Žarko Kevrešan

Cadmium in meat and edible offal of free-range reared Swallow-belly Mangulica pigs from Vojvodina (northern Serbia)

The aim of this study was to determine the cadmium concentration in four muscles and 10 edible offal items of 15 free-range reared Swallow-belly Mangulica pigs from Vojvodina, by flame atomic absorption spectrometry after mineralisation by dry ashing. All individual concentrations in muscles and heart, tongue, spinal cord, back fat and leaf fat were below the limit of detection (LOD = 0.050 mg/kg). In lungs, spleen and brain, cadmium concentrations ranked from below LOD, 0.055 and 0.058 to 0.057, 0.065 and 0.074 mg/kg, respectively. The concentration of cadmium in liver and kidney ranged from 0.089 to 0.116 mg/kg and from 0.204 to 0.440 mg/kg, respectively. Cadmium concentrations in liver and kidney of free-range reared Swallow-belly Mangulica pigs slaughtered at about 20 months of age were lower than in liver and kidney of commercial pigs from Vojvodina, slaughtered at about 6 months of age.

Effect of Different Ripening Conditions on Pigments of Pepper for Paprika Production at Green Stage of Maturity

The content and composition of pigments and CIELab color properties in fruits ripened in the field were compared with those obtained in ground paprika produced from green pepper fruits after postharvest ripening for 15 days in a greenhouse under different conditions. Obtained data for pigment content, composition, and esterification rate have shown that the processes of pigment biosynthesis in fruits ripened under greenhouse conditions are different from those occurring in fruits naturally matured in the field: the red/yellow pigment ratio (3:1) in greenhouse-ripened fruits is much higher than in naturally ripened pepper in breaker (1:1) and also in faint red (2:1) ripening stages from the field. Additionally, during the postharvest ripening of green pepper in the greenhouse esterification processes are less expressed than during the ripening of the fruits in the field. Postharvest ripening under natural daylight resulted in higher content of red pigments, followed by higher ASTA value.

Effect of Climate Change on Wheat Quality and HMW Glutenin Subunit Composition in the Pannonian Plain

The primary goal of this study is to improve our understanding of the extent of influence of climatic factors in Serbia and high-molecular-weight glutenin subunit (HMW-GS) composition upon wheat end-use quality. In-depth analyses were performed on four bread wheat cultivars that are the most common in agricultural practice in Serbia. Total glutenin content showed significant difference between the production years, in opposition to gliadins. Cluster analysis of different percentages of glutenin and gliadin subunit molecular weight ranges ( 120,000) indicated that the year of production and the cultivar did not have a significant effect on the percentage ranges for glutenins. However, they had a considerable impact on the percentage ranges for gliadins. Production year and the interaction of year and cultivar had the strongest influences on the percentage of SDS-unextractable polymeric proteins. A synergistic effect of the HMW-GS composition and climatic conditio...

Effects of Wheat Bug (Eurygaster spp. and Aelia spp.) Infestation in Preharvest Period on Wheat Technological Quality and Gluten Composition

The effects of wheat bug infestation (Eurygaster spp. and Aelia spp.) on the composition of wheat gluten proteins and its influence on flour technological quality were investigated in the present study. Wheat samples of six wheat varieties, collected from two localities in northern Serbia, were characterized by significantly different level of wheat bug infestation. Composition of wheat gluten proteins was determined using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE), while the selected parameters of technological quality were determined according to standard and modified empirical rheological methods (Farinograph, Extensograph, Alveograph, and Gluten Index). The surface morphology of the selected samples was viewed using scanning electron microscopy (SEM). Wheat from wheat bug-infested locality regardless of the variety had deteriorated technological quality expressed with higher Farinograph softening degree, lower or immeasurable Extensograph energy, and Alveograph deformation energy. The most important changes in the gluten proteins composition of bug-infested wheat were related to gliadin subunits with molecular weights below 75 kDa, which consequently caused deterioration of uniaxial and biaxial extensibility and dough softening during mixing.

Effects of High Temperatures and Drought During Anthesis and Grain Filling Period on Wheat Processing Quality and Underlying Gluten Structural Changes

BACKGROUND Climate changes do not only affect wheat yield, but also its quality. Information on this topic gathered so far is somewhat contradictory and insufficient. Climate changes also affect wheat indirectly through their influence on the ecosystem, including insects and fungi that affect wheat technological quality. The aim of this study was to examine trends in structural and technological changes of wheat quality under conditions typical of climate changes. With this in mind, three groups of wheat varieties with the same Glu-score were examined in three production years, characterized by different production conditions. RESULTS A production season characterized by climate change conditions results in lower activity of amylolytic enzymes. What is more, it results in lower content of gluten, higher gluten index value, its decrease after 1 h to 37 °C, lower number of free SH groups and higher content of free amino groups, which result in lower alveograph W, lower farinograph WA and higher extensograph dough resistance. CONCLUSION Variability in wheat quality produced under different climatic conditions is mainly influenced by the production conditions, including their influence on ecosystem factors. The influence of wheat cultivar genetic predisposition is much less expressed. This indicates that differences among cultivars with different Glu-score might be diminished under the influence of altered production conditions, as a consequence of climate change.

Physicochemical properties and mineral content of honey samples from Vojvodina (Republic of Serbia)

Forty-five honey samples of three honey types - two monofloral (acacia and sunflower) and one polyfloral (meadow) were collected from the Autonomous Province of Vojvodina (Republic of Serbia) and analysed for their physicochemical parameters (moisture, acidity, pH, ash, electrical conductivity, glucose, fructose, hydroxymethylfurfural (HMF), CIE L∗a∗b∗ colour and mineral content). All tested physicochemical parameters were in agreement with the EU regulation except for moisture (4 samples) and HMF content (1 sample). Principal component analysis (PCA) was used for assessing the effects of three honey types on all investigated physicochemical parameters. According to PCA, acacia honey samples can be clearly isolated and form a cluster, while, regarding other honey types, PCA can offer the possibility to distinguish sunflower and meadow honey samples regarding examined physicochemical parameters and mineral content.

Postharvest Practices for Organically Grown Products

Summary Quality of produce cannot be improved after harvest, only maintained. Postharvest handling depends on the specific conditions of production, season, method of handling, and distance to market. Under organic production, growers harvest and market their produce at or near the peak ripeness more commonly than in many conventional systems. Organic production often includes more specialty varieties whose shelf life and shipping traits are reduced or even inherently poor. Harvesting and handling techniques that minimize injury to the commodity, as well as increased care with field and packinghouse sanitation, (chlorine, ozone, calcium hypochlorite, sodium hypochlorite and chlorine dioxide, acetic acid, peroxyacetic acid, vinegar, ethyl alcohol, hydrogen peroxide, etc.) during postharvest processes are vital components of a postharvest management plan for organic products. Sodium carbonate, sodium bicarbonate, and physical treatments such as heat treatments (as hot water treatment or dips, short hot water rinsing and brushing or hot air) can significantly lower the disease pressure on the harvested commodities. These sanitation practices are very easy to implement in the organic food production chain. They start in the field and continue during harvesting, sorting, packing, and transportation and continue even in the consumer’s home. All those treatments reduce rot development, provide quarantine security, and preserve fruit quality during cold storage and shelf life. In addition, the use chitosan, propolis, methyl jasmonate, essential oils, carnuba wax, biocontrol agents and modified atmosphere packaging can also reduce decay development during prolonged storage. All these treatments can be applied alone or in combination with each other in order to improve decay control after harvest and provide a healthy and safe product to the consumer. The aim of this chapter is to shed more light on the latest information on permitted treatments for organic products and on the possible mode-of-action of these treatments. This chapter summarizes technologies developed over the past five years that explore special physical treatments applied either directly, or in combination with other means to control rot development and insect infestation on fresh produce.

Application of multicriteria analysis for assessment of wheat quality in trade and processing

The quality related value of grains, especially wheat is defined with a number of quality parameters. Numerous parameters that are often mutually inconsistent result in the fact that decision making related to selection of wheat lots based on their quality is a complex multidimensional problem. The aim of the research was to test the possibility of application of multicriteria analysis for ranking of wheat lots in respect to their overall quality and its variation. A modified version of the preference ranking organisation method for enrichment evaluation, MODIPRIM, was used for multicriteria analysis of wheat intended for sales and processing purposes. The results of determining the quality parameters of wheat lots in six consequent crop years were used to form the input database. Multicriteria analysis was conducted with developed optimisation criteria and assessment of the significance coefficients resulted in a reduction of the complexity of the decision making problem involving numerous quality parame...

Comparative study of white cabbage, traditional variety and hybrid intended for biological fermentation

Traditional Serbian variety of white cabbage, cultivar “Futoski” (33 samples) and hybrid “Bravo” (10 samples) were investigated in this study for their applicability to biological fermentation. Different chemical, physical, texture and sensory characteristics of raw cabbage heads were investigated. Obtained experimental results were analyzed using descriptive statistics, while correlation analysis showed the relations between different assays. Also, Principal Component Analysis (PCA) has been applied to classify and discriminate between different cultivars cabbage heads. Furthermore, standard score has been introduced to enable more comprehensive comparison between the investigated samples, in order to find the optimum sample, regarding observed chemical, physical, texture and sensory properties. PCA analysis showed that the best sample for cabbage cultivar “Futoski” was sample 9, while sample 34 was the best for hybrid “Bravo”, regarding their chemical, morphological and sensory characteristics.