Potravinarstvo Slovak Journal of Food Sciences
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Optimization of infrared drying condition for whole duku fruit using response surface methodology
Get PDFDuku (Lansium domesticum), tropical exotic fruit, was successfully preserved by drying using exposure to infrared radiation emitters. Response surface methodology (RSM) is used to optimize independent variables (IRE distance of 6 cm and 10 cm, IRE temperature of 200 °C, 300 °C, 400 °C, and IRE exposure time of 50 s, 60 s, 70 s, and to produce response variables (weight loss, fruit firmness, titratable acidity, total soluble solid, and browning index). It could be concluded from the optimization performed that drying duku skin in a whole fruit by exposing the fruit to the infrared emitter resulted in a duku fruit with a relatively good physical and chemical conditions and still be consumable. The IRE distance of 6 cm gave a desirability value of 0.80 while the IRE distance of 10 cm gave a desirability value of 0.92 however the IRE distance of6 cm gave a better storage time. The IRE distance of 6 cm has an optimum value of weight loss 2.2%; optimum value of fruit firmness of 40.92 N; optimum value of total soluble solid of 17.48 brix; optimum value of titratable acidity of 0.33%; and optimum value of browning index of 0.9. The fitting model base on RSM resulted from this research indicated that this study could be used as the basis for alternative process in food processing of duku but still need further research to increase the shelf life and a better result in the chemical and physical characteristics of duku
Factors influencing interest of Slovak consumers' in organic dairy products
Get PDFThe aim of the article is to analyse the dependency of selected factors (age category, level of income and gender) on consumers' willingness to buy organic dairy products. The primary research based on the electronic interview survey carried out on the sample of 203 Slovak respondents of all ages, in different social situations and with different views on the issue. The questionnaire consisted of seven sorting questions and six questions addressed consumers' perception of organic dairy products and the reasons for their purchase or rejection. For evaluation the Chi square test of square contingency was used. Results were sorted into tree parts. The aim of the firts part of research was to find out whether there is a dependency between the age category of the respondents and whether they are buying organic dairy products. Results showed that the age category of the respondents and purchase of organic dairy products are independent. The second part of the research based on the examination of the dependency between the level of income of the respondents and their willingness to pay for organic products. In this case we confirmed the dependency between the customers' average income per month and their willingness to pay for organic dairy products. Last but not least, the dependency between the reasons that would discourage consumers from buying organic dairy products and their gender was examined. The results of analysis clearly showed that these two variables are independent. Despite generally persisted opinions that food of daily consumption in bio quality (organic) is mainly bought by women of specific age categories (joung independent woman after graduation, mothers on maternity leave) we can confirm just the significance of the impact of customers' average income per month on their willingness to pay for these high quality and therefore expensive products
Analysis of development of raw cow milk prices in the conditions of the Slovak Republic
Get PDFThe paper is focused on the evaluation of the price development of raw cow milk in the Slovak Republic. The aim of the paper is to analyse the development of average prices of the raw Q class cow´s milk in 2006 – 2018 and to forecast the trend of these prices by June 2019. Monthly data from the Market Report of Milk and Dairy Products issued by the Agricultural Information Department – ATIS, as part of the Agricultural Paying Agency, were the base of our information resource. These data were analyzed by using the statistical software called SAS. Box-Jenkins methodology was used to model the future trend of average purchase prices of the raw Q class cow´s milk, designed for modeling stationary and non-stationary time series and time series with seasonal components. During the period of 2006 – 2018 the Slovak dairy market showed significant changes in the prices of raw Q class cow´s milk. Three crisis periods of the dairy sector have been identified, during which the milk price has fallen below 0.30 € per kilogram. Long-term low prices of raw cow milk led to the liquidation of primary milk producers. In the next forecast period, by February 2019 a moderate increase in the average purchase price of rawQ class cow´s milk is expected, followed by a decrease by June 2019
Vegetable ingredient in cheese product
Get PDFSesame seeds are a functional food ingredient with vasoprotective, antioxidant, prebiotic, chondro- and osteoprotective characteristics. In this study, sesame seeds were used to enrich a cheese product. The dose, method and technological production stage of the cheese product in which to add sesame seeds were determined, in addition to the effect of sesame seeds on the product’s quantitative indicators. The nutritional value of sesame seeds, their total amino acid and fatty acid compositions and microbiological parameters were evaluated, depending on the method of the filler temperature treatment. The appropriate heat treatment method was holding the functional component in milk at 73 ±2 °C for 25 min, followed by cooling to 30 ±2 °C. Adding the filler into the cheese mass before moulding the cheese head was determined as the appropriate technological step to introduce the previously prepared sesame seeds. The cheese product was found to have the best sensory characteristics at the 3% sesame seed dose compared with the doses of 1% and 5%. The cheese product enriched with sesame seeds can be recommended as a functional product for systematic consumption without restrictions for all groups in a healthy population
Antibacterial and antioxidant potentials of leave extracts of Helianthus annuus
Get PDFHelianthus annuus has been widely used for its medicinal and nutritional properties. This study was aimed at assessing the ethyl acetate, n-hexane and methanol extracts of Helianthus annuus for antibacterial and antioxidant potentials. The phytochemical screening, total phenols, DPPH radical scavenging assay and nitric oxide radical scavenging activity were carried out following standard procedures. Preliminary screening of the antibacterial activities of the extracts was carried out on five bacterial species (Bacillus subtilis, E. coli, Pseudomonas aeruginosa, Staphylococcus aureus and Klebsiella pneumoniae), using the agar-diffusion method. Growth rate studies in presence of the extract was investigated on two bacterial species (Bacillus subtilis and E. coli). The methanol extract was observed to inhibit the growth of the five bacterial species while ethyl acetate and N-hexane extracts showed inhibition against Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. Extended lag periods of 5 - 6 h were observed when the Bacillus subtilis and Escherichia coli were grown in broth medium that contained the respective extracts. In broth medium with mixture of extract and ascorbic acid, there was no observed growth of the Bacillus subtilis and Escherichia coli throughout the 7 h incubation period. The total phenolics content of the extracts revealed concentrations of 6.66 ±0.45, 5.58 ±0.11 and 6.06±0.41 mg TAE.g-1) for the methanol, N-hexane and ethyl acetate extracts respectively. The DPPH radical scavenging assay results displayed gradual increase in percentage inhibition from the lowest to the highest concentration across all the standard groups, a similar trend was observed with the extracts, the ethyl acetate extract showed highest percentage inhibition amongst the other extracts. All the extracts showed high reducing power ability. The nitric oxide scavenging ability of the extracts showed constant increase with increase in concentration. Helianthus annus, it could be a good source of antimicrobial and antioxidant especially in a world where resistance to antibiotic has increasingly become a global concern
Consumers´ awareness of food safety
Get PDFEating food is one of the most important needs of every person, so their safety and quality should be crucial for everyone. People expect, that food they eat is hygienically and health safe. Unfortunately, people usually start to focus on food safety only when various food scandals are exposed and it is too late. Mass consumption of food is the cause of a high risk to human health, but only in the case of harmful food. Food-borne diseases are a common and widespread phenomenon in all parts of the world, regardless of the economic development of the country. Protection of human, animal and plant health is one of the main economic priorities of each country. The political objective of the European Union is therefore to ensure that European Union citizens have access to safe and nutritious foods, so it must meet strict safety standards. In ensuring food safety, it is necessary to take into account all aspects of the food production chain as a whole, because each subject can have a potential impact on food safety. This paper deals with the issues of food safety and food quality. The main objective was to find out how consumers perceive higher quality food and whether they read information included on the food packaging. Primary data were obtained from a survey that was conducted on the sample of 478 respondents living in Slovakia. For a deeper analysis, several assumptions, which were verified by Friedman Test, Chi-Square Test of Independence, Wilcoxon Signed-Rank Test, were formulated. The survey has found out that 84% of respondents buy higher quality food and 60% purchase them because of health-related reasons. More than half of respondents search for the information about food safety on the Internet and the same percentage considere government as the most reliable source of information about food safety. Unfortunately, just more than one quarter of them read the information on food label and for 34% is this information unsufficient
The field and laboratory study of the collection samples of onion breed Allium cepa L.
Get PDFThirteen collection samples of Allium cepa L. of different ecology-geographical origin grown in the Crimea conditions are given. Morphometric characteristics of the bulbs - the form index, the diameter, the height, the weight, the thickness and the quantity of rich skins are analyzed. The greatest output of standart production (90 - 95.6%) was observed for all breeds. The biochemical values of the Allium cepa L. samples under study were examined by the traditional methods. It is marked that the dry substances, the sugars sum, the mono- and disaccharides in the majority of the samples exceed the standart (Yaltinsky rubin) on 14 - 39%, 11 - 48% and 36 - 150% correspondently. The samples with the high concentration of essential oil are singled out: Yaltinsky rubin (Crimea), Tavrichesky (Crimea), Blood red flat (Netherlands) and Brown Beauty (USA) - 4.5, 6.2, 5.6 and 4.4% correspondently. The microsculpture of Allium cepa L. leaf was studied by the method of raster electron mi-croscopy and the essential breed differences of the stomata quantity and their arrangement towards the leaf level were distinguished. The results of electron-microscopic research indicate the different level of Allium cepa L. samples adaptability. Allium cepa L. samples under study of the southern subspecies are recommended for the development of the new breeds with the advanced nutritional qualities
Natural fruit beverages fortified by biologically active substances of grape vines
Get PDFBased on the study of general knowledge of biochemical and all subsequent developmental studies of organic matter, especially products of grapevine and selected fruit products, a comprehensive study of processing technologies is prepared. Use of a combination of vine products and fruit products in the form of natural grapes. Beverages are researched and developed to be purely natural on the basis of grape musts, blue and white, either individually and again separately in targeted combinations, both biochemically, organoleptically and colorfully, with fruit sources. The core of grape value of biologically active substances is an integral and essential new part and condition of designing these beverages. Their increased biological values, which create the preconditions for containment and if properly managed on the basis of scientific knowledge, may in some cases almost result in the elimination of synthetic additives. It should be noted that 20 - 25% of the adult population suffers from many unexpected allergies, for example, to the sulphite content, although its content in the final product does not exceed the health-approved normatives. And there are many other, interrelated relationships. Beverages are technologically dealt with both without alcohol fermentation and with this fermentation, but only based on their compositional natural resources. They are therefore suitable for the entire population profile. The whole set contains 7 variants and a combination of natural beverages from different fruits. Including natural beverages with or without alcoholic fermentation from the must of white wine grapes, the juice of apple puree with those of biologically active substances from the products grapevine. Three months of monitoring and determination of basic (oenological) values and biologically active substances were performed on these products. The high-performance liquid chromatography method with a refractometric detector determined amount of sugar and alcohol, whilst titrating determined total and volatile acids and free sulfur dioxide. Yeast assimilable nitrogen, total anthocyanins and polyphenols were determined by spectrophotometry, antioxidant activity by DPPH and ABTS methods
Occurence and antimicrobial resistance of common udder pathogens isolated from sheep milk in Slovakia
Get PDFThe aim of this work is to identify the spectrum, frequency and antimicrobial resistance of bacterial pathogens occurring in sheep dairy herds in Slovakia. Of a total of 310 samples of sheep's milk coming from three breeds during two seasons (2017 and 2018), at least one potential pathogen was isolated from 102 samples (32.9%). A total of 131 microbial isolates were isolated. The most represented species were coagulase negative staphylococci CoNS (75.6%), followed by Streptococcus agalactiae (10.7%), Staphylococcus aureus (6.9%), Streptococcus dysgalactiae (4.6%), Escherichia coli (1.5%), Enterococcus faecium (1.5%), and others (Streptococcus uberis, Streptococcus parauberis, Candida sp., Klebsiella sp., moulds) below 1%. A total of 99 isolates of CoNS were tested for antimicrobial resistance. Of these, 63.6% were resistant to at least one antibiotic. A total of 24.2% of the tested isolates were resistant to 3 groups of antimicrobials simultaneously (multi-drug resistance). The highest resistance was observed to lincomycin (57.6%) and neomycin (36.4%), the lowest to sulfamethoxazolum+trimethoprim (0%) and enrofloxacin (3.0%). Based on the results of this work, it is possible to assume a similar spectrum of pathogens and their antimicrobial resistance described in the literature also within the Slovak sheep farms focused on milk production
Antioxidant profile of mulled wine
Get PDFThe aim of the study was to compare chemical and nutritional profile of wine and heat-treated wine, called mulled wine. The experiment was focused on simulation of ordinary produce mulled wine by the majority of consumers. Cabernet Moravia (bottled in Velkobílovická vína s.r.o., Czech Republic) was used for the experimental production of mulled wine. Following spices were added to wine during cooking: cloves (Vitana, Czech Republic) and cinnamon (KOTíNY, Austria). The samples of wine were heat treated in stainless steel pot for 5 minutes. The relative density, acidity, alcohol content, phenol content and antioxidant capacity were monitored in experimentally produced wine and mulled wine. The gained results showed that samples of mulled wine with added cloves had statistically significant (p <0.05) higher phenol content and higher antioxidant properties in comparison with wine before heat treatment and spices addition. The results clearly showed that mulled wine can be considered as the product with better health beneficial nutritional profile than wine from which it is produced; in addition, mulled wine sample had significantly (p <0.05) lower alcoholic content (8.27 ±0.04 vol.%)