Analysis of Selected Physicochemical Properties of Commercial Apple Juices

The paper presents the comparison of quality of six different commercial apple juices produced in Poland. The apple juices came from two different Polish companies. From each manufacturer three various juices were selected: two cloudy and clarified one produced as a mixture of different apple varieties. The following properties were evaluated: density, soluble solid content, viscosity, total phenolic contents, phenolic acid, and antiradical activity. The obtained results showed that three from fourth cloudy juices (M1Sz, M1A and M2A) differed from clarified juices. The highest differences were noticed for total phenolic contents, phenolic acids, antiradical activity and viscosity. The values of these properties ranged between 60.72–103.6 mg GAE·100-1 mL-1 for phenolic contents, 78.3–90.9% for antiradical activity and 2.68–5.79 mPa·s for viscosity. The remaining cloudy juice (M2Sz) was more similar to the clarified ones. The strong correlation between total phenolic content and antiradical activity of apple juices was found. The high correlation coefficient obtained between these features indicates that both producers do not apply excessive amounts of vitamin C during the production of cloudy apple juices. There was also a strong interrelation between the density of juice and solid soluble content. However, no correlation was found between the solid soluble content and the viscosity of the tested juices

Simulation decision games and effectiveness of their use for higher education – theoretical view

Purpose: The article presents the essence, characteristics and types of simulation decision games, as well as the effectiveness of their use in academic conditions in the theoretical context. Design/methodology/approach: The article is based of analysis of research results published in national and world publications. Findings: The didactic process carried out at universities with the use of direct forms of teaching can be supported by additional tools, including simulation decision games, because it brings many benefits in different areas. By playing we are able to learn many issues in a natural way, to refer to the mechanisms of the organization's functioning, and to use – sometimes dormant – soft competences of game participants. Research limitations/implications: It is advisable to carry out further scientific research in the field of using simulation games due to the fact that they are increasingly used as a tool to support the process of practical learning. Despite its popularity, the assessment of the effectiveness of using simulation games as an educational or training tool is still unclear. Social implications: Game-based learning (GBL) is used not only in higher education (especially in a wide range of economic and management disciplines, such as: marketing, economics, international business, project management, strategic management or human resources management), but also in other fields, including: army, education, advertising, trade, medicine and employee training. Originality/value: The work is theoretical. However, the problem raised in the article, in the context of new challenges posed by teachers in the teaching process, is an inspiring introduction to further research

Durability Assessment of Wooden Pellets in Relation with Vibrations Occurring in a Logistic Process of the Final Product

Vibrations occurring during road transport can vary in a wide spectrum and they can lead to losses in quality of transported materials. However, the vibrations are definitely different than the loads experienced by pellet samples in the tester used for durability tests according to the standard ISO 17831-1. pThe aim of the study was to evaluate the durability of wood biomass pellets available for sale in large-area stores, in terms of loads occurring in transport. The durability of the ellets was tested by subjecting them to vertical and horizontal vibrations similar to those occurring during local transport of this type of fuel for the needs of households. Durability tests were also carried out in accordance with ISO 17831-1. The results were analyzed statistically. Among other, it was found that the vibration time impact on the tested pellet durability was significantly lower in case of horizontal vibrations than in vertical. Moreover, pellets with a diameter of 8 mm showed lower durability than pellets with a diameter of 6 mm. Durability tests carried out in accordance with ISO 17831-1 showed lower pellet strength results compared to the test methods based on lateral and vertical vibrations

Sensory identification of cola-type soft drinks among students

Purpose: The aim of the study was to make an attempt at evaluating factors that affect the choice and, consequently, purchase and consumption of selected brands of cola-type beverages by students of Lublin universities. Design/methodology/approach: The study was followed by testing sensory recognition of a selected brand of a cola-type beverage. The applied research tool was a survey containing closed-ended and open-ended questions regarding the subject related to the beverage market in Poland. The study was conducted among 100 students of Lublin universities, both male and female, at various age. Findings: The collected results were processed using statistical analysis tools. The drink that was most often selected among the students proved to be Coca-Cola. In the chosen market segment, consumers also show a strong attachment to the brand. At the end of the study, selected cross analyses were performed, which provided an answer to how smoking cigarettes and alcohol consumption affect sensory sensitivity in the study group of students. Originality/value: A novelty in the work is the use of a question in the survey regarding sensory recognition that eliminates the subjectivity of surveys. The respondent may recognize the brand or not

Assessment of the Potential Use of Young Barley Shoots and Leaves for the Production of Green Juices

It is possible to use the aboveground parts of barley, which are cultivated as a forecrop. They are often simply composted or dried for bedding. It is worth trying other more effective methods of processing aboveground biomass. The aim of this study was to preliminary investigate the possibility of using young barley leaves and shoots for the production of green juice with potential health properties. The material was collected at days 7, 14, 21, and 28 after plant emergence. The length and strength of the shoots were measured and the pressing yield was calculated. The pH value and the content of protein, chlorides, and reducing sugars were also determined. The juice was additionally subjected to pasteurisation and freezing, and changes in pH and chlorophyll content occurring during storage were determined. The pressing yield of young barley leaves and shoots was estimated to be between 69% and 73%. The product was characterised by a high content of total protein (34.45%–51.81%d.w.) and chlorophylls (6.62 mg·g−1). The chlorophyll content declined during barley juice storage. Pasteurisation of the juice from young barley leaves does not induce statistically significant changes in the pH of the juice, but reduces the chlorophyll content. Our results revealed that the most effective way to preserve the green juice is by freezing. This process does not induce changes in juice acidity and only slightly reduces the chlorophyll content during storage of the product

Effect of the black chokeberry (Aronia melanocarpa (Michx.) Elliott) juice acquisition method on the content of polyphenols and antioxidant activity.

The primary objective of the study was to determine the effect of process conditions on extraction efficiency and the total amount of released polyphenols and antioxidant activity (AA) in black chokeberry juice. The study samples were fruits of black chokeberry (Aronia melanocarpa (Michx.) Elliott) cv. Galicjanka. In the study, two kinds of presses-piston press and twin gear juice extractor-were used, and two raw material pretreatment methods-freezing and thawing and enzymatic liquefaction-were applied. The study showed that pressing efficiency depends on the design of press and the nature of pretreatment. The highest pressing efficiency was obtained using the twin gear juice extractor. Enzymatic liquefaction of shredded fruits significantly increased the efficiency of pressing by the piston press. The type of press and the pretreatment method used had an effect on the quality traits of the extracted juices. The highest content of soluble solids was obtained for fruits not subjected to any pretreatment and pressed using the twin gear press. The highest total phenolic content was obtained in juice extracted using the piston press from shredded fruits subjected to enzymatic treatment at 45°C. A higher total phenolic content was also a characteristic of juice obtained from fruits not subjected to any pretreatment and extracted using the twin gear press. The capacity of the black chokeberry juices for free radical quenching oscillated around the level of approximately 90%. The study showed that the application of suitable processing methods is necessary for the acquisition of products with desirable quality traits

Improving the Performance Properties of Eutectoid Steel Products by a Complex Effect

This study focuses on the assessment of possible hypereutectoid steel carbide mesh crushing. It is used for tools production, including forming rolls of various diameters, with modification and cyclic heat treatment methods. For steel containing 1.79–1.83% C, we studied the effect of 0.35–1.15% Si on the possible crushing of the cementite mesh within crystallization by introducing modifiers Ti, V, N, as well as simultaneously modifying V with N and Ti with N. The obtained castings of Ø200 mm, 400 mm high were cut into discs, from which we made samples for tests on wear, determining mechanical properties, thermal resistance, and susceptibility to brittle fracture. The assessment was performed in the as-cast and after double and triple normalizing and annealing with drawback. With additional fans blowing, we changed the cooling rate from 25 °C/h to 100–150 °C/h. We performed the microstructure analyses using traditional metallographic, micro-X-ray spectral analyses, and also used the segmentation process based on 2D image markers. It was found that the as-cast modifying additives infusion is insufficient for carbide mesh crushing. It can be made by multi-stage normalizing with accelerated cool-down for products up to 600 mm in diameter to cycle temperatures above the steel transfer from a plastic to elastic state (above 450 °C)