Dalibor Bedeković

Lead, cadmium and mercury contents and bioaccumulation potential of wild edible saprophytic and ectomycorrhizal mushrooms, Croatia

ABSTRACT Lead (Pb), cadmium (Cd), and mercury (Hg) contents in ten species of edible mushrooms in Trakošćan, Croatia were determined. In addition, the similarity between the studied species was determined by cluster analysis. The caps and stipes of the fruiting bodies were analysed separately. The analyses were carried out by inductively coupled plasma - optical emission spectrometry (ICP-OES). The greatest mean lead concentrations of 1.91 and 1.60 mg kg −1 were determined in caps and stipes of Macrolepiota procera. The greatest mean concentrations of cadmium (3.23 and 2.24 mg kg−1) were determined in caps and stipes of Agaricus campestris and of mercury (2.56 and 2.35 mg kg−1) in Boletus edulis. In terms of the anatomical parts of the fruiting body (cap-stipe), a considerably greater concentration of the analysed elements was found in the cap for all mushroom species. According to calculated bio-concentration factors, all the examined species were found to be bio-accumulators of Cd and Hg. On the basis of the accumulation of the studied metals, great similarity of mushroom species belonging to the same genus and partial similarity of species of the same ecological affiliation was obtained by cluster analysis.

Immunomodulatory and antimicrobial effects of selected herbs on laying hens

The aim of the study was to investigate the efficiency of feed supplementation with dried calendula (C. officinalis), dandelion (T. officinale) and marigold (T. erecta) flowers, as well as dried basil (O. basilicum ‘Genovese’) leaves on the kinetics of the total leukocytes, helper and cytotoxic T lymphocytes, and B lymphocytes in peripheral blood, as well as on intestinal excretion of Escherichia coli in laying hens. Laying hens of Tetra SL line, aged 25 weeks, were used in the study. The animals were divided into nine groups of 15 birds. The laying hens were fed common feed with the addition of 1% (10 g/kg) and 3% (30 g/kg) chopped flowers or leaves of the above mentioned herbs. The immunomodulatory and antimicrobial effects of medicinal herbs in laying hens were estimated by the above mentioned parameters determined at the beginning of the experiment and on day 14 and day 28 of the study, i.e. at the birds’ ages of 25, 27 and 29 weeks. The study results showed that the addition of chopped calendula and dandelion flowers to laying hen feed stimulated proliferation of total leukocytes as well as T and B lymphocytes, particularly in the groups receiving 3% chopped herbs (P<0.01). All study herbs were found to have antimicrobial activity. The results obtained definitely confirm the favorable impact of adding herbs to hen feed because of their antimicrobial and immunostimulatory effects. Phytogenic feed additives exert favourable effects, however, knowledge of their use in poultry feed is still inadequate, thus requiring additional research. It was concluded that phytobiotics might be combined with other feed additives such as probiotics or prebiotics, in order to attain better results in poultry production.

Mechanical properties of ten-egg boxes made of different materials

This study was conducted to evaluate mechanical properties of ten-egg boxes, which are the most commonly used egg boxes in many countries of Central and South-Eastern Europe. Six ten-egg boxes were tested, two made of cardboard, two made of expanded polystyrene and two made of general purpose solid polystyrene, each from a different producer. There were no significant differences in basic dimensions between tested boxes of various materials, while the significant differences were occurred in weight and box wall thickness. Test included measuring of vertical forces required for deforming complete box and at particular place for each egg in a box till contact with eggs. According to the obtained results, cardboard boxes can provide the best mechanical protection for eggs. The average force required for deforming complete cardboard box was 83.6% higher than for solid polystyrene box, and even 289.5% higher than for expanded polystyrene box. The average force required for deforming cardboard box at particular place for each egg in a box was 60.8% higher than for polystyrene box, and 74.0% higher than for expanded polystyrene box. The disadvantage of cardboard boxes is that they are not resistant to the impact of moisture as polystyrene boxes and in the case of an increase in box moisture due to storage in inappropriate conditions their mechanical resistance decreases.

Some Physical, Morphological and Mechanical Characteristics of Turkey (Meleagris gallopavo) Eggs

The physical, morphological, and mechanical characteristics of eggs play an important role in the processes of embryo development and hatching. Some physical, morphological, and mechanical characteristics of turkey (Meleagris gallopavo; Zagorje breed) eggs collected during two laying cycles from same turkey hens were determined in this study. The average values of length, width, geometric mean diameter, weight, surface area, volume, sphericity, eggshell thickness, and eggshell density were determined as 66.61 mm, 46.84 mm, 52.66 mm, 77.74 g, 8712.42 mm2, 76553.49 mm3, 79.31%, 0.354 mm and 3.13 g cm-3, respectively. Eggs collected during second laying cycle were, on average, larger and heavier in comparison with those collected during first cycle. Average albumen, yolk and eggshell percentages of the eggs collected during two laying cycles were 58.11%, 29.50% and 12.39%, respectively. The highest breaking strength was obtained when the eggs were loaded along the X-front axis and the least breaking strength was required along the Z-axis. The average breaking strength, absorbed energy and firmness in loading along the X-front axis were found to be 73.80 N, 9.75 N mm and 280.30 N mm-1, respectively.

Technological characterization and consumer perception of dry fermented game sausages with bay leaf (Laurus nobilis L.) essential oil

The aim of this paper was to determine basic technological traits and sensory acceptance of dry game sausages with addition of bay leaf (Laurus nobilis L.) essential oil. For that purpose, three treatments were established: controlled C, L1 with addition of 0.005% of bay leaf essential oil, and L2 with addition of 0.01% of bay leaf essential oil. Measurement of pH, water activity and thiobarbituric acid reactive substances (TBARS) values were performed at the end of production, while after storage for 2 months in vacuum and cold sensory hedonic test on 106 subjects was done. It was found that sausages with added bay leaf essential oil had significantly lower pH values (L1 and L2 treatment), water activity (L1 treatment) and TBARS values (L1 and L2 treatment) compared to control treatment C. Statistical analysis of sensory data revealed that sausages from C treatment were rated with significantly higher acceptability and willingness to buy than L1 and L2 treatments. It was established that sensory traits of sausages from treatment C were liked in 98.61% of consumers, from treatment L1 in 90.93%, while sausages from treatment L2 were liked in 85.71% of consumers. The highest proportion of consumers willing to buy sausages were in treatment C (91.11%), followed by sausages in treatment L1 (84.31%), and the lowest proportion were in treatment L2 (66.67%). Although beneficial impact of addition of bay leaf essential oil on technological traits was found, there was an unfavorable effect on sensory traits and willingness to buy sausages possibly due to the consumers’ existing expectation of sensory characteristics of dry game sausages.