Martina Fikselová

Environmental concentration of selected elements and relation to physicochemical parameters in honey

The purpose of this study was to evaluate the content of selected elements and physicochemical indicators of the honey of Apis mellifera. Samples of blossom, blend and honeydew honeys were randomly obtained from the Eastern, Western and Central of Slovakia. Contents of elements were measured with the use of flame atomic absorption spectrophotometry (FAAS) method and anodic stripping voltammetry (ASV) method with CGMDE as working electrode. The content of heavy metals (mg/kg dry weight) ranged as follows: Zn 0.25–3.82; Cu 0.12–1.37; Ni 0.06–0.60; Mg 0.10–50.43; Ca 10.32–87.21; Pb and Cd were under detectable limit (0.001 mg/kg). The physical and chemical indicators ranged as follows: moisture (%) 16.00–19.80; HMF (mg/kg) 10.00–40.00; pH 3.58–5.12; conductivity (mS/m) 13.45–99.12 and a w 0.456–0.659. Significant difference (P < 0.05) for elements and physicochemical indicators was analyzed. Significant correlations between Cu – Zn, Cu – Ni, Cu – Mg, Ca – Zn and Ca – Mg were detected. With reference to Codex Alimentarius of Slovakia, maximal levels of heavy metals content and selected physicochemical properties were not exceeded. On average, the content of trace elements decreased in the order: Ca > Mg > Zn > Cu > Ni and physicochemical indicators decreased: conductivity > HMF > moisture > pH > aw.

Determination of wine microbiota using classical method, polymerase chain method and Step One Real-Time PCR during fermentation process

The aim of our study was the identification of grape, must and wine microbiota during the fermentation process using a classical microbiological method and Real-Time PCR. The changes in different groups of microorganisms were monitored in total counts of bacteria, lactobacilli and yeasts. Microbiological parameters were observed during the current collection and processing of grapes in 2009. Samples were taken during the fermentation process in wine enterprises and a private vineyard. During this period 30 samples of wine among Müller Thurgau, Cabernet Sauvignon, Chardonnay, Tramin and Red Bio-wine were examined. Samples were collected from stages of grape-must unfiltered, grape-must filtered, the beginning of fermentation, fermentation, late fermentation and young wine. The highest total counts of bacteria ranged from 0.00 to 176 ± 15 CFU.mL−1 in the wine of Müller Thurgau, the highest number of yeast ranged from 0.00 to 150 ± 9 CFU.mL−1 in the wine of Müller Thurgau and the number of Lactobacillus spp. ranged from 0.00 to 92 ± 5 CFU.mL−1 in the sample of Cabernet Sauvignon wine. The presence and sensitivity of Gram-positive and Gram-negative bacterial species Enterococcus faecium, Lactobacillus acidophilus, Lactobacillus crispatus and Lactobacillus salivarius were detected using Real-Time PCR (RTQ PCR). Susceptibility of Enterococcus faecium varied in different isolates from 1 to 106 CFU.mL−1, the sensitivity of the species Lactobacillus acidophilus in different isolates of the wine samples ranged from 1 to 105 CFU.mL−1. We also monitored representation of species Lactobacillus crispatus, which were captured by RTQ PCR sensitivity and ranged from 1 to 105 CFU.mL−1 . Identification of the species Lactobacillus salivarius in each of isolates by RTQ PCR method showed the presence of these bacteria in the range of 1 to 104 CFU.mL−1.

Carotenes Content in Carrot Roots (Daucus carota L.) as affected by Cultivation and Storage

Carotenes Content in Carrot Roots (Daucus carota L.) as affected by Cultivation and Storage The influence of area, variety, year and storage on β-carotene content and dry matter content of selected carrot varieties were tested. Carrot roots of four varieties were examined during two years period (2002-2003), cultivated under different climatic and soil conditions in three areas of Slovakia - Nitra, Komárno and Prusy. Carrot varieties (Nevis F1, Idaho F1, Florida F1, Kathmandu F1) showed the greatest mean content of β-carotene (23.25 mg·100 g-1) in Nitra area, year 2003. Irrigation showed negative influence on β-carotene content. The highest content of β-carotene showed variety Florida F1 (26.3 mg·100 g-1). Mean higher contents of dry matter were determined in the year 2003 compared to the year 2002. Loss of β-carotene during carrot storage was observed higher in the cellar than in the cold storage. Mean loss of β-carotene in dry matter for cold storage was 13.57-14.28%, compared to cellar 20-27.3%. Zawartość Karotenu w Korzeniach Marchwi (Daucus Carota L.) w Zależności od Warunków Uprawy i Przechowywania Badano wpływ rejonu uprawy, odmiany, roku i przechowywania na zawartość β-karotenu i zawartość suchej masy u wybranych odmian marchwi. Oceniano korzenie czterech odmian marchwi przez okres dwóch lat (2002-2003), uprawianych w różnych warunkach glebowo-klimatycznych w trzech rejonach Słowacji - Nitra, Komárno i Prusy. Odmiany marchwi (Nevis F1, Idaho F1, Florida F1, Kathmandu F1) wykazały największą średnią zawartość β-karotenu (23,25 mg·100 g-1) w rejonie Nitra w roku 2003. Nawadnianie miało negatywny wpływ na zawartość β-karotenu. Największą zawartością β-karotenu wykazała się odmiana Florida F1 (26,3 mg·100 g-1). Wyższe wartości średniej zawartości suchej masy odnotowano w roku 2003 w porównaniu z rokiem 2002. Większe straty w zawartości β-karotenu obserwowano podczas przechowywania marchwi w piwnicy niż w chłodni. Średni ubytek β-karotenu w suchej masie wynosił 13,57-14,28% w chłodni w porównaniu do 20-27,3% w piwnicy.

Antioxidant effect of natural honeys affected by their source and origin

Abstract In purpose to examine the antioxidant activity of 15 natural honeys of different origin ABTS method was used, total phenol content and dry matter content of honey samples were determined. Honeys were collected from different locations of Slovakia, Poland and Serbia and were represented as monofloral and multifloral samples (10) which originated from Poland and Slovakia, forest samples (4) originated from Serbia and honeydew honey. Average values of antioxidant activity observed in samples of honeys ranged from 0.62 to 4.63 mmol/kg. The highest antioxidant activity was detected in buckwheat honey and the lowest was shown in acacia honey. By observing the impact of individual honey samples on antioxidant activity it was found that the sample had a highly statistically significant effect. 10 homogeneous groups which varied in the antioxidant activity among each other were established by all 15 samples. Antioxidant activity of honeys could be a positive influence factor in terms of honey differentiation, especially in the case of the forest honeys collected from different places. Monofloral and multifloral honeys (10) established 5 homogenous groups, but in the case of several multifloral honeys which originated from different places of Poland and Slovakia no statistically significant differences were found.

ANALYSIS OF CONSUMER BEHAVIOR AT CHOCOLATE PURCHASE

At food purchase consumer is affected by several factors. In this work analysis of consumer behavior at chocolate purchase was performed involving 277 respondents. Statistical testing of results was performed by Chi - Square statistic, correlations have been tested with use of the Cramers coefficient. It was found, that 86% of respondents consume chocolate. Factors affecting respondents at purchase were recommendations of friends, acquaintances (32%), brand of chocolate (24%), price (16%), personal experience (12%), health restrictions and allergies (11%). Less important factors when choosing chocolates are flavor (4%), nutritional quality (3%), country of origin (2%) and chocolate packaging (1%). In the consumption of chocolate moderate correlation among various categories of economic activity of respondents was confirmed. Chocolate was consumed mainly by respondents whose monthly income ranges from 801 to 1001 €. We found that consumers prefer milk chocolate followed by dark and white at the end. In terms of gender the most commonly was chocolate consumed by women, once to three times a week. The same frequency of chocolate consumption dominates at the categories of students and employee. Expenses frequently spent to buy chocolates were from 1-3 € per week by young people (18-23 years) and middle age generation of people (46-55 years).

Effect of drying temperature on lycopene content of processed tomatoes.

Recently it has been increasing interest worldwide in the production of dehydrated tomato products, which are used in food industry and in pharmacy. An important indicator of the quality of products, beside the microbiological stability is health safety and lycopene content. The aim of this work was to evaluate the effect of drying temperature on changes of the content of lycopene in selected varieties of tomato. Drying was performed at 45 °C, 70 °C and 90 °C. Varieties of Darina F1, Denar, Kecskemety, Orange, Paulina F1, Sejk F1 were used. Tomatoes were processed into dried slices with the dry matter content of 80-85%. Content of lycopene was determined spectrophotometrically. The content of lycopene in fresh tomatoes ranged from 63.378 mg 100 g -1 of dry matter (Orange) to 302.37 mg 100 g -1 of dry matter (Sejk F1). After drying at all temperatures, content of lycopene decreased on average of 64.48 to 68.3%. The most significant changes were found at temperature of 90 °C. Based on the results the most appropriate temperature for drying among the monitored temperatures was at 70 °C, in this case the content of lycopene in the product ranged from 12.839 mg 100 g -1 dry matter (Orange) to 115.9 mg 100 g -1 of dry matter.

The StepOne real-time polymerase chain reaction detection of Salmonella sp., Salmonella enterica ser. typhimurium and enteritidis in milk and meat

The aim of this study was to follow contamination of ready to eat milk and meat products with Salmonella spp. by using the StepOne real-time polymerase chain reaction (PCR). Classical microbiological methods for detection of foodborne bacteria involve the use of pre-enrichment and/or specific enrichment, following isolation of bacteria in solid media and the final confirmation by biochemical and/or serological tests. We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and MicroSEQ® Salmonella spp. Detection Kit for pursuance of the real-time PCR (Applied Biosystems). In samples without incubation we detected strain of Salmonella sp. in 5 out of 25 samples (swabs), as well as in the internal positive control (IPC), which was positive in all samples. This StepOne real-time PCR assay is extremely useful for any laboratory equipped by real-time PCR. It is a fast, reproducible, simple, specific and sensitive way to detect nucleic acids, which could be used in clinical diagnostic tests in the future. Our results indicated that real-time PCR assay developed in this study could sensitively detect Salmonella spp. in ready-to-eat food. This could prevent infection caused by Salmonella, and also could benefit food manufacturing companies by extending their products shelf-life as well as saving the cost of warehousing their food products while awaiting pathogen testing results.

ANTIOXIDANT EFFECTS OF HERBAL EXTRACTS AND THEIR FOOD APPLICATION

Herbal extracts are considered as a good sources of antioxidant compounds. This work describes antioxidant effect of 15 kinds of herbs. Three different antioxidant assays were used, Trolox equivalent antiradical activity (TEAC), test based on deoxyribose oxidation and DPPH method. The TEAC values ranged from 0.38mM to 0.77 mM. Deoxyribose assay showed antioxidant activity of selected extracts expressed as the inhibition of formation of oxidative products of deoxyribose from 2.68 to 50.05 %. The DPPH method values ranged from 6.47 to 73.80 %. Extracts of Prunus spinosa L., Euphrasia rostkoviana Hayne were the best antioxidants confirmed by all methods. Scrophularia nodosa L. extract showed the weak antioxidant effect determined by all selected methods. Phenolic content was in relation to the antioxidant effect of herbs, very high significancy between DPPH and polyphenols content was found. To improve selected properties of apple juice (taste, smell, functional properties) by addition of medicinal herbs was achieved in this work. Antioxidant effect of apple juice variants with herbs additions determined by DPPH method was high and ranged from 73 to 78.49 %. Herbal extracts can be utilised in selected combinations to improve sensory and functional properties of some kinds of beverages. doi:10.5219/75

Analysis of Consumer Preferences at Organic Food Purchase in Romania

Abstract The decision-making process of consumers buying organic food is affected by several factors. Because of organic agriculture in Romania is growing, the objective of this paper was to analyze consumer opinions and preferences concerning organic food products in Romania. The survey involved 350 respondents. The respondents were divided into two groups using the Hierarchical multiple factor analysis (HMFA). The strongest reason for buying organic food for Romanian respondents is health care, presented by 42% of respondents. Respondents prefer to buy organic foods directly from the producers, followed by supermarkets, specialized shops and pharmacies. The prevailing price of monthly purchase of organic food is 10 to 20€. The respondents are able to pay for organic food from 5 to 10% more than for conventional food.

Sauvignon wine quality as affected by its processing and storage

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.