Tomasz Kiczek

One of the key stages of faba bean processing is dehulling, the removal of the husk surrounding the core, which consists of the cotyledons and embryo. This process influences the digestibility, color, functional properties, and quality of the final products. The aim of the research was to develop a technology for dehulling faba beans using separation that would effectively separate the husk from the endosperm. The scope of the research included characterizing various faba bean varieties in terms of their physical properties, conducting preliminary tests on a selected device, and designing a station for separating the husk from the endosperm. The designed system allows for obtaining a fraction with a high endosperm content while effectively removing the light husk, which is a prerequisite for the effective further use of the raw material (e.g., in the production of flour, protein concentrates, or feed).

The paper presents the results of tribocorrosion resistance tests of AISI 420 stainless steel in onion juice. The study constitutes one of the stages in selecting a suitable material for the production of onion-cutting knives. The main objective was to identify the optimal heat treatment conditions to minimize tribocorrosive wear. Tribocorrosion tests were carried out using a ball-on-plate configuration under a low normal load of 1.7 N, simulating the operating conditions of an onion-cutting knife. Two heat treatment variants of quenched AISI 420 steel were investigated: tempering at 400 C (medium tempering) and tempering at 200 C (low tempering). The results showed that the highest hardness (approximately 54 HRC) was obtained after low-temperature tempering. However, the samples tempered at 400 C, which exhibited slightly lower hardness (about 51 HRC), demonstrated better tribocorrosion resistance in onion juice under low loads. In contrast, the harder samples (54 HRC) showed reduced corrosion resistance in onion juice and slightly higher susceptibility to cracking, resulting in lower tribocorrosion resistance compared with the samples tempered at 400 C.

Due to the widespread application of plate heat exchangers (PHE) in the food industry, a key aspect of their operation is ensuring a high level of hygiene, which guarantees the microbiological cleanliness of the final product. This is achieved through the cleaning of installations containing PHE using the Clean-in-Place (CIP) system. An important aspect is the determination of flow resistance, as this enables the specification of drive parameters and the selection of a pump that provides a sufficiently high flow rate through the installation, particularly required during the pre-rinsing stage. The subject of the research was a three-section plate heat exchanger, which forms part of a prototype technological line designed for the pasteurisation of liquid egg mass and its fractions – egg white and yolk. As part of the study, the effectiveness of the cleaning process was assessed depending on the flow rate. Based on experimental results, the minimum flow rate necessary for effective cleaning using commercial sodium hydroxide (NaOH)-based cleaning agents was determined. In addition, the extent to which the relationship described in the literature – linking flow rate with hydraulic resistance in PHE – is confirmed under real operating conditions during the cleaning process in the CIP system was analysed. The results obtained may be used to optimise the parameters of the CIP process, which will contribute to increased efficiency, reduced consumption of chemical agents, and improved microbiological safety of the final product.

Onions are one of the most popular cultivated vegetables. In Europe, Poland is a leading producer of this vegetable and a hub where it is peeled and then sent in peeled or chopped form to western EU countries. After the top and root removal process, husks remain that require further manage-ment. It is also crucial to minimise their amount by applying appropriate topping and tailing processes in industrial machines. This is done in order to help prevent food waste and reduce the amount of waste generated. The article presents methods of cleaning onions in terms of cutting off the roots and green parts of the vegetable, focusing on the amount of waste generated in this process. The authors present examples of possible solutions for the cutting process and compare them in terms of the theoretical waste they generate, to identify the method with the greatest raw material savings. Additionally, the article presents the results of theoretical studies on the waste generated by the selected method, considering its various geometric variables. An analysis of the results is made and conclusions are drawn.