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Microbiological status of bulk tank milk and different flavored gomolya cheeses produced by a milk producing and processing plant
73-78Views:228The microbiological quality of milk is important not only for food safety, but it can also influence the quality of dairy products. In this study, our aim was to assess the microbiological status of the bulk milk of a milk-producing farm, and some natural and flavored (garlic, dill, onion) gomolya cheeses made from pasteurized milk produced by their own processing plant. We determined the number of coliform bacteria, Escherichia coli, Staphylococcus aureus, and molds of three milk and eight cheese samples. The tests were conducted between July and September, 2017.
In bulk milk, the mean coliform count was 3.83±0.17 log10 CFU/ml; the mean E. coli count was 1.38±0.14 log10 CFU/ml; the mean mold count was 3.74±1.30 log10 CFU/ml; and the S. aureus count was <1.00 log10 CFU/ml, respectively. The mean coliform count in gomolya cheeses was 3.69±1.00 log10 CFU/g; the mean E. coli count was 2.63±0.58 log10 CFU/g; the mean S. aureus count was 3.69±1.35 log10 CFU/g and the mean mold count was 1.74±0.37 log10 CFU/g. The amount of coliforms detected in different flavored gomolya cheeses were significantly different (P<0.05). More than 10 CFU/g of E. coli was found only in the dill flavored cheeses, and S. aureus was found only in dill (3.66±1.86 log10 CFU/g) and onion (3.71±0.52 log10 CFU/g) flavored gomolya cheeses. Based on the obtained results, it was found that the amount of coliform bacteria and E. coli in bulk milk exceeded the limit set in regulation of the Hungarian Ministry of Health (MoH) 4/1998 (XI. 11.) and the amount of S. aureus was below the limit. For gomolya cheeses, the S. aureus count exceeded the limit. The amount of coliform bacteria remained above the limit in cheeses, except for the garlic flavored gomolya cheese. In cheeses, a larger E. coli count was detected than in the bulk milk, but there is no specific limit for cheeses in the regulation. The mold count exceeded the limit specified in the regulation in cheeses, but a lower value was detected relative to milk.
The results show that, in the case of bulk milk and gomolya cheeses, certain detected quantities exceeded the limit values set forth in regulation of MoH 4/1998 (XI. 11.). The results indicate an inadequate microbiological state of the raw material and the finished products. The reasons for these are due to reduced technological hygiene or the inappropriate handling of raw material and finished products. In this study, we have summarized the results of our preliminary studies, which can provide a basis for further hygiene studies.
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The effect of breed and stage of lactation on the microbiological status of raw milk
37-45Views:296The microbiological quality of the milk is important not only for food safety, but it can also influence the quality of dairy products. The microbiological status of raw cow milk can be influenced by many factors. Our aim was to determine whether there was a difference between the microbiological quality of milk of two different cow breeds (Holstein Friesian and Jersey) kept and milked in the same conditions, and how the microbiological quality of the raw cow milk changed during lactation (beginning, mid, and end). Samples were taken and analysed in July, August and September in 2018 from two dairy farms in Hajdú-Bihar county. During the conducted studies, the total plate count (TPC), the coliform count, the Staphylococcus aureus count and the coagulase-negative Staphylococcus (CNS) count of raw milk samples were determined.
There was no significant difference (P>0.05) between the milk of the Holstein Friesian and Jersey breeds in the case of TPC. However, the mean coliform count of milk samples taken from Holstein Friesian cows was significantly lower (P<0.05) than the mean coliform count of milk samples taken from Jersey cows. S. aureus was detected in one of the twelve milk samples taken from Holstein Friesian cows, and in two of the eleven milk samples taken from Jersey cows. CNS was found in larger amount in milk samples taken from Holstein Friesian cows, and the difference was significant (P<0.05). Both TPC and CNS count were significantly higher (P<0.05) in individual milk samples taken at the end stage of lactation, than in samples taken in the earlier stages of lactation from Farm “A”. However, in the case of Farm “B”, there was no significant difference (P>0.05) in colony counts at different stages of lactation. S. aureus was only present in milk samples that collected from cows, which were at the beginning and middle stages of lactation. Testimg the hemolysin production ability of S. aureus strains isolated from the raw milk samples, only weak hemolysis was observed on blood agar. In case of antibiotic resistance testing, it was found that all strains were susceptible to cefoxitin, chloramphenicol, clindamycin, erythromycin, gentamicin, penicillin G, tetracycline and trimethoprim/sulphamethoxazole.
Based on the results of our studies, staphylococci were detected in a higher amount in the milk of Holstein Friesian cows, and coliform bacteria were detected in a higher number in the milk of Jersey cows. Summing up the results of the milk samples taken from the different stages of lactation in one of the farms, it can be concluded that higher TPC and CNS count could be detected at the end stage of lactation than in the samples taken from the earlier stages of lactation. The fact that at the end of lactation the microorganisms could be detected in a higher colony count may be related to the fact that teats could be damaged during lactation by the milking machine, which increased the chance of imvading the microorganisms into the udder.
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Usage of microbiological products in the protection of the sunflower
36-40Views:73White mould is the most important desease of sunflower. We are not able to grow sunflower on the same area for 5-6 years, because of sclerotia. One of the protection methods is if we destroy the sclerotia in the soil with hyperparasite microorganisms, so we can reduce the comeback time of sunflower.
We carried out our farm size researches through 3 years, with the most important sunflower hybrids of Hungary in the area of Vásárhelyi Róna Kft. We can conclude that the microbiological products (Koni, Trifender, Mico’sol) effect positively on the yield of sunflower hybrids, but the weather (moisture) can significantly modify this effect.
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Microbial assessment of potential functional dairy products with added dried herbs
59-63Views:114The market of dairy products is a dynamically developing sector of the food industry. Potential, functional dairy products, made by adding herbs or spices, will have antimicrobial and antioxidant effect due to the active biochemical agents of the plant additives. Furthermore, these active components will widen the storage life of food products and enhance their organoleptic properties too. We worked out a technology for creating fresh cheeses using a gentle pasteurizing method by treating the mixture of raw milk and 1.5% fat contained in commercial milk. As herb additives, we used citronella (Melissa officinalis), and peppermint (Mentha x piperita) harvested by us and dried them via Tyndall-method in convective dryer on 40 °C for 5.5 hours per day. The drying period took three days. We bought dried citronella and mint from the supermarket, which were dried by ionizing radiation, to compare the microbiological pollution with the herbs dried by us.
The main target of this research was to create a microbiologically stable, potential functional dairy product. However, because of the bad quality of the raw milk and the gentle heat treatment we used for sterilizing bulk milk, or else, cheeses were not safe for human consumption. As a consequence, we need further studies to modify our technology and get a microbiologically stable product.
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Microbiological quality of bulk tank raw milk from two dairy farms in Hajdú-Bihar County, Hungary
105-112Views:289Two main channels have been identified to be responsible for microbiological contamination of raw milk and milk products. Firstly, contamination has occurred due to udder infection from the cow or the blood which harbours most bacteria that come in contact with the raw milk. Secondly, via external factors (may include faeces, skin, contaminated water, environment etc.) which are associated with the operation of milking. There is direct contact with the milk and/or surfaces before, during or after the milking, posing public health risk and economic decline. The aim of this study was to examine the bacteriological quality of bulk tank raw milk samples collected from two different size dairy farms (Farm 1 and Farm 2) of different housing forms (cubicle loose and deep litter) in Hajdú-Bihar County, Hungary in July, 2017. Three samples were taken from each farm, and the total plate count, coliform count, Escherichia coli count, Staphylococcus aureus count, and yeast and mould count were determined in them.
The results clearly showed low level of all measured bacteria group load in Farm 1 samples in comparison to Farm 2 with the exception of coagulase-negative Staphylococcus (CNS) which represented high level in general, indicating significant difference (P<0.05). The mean value of total plate count in Farm 2 samples was higher (1.0 × 105 CFU/mL) than Farm 1 samples (2.8 × 104 CFU/mL). There was a significant difference (P<0.05) in mean count of coliforms in raw milk samples between Farm 1 and Farm 2. Similarly, results of E. coli were significantly different (P<0.05) with mean count of 1.44 × 102 CFU/mL and 2.02 × 103 CFU/mL for Farm 1 and Farm 2 respectively.
Results of Staphylococcus aureus also showed significant difference (P<0.05) with mean count of 9.7 × 101 CFU/mL for Farm 1 and 6.28 × 102 CFU/mL for Farm 2. The mean of mould count recorded was 1.07 × 102 CFU/mL and 4.93 × 102 CFU/mL for Farm 1 and Farm 2 respectively. The recorded mean of yeast count was 1.68 × 103 CFU/mL and 3.41 × 103 CFU/mL for Farm 1 and Farm 2 respectively; however, both farms showed no significant difference (P>0.05) in terms of mean of mould and yeast count. Although Farm 2 produced six times lower milk quantity than Farm 1, the measured microbial parameters were high. Both farms’ microbiological numbers were higher above the permitted limit values as stated by Regulation (EC) No 853/2004, Hungarian Ministry of Health (MoH) 4/1998 (XI. 11.).
This could be an indication of non-conformance to effective GMP, ineffective pre–milking disinfection or udder preparation, poor handling and storage practice, time and temperature abuse and inadequate Food Safety Management System Implementation. Therefore, our recommendation is as follows; establish control measures for pre- and postharvest activities involved in the milking process which would be an effective approach to reduce contamination of the raw milk by pathogenic microorganisms from these farms, strict sanitation regime and hygiene protocol be employed and applied to cows, all equipment, contact surfaces and minimize handling of the milk prior, during and after milking. This will also serve as scientific information to the producers for continual improvement in their operations.
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The Relationship Between the Moisture Content of Sweetcorn Raw Material and the Quality of the Deep-Frozen End Product
135-139Views:71One of the remarkable effects of the economical and social development is the changing of the eating habits, first of all increasing consumption of deep-frozen products. The spreading of the sweet corn under these vegetables is characteristic.
The parameters exerting influence on the quality of the deepfrozen sweetcorn is classed in 3 categories:
• Physical quality: foreign matter, clumps, blemished corn, broken kernel, miscut, pulled kernel.
• Organoleptical features: taste, colour, texture, and sweetness.
• Microbiological features: TVC, mould, yeast.
The moisture content of the raw material influences the organoleptical features to the highest degree.
We take continuously samples from the raw material arriving in to the factory to determinate moisture content, and from the product to specify the organoleptical features.
Based on the data of 2002 we can make the following findings:
The colour of the deepfrozen sweetcorn is less influenced by the moisture content. The taste is between 69% and 72% the most optimal, but over 72% get worse, more „milky”, water-tasted because of the underdevelopment of sweetcorn. The texture continuously becomes better with the increasing of moisture content. Under 67% of water the class „C” is typical, which means a taste with weak charasteric, a bit scathing or bitter, and texture with rubbery inner part and hard pericarpia. The decadence of taste is caused by converting a great part of sugar into starch.
The correlation between moisture and quality is varying by varieties; different varieties have their best quality by different moisture content. By our investigations the best harvest time is at the 69-72% moisture content. At this point are the organoleptical features the most optimal, and the grower has not the loss of yield caused by early harvesting. -
Deproteinized plant juice as part of circular economy: A short review and brief experimental data
23-26Views:1482As the population of the Earth is constantly growing it generates an unmet demand for protein, which is an urgent problem. The protein extraction process is a potential solution, which offers high-quality plant protein suitable for animal and human nutrition at a favorable price. The process used within our project produces green juice from the green alfalfa biomass through pressing. After the coagulation of protein from this green juice, the by-product is called DPJ (Deproteinized Plant Juices) or brown juice. Our preliminary results match the international literature, namely that brown juice take up as much as 50% of the fresh biomass in weight. To utilize this by-product is a crucial part of the process to make it environmental-friendly and financially viable as well. The examined brown juice samples came from a small-scale experiment of alfalfa varieties carried out in the experimental farm at the University of Debrecen. According to our preliminary results, brown juice has high macro- and micronutrient values, furthermore, it has a potentially high amount of antioxidant compounds. The study highlights that brown juice is suitable as an ingredient in microbiological media, in plant nutrition as a supplementary solution, for feedstock and for preparing human food supplements or functional foods. The potential utilization of all biorefinery products makes it a very appropriate technology for today’s challenges.
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Study of the biodegradation of slaughterhause feather waste by Bradford method
77-81Views:119The 15–20% of the by-products of meat- and poultry industry – that unsuitable for human consumption – contains keratin. The slaughter technology of poultry produces large amount of poultry feather with 50–70% moisture content. This means more million tons annually worldwide (Williams et al., 1991; Hegedűs et al., 1998). The keratin content of feather can be difficulty digested, so physical, chemical and/or biological pre-treatment is needed in practice, which has to be set according to the utilization method. The microbiological and enzymatic degradation of feather to soluble protein and amino acids is a very favourable and relatively cheap opportunity to produce valuable products of the resulting feather. Our applied treatments were based on the determination of the most effective method, which is able to follow the biodegradation of waste poultry feather.
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Examination the effects of different herbicides on the soil microorganisms of a calcareous chernozem
121-126Views:74Pesticides play a key role in fighting weeds, pests and parasitic fungi. According to surveys, pests reduce the yield of agricultural crops by 35% worldwide. Pests, fungi and weeds account for 14%, 12% and 9% yield loss, respectively (Gáborjányi et al., 1995). Chemicals have contributed to increasing and maintaining the yields of crop production for decades. Today, agricultural production (in spite of many efforts) is unthinkable without the use of pesticides (herbicides, insecticides and fungicides). On the other hand, these chemicals contribute to the pollution of the atmosphere, surface and underground waters, and agricultural soils, especially if they are applied improperly.
The sustainable agricultural production pays attention to environment-friendly cultivation-technologies; but at the same time it makes an effort to produce good quality and economical products. The examination of the herbicides’ secondary effects, fits into this chain of idas namely, how the herbicides affect – stimulating or inhibiting – the soil microbiological processes, prevention of soil fertility.
In the course of the experimental work the effect of herbicides on soil biological properties were examined in different maize (Zea mays) cultures. We wanted wished to know that how the herbicides affect the quantity change of soil microorganisms, the life of different physiological groups of bacteria and the activity of microorganisms. A small pot experiment was set up in 2008 with the application of two herbicides - Acenit A 880 EC and Merlin 480 SC – in the breeding house of the Department. The moisture content and nutrient supply were at optimal level in the experiment.
On the basis of results the following can be stated:
1. It can be stated that the two herbicides and all their doses affected negatively the number of total soil bacteria, the
inhibiting effects were significant. The quantity of microscopical fungi increased by the effect of Merlin 480 SC and decreased in the treatments of Acenit A 880 EC.
2. The Acenit A 880 EC had stimulating effect on the nitrate mobilization. The CO2-production was stimulated by the basic doses of herbicides; the other treatments did not influence the CO2-production significantly.
3. The quantity of microbial biomass-carbon –except for only one treatment- decreased significantly by the effect of herbicides. Besides it, the quantity of microbial biomass-nitrogen increased significantly in the treatments of Acenit A 880 EC.
4. The biomass of test plant decreased in the treatments of herbicides, their quantities were smaller than in the control. In the pots treated by Merlin 480 SC, parallel with the increase of doses decreased the quantity of plant-biomass.