Peter Zajác

QUALITY AND SAFETY OF RAW COW’S MILK IN SLOVAKIA IN 2011

The quality and safety of raw cow’s milk is very important for dairy companies and consumers of milk products. Due to the methods of production, it is impossible to completely eliminate contamination of milk with microorganisms, therefore the microbial content of milk is a major feature in determining its quality. Other important factors to consider include somatic cells count, veterinary drug residues, milk composition and freezing point. Somatic cells represent the udder health and can be used for monitoring of subclinical mastitis. A high level of somatic cells can increase proteolysis in milk which affects technological processes. Veterinary drugs administered to cows may lead to residues in the milk which are harmful to humans. The content of fat, protein and solids-non-fat are the main indicators used by dairies for technological purposes. In this article we discuss the quality and safety of raw cow’s milk in Slovakia during 2011. We found that 73.53% of samples tested for somatic cell count, and 84.54% of samples tested for total bacterial count, met the European Union legislation limits. We found the largest decrease in fat and protein content was during the summer period and the largest increase was in the winter period. We found that 92.14 %, 98.7% and 91.38% of samples met the limit presented in STN 570529:1999 for fat content, protein content and freezing point respectively. The percentage of drug positive samples was 0.087%.doi:10.5219/189

New methodologies for biofilms control in food industry

The complete removal of biofilms on food equipment surfaces is essential to ensure food safety and quality. However, cells in biofilms exhibit greater resistance against the action of sanitizers and other antimicrobial agents compared to their free living counterparts, making them much more difficult to remove. They can be a significant source of post - processing contamination and could potentially harbor pathogens in food processing platns. The biotechnology sector is just beginning to tackle the problem of biofilms by developing antimicrobial agents with novel mechanisms of action. Some studies seek to prevent biofilm formation, others aim to develop antimicrobial agents to treat existing biofilms, and still others are trying to disrupt the polymeric ties that bind the biofilms together. doi:10.5219/17

Identification of differences in chemical composition among whole stick and sliced Nitran salamis trough principal component analysis

The subject of this work was to examine differences in chemical composition of sliced and whole stick Nitran salamis, purchased from various manufacturers. Nitran salamis are traditional dry fermented meat products of Slovak origin. Taking into account variations in raw materials, production process and potential adulteration, differences in chemical composition within one brand of salami from different manufacturers might be expected. Ten salamis were determined for basic chemical composition attributes and Principal Component Analysis was applied on data matrix to identify anomalous ones. It has been shown that six attributes, namely: protein without collagen of total protein, total protein, total meat, total fat, collagen of total protein and NaCl, were the most important for salamis as first two Principal Components together explained 70.16% of variance among them. Nitran D was found to be the most anomalous salami, as had the lowest value of protein without collagen of total protein (14.14% ±0.26%), total protein (17.42% ±0.44%), total meat (120.29% ±0.98%) and the highest one of total fat (50.85% ±0.95%), collagen of total protein (18.83% ±0.50%) and NaCl (9.55% ±1.93%), when compared to its whole stick variant Nitran C and other samples. In addition to collagen of total protein content, Nitran D together with Nitran A, F and H did not satisfied the legislatively determined criterion, which is ≤16%. This suggested that extra connective tissues were added to intermediate products, which resulted in high variability and inferior quality of final products. It is a common practice in the meat industry to increase the protein content or water binding properties of meat products.

Comparison of fatty acid profile in the chicken meat after feeding with narasin, nicarbazin and salinomycin sodium and phyto-additive substances

ABSTRACT The purpose of this study was an experimental investigation and a statistical evaluation of the influence of various additives in feed mixtures of broiler chickens on fatty acids content and their ratio in breast and thigh muscles. First feed additive consisted of narasin, nicarbasin and salinomycin sodium, and other five additives were of phytogenic origin. In vivo experiment was realized on the poultry experimental station with deep litter breeding system. A total of 300 one-day-old hybrid chickens Cobb 500 divided into six groups were used for the experiment. The experimental period was divided into four phases, i.e. Starter, Grower 1, Grower 2 and Final, according to the application of commercial feed mixture of soy cereal type. Additive substances used in feed mixtures were different for each group. Basic feed mixtures were equal for all groups. Fatty acid profile of breast and thigh muscles was measured by the method of FT IR Nicolet 6700. Investigated additive substances in the feed mixtures did not have statistically significant effect on fatty acid content and omega-6/omega-3 polyunsaturated fatty acid (PUFA) ratio in breast and thigh muscles. Strong statistically significant relation between omega-6 PUFAs and total PUFAs were proved by experiment. A relation between omega-3 PUFAs and total PUFAs was found only in the group with Biocitro additive.

Phytoestrogens dietary intake and health status of retiree from middle-notrh Slovakia region

Phytoestrogens found in foods of plant origin presents chemical substances that possess a wide range of biochemical benefits. It has been found that they contribute in different health related problems. A wide range of commonly consumed foods contain appreciable amounts of phytoestrogens. Consumption of diet rich to phytoestrogen acts as a protective factor against many diseases such as cardiovascular diseases, post-menopausal symptoms in the context of osteoporosis, cancerous illnesses of colon, prostate and breast. Three main classes of phytoestrogens covers: isoflavones, lignans and coumestans. Selected nine major phytoestrogens had been analyzed simultaneously in the same foods. Questionnaire designed to determine intake frequency as well as amount of selected foods and the most common diseases presented in the population has been used to find relationships between dietary habits and health status. Evaluation of selected goals in the present study has been realized in cooperation with 140 respondents in retired age (divided into Males - covered by 34 individuals and Females - 106 individuals), comming from middle-north Slovakia region. On the base of collected data it can be concluded, that evaluated population is presented by high values of lignans intake and particularly secoisolariciresinol, mainly caused by relative high proportion of cereals and linseed in the diet. Furthermore, the relationship between phytoestrogens intake and eating habits as well as its contribution in protection against selected diseases was demonstrated. Normal 0 21 false false false CS JA X-NONE

Comparison of the sensitivity of determining soyeabean allergens by ELISA method and SYBR green I

Normal 0 false false false SK JA X-NONE The aim of this study was to compare the suitability of two methods for detecting defatted soybean powder; SYBR Green I Real-time PCR and enzyme-linked immunosorbent assay (ELISA). Analysis of 20 artificially contaminated samples prepared by simple dilution with wheat flour revealed that both techniques were able to detect defatted soybean powder, although there were significant differences between the two methods. Wheat flour contamination with defatted soybean powder was detected in samples 1-5, (0.012 %; 120 mg.kg -1 ), but not in samples with lower contamination with soybean powder saples 6-20 using SYBR Green I real-time PCR. Samples 1-10 could not be quantified by ELISA as the absorbance values were greater than the detection limit, and while samples 11-20 were measured, only the values of samples 16, 17 and 18 were within the guaranteed quantification range specified by the ELISA kit manufacturer. Defatted soybean powder contamination was detected in samples 19 and 20, but absorbance values were highly similar to those of the negative control sample.

Protein quality chicken meat after feeding with active substances of citrus fruits and diclazuril and salinomycin sodium

The purpose of this study was an experimental investigation of the influence of active substances obtained mainly from citrus fruits in the experimental feed mixtures, and diclazuril and salinomycin sodium in the control feed mixtures of broiler chickens on productive efficiency and protein quality of the breast and thigh muscles. In vivo experiment was carried out with hybrid chickens Cobb 500. Basic feed mixtures were equal a soy cereal type for experimental and control group. Indicators of productive efficiency were measured and calculated, and protein, lysine and methionine contents in the breast and thigh muscles were measured by the method of FT IR, Nicolet 6700. Active substances obtained mainly from citrus fruits confirmed a statistically significant (p ˂0.05) positive effect on the body weight gain; tended to slightly increase feed intake per bird, protein, energy, lysine and methionine intake per bird; slightly decrease feed intake per 1 kg of body weight gain, protein, energy, lysine and methionine intake per 1 kg of body weight gain; slightly increase protein efficiency ratio and energy efficiency ratio. Additive substances used in the feed mixtures did not have a statistically significant effect on protein, lysine and methionine contents in the breast and thigh muscles but displayed a strong positive, statistically significant relation between lysine and methionine in them.

The effect of UV-C irradiation on grape juice turbidity, sensoric properties and microbial count

In this work, we investigated the effect of UV-C radiation (254 nm) on turbidity, microbial count and sensoric properties of the grape juices treated or not treated with sulphur dioxide. The UV-C radiation is considered to be germicidal against microorganisms. This technology is routinely used to treat drinking water. Application of this method for the purpose of treating the wine was tested in few studies. These studies have shown a positive effect on the inactivation of microorganisms, but they not dealt in detail with the sensory properties of grape juice after the treatment. The main idea of using this method appears to eliminate the sulphur dioxide from wine making technology. There are people who have a genuine allergy to sulfites, and these allergies are often linked with asthma. These people have an rapid onset of symptoms when drinking liquids like wine treated with sulphur dioxide. In our work we have found that the application of this method of treating the grape juice is problematic. Intensity of UV-C radiation increases the turbidity of grape juices. This effect was observed in all grape juices with or without addition of sulphur dioxide and also in clarified or not clarified grape juices. We found that UV-C radiation negatively affect the sensory properties of grape juices. This effect was more pronounced in grape juices treated with SO2. The smell and taste were significantly negatively changed. Exposure of grape juice treated with sulphur dioxide to UV-C radiation can probably lead to arising the sulphur compounds, which affects the smell and taste of grape juices. Also, it is very likely that the negative change in taste and smell may affect the quality of produced wines. For this purpose, we do not recommend to use UV-C treatment for the grape juice treatment. It will be interesting to conduct a detailed analysis of the grape juices composition before and after UV-C radiation treatment.

Food safety from consumer perspective: health safety

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 consumers health is endangered by food, the guilty party should be punished by ban (61.9%) or by suspension (19.5%).

Authentication of caprine milk and cheese by commercial qPCR assay

The objective of the study was to investigate potential adulteration of commercial caprine milks and cheeses with bovine milk using commercial qPCR assay. The assay comprised of bovine-, ovine- and caprine-specific primers and TaqMan probe and mammalian internal control. Specificity, sensitivity, linearity, reproducibility and efficiency of the bovine assay were tested as well. Specificity was verified by running reaction on the DNA of other milk-producing species (caprine and ovine) and made-up bovine-caprine (v/v) milk mixes. In both experiments, a bovine DNA fragment was amplified whereas no amplification was obtained from the other species. Sensitivity, linearity, reproducibility and efficiency were tested on 10-fold dilution series of 10 ng bovine DNA. The assay has shown good linearity (R 2 = 0.983) within whole range, with efficiency of 86% and excellent reproducibility (SD around the C T for the technical replicates <0.5). The sensitivity was adequate, as calculated LOD and LOQ were 1.44 pg and 2.94 pg of bovine DNA, respectively. Finally, the assay was used to authenticate 5 caprine milk samples and 5 caprine cheese samples, purchased from local supermarkets. Totally, 1 milk sample has shown the fluorescence signal, which exceeded baseline in cycle 39.01 ±0.69. However, the signal was above LOD and LOQ suggesting that there could not be unambiguously declared any adulteration with bovine milk. Amplification of bovine-specific DNA was not observed in the other samples indicating products were not adulterated. The commercial qPCR assay has proved that real-time PCR assays, as well as DNA-based techniques in a general, are the excellent and reliable tools for fighting with frauds in the food industry and protecting the public health. Normal 0 21 false false false SK X-NONE X-NONE