Potravinarstvo Slovak Journal of Food Sciences
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Consumer sensory evaluation of honey across age cohorts in Slovakia
Get PDFThe growing popularity of honey among consumers has caused many frauds and cases when honey of high quality is adulterated by cheap imported honey of very low quality. The aim of this research paper was to study consumer perception of honey quality based on sensory attributes such as taste, aroma, colour and consistency. The primary research comprised the sensory blind test conducted as a part of questionnaire survey at selected shopping mall and at university. Research sample reached 400 respondents living in the Nitra region between 18 and 70 years. Respondents tested sensory attributes of two samples. Sample A represented Slovak honey from a local beekeeper and sample B was honey purchased from selected supermarket with country of origin „blend of EU and non - EU honeys" and represented imported honey. Besides descriptive statistics, the following statistical tests were applied: Fisher's Exact Test, Chi-Square Test of Independence, Cramer´V coefficient and Mann-Whitney U test. Results showed significant differences in perception of honey quality across age cohorts. Respondents older than 40 years (Generation X and Babyboomers) evaluated better the local honey from a beekeeper (sample A) than younger generations (Generation Y and Generation Z). Imported honey from selected supermarket (sample B) obtained the best evaluation in case of colour in both age cohorts while sample A obtained it in terms of aroma. The majority of respondents in both age cohorts mostly decided their preference according to taste, however there exist some differences. While Generation X and Baby boomers took into consideration also aroma, the generations Y and Z considered consistency. More interesting observation appealed in case of aroma where more than 90% of respondents, who decided according to aroma, preferred sample A - local Slovak honey. According to physico-chemical analysis, both samples fulfilled standard of EU legislation, however better parameters were reached in sample A. All in all, better perception of honey quality through sensory attributes in older age cohorts could be caused by the deeper experience in honey consumption as well as due to the fact that younger cohorts consume more semiproducts and industrial food products characterised by intensive, sweet taste which could confuse their assessments
Determination of the carrot (Daucus carota L.) yields parameters by vermicompost and earthworms (Eisenia foetida)
Get PDFThe impact of different types of vermicomposts as well as different species and genera of earthworms on the quantity of the cultivated crops yield has been studied for decades. There is scarce information about the effects of these factors on the quality of plant production. One of the qualitative parameters of vegetables, to which a special attention is paid, is the content of antioxidants (vitamin C, total polyphenols and other substances). The pot experiment carried out in the vegetation cage studied: A) the influence of soil itself, soil mixed with vermicompost in a ratio of 4:1; B) the influence of earthworms number (genus Eisenia foetida, 10 and 20 individuals per pot) supplied to soil mixed with vermicompost in a ratio of 4:1 on the weight of radish roots and leaves, to the total chlorophylls content in leaves, to the selected qualitative parameters of the roots and leaves (vitamin C, total polyphenols content, total antioxidant activity). The results showed that the supplementation of vermicompost into soil increased the content of the total chlorophylls in leaves. The carrot roots and leaves yield has also been risen. In the roots the content of vitamin C and content of total polyphenols (TPC) was decreased and the total antioxidant activity (TAA) dropped, too. The increased content of vitamin C and TPC was detected in leaves. The inoculation of soil containing vermicompost by earthworms increased the root yield and TAA in roots. It increased the content of vitamin C and TPC in leaves. From the viewpoint of antioxidant content (vitamin C and total polyphenols) the leaves are more attractive than a root. 
Effect of TiO2 nanoparticles in thyme under reduced irrigation conditions
Get PDFThe nanotechnology is a relatively new technology that has recently entered the field of agriculture. Nanotechnology covers the integration or manipulation of individual atoms, molecules or molecular masses to a diverse array of structures allowing the production of new characteristics and traits of interest. The aim of this study was to evaluate the effects of foliar application of TiO2 nanoparticles on quantitative traits (plant height, number of branches, dry weight of shoots and roots) and the essential oil content of thyme under different levels of field capacity. Our results showed that the application of TiO2 nanoparticles had significant effects on thyme growth, while the essential oil concentrations not affected. These results imply that the application of TiO2 nanoparticles in plants increase agronomic value under reduced irrigation conditions but has not different significant on essential oil
The importance of higher alcohols and esters for sensory evaluation of rheinriesling and chardonnay wine varieties
Get PDFFor a consumer, one of the first characters for evaluation of wine is its scent. A pleasant aroma of wine associated with the subsequent taste experience can be remembered by the consumer for a long time and appreciated appropriately. For this reason, the aromatic properties of wine are very important to both consumers and producers. The question, however, is to assess the evaluation of wine sensory evaluation based on a rapidly developing chemical analysis without the use of a panel of evaluators. This study has dealt with the problem of the correlation of sensory evaluation of wine with the total content of higher alcohols and esters in wine prepared from the same wine varieties (Rheinriesling and Chardonnay) on the same vineyard under the same climatic conditions and processed using the same production technology in the years 2008 - 2012. The total content of higher alcohols and esters was determined by gas chromatography with a mass spectrometer (GC/MS). The correlation between the sensory evaluation and the total content of higher alcohols has not been established. However, the direct effect of the total content of the esters on the level of the sensory analysis of the two varieties studied was demonstrated. This can be an important economic indicator for a manufacturer who can estimate the sensory quality of the wine only on the basis of chemical analysis and thus estimate the success of the wine on the consumer market
Phenolic content and antioxidant activity of variety grapes from kurdistan Iraq
Get PDFThis study was carried out to determine the amount of total phenols, total flavonoid and antioxidant activity of 7 grape cultivars grown in Kurdistan rejoin of Iraq. The results showed that total phenols, flavonoid and antioxidant activity in the berries varied among the investigated cultivars. Total phenolic content, total flavonoid content ranged from 112.77 to 249.19 mg GAE/100g FW, 584.23 to 288.55 mg of rutin equivalents/100 g of (fresh sample) respectly and antioxidant capacity value ranged from 41.79 to 92.30%. Tahlik cultivar had the highest value of antioxidant capacity, flavonoid and total phenolic content. The lowest total phenolic, flavonoid content and the lowest value of antioxidant capacity were found in Abhar cultivar. Present results showed statistically significant correlations with the free radical scavenging activity. There was a very strong positive correlation (R² =1, p <0.05) between the antioxidant activity and total phenolic content and a strong positive correlation (R² =0.9735, p <0.05) between the antioxidant activity and total flavonoid content. 
Effect of infrared radiation on chemical and physical properties on Duku’s peel
Get PDFInfrared radiation has a potential for drying agricultural commodities such as the peel of duku. Drying of duku's peel in a whole duku using infrared radiation could become an effective method to eliminate the water on the peel but not in the flesh and could increase the shelf life of duku. The objective of this study was to investigate the potential of using infrared radiation for drying the peel of duku which would increase the shelf life of duku during storage. Duku's peel drying process was achieved by means of heating duku using a pairs of electric infrared emitters (IRE) facing each other with the emitter distance of 6 cm and 10 cm for a relatively short heating time of 50, 60, 70 and 80 seconds and after that stored at a cool room at the temperature of 15 °C for the length of one month. During storage, the physical and chemical changes of duku were then evaluated. It was found that the weight loss, fruit firmness, and total soluble solid of duku dried by means of exposing to Infra Red Emitter (IRE) were significantly affected by the distance of IRE, the temperature of IRE and the time exposed to IRE. However the titratable acidity only affected significantly by the distance of IRE. There were no significantly changes of browning index on duku during drying by exposing to IRE and while stored up to 25th day of storage. Drying duku by exposing it to IRE show a slightly better shelf life than the previous work
Cluster analysis of beef production distribution in Europe
Get PDFFragmentation and poor connection within the beef production industry affects its positive contribution to the economy, land management, and development of rural areas. Despite the third place in world beef production European countries have achieved one of the best results in environmental management of cattle breeding worldwide. On the other side there is a huge variability of beef and veal production on national and regional level, reflecting the varied geographical, economic and social requirements of different European regions. Even in case of moderate beef consumption (16 kg per capita per year) in the European Union, meat as the source of proteins of animal origin is connected to higher value added, higher employment, profit and incomes in agriculture comparing to crop production. On the other side it also requires higher investments and represents a greater risk. Different levels of agrarian subsidies and the efficiency of their use exacerbate the differences in the production of beef and veal in the countries of the European Union. In submitted paper we investigated beef production distribution similarity of selected countries in Europe. Quantitative approach was applied using cluster analysis in accordance with the Ward's minimum variance method with previous computation of similarity of the territories through the Euclidean distance. Three clusters representing the beef production similarity among the explored countries were visualised by dendrograms within observed steps in the year 2008 and the year 2017. Order of similarity and dissimilarity in beef production according to the Euclidean distance values of all the possible pairs of the districts from the whole data set in observed countries was processed for examined period of time. Finally, the heat maps were constructed to demonstrate the similaritity between each pair of the comprised countries. Obtained results could serve as a valuable resource for meat producers to understand the time dynamics impact and differences in level of beef production in European countries
Tibia mineralization of chickens determined to meat production using a microbial phytase
Get PDFThe target of the research was 6-phytase of microbial origin. It was used in feed mixtures for chickens determined to meat production. Its effect has been studied in relation to the tibia mineralization by calcium, phosphorus and magnesium. 6-phytase is a product of Aspergillus oryzae. That was obtained by means of biotechnological processes of production of commercially available enzymes. It was incorporated in the feed mixtures 0.1%. In a 38-day feeding trial, 300 one-day-old, as hatched, Cobb 500 chickens determined to meat production (100 birds per group) were fed on one concentrations of dietary non-phytate phosphorus (2.32, 2.31 g.kg-1, respectively and supplemental microbial phytase (0 and 500 FTU.kg-1 feed mixtures). Control group was used to compare the results and control feed mixtures contained 4.5 g.kg-1 without microbial phytase. At days 40 it was selected 6 birds in every group, which were slaughter in accordance with the principles of welfare. Left tibias of every bird were used to determination of calcium, phosphorus and magnesium contents. According to in vivo, it was found that the addition of microbial phytase to reduced dietary non-phytate phosphorus increased concentrations of calcium (Ca), phosphorus (P) and magnesium (Mg) in tibia. The differences among groups were statistically significant (p <0.05). It was concluded that reducing of dietary non-phytate phosphorus on the 2.32, 2.31 g.kg-1, respectively, by monocalcium phosphate and microbial phytase supplementation in feed mixtures facilitated tibia mineralization at chicken determined to meat production
Software support for cost calculation - application to the agricultural sector
Get PDFCalculation of product costs is the source of information on the costs of selected produced products with great explanatory power. In current practice, the overhead costs on farms are monitored and calculated by species. They are allocated using an allocation base (average state of the animals, harvested area in hectares) or are converted using direct costs of the activity as an allocation base. With the current high level of overheads, this method cannot be considered effective. Only type classifications are monitored and are therefore anonymous in relation to activities. We consider high overhead costs as a good reason for implementing and using the methods of Activity Based Costing. In this paper we present a proposed model of Activity Based Costing for its use in agriculture, created in MS Excel. We create the model as a basic version, which can be more closely defined depending on the particular conditions of the business implementing the model. We complete the general model for better illustration with figures on costs. We present a comparison of model results with the traditional approach of calculating costs in agriculture. One of the biggest benefits of the ABC system is the binding of costs from accounts, activities performed and the cost of products in one system. We present a statistical comparison of model results with the traditional approach of calculating costs in agriculture
Square wave voltammetry at carbon paste electrode modified with surfactant for alpha tocopheryl acetate determination in cosmetics
Get PDFThe aim of this study was describe electrochemical properties of a carbon paste electrode (CPE) bulk modified with 30% (w/w) surfactant sodium dodecyl sulphate (CPE/SDS) and demonstrates its application in the determination of α‑tocopheryl acetate (α‑TAc), known as vitamin E acetate, in selected cosmetic products, especially body creams. In addition to anionic SDS, cationic hexadecylpyridinium chloride monohydrate (CPC) was also tested as possible modifier. It was found that selection of surfactant type and its content significantly affect an electrical conductivity and mechanical stability of these heterogeneous electroanalytical sensors in pure organic solvents. Under this study, it was found that CPC is a totally inappropriate mediator due to very high backgroundcurrent. Together with other lipophilic vitamins characterized by antioxidant activity (dominantly retionoids), this completely synthetic substance is widely used as significant cosmetic additive due its preservative properties. Monitoring of its content in cosmetic products is usually performed by high‑performance liquid chromatography (HPLC) with UV detection. This standard analytical protocol is always burdened with the complex and time‑consuming preparation of the sample before analysis. For that reason, robust and simple electroanalytical method based on anodic oxidation of the α‑TAc at CPE/SDS by square wave voltammetry (SWV) performed in pure organic electrolyte (99.8% acetonitrile containing 0.1 mol·L‑1 LiClO4) was developed. Moreover, simple dissolution of sample in supporting electrolyte using ultrasonic bath and subsequent filtering through a stacked filter included all the necessary procedures for sample preparation. The linear range from 0.1 to 1.2 mmol·L‑1and limit of detection 37 µmol·L‑1 were found at pulse amplitude 10 mV and frequency 10 Hz as optimum. In analysis of selected cosmetics, the developed electroanalytical method was not validated using comparison with standard HPLC. At least, the recovery was verified by analysis of model sample and value 95.8% was calculated