Potravinarstvo最新文献

{"title":"Thermal aging of edible oils: Spectrophotometric study","authors":"B. Lapčíková, T. Valenta, L. Lapčík, Martina Fuksová","doi":"10.5219/871","DOIUrl":"https://doi.org/10.5219/871","url":null,"abstract":"The aim of the present study was to determine the spectrophotometric and thermal aging properties of various edible oils (olive, peanut, rapeseed, soybean and sunflower oils) which are commonly available in the Czech market. The samples were measured by UV/VIS absorption spectrometry and fluorescence spectroscopy. Detected substances of UV/VIS spectra were compared to expected oil composition; the highest absorbance values were detected in a wavelength range 300-550 nm which can be related to the presence of unsaturated fatty acids. The mixtures of oils were characterized by fluorescence spectroscopy; the individual oils were successfully distinguished according to their excitation-emission profiles. This method was also used to detect the samples of adulterated oils, i.e., the adulteration of high-quality oils with soybean oil. From a physicochemical point of view, the influence of temperature on the compounds of extra virgin olive oil was examined by thermal stress simulation. This thermal aging analysis demonstrated that the amount of oxidation products in olive oil increased during the heating whereas the chlorophyll content decreased. The results showed the ability of the techniques used, UV/VIS absorption spectrometry and fluorescence spectroscopy, to characterize the quality and composition of oils, and to distinguish individual oils in blends. UV/VIS spectrometry was also successfully employed for the evaluation of olive oil qualitative parameters according to the standard quality parameters by the \"International Olive Council\" (EEC 702/2007).","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"38 1","pages":"372-378"},"PeriodicalIF":0.0,"publicationDate":"2018-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86655672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Food safety from a consumers´point of view: food quality","authors":"Ľ. Nagyová, J. Golian, Andrej Géci, J. Palkovič, Jozef Čapla, Z. Kádeková","doi":"10.5219/918","DOIUrl":"https://doi.org/10.5219/918","url":null,"abstract":"Food safety is a topic that is currently very much and often discussed. This may be a debate among political representatives, representatives of the food industry, but also among consumers, ie. general public. The issue of food safety and quality is very important in view of the growing globalization of economy, whose mission is to encourage food businesses to improve the production process as a whole and competitiveness. As in every sector, the food market faces many problems arising from market opening, business environment diversity or non-compliance with legislative requirements. The effects of these market imperfections are ultimately borne by the consumer. It is, therefore, appropriate to ensure that consumers are adequately informed about the food they consume. Food production is carried out according to European and world standards. A Slovak customer purchases food imported from abroad. This fact can be caused by the pricing of individual foods but also by the lack of Slovak producers. Foreign competition liquidates the quality Slovak producers. The principle of customers should be to support the economy of the state and to buy domestic food. The submitted document deals with issues of food safety, control and quality of food. The aim of the work was to examine the attitudes of consumers to food safety based on the acquired knowledge and research results, to identify their interest in food safety. It also involved identifying global food safety issues and analyzing consumers' views on the problem under consideration and its impact on their purchasing behavior. Primary data was obtained from a survey that was performed on a sample of 478 respondents. Based on the survey, it was confirmed that 85% of respondents perceive the different quality of the food sold on the Slovak market. Nearly two-thirds of the respondents said they were paying attention to the quality of the groceries. More than half of respondents expressed satisfaction with hygienic sales conditions. Almost 80% think that high-quality food is commonly available. Statistical testing has confirmed the significantly lower quality of food produced abroad. Other assumptions were formulated for more detailed analysis and their relationships were verified by using the statistical methods (Friedman Test, Chi-Square Test of Independence, Wilcoxon Signed-Rank Test).","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"1 1","pages":"355-363"},"PeriodicalIF":0.0,"publicationDate":"2018-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90923415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibitory effect of aqueous extracts of raw and roasted Sesamum indicum L. seeds on key enzymes linked to type-2 diabetes (α-amylase and α-glucosidase) and Alzheimer’s disease (acetylcholinesterase and butyrylcholinesterase)","authors":"J. Y. Talabi, Sekinat Adeyemi, Sefunmi Awopetu, B. Ajiboye, O. Ojo","doi":"10.5219/866","DOIUrl":"https://doi.org/10.5219/866","url":null,"abstract":"Sesame ( Sesamum indicum  L.) seeds are nutritional food, but researches have limited knowledge about the antioxidant, antidiabetic and anticholinesterase activities of the seed. This study was conducted to determine the antioxidant activity, enzyme inhibitory potential (α-amylase and α-glucosidase) and acetylcholinesterase inhibitory property of aqueous extracts of raw and roasted sesame seeds. Antioxidant activities were analyzed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging property, 2,2-azino-bis-(3-ethylbenthiazoline-6- sulphonic acid (ABTS) scavenging ability, iron chelating ability and ferric reducing antioxidant power (FRAP). Anti-Alzheimer's potential was determined using acetylcholinesterase and butyrylcholinesterase enzyme inhibition assay. The results showed that the total phenolic and flavonoid contents were higher in the roasted S. indicum sample with the values of 19.81mg/100g and 17.19 mg/100g respectively. The raw S. indicum sample showed higher antioxidant activity in DPPH, and iron chelation assays; while roasted S. indicum sample showed higher in the reducing power and ABTS scavenging activity. However, anticholinesterase activity was higher in the roasted S. indicum sample than in the raw S. indicum sample. The extracts inhibited α-amylase activity in a concentration-dependent manner (20 - 100 µg.mL -1 ). The raw sample (16.55 ±0.89%) had higher inhibitory α-amylase activity compared to the roasted sample (15.78 ±0.48%) at 100 µg.mL -1 . Inhibition of α-glucosidase was higher in the roasted sample at 100 µg.mL -1 (19.40 ±0.26%) compared to the raw sample at the same concentration (3.65 ±0.52%). These findings suggest that S. indicum L. is not only nutritious but also showed potential pharmacological properties.","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"56 1","pages":"337-346"},"PeriodicalIF":0.0,"publicationDate":"2018-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80162580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physico-chemical study of flavonoids from different matureness corn silk material","authors":"Peng Li, L. Lapčík, B. Lapčíková, S. Kalytchuk","doi":"10.5219/869","DOIUrl":"https://doi.org/10.5219/869","url":null,"abstract":"There was tested a simple extraction procedure of flavonoids separation from the original corn silk (CS) material. It was found, that the total flavonoids content differs with the extraction time and extraction temperature. There were found different flavonoids contents in extracts prepared from different maturity stages of the original corn silk material (silking stage (CS-S), milky stage (CS-M)). Extracted flavonoids content was quantified by the lutin standardization method by means of colorimetry at 510 nm wavelength. Obsreved flavonoids concentration was ranging from 2×10 -3 mg.mL -1 to 7 ×10 -3 mg.mL -1 dependent on the extraction time period and extraction temperature. The highest flavonoids concentration of 7.5×10 -3 mg.mL -1 was found for CS-M after 20 minutes extraction time and 80  °C extraction temperature. There was confirmed the presence of flavonoids by fluorescence mapping experiments. There was found a typical multistep decomposition process for both CS-S and CS-M materials by TG analysis. There was found a melting temperature of flavonoids of 54.3 °C for corn silk silking stage material exhibiting 58.9 J.g -1 heat of fusion and 60.2 °C for corn silk milky stage material with 112.9 J.g -1 heat of fusion. The optimal conditions of corn silk flavonoids extraction were 40 ℃, 50 minutes for CS-S, the optimal flavonoids extraction content was (6.8 ±2.1)×10 -3 mg.mL -1 , 80℃, 20 minutes for CS-M and the optimal extraction content was (7.2 ±0.3)×10 -3 mg.mL -1 .","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"35 1","pages":"347-354"},"PeriodicalIF":0.0,"publicationDate":"2018-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78606944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Food safety from consumer perspective: health safety","authors":"J. Golian, Ľ. Nagyová, Alexandra Andocsová, P. Zajác, J. Palkovič","doi":"10.5219/917","DOIUrl":"https://doi.org/10.5219/917","url":null,"abstract":"Food industry along with agriculture constitute a major economy sector in most countries, because in addition to water intake and oxygen availability, food is another basic determinant for functioning of the human organism. For the proper functioning of human body, it is imperative that the customer chooses food so that the daily diet includes all the necessary nutrients in a reasonable proportion. At present, however, it is becoming more and more common that foodstuffs do not meet strict standards, are not properly stored, the packaging is damaged, or hygiene standards are not being adhered to, and therefore, in addition to health benefiting substances, they also contain harmful ones. According to the World Health Organization, the death of up to 2 million people a year around the world is caused by foods harmful to human health. The main objective of this report was to assess how consumers perceive the health safety of food in Slovakia and to find out whether some types of food are considered as potentially harmful to health. Primary data were obtained through a questionnaire survey conducted from October to December 2017 on a sample of 478 respondents. Respondents answered to 12 factual, and 9 classification questions, which were consequently analyzed using the Friedman test, Nemenyi test and Chi-Square test of Independence. Survey results showed that the majority of respondents had concerns about the health harming effects of food only occasionally and they trust the hygienic level of the restaurant facilities (60.5%), fast food (53%) and frozen food (49.2%) with few reservations. As the most hazardous foods are considered poultry meat, eggs and mayonnaise. If the consumer's health is endangered by food, the guilty party should be punished by ban (61.9%) or by suspension (19.5%).","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"90 1","pages":"313-322"},"PeriodicalIF":0.0,"publicationDate":"2018-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77907686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antioxidant activity of tokaj essence","authors":"Zuzana Eftimova, J. Eftimová, Ľ. Balážová","doi":"10.5219/829","DOIUrl":"https://doi.org/10.5219/829","url":null,"abstract":"The aim of the presented experiment was to measure the content of total polyphenols and antioxidant potential of Tokaj essence from the years 1999, 2006, 2007, 2009, 2013, 2015. Tokaj essence is produced by fermentation of concentrated must from botrytised grape berries. The highest content of polyphenols was determined in the essence of 1999 (275.8 ±18.17 mg.L -1 ) and the lowest in the sample of 2015 (118.8 ±12.28 mg.L -1 ). Antioxidant activity was determined by two methods DPPH and PRAC (permanganate reducing antioxidant capacity). Antioxidant DPPH method showed that the essence of year 1999 had significantly the highest activity (63.4 ±0.81 µmol.L -1 Trolox) while essence of year 2015 (47.5 ±1.58 µmol.L -1 Trolox) featured the lowest activity. The results of method PRAC, which determine the total reducing capacity of the essence, do not correlate with the results of DPPH and total phenolic content, because of higher content of saccharides, which gave false positive test results. The method PRAC is not suitable for measuring antioxidant activity of tokaj esence. The results showed that aging of wine increased the content of polyphenols and also its antioxidant activity. High content of polyphenols and the great antioxidant activity of Tokaj wine receive their beneficial effect to human health.","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"30 1","pages":"323-329"},"PeriodicalIF":0.0,"publicationDate":"2018-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77120075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of Escherichia coli strains isolated from raw vegetables","authors":"P. Pleva, Magda Janalíková, Silvie Pavlíčková, M. Lecomte, Tanguy Godillon, I. Holko","doi":"10.5219/897","DOIUrl":"https://doi.org/10.5219/897","url":null,"abstract":"Vegetables are an important part of the human diet. Sometimes, contamination by pathogenic Escherichia coli can be underestimated; moreover there is a risk of antibiotic resistance spreading via the food chain. The purpose of this study was to examine the prevalence of Escherichia coli in fresh vegetables sold in retail market in the Czech Republic and to evaluate the risk to human health. Antibiotic resistance against 12 antibiotics, the presence of 12 virulence and 15 resistance genes were determined among 15 isolated strains. Most of tested strains belonged to B1 phylogenetic group, less frequently represented was B2 and D phylogroup. These results indicate that most strains are probably of human origin. All E. coli strains were resistant to at least one of twelve tested antibiotics. A multidrug resistance was observed in four strains. In this study, the presence of virulence factors Einv and papC and also genes encoding toxins (CNF1, CNF2) was detected. Nevertheless, none strain can be considered as STEC or EHEC. The widespread appearance of a growing trend associated with the prevalence of antibiotic resistance among enterobacterial isolates is undeniable and the possibility of transfer to humans cannot be ignored. Nevertheless, these results indicate that raw vegetables sold in the retail market can constitute a potential health risk for consumers.","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"49 1","pages":"304-312"},"PeriodicalIF":0.0,"publicationDate":"2018-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76736903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sauvignon wine quality as affected by its processing and storage","authors":"M. Fikselová, P. Czako, J. Gaz̆o, A. Mendelova, M. Mellen","doi":"10.5219/885","DOIUrl":"https://doi.org/10.5219/885","url":null,"abstract":"The colour and limpidity are the first sensory attributes of wines that are appreciated by consumers, predisposing their acceptance or rejection. The aim of this work was to monitor the effect of harvest, processing (different clarification and treatment of must) and storage on the quality of Sauvignon wine. The wines were stored for two years in the wine cellar at 12°C and 70 % of humidity, in the bottles. The acid content, residual sugar and alcohol content among chemical parameters and sensory profile of wines were observed. Sensory quality of wines was evaluated by the aromatic profile (profile method). Based on acquired results, two years of wine storage significantly affected the total acid content of wines and alcohol content. Different treatments of must affected residual sugars, the variant with the maximum dose of the clarification preparation (highly pure cellulose, polyvinylpolypyrrolidone, gelatin and mineral adsorbents) showed statistically the highest content of residual sugars. From the sensory point of view, sensory profiles of wines were different compared to the first and second harvest of grape, sensory profiles of wines were changed also after two years of storage. The fourth variant appeared to be the best stable, treated with the addition of clarification preparation at the dose of 30 g. 100 L-1 must. Because from the same variety Sauvignon were produced wines of different chemical and sensory qualities, some gastronomy recommendations were done as well.","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"28 1","pages":"299-303"},"PeriodicalIF":0.0,"publicationDate":"2018-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81296558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The quality of ketchups from the Czech Republic's market in terms of their physico-chemical properties","authors":"P. Diviš, J. Smilek, J. Pořízka, V. Štursa","doi":"10.5219/898","DOIUrl":"https://doi.org/10.5219/898","url":null,"abstract":"Ketchup is a tomato-based condiment with a tang contributed by vinegar, sugar, salt and spices. Physical and chemical quality requirements for ketchup are regulated in the Czech Republic by Decree No. 157/2003 as amended. The main monitored parameters determining the quality of ketchups are total tomato content, total soluble solids, total organic acids and total salt content. In this work the following parameters were monitored in a total of eight ketchups from the commercial markets in the Czech Republic: pH, total solids, total soluble solids, citric acid content, acetic acid content, lycopene content, fructose, glucose and sucrose content and content of Ca, K, Mg and Na. In addition to chemical analyses, rheological measurements were performed and dynamic viscosity and yield stress were determined. The results obtained were statistically processed and the hypothesis i) whether the sales price of ketchups is related to the quality of ketchups expressed in chemical composition and ii) whether the chemical composition affects the rheological properties of ketchups has been verified. The Pearson correlation matrix showed very good correlation between the total solids and tomato content in the ketchup (R = 0.8464) as well as between the total soluble solids and tomato content in the ketchup (R = 0.8583). Another significant correlation was found between total soluble solids and total saccharides content in ketchup (R = 0.7309) as well as between potassium content and and tomato content in the ketchup (R = 0.8864). The chemical composition of ketchups did not significantly affect the dynamic viscosity of ketchups, however strong correlation between tomato content in ketchup and between yield stresses was found (R = 0.8436). No correlation was found between the ketchup price and chemical composition of ketchup, however cheaper ketchups contained more salt.","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"16 1","pages":"233-240"},"PeriodicalIF":0.0,"publicationDate":"2018-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90111387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of different reverse transcription aproaches in Pru p 3 transcripts semiquantitative amplification","authors":"J. Žiarovská, Matúš Kyseľ, L. Zeleňáková","doi":"10.5219/891","DOIUrl":"https://doi.org/10.5219/891","url":null,"abstract":"Normal 0 21 false false false MicrosoftInternetExplorer4 Reverse transcriptase transcribes the cDNA based on its previous extraction and standardization. Reverse transcription step is considered to be critical in the workflow of quantification of transcribed genes. The aim of the study was to extract total RNA by different methods and to analyse the results of the subsequent reverse transcription reaction when different commercial RT kits were used to process RNA extracted from pulp of matured peach fruit. Mature peach pulp was used in the study. The fruit of variety Vistarich was collected in summer 2017 in the orchard of Dvory nad Žitavou. Two RNA extraction methods, TRIzol® Reagent and GeneJET Plant RNA Purification Kit, were tested in to determine the suitable method for peach fruit RNA extraction. Three different cDNA reagent sets were used to transcribe 115 ng/500 ng total RNA or 11 ng/115 ng, respectively. Both variants of the primers, random hexamers as well as oligo (dT) 18, were used to anneal the target mRNA of Pru p 3 allergen following the manufacturer instructions. No specific effect was obtained in the case of peach fruit when using ethanol-extracted tissue treatment and the effect of the used extraction method was more significant. The A260/230 ratios were similar for three from four tested methods. In the case of these three methods, the A260/A230 ratios for all the extracted samples were higher than 1.9 which indicates high purity without contamination by polyphenols and polysaccharides. The specificity of obtained amplicons was proved by restriction cleavage using Tse I restriction endonuclease. This provided the cleavage of the 179 bp long product in all amplicons. Working with mature fruit meet a specific situation in the field of RNA extraction and subsequently all the downstream applications. That is, why choosing the most fitting methods and kits is a crucial step. Here, the method for the semi-quantitative analysis of the Pru p 3 allergen expressions was set up in the way that will be directly applicable for Pru p 3 expression analyses.","PeriodicalId":20379,"journal":{"name":"Potravinarstvo","volume":"91 1","pages":"209-215"},"PeriodicalIF":0.0,"publicationDate":"2018-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79990628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}