The present study was conducted to investigate how raw rapeseed cake (RRC), hydrobarothermally-treated rapeseed cake (HRC) and fermented rapeseed cake (FRC) fed to laying hens over a period of 12 weeks affected their performance, and the quality, fatty acid (FA) profile and oxidative stability of eggs. A total of 304 Hy-Line Brown laying hens at 36 weeks of age were distributed in a completely randomized design to four treatment groups with 38 replicates per treatment and two hens per replicate. The birds had ad libitum access to feed and water throughout the study. During the experiment, the birds were fed isonitrogenous and isocaloric diets in mash form, with various protein sources. In the control group (C), soybean meal (SBM) was the main source of dietary protein, whereas the experimental groups were fed diets containing 20% of RRC, HRC or FRC. Hydrobarothermal treatment and fermentation decreased the glucosinolate (GLS) content of RC, and fermentation reduced the concentration of phytate phosphorus (PP). In comparison with the RRC group, layers from the HRC and FRC groups were characterized by higher laying performance, comparable with that in group C. Irrespective of its physical form, RC added to layer diets adversely affected eggshell quality in all experimental groups, whereas albumen quality was highest in the FRC group. In comparison with group C, diets containing RRC, HRC and HRC led to a significant decrease in the content of saturated fatty acids (SFAs), an increase in the proportion of n-3 and n-6 polyunsaturated fatty acids (PUFAs) in the total FA pool in egg yolks, and a decrease in the n-6/n-3 PUFA ratio. The inclusion of RRC, HRC and FRC in layer diets decreased the activity of superoxide dismutase (SOD) in egg yolks, relative to group C. Group FCR eggs were characterized by the highest activity of catalase (CAT) and the lowest lipid peroxides LOOH concentration, compared with the remaining groups. The addition of RC to layer diets did not compromise the sensory quality of eggs, and eggs produced in group FRC received the highest overall score. It can be concluded that the inclusion of 20% RRC, HRC and FRC in layer diets does not compromise the sensory quality of eggs and has a beneficial influence on the FA profile and antioxidant potential of egg yolks. The use of FRC is recommended because it contributes to the highest laying performance, superior albumen quality and the highest sensory quality of eggs, relative to RRC and HRC.

The aim of the research was to determine the changes occurring in table eggs depending on storage time at room temperature and in refrigeration conditions. The experimental material consisted of 75 eggs, which were randomly divided into five groups of 15. The first group (the control) comprised fresh eggs, which were tested on the day they were collected. The remaining 60 eggs were divided into two groups (30 eggs in each) and stored under different conditions for a period of 28 days. Eggs from the first group (I) were stored at room temperature, which was about 20°C with 50% humidity. Eggs from the second group (II) were placed in cold storage at 4°C and about 30% humidity. After 14 and 28 days of storage, the physicochemical properties of the eggs were analysed: the height of the air space, egg density, egg weight loss, albumen and shell quality, and yolk colour. The results indicate that the storage method had a significant (P≤0.05) effect on most of the egg quality traits analysed. Eggs stored at 4°C were of good quality and were classified as EXTRA class eggs even after 28 days. Eggs stored at 20°C were eliminated as Class A eggs as early as day 14, and on day 28 their quality disqualified them as fit for consumption. To sum up, food eggs should be refrigerated before being sold to the consumer to prevent premature ageing and thus deterioration of quality.

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In recent years, an increase has been reported in consumer awareness of balanced diet and health prevention. This caused the consumer interest in functional foods to increase. The major functional foods are products that contain prebiotics and probiotics. The most often eaten probiotic product is classic yogurt, however the fermented dairy and non-dairy drinks tend to be more and more important. The increase in number and types of milk-free drinks on the market is due to increasing lactose intolerance among consumers. Additionally, in the developed countries gradually rises the number of people who are switching to veganism. The search for suitable substitutes for dairy milk and dairy products has become an important direction of scientific research and implementation projects in industry. The objective of the paper is to review the reference literature presenting results of research studies and experiments on the production and qualities of non-dairy probiotic products, that could be classified into vegan foods. New probiotic food in the form of drinks, which are already on the market or are still in research phase, are made of raw materials such as: vegetables, fruits, grains (oats, buckwheat, spelt wheat, corn, quinoa, amaranth), hazelnuts, coconuts, almonds, cashew nuts, and also sesame and hemp seeds. It is a big challenge for technologists to manufacture food products for vegans, because the vegan diet is more restrictive than a vegetarian one, therefore possibilities of using many raw materials are limited.