal methyl (-CH3) group from the three fatty acyl chains. Consequently, chemometric equations based on the integral values of the 1H-NMR resonances allow for the calculation of the mean molecular weight of triacylglycerol species, leading to the determination of the number of moles of triacylglycerol species per 1 g of fat and eventually to the calculation of the saponification value (SV), expressed as mg KOH/g of fat. The algorithm was verified on a series of binary mixtures of tributyrin (TB) and vegetable oils (i.e., soybean and rapeseed oils) in various ratios, ensuring a wide range of SV. Compared to the conventional technique for SV determination (ISO 3657:2013) based on titration, the obtained 1H-NMR-based saponification values differed by a mean percent deviation of 3%, suggesting the new method is a convenient and rapid alternate approach. Moreover, compared to other reported methods of determining the SV from spectroscopic data, this method is not based on regression equations and, consequently, does not require calibration from a database, as the SV is computed directly and independently from the 1H-NMR spectrum of a given oil/fat sample.

The aim of the present study was to manufacture fresh cheese Labneh enriched with antioxidative compounds from pepper (Capsicum annuum) extracts encapsulated in alginate beads. The carbohydrate content, total phenolic, and carotenoids content, as well as the antioxidant activity of prepared Labneh samples, were evaluated. The microbiological screening on the 1st and 20th day of storage period at 4 ± 1 °C was performed as well. The obtained results for chemical properties illustrated that the addition of alginate-encapsulated pepper (Capsicum annuum) extracts in Labneh had a significant effect (p<0.05) on the level of total phenols and antioxidant activity in comparison with the control sample. The presence of lactose, galactose and glucose were detected in all samples. It was established that the total viable lactic acid bacterial count (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus) in the experimental samples decreased at the end of the storage period. Coliforms, yeasts, and moulds were not detected in the samples with encapsulated pepper extracts. The sensory evaluation demonstrated a higher score for most Labneh samples with encapsulated pepper extracts in comparison with the control sample. A new cheese product was developed and alginate-encapsulated pepper (Capsicum annuum) extracts were evaluated as a proper approach for the fortification of natural pigments and antioxidants in Labneh samples.

No abstract

Workers in occupational settings are usually exposed to numerous sources of electromagnetic fields (EMF) and to different physical agents. Risk assessment for industrial workplaces concerning EMF is not only relevant to operators of devices or machinery emitting EMF, but also to support-workers, bystanders, service and maintenance personnel, and even visitors. Radiofrequency EMF guidelines published in 2020 by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) may also be indirectly applied to assess risks emerging from EMF sources at workplaces by technical standards or legislation. To review the applicability and adequacy to assess exposure to EMF in occupational settings in the European Union, the most current ICNIRP guidelines on radiofrequency EMF are reviewed. Relevant ICNIRP fundamentals and principles are introduced, followed by practical aspects of exposure assessment. To conclude, open questions are formulated pointing out gaps between the guidelines' principles and occupational practice, such as the impact of hot and humid environments and physical activity or controversies around ICNIRPS's reduction factors in view of assessment uncertainty in general. Thus, the article aims to provide scientific policy advisors, labor inspectors, or experts developing standards with a profound understanding about ICNIRP guidelines' applicability to assess hazards related to radiofrequency EMF in occupational settings.

The aim of the present study was to establish a correlation between phenotypic characteristics of chemical composition, somatic cell count and rennet coagulation of sheep milk during different stages of lactation. The experimental milk samples were taken from Bulgarian autochthonous sheep breed-Local Stara Zagora sheep, newly developed breed-Bulgarian dairy synthetic population (BDSP), and Lacaune sheep breed. From the data obtained about the chemical composition of sheep milk, it was established that Bulgarian dairy synthetic population sheep breed had the highest fat value – 9.50%, whereas for the other breeds the fat value was approximately 8.30%. A slight variation in values for protein, lactose, solids-non-fat (SNF) and density was observed in the individual milk samples. The determined somatic cell count in the experimental samples ranged from 11 400 to 9 560 866 cells/ml, as the average value for the whole lactation period was 643 259 cells/ml. Strong negative correlation between somatic cell count value and parameters of milk coagulation ability was also established – SSC:RCT (-0.170); SCC:K20 (-0.142) and SCC:A30 (-0.254). The collected data showed undeniably that in order to improve rennet coagulation of sheep milk, conduction of thorough research, analysis and evaluation of milk productivity was needed, as well as application of selective breeding approaches and reduction of somatic cell count in milk.