Robert Rusinek

Electronic nose with polymer-composite sensors for monitoring fungal deterioration of stored rapeseed

Abstract Investigations were performed to examine the possibility of using an electronic nose to monitor development of fungal microflora during the first eighteen days of rapeseed storage. The Cyranose 320 device manufactured by Sensigent was used to analyse volatile organic compounds. Each sample of infected material was divided into three parts and the degree of spoilage was measured in three ways: analysis of colony forming units, determination of ergosterol content, and measurement of volatile organic compounds with the e-nose. Principal component analysis was performed on the generated patterns of signals and six groups of different spoilage levels were isolated. An analysis of sensorgrams for a few sensors with a strong signal for each group of rapeseed spoilage was performed. The ratio of the association time to the steady state was calculated. This ratio was different for the low level and the highest level of ergosterol and colony forming units. The results have shown that the e-nose can be a useful tool for quick estimation of the degree of rapeseed spoilage.

Analysis of interspecies physicochemical variation of grain legume seeds

Abstract The paper presents an attempt to assess the reaction of seeds to mechanical loads taking into account their geometry expressed as seed thickness and 1000 seed weight. The initial material comprised 33 genotypes of grain legume plants and included cultivars registered in the country and breeding lines that are subject to pre-registration trials. The analysis of variance revealed significant diversity of the cultivars and lines of the species studied in terms of each of the analysed trait. The highest weight of 1000 seeds were obtained for white lupine seeds and peas, the lowest for andean lupine seeds. The maximum deformation and energy were obtained for white lupine seeds, the lowest for pea seeds, the maximum force and module the lowest values were determined for narrow-leafed lupine and pea. The highest values of protein were obtained for andean and yellow lupine, a fat content for andean and white lupine. The fatty acid profile as much as 70% or more were linoleic and oleic acids. Against the background of all the species are distinguished by white lupine seeds with a high content of oleic acid and the lowest of linoleic acid, for yellow lupine were obtained the inverse ratio of the two acids.

Degradation of tocopherols during rapeseed storage in simulated conditions of industrial silos

Abstract The investigations consisted in laboratory simulation of conditions prevailing in the real ecosystem in an industrial rapeseed storage facility. The aim of the study was to assess the impact of temperature, moisture, and static pressure on degradation of tocopherols contained in rapeseed. Rapeseed varieties with high oil content were analysed in the investigations. Samples of seeds with 7, 10, 13, and 16% moisture levels were stored at a temperature of 25, 30, and 35°C in specially designed airtight pressure silos for storage in controlled conditions. During the storage, the seeds were subjected to overpressure in the range of 20-60 kPa. The seeds were stored in these conditions for 28 days. It was demonstrated that primarily moisture induced the greatest loss of the total content of tocopherol and its α-T and γ-T homologues, followed by temperature and, to a lesser extent, pressure. In addition, the results obtained showed that, in the case of seeds characterised by higher moisture levels (13 and 16%), an increase in the storage temperature in the range of 25-30°C rather than 30-35°C intensified tocopherol loss more efficiently.

Effect of self-heating on the processing quality of rapeseed

Abstract The paper concerns the effect of adverse thermal phenomena on the processing quality of rapeseed. A measurement station was developed for the study, composed of a model cylindrical silo with a capacity of 3.85 m3, which was filled with seeds of winter rape cv. Suzy (2.5 t). In the conducted experiment, the silo was filled with three layers of seeds, the bottom layer witha moisture content of 7%, the middle layer with a moisture content of 12.7%, and the top layer with a moisture content of 7%. The experiment was carried out with temperature and humidity sensors in the vertical and horizontal axes, placed in a distance of 0.15 m from one another. The increase in temperature in the intergranular space measured during the self-heating pheno-menon can be divided into two stages: I – slow (up to approx. 150 h)and II – significant (from 150 h, 2-3ºC per day). As a result of the development of the self-heating phenomenon, the processing quality of rapeseed deteriorated. Indeed, under increased temperature the quality changes were so significant that they rendered the seeds unfit for any kind of consumption purposes.