Summary A semi‐industrial spray drying process of chokeberry juice concentrate using maltodextrin was analysed. The influence of the content and dextrose equivalent (DE) of maltodextrin, inlet air temperature and rotary disc atomiser speed was studied on the physicochemical properties of the obtained powders. The size and structure of the powder particles, bulk density, moisture content, flowability, yield and total polyphenol content were analysed. An increase in carrier content from 50% to 70% caused a 4.9% increase in total polyphenol retention, better flowability (Hausner ratio decrease of 0.17) and greater yield of the powder (60%). An increase in the drying temperature (150–170 °C) caused larger particle size and improved powder flowability but also resulted in greater loss of total polyphenols. A decrease in rotary atomiser speed (11 000–15 000 rpm) had a moderate influence on particle size and improvement in flowability but had no effect on polyphenol retention. Changes in the DE (8–22) of maltodextrin as a carrier indicated a moderate growing dependence on particle size and worse flowability.

A b s t r a c t. This paper provides the analysis of results of biogas and methane yield for vegetable dumplings waste: dough with fat, vegetable waste, and sludge from the clarifier. Anaerobic digestion of food waste used in the experiments was stable after combining the substrates with a digested pulp composed of maize silage and liquid manure (as inoculum), at suitable ratios. The study was carried out in a laboratory scale using anaerobic batch reactors, at controlled (mesophilic) temperature and pH conditions. The authors present the chemical reactions accompanying biodegradation of the substrates and indicate the chemical compounds which may lead to acidification during the anaerobic digestion. An anaerobic digestion process carried out with the use of a dough-and-fat mixture provided the highest biogas and methane yields.

The quality of rapeseed oil largely depends on the quality of postharvest preservation of raw seeds. Fungal infestation at early stages of the storage of rapeseeds is a major cause of their spoilage. The knowledge of relations between the storage conditions, fungal contamination, and technological quality of rapeseeds is essential to specify key control points that can be used to improve postharvest management systems and maintain rapeseed quality. The aim of this study was to define decisive control points on the basis of the kinetics of early mold growth in ecosystems of rapeseeds in a hazardous initial microbiological state, stored under various water activity and temperature conditions (a w =0.78-0.96 and t =12-30 C). A correlation between the acid value (AV), germination, and fungal infestation of seeds was found in ecosystems with significant mold activity. The analysis of the mold growth kinetics with regard to AV, seed germination, and visible mold time showed that the detection of early (invisible) fungal growth could be a good basis for determining the time during which rapeseeds should be protected from deterioration. The research results showed how to use the length of the lag phase to identify decisive control points, which are necessary to improve the existing control systems of rapeseed preservation and storage.

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