Zeszyty Problemowe Postępów Nauk Rolniczych

EFFECT OF PACKAGING METHOD, STORAGE TIME AND CONDITIONS ON THE CHICKEN THIGHS QUALITY

Marta Chmiel — 2021-08-24

The aim of the study was to determine the effect of packaging method (PVC overwrap – in air, and under high-oxygen modified atmosphere – MAP), storage time and conditions (cooling room or display case) on the quality of chicken thighs. In MAP packages the gas mixture composition was measured. In all samples, the drip loss, pH of muscle tissue and L*, a*, b* color components of skin and muscle tissue were determined. It was found that along with the extension of storage time a tendency toward decreasing O₂ and an increasing in CO₂ content in MAP packages was observed. The amount of drip loss in MAP packaging for all days of storage was significantly higher (p ≤0.05) in comparison to the PVC overwrap. Also the amount of drip loss systematically increased with the extension of storage time, regardless of the packaging method and storage conditions of raw material.

EFFECT OF AVOCADO OIL ON THE INDUCTION OF YEAST HYDROLASES

Jolanta Małajowicz — 2021-08-24

DEPENDENCE BETWEEN THE ANTIMICROBIAL ACTIVITY AND THE MOLECULAR STRUCTURE OF PHENOLIC ACIDS AND THEIR SALTS WITH ALKALI METALS AS BIOLOGICALLY ACTIVE SUBSTANCES PRESENT IN THE NATURAL PRODUCTS

Jolanta Piekut — 2021-08-24

This paper presents the dependence of antibacterial activity on the structure of phenolic acids as biologically active substances of natural origin. The biological activity of selected compounds was assessed by means of microbiological tests on selected strains of tested bacteria Staphylococcus aureus, Proteus vulgaris and Bacillus subtilis. Microbiological assays were correlated with spectroscopic data. The dependencies between the percentage growth inhibition of microorganisms under the influence of test compounds vs. values of the wavenumbers for individual bands present in the infrared spectra (FT-IR) of these compounds, were determined. These results suggest that the biological activity of the compounds depends on the electron density distribution both in the ring and the carboxylate anion. Therefore, the dependence structure-activity may be useful for predicting the biological properties of a series of novel synthetic compounds without the need for biological tests for each compound.

WEATHER FACTORS AND BASIC NUTRIENT REQUIREMENTS FOR THE CULTIVATION OF INDUSTRIAL HEMP ( Cannabis sativa L.)

Małgorzata Strzelczyk — 2021-08-24

Hemp (Cannabis sativa L.) is one of the plants that have accompanied mankind for thousands of years. Fiber hemp belongs to the group of useful plants whose large yields of biomass can be used in a variety of ways. The enormous potential of this plant is used in almost every industry sector: from pulp and paper industry to light industry (clothing, textiles) as well as in other manufacturing branches which include toys, flower pots, disinfecting mats and even funeral urns. Hemp is characterized by high plasticity and resistance to changing agro-climatic factors, thanks to which extreme weather conditions are not an obstacle to its cultivation. However, similarly to other species, the final yield is contingent on the interaction of several important factors. Hemp variety, sowing density, harvest time and fertilization are relevant factors which have a bearing on shaping hemp’s biomass. The influence of weather conditions on the yield of biomass and the content of cannabinoids is not to be underestimated either. Poland has a long-standing tradition of growing and processing hemp. The nineteenth century and the beginning of the twentieth century turned out to be extremely successful for hemp, because its cultivation was widespread almost all over Poland. In the 1920s and 1930s, the hemp acreage was about 29,000 ha. The cultivation of industrial hemp in our country is subject to strict legal restrictions formulated in the Act of July 29, 2005 on Counteracting Drug Addiction (with further amendments). Nevertheless, interest in this fascinating plant is growing.

FATTY ACID PROFILE OF RAW MATERIALS AND CHOCOLATE MILK MASS DEPENDING ON TEMPERATURE AND TIME OF MIXING

Bogumiła Urbańska — 2021-08-24

The effect of time and temperature of mixing on the fatty acids profile of chocolate milk mass was analyzed. An analysis of fatty acid composition was performed using chromatographic methods in roasted and unroasted cocoa beans and liquor, milk powder, and prepared chocolate milk mass (CM). Both cylinder-dried and spray-dried milk powders had very similar fatty acid profiles. The effect of mixing parameters on the fatty acids composition was shown, but it was ambiguous. The greatest differences were found after 85 and 120 minutes of basketing at temperatures of 70 and 80°C, especially in unsaturated acids.