Ivan Širić

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.

Tuber donnagotto, a new winter truffle species from Istria, Croatia

Abstract - Tuber donnagotto is a new winter black truffle belonging to the order Pezizales and the family Tuberaceae. It grows in winter in the calcareous gravel soil (pH 7.6-7.8) near the Adriatic Sea (Rovinj, Istria, Croatia) in predominantly pine forests (Pinus halepensis). Although similar to other black truffles, it has very irregular and hard fruit bodies, lobate and knotted in form, with deep irregular cavities reaching the middle of the fruit bodies. These cavities are clearly evident in the cross-section of the fruit bodies. Adistinctive characteristic of this truffle is the fact that when it is hermetically closed it can be kept in a refrigerator (2-4 °C) for more than 60 days. Tuber donnagotto has a slight but pleasant odor, reminiscent of boletus (Boletus reticulates, B. edulis). Furthermore, T. donnagotto has yellow-brownish and reticulate-alveolate spores, measuring 20-30 × 20-25 mm.

137 Cs in mushrooms from Croatia sampled 15–30 years after Chernobyl

The aim of this study was to select species with higher potential to accumulate 137Cs among the available mushroom species, by determining the activity concentrations of 137Cs in mushrooms collected along north and north-western part of Croatia. A total of 55 samples of 14 different species were analyzed and the potential of mycorrhizal and saprotrophic species to accumulate 137Cs was compared. A wide range of the dry weight activity concentrations of 137Cs was detected, ranging from 0.95 to 1210 Bq/kg (154 Bq/kg mean value; 52.3 Bq/kg geometric mean) in mycorrhizal and 1.05-36.8 Bq/kg (8.90 Bq/kg mean value; 5.49 Bq/kg geometric mean) in saprotrophic species. Statistical analyses showed that mycorrhizal species accumulate significantly higher concentrations of 137Cs and thus could perform better as long-term bioindicators of environmental pollution by radiocaesium then saprotrophic species. The comparison of Boletus sp. and Hydnum repandum (both mycorrhizal species commonly found in Croatia) showed, in general order of magnitude, higher accumulation in Hydnum repandum. Clearly, mushrooms, especially mycorrhizal species, can be used as significant indicators even decades after the occurrence of any serious 137Cs contamination event. However, as a wide range of values indicates that various parameters may influence the total uptake of the 137Cs into the mushroom fruit bodies, it is necessary to emphasize that 137Cs activity detected in a single mushroom sample is very site-specific.

The application of mycorrhiza in horticulture

This article gives a review of scientific and professional literature regarding the application of mycorrhizas in horticulture. It defines the phenomenon of mycorrhizal symbiosis and describes some of the basic features of symbiotic relationships between plants and fungi. It specifies most common types of mycorrhizas appearing in nature, their characteristics and differences considering diverse hosts, symbiotic fungi and nature of their relationship. The main objective of the article is to demonstrate the effects of mycorrhizal colonizationon various agricultural, physiological and biochemical properties of horticultural crops. It also proposes an important influence of mycorrhization on plant nutrition, nutrient uptake and crop yields. Researches show that plants with mycorrhiza are more tolerant to nutrients and water stress, soil salinity and high heavy metals concentrations. Also, it has been shown that mycorrhizal symbiosis positively affects plants during attacks of foliar pathogens and plant-parasitic nematodes. These effects propose the possibility of use of mycorrhizas in sustainable agroecosystems, but the relationship between plants, mycorrhizal fungi and soil type is yet to be elucidated.

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.

Effect of sex on slaughter traits and carcass measurements of Travnik pramenka sheep lambs

Cilj ovog istraživanja bio je utvrditi utjecaj spola na klaonicke pokazatelje i razvijenost trupova janjadi travnicke pramenke. U tu svrhu, u mjesecu travnju 2017. godine, zaklano je ukupno 70 janjadi travnicke pramenke, od toga 48 muske i 22 ženske. Janjad je uzgojena na obiteljskom poljoprivrednom gospodarstvu u Velikoj Peratovici – Bjelovarsko-bilogorska županija. U dobi između 90 i 100 dana janjad je pojedinacno izvagana i podvrgnuta klanju. Neposredno nakon klanja i klaonicke obrade obavljenja su mjerenja trupova i pojedinih organa. Prosjecna tjelesna masa janjadi izmjerena neposredno prije klanja bila je 21, 85 kg s tim da je muska janjad bila statisticki znacajno (P<0, 05) teža od ženske (22, 47 kg : 20, 38 kg). Utvrđena je prosjecna masa janjeceg trupa od 11, 04 kg koja je bila statisticki znacajno veca (P<0, 05) u muskih (11, 32 kg) u odnosu na trupove ženske janjadi (10, 42). Iako je randman ženske janjadi (51, 04%) bio veci od onog utvrđenog u muske travnicke janjadi (50, 33%) razlika nije bila statisticki znacajna. Dubina prsa i duljina stražnje noge bile su znacajno razlicite ovisno o spolu janjadi (p<0, 05 ; p<0, 01). Temeljem utvrđenih mjera klaonicki obrađenih trupova, trupovi istraživane janjadi travnicke pramenke pripadaju kategoriji lakih janjecih trupova.

Proximate and mineral composition of M. longissimus thoracis et lumborum of suckling lambs from three Croatian indigenous breeds reared in outdoor conditions

Abstract Lamb meat represents an important source of nutrients for humans worldwide. However, nutritional value of lamb meat, and particularly that obtained from suckling lambs, has been scarcely investigated in comparison to other categories of meat. The study aimed to provide some basic insights into proximate and mineral composition of lamb meat and to disclose some important sources of its variability. Three Croatian indigenous insular sheep breeds were included in the study: Rab sheep, Cres sheep, and Krk. The lambs were reared in outdoor insular environment where lambs were fed exclusively by suckling their mothers and by grazing wild grown vegetation. It has been determined that gender significantly affected fat (p < .001) and moisture ratio (p < .05), and had no effect on concentration of the examined minerals, except Zn (p < .01). The factor composed of breed and environment significantly affected moisture ratio (p < .001), fat ratio (p < .01), and concentrations of Ca, Na, Cu, and Mn (p < .001), Zn (p < .01), and K (p < .05). The concentrations of Mn and Ca were by far the most influenced by breed-environment effect. The results of the study evidenced that factor composed of breed and environment represents important source of variability of nutritional value of lamb meat produced in extensive rearing systems.

Heavy metals bioaccumulation by edible saprophytic mushrooms

The aim of this study was to determine the concentration of heavy metals Fe, Zn, Cu, Ni, Pb i Cd in certain edible species of saprophytic fungi and the substrate on three area of sampling, and to assess the role of individual species as biological indicators of environmental pollution. In this study were used three species of wild edible mushrooms (Agaricus macroarpus Bohus, Clitocybe inversa (Scop. ex Fr.) Pat. and Macrolepiota procera (Scop. ex Fr.) Sing.,). Completely developed and mature fruiting bodies were collected at random selection in localities of Trakoscan, Jaska and Petrova gora. At the same time, the substrate soil samples were collected from the upper horizon (0-10). Determination of heavy metals in mushrooms and the substrate soil were carried out by X-ray Fluorescence Spectrometry. The data obtained were analysed by means of the statistical program SAS V9.2. Significant differences were found in the concentrations of Fe, Zn, Cu, Ni, Pb and Cd between analysed species of mushrooms and localities of sampling (P 1). The consumption of investigated mushrooms poses no toxicological risk to human health due to low concentrations analysed metals.