Marian Panasiewicz

Application of Freezing and Thawing to Carrot (Daucus carota L.) Juice Extraction

This paper presents a study of the effects of freezing and thawing carrot pulp and pomace on the efficiency of the pressing process and the quality of juice. In this study, various combinations of pretreatment strategies were used based on freezing and thawing the carrot pulp and pomace before pressing. The pressing process for pulp and pomace was carried out using a laboratory press with a perforated base. The juice obtained as a result of freezing and thawing the carrot pulp and pomace was characterized by a higher sugar content (°Brix) and a slightly lower dynamic viscosity. Furthermore, the study showed the impact of pretreatment on the chemical composition of the juice produced. On the basis of energy use and quality indicators of the resultant carrot juice (viscosity, pH, selected minerals, sugars, total carotenoid content, and vitamin C), a recommended solution is to press the pulp directly after grinding the carrots and then to press the pomace again after freezing and thawing. The proposed method for juice production using freezing and thawing allows a reduction in pomace quantity and the use of its valuable nutrients.

Evaluation of the Improvement Possibilities of Physical Properties of Mineral Fodder Additives

Abstract The paper presents a change in physical properties of loose, dust fodder additives (aluminosilicate) after mixing them with oil or glycerine. Additives where mixed in a blade mixer with the same mixing time for all samples, which was 1 minute. Tests with oil or glycerine were carried out in the following amounts: 5%, 10%. For mixtures of additives with oil or glycerine a selected group of physical properties was determined. Method of determination of physical properties was the same for all samples i.e. the same additives − without oil and glycerine as well as mixtures with their participation. Obtained research results and their analysis unanimously indicate that adding any amount of oil or glycerine for additives improves selected physical properties of mixtures.

Assessment of Selected Technical Parameters of Soya Seeds Oil Pressing Process

Abstract The objective of the paper was to determine the impact of the value of the oil pressing pressure with the cold pressing method in a screw press on the pressing course and performance. Varied values of pressure were obtained through the use of three replaceable attachments of the pressing unit with a varied diameter of the outlet conduit (ф1=2 mm, ф2=4 mm and ф3=6 mm). The soya oil pressing process performance was determined in relation to the applied attachment and the soya cultivar. Seeds of 7 Polish non-genetically modified soya cultivars constituted research material. It was proved that both variable pressure values and the used soya cultivars have impact on the pressing performance. Based on the analysis of the obtained research results it was proved that varied technical parameters and soya cultivars influence both the process performance and the remaining parameters and pressing conditions.

The impact of size and shape of particles of undergrowth and herbs mixtures on aerodynamic properties

The impact of the size and shape of a selected group of herbs (dried juniper berries – Juniperus communis, dry blueberries – Vaccinium myrtillus, petals of cornflower – Centaurea cyanus) on the value of the volatility coefficient, the coefficient of sphericity and the critical speed was analysed in the presented research. A laboratory anemometer to measure the speed of air was used. The determination of the volatility coefficient of particular size fractions was conducted on the basis of critical speed values, calculated as an average established after five measurements. The established aerodynamic properties of particular mixtures allow the determination and the assessment of differences among fractions of valuable resources and different impurities. The presented data might constitute a basis to determine the scope of differences among them and establish interrelations which allow the application of proper parameters for the pneumatic separation process in practice.