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  • Author: Marzena Gawrysiak-Witulska x
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Marzena Gawrysiak-Witulska, Aleksander Siger and Robert Rusinek

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.

Open access

Marzena Gawrysiak-Witulska, Aleksander Siger, Magdalena Rudzińska, Kinga Stuper-Szablewska and Robert Rusinek

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.

Open access

Marek Gancarz, Jolanta Wawrzyniak, Marzena Gawrysiak-Witulska, Dariusz Wiącek, Agnieszka Nawrocka and Robert Rusinek

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.