Potravinarstvo Slovak Journal of Food Sciences
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The effect of melon and watermelon concentrates on consumer properties of polycomponent dairy dessert
Get PDFA full balanced nutrition is a necessary condition for a person”™s normal physical and mental development, resistance to the effects of adverse environmental factors and strengthening immunity, which is of particular importance in the bad ecological situation in the world. Providing the population with high-quality bio-functional food is an important state task, the fulfillment of which is the key to the health of the nation, and ultimately ensures the security of the country. One of the effective ways to prevent and treat various diseases is the development of a new generation of functional dessert products with dietary properties. As a basis, there has been a principle considered, i.e., the high nutritional, biological value and physiological activity of the product are predetermined by the high quality of the raw materials. The article analyzes the state of the dairy industry at the present stage. The efficiency of melon and watermelon concentrates in the production of multicomponent dairy dessert has been substantiated. The positive effect of the tested concentrates on the structural and mechanical properties of the jelly part of the dessert, organoleptic characteristics and nutritional value of the product has been established. The optimal concentration of the gelling agent in the jelly has been determined. There were some conducted experiments aimed at maximum reducing of the gelling agent”™s weight fraction in the product
Potency of Okra flour (Abelmoschus esculentus) in improving adiponectin level and total antioxidant capacity of high fat diet streptozotocin rat model
Get PDFT2DM has increase in global-morbidity and mortality. Oxidative stress and adiponectin-levels are important for insulin-resistance and pancreatic-b-cell-dysfunction in T2DM. Okra fruit is rich of quercetin and phytosterol which have positive-effect for T2DM. Research aimed was to study the effect of okra-flour to adiponectin-levels and total-antioxidant-capacity (TAC) in T2DM. Thirty Wistar-rats were divided randomly in five groups. K1 and (X1, X2 and X3)-treated-groups were in T2DM-condition-induced by high-fat-diet-(HFD)-Streptozotochin-(STZ)-nicotinamid-(NA). Healthy-controls-(K2)-group was also used. Okra-flour was given orally for 28 days at doses of 0.1; 0.2 and 0.3 g/Kg-body-weight/d to X1, X2 and X3-groups, respectively. Statistical program was used to analyse the different between pre-post-intervention, and between groups. Correlations between variables were also analysed. The serum-adiponectin and TAC-levels were measured by ELISA and ABTS-methods, respectively. By comparing pre and post-intervention, adiponectin levels of all-intervention-(X1, X2, X3)-group were increase (p = 0.027 for X1 and X2; p = 0.028 for X3), while in the same period the decrease were found in group K1 (p = 0.026) and K2 (p = 0.028). Increase-TAC-levels pre-post-intervention was observed in group all-intervention-groups (p = 0.027), while no change in K1 (p = 0.66) and the decrease in group K2 (p = 0.039). Reduce-fasting-blood-glucose-levels pre-post-intervention were shown in the all-intervention-groups (p = 0.028), while for the K1 groups was increase (p = 0.028). There were significant differences between the five-groups on fasting-blood-glucose-levels, adiponectin and TAC-levels, and X3-group showed the highest adiponectin and TAC-levels. Very-strong-correlations were found between glucose-adiponectin-TAC-levels-post-intervention. Okra-flour make better glucose-adiponectin and TAC-levels in T2DM-conditions. Okra dose of 0.30 g/Kg-body-weight/day is the best in increasing adiponectin and TAC-levels
Microbiological comparison of visibly dirty and visibly clean mature green tomatoes before and after treatments with deionized water or chlorine in model overhead spray brush roller system
Get PDFThe purpose of the current study was to compare natural microflora counts of mature green tomatoes as influenced by visual cleanness, and investigate ability of chlorine sanitizer to reduce different groups of natural microflora on the surface of tomatoes using overhead spray brush roller system. We hypothesized that natural microflora might not be equally affected, with vegetative Gram negative bacteria being more sensitive and soil-related Gram positive sporoforming bacilli and molds more resistant. Microflora from untreated visibly clean and visibly dirty tomatoes, as well as from visibly clean tomatoes after 30 seconds deionized water or 100 ppm chlorine treatments, was recovered and spread plated on Tryptic Soy agar, MacConkey agar, and acidified Potato Dextrose agar. Microflora from untreated and chlorine-treated tomatoes was non-specifically enriched and plated on agar with chlorine paper disc diffusion assay applied to check for inhibition zone differences. Interestingly, there was no significant difference in plate counts between visibly clean and dirty tomatoes (p >0.05). Chlorine was more effective than water alone to reduce microbial counts on tomatoes for all microbiological media tested. Based on similar relative reductions of microorganisms in each group, it was concluded that chlorine may have no preferential kill for investigated groups of microorganisms. High counts remaining after treatment with chlorine solution suggested possibility of resistant microbial biofilm formation on the surface of tomatoes
Detection of microbiota in the vineyards of the Tokaj wine region
Get PDFTokaj is an important Central European wine-growing area with controlled planting and authorized varieties of white vines. This area has a specific microflora composition which changes based on its climate dependence, as well as during the fermentation process of wine production. Therefore, the aim of this study was, by culture examination of the samples, to detect the microbiota of soil, leaves, berries and fermentation must from two vineyards from the Slovak part of Tokaj. The highest total viable count (5.60 ±0.01 log cfu.g-1) and the highest total yeast and mould count (4.32 ±0.01 log cfu.g-1) in soil samples were recorded in vineyard Berecký. The highest total viable count in soil samples (6.71 ±0.01 log cfu.g-1) was confirmed by examination of samples originating from the vineyard of Čierna Hora. When determining the total yeast and mould count, the highest numbers were recorded in the must samples (4.15 ±0.01 log cfu.mL-1). Lactic acid bacteria were collected in samples from both vineyards, only in very low numbers. Overall, statistically significant differences (p <0.001) were detected by comparing the microbiota of the samples taken from the Berecký and Čierna Hora vineyards. The specific characterisation and identification of yeast was carried out using ITS-PCR-RFLP methods. The analysis confirmed the presence of yeasts of Saccharomyces cerevisiae, Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Candida parapsilosis and Candida tenuis and their subsequent transfer to the must at varying percentages
Study on the meat isotopic composition for origin identification
Get PDFRussian consumer and governmental authorities are equally concerned to know where food products come from. This requires more accurate and specialized methods for the evaluation of geographical location. The following methods are used: chemometrics, histological and histochemical, genomic and proteomic, microbiological, immunochemical and mass spectrometric. Method of stable isotope analysis is becoming increasingly promising nowadays for the identification of meat and meat products' place of origin. The isotope ratios of the four elements - carbon, nitrogen, oxygen and hydrogen, are mainly determined. The method is successfully used to identify a country of origin of wines, juices and water. The aim of the research was to study the stable isotope ratios for pork and beef samples purchased in Moscow supermarkets (Russian Federation). The country of production of meat samples was determined according to specifications and/or labels. The geography of countries of meat samples origin includes Europe, both America continents and Australia. Databases collected by the All-Russian Scientific Research Institute of the Brewing, Non-Alcoholic and Wine Industrywere used for the analysis and interpretation of the results. Values of 13С/12С, δ13С, 18О/16О, δ18О, 2Ð/1Ð, δ2Ð for 30 pork and beef samples from 13 countries were obtained. Differences in stable isotope ratios were found depending on place of origin. The data correlated with the oxygen isotope characteristics for wine, which were in the range from 2.5 to 4.5 ppm. According to the 13С/12С, δ13С results, the assumption was made about a false indication of the region for the beef sample. Despite the fact that beef was labeled as a product of Lithuania, the region of origin was most probably defined as Germany. The studies carried out showed the possibility to identify the region of raw meat origin by the stable isotope ratio
Acceptability and sensory evaluation of energy bars and protein bars enriched with edible insect
Get PDFFor consumers, one of the basic criteria of choosing a foodstuff, apart from nutritional values, is their taste and smell. In edible insect as a novel food, these criteria are not quite decisive. The main criterion in the Western countries is the acceptability of the food. This work deals with sensory evaluation of protein and energy bars, enriched with cricket flour from American and Czech producers, and their acceptability for consumers from the Czech Republic. The sensory evaluation was done using the questionnaire survey and a simple electronic nose. The survey has shown that edible insect bars are acceptable as a new type of food for consumers in the Czech Republic. Best rated by consumers were orange and pineapple flavour bars from the Czech manufacturer. Statistically significant difference was not detected between evaluation of the bars from the American and Czech manufacturers. Also, the difference between the bars of different flavours from the Czech producer was evaluated using a simple machine - a portable electronic nose. There was not a statistically significant difference between bars of different flavours from the American manufacturer. The positive contribution of the survey is that more than 80% of consumers are willing to consume food enriched with edible insect. This fact shows a change in public attitude to these foods
Comparison of two methods of protein quality evaluation in rice, rye and barley as food protein sources in human nutrition
Get PDFDifferent foods differ in their protein quality, which is characterized by the content and digestibility of individual amino acids. The Food and Agriculture Organisation has recommended replacing the method for protein quality evaluation of foods called protein digestibility corrected amino acid score (PDCAAS) with the new method - digestible indispensable amino acid score (DIAAS), in which the values of ileal amino acid digestibility obtained in pigs are used. However, the information about DIAAS values of foods are limited. Therefore, the study on growing pigs was conducted to determine true fecal protein digestibility and standardized ileal amino acid digestibility of rice, rye and barley. Using these values, the PDCAAS and DIAAS were calculated and compared. A total of 18 gilts with a T-cannula inserted in the terminal ileum were allotted to 3 diets with six replicate pigs per diet. Three semi-purified diets were formulated to contain the tested cereal grains (rice, rye, barley) as the sole nitrogen source. Chromic oxide was used as indigestible marker. Each experimental period comprised of a 7-d adaptation period followed by 24 h collection of feces and ileal digesta. The content of nitrogen, dry matter and chromic oxide was analyzed in samples of diets, feces and ileal digesta. Moreover, in the samples of diets and ileal digesta the content of amino acids was determined. Calculated ratio of crude protein to lysine was greatest in rice (4.50) followed by rye (3.65) and the lowest one in barley (3.35). True fecal protein digestibility was greater when compared with ileal amino acid digestibility for all tested samples, thus suggesting an overestimation of protein quality determined by PDCAAS. Calculated PDCAAS values for rice, rye and barley (81, 65 and 61%) were generally greater than the DIAAS values (79, 56 and 55%), especially for the poorer quality protein sources such as rye and barley in comparison with rice. The lysine was the first limiting amino acid in all tested cereal grains. Based on the DIAAS evaluation, rice is better protein source in human nutrition in comparison with rye or barley
Antioxidant properties of cumin (Bunium persicum Boiss.) extract and its protective role against abiotic stress tested by microRNA markers
No full textBunium persicum Boiss. seeds have been used for medicinal and nutritional properties such as antioxidant, antihelmetic and antimicrobial activity. The aim of this study was to to tested protective role of cumin extract against abiotic stress by microRNA markers. Secondary also was to evaluate antioxidant activity as well as total polyphenol, flavonoid and phenolic acid content of cumin extract. We observed that cumin DNA itself has not been damaged by sonication teratment. This protective impact indicates that cumin antioxidant properties can efficiently quench free radicals induced by sonication. On the other side, ultrasound-mediated formation of reactive oxygen species did induce the DNA polymorphism of lettuce samples which was detected by miRNAs-based markers. The range of sonication impact was time-dependent. Markers based of miRNA-DNA sequences has proven to be an effective tool. We have confirmed statistically significant differences (p ≤0.01) in miRNAs markers ability to detect the polymorphism due to sonication treatment. The antioxidant activity was determined by a method using DPPH radical and phosphomolybdenum method, total polyphenol content with Folin - Ciocalteu reagent, total flavonoid with aluminium-chloride mehod and total phenolic acid with Arnova reagent. Results showed that cumin is rich for biologically active substances and can be used more in different kind of industry as a cheap source of these substances. Antioxidant activity with DPPH method was 1.18 mg TEAC.g-1 (TEAC - Trolox equivalent antioxidant capacity per g of sample) and by phosphomolybdenum method 45.23 mg TEAC.g-1. Total polyphenol content achieved value 4.22 mg GAE.g-1 (GAE - gallic acid equivalent per g of sample), total flavonoid content value 10.91 mg QE.g-1 (QE - quercetin equivalent per g of sample) and total phenolic acid content value 5.07 mg CAE.g-1 (CAE - caffeic acid equivalent per g of sample)
Evaluation of quantitative and qualitative characteristics of selected celery (Apium graveolens var. Dulce) varieties in the context of juices production
Get PDFCelery, Apium graveolens var. Dulce (Mill.) is a biennial plant, lesser used in Slovakia in comparison with celeriac, but with increasing popularity because of its very health beneficial properties. The aim of the study was to evaluate quantitative (yields) and qualitative (chlorophyll a and b, soluble solids) parameters in selected patioles of celery in the context of raw juice production in a small-plot field experiment. Six varieties of celery (var. Dulce) were planted - ´Helios´, ´Red Soup´, ´Malachit´, ´Verde Pascal´, ´Golden Self- Blanching´ and ´Celebrity´. The harvest was carried out twice a season in terms of August and September. The chlorophyll a and chlorophyll b were determined spectrophotometrically, Total soluble solids were estimated by the help of refractometer. The lowest values in yields reached ´Malachit´variety, the highest ´Red Soup´ variety. In the evaluation of both harvests the ´Celebrity´ and ´Golden S.´ varieties showed the lowest chlorophyll content. The total soluble solid content reached values ranging from 5.00 to 8.77 °BRIX, in the following order: ´Celebrity´ <´Helios´ <´Golden S.´ < ´Red Soup´ <´Verde Pascal´. The term of harvest had significant influence on chlorophyll a and b. The effect wasn´t confirmed on yields and soluble solids according to used statistical analyse. There were mainly other kind of characteristics followed in previous scientific studies about celery (var. Dulce), such a flavonoids, vitamins, minerals, fibre, the essential oils and phenolic acids, etc. Processing to juices or smoothies allow consuming of other antioxidant - chlorophyll
Voltammetric determination of cholecalciferol at glassy carbon electrode performed in water ethanol mixture
Get PDFTo confirm or disprove previous hypotheses, cyclic voltammetry of 0.5 mM cholecalciferol (vitamin D3) at glassy carbon electrode (GCE) and platinum disk electrode (PtE) in pure acetonitrile and water‑ethanol mixture at 50 mV·s‑1 has been used to investigate the oxidation mechanism. The oxidation occurs in two one-electrone steps. According to calculation of the highest electron density in cholecalciferol molecule which is evidently delocalized over carbon atoms of the three conjugated double bonds (C19, C10, C5-C8) points to part of the molecule involved in oxidation processes. An oxidation peak (at +0.925 V vs. Ag/AgCl) was used to develop direct voltammetric method based on differential pulse voltammetry for the vitamin D3 determination at GCE performed in 40% ethanol containing 0.1 M LiClO4. Under optimization of analytical procedure, it was found that a composition of the supporting electrolyte used significantly affects a current response of oxidation peak obtained. Satisfactory sensitivity was achieved in the 1:1 water‑ethanol mixture containing 0.05 M lithium perchlorate as as supporting electrolyte. The linear range for vitamin D3 determination was2.4 × 10-6 - 3.5 × 10-4 M with the detection limit of 8.0 × 10-7 M. This work demonstrates a fact that the GCE is suitable electroanalytical device for analysis of various food supplements and medicaments