Microbiological quality of smear-ripened cheeses stored in different temperature regimes

The purpose of this work was to study smear-ripened cheese, especially its microbiological quality. Samples were stored in different temperature conditions. The first group (A) of samples was stored in a refrigerator at 6 °C. The second group (B) of samples was stored at 6 °C for 21 days, next at -18 °C for 7 days and 7 days at 6 °C. The third group (C) of samples was stored  at  6 °C before the date of minimum durability, next 7 weeks at -18 °C and after that at 6 °C for 7 days. I have observed  lactic  acid  bacteria, Brevibacterium  linens, coliforms,  psychrotrophic  organisms, Escherichia  coli, moulds  and yeast. The number of Brevibacterium linens was higher (p <0.05) at cool ing/freezing for 1 week (log CFU.g-1) than cooling (log CFU.g-1) and cooling/freezing for 7 weeks after 35 days. A higher (p <0.05) number of psychrotrophic microorganisms was recorded at the end of the monitoring in samples stored in a refrigerator (A/49) in comparison with cheeses stored using cooling/freezing  regime  for  one  week  (B/49). Among  the  samples  stored  at  these  temperature  regimes,  there  were  no statistically significant differences (p >0.05) in the numbers of LAB, coliforms, E. coli, moulds and yeast, neither at the end of the DMD nor at storage for 49 or 91 days, respectively

Microbiological quality of egg liquid products

Egg liquid products are most commonly used as semi-products in different branches of food industry and catering industry. The main goal of this work was to assess the microbiological quality of egg liquid products (liquid pasteurized egg white, pasteurized egg yolk with sugar 33%, pasteurized whole egg-blend) sampled in a period from April until February, and evaluate whether parameters such as the total aerobic count (TAC), coliform bacteria (KFB), enterococci, staphylococci, moulds and yeast changed significantly during this period of time. Microbiological analysis detected the highest (P <0.05) total aerobic count in egg yolk (2.8 log CFU.ml-1). The incidence of coliform bacteria was also highest (P <0.05) in egg yolk (1.7 log CFU.ml-1) but very low in egg white and whole egg. The highest count (P <0.05) of enterococci was detected in samples of egg white (1.0 log CFU.ml-1). The counts of staphylococci, moulds and yeast were particularly high (P <0.05) in egg yolk (1.2 log CFU.ml-1 for staphylococci and 1.1 log CFU.ml-1 for moulds and yeast). Statistical analysis showed (P >0.05) no correlation between respective seasons and microbial counts for any of the egg substances investigated. It follows from our results that all analysed egg products comply with the TAC limit defined by Council Directive (EC) 89/437/EEC on hygiene and healthy problems affecting the production of egg products, however, all egg products analysed in our study would fail to meet the required criteria for other groups of microorganisms

Evaluation of rabbit meat microbiota from the viewpoint of marketing method

Microbiological analysis was performed on carcasses of rabbits coming from domestic slaughter, purchased at butcher shops, vacuum-packaged and purchased in supermarkets, as well as frozen. The total number of analysed rabbits was 20. For all samples the following microbiological parameters were determined: total microorganisms count (TAC), the count of lactic acid bacteria (LAB), psychrotropic microorganisms, moulds and yeasts, as well as bacteria of the Enterobacteriaceae family. Total microorganisms count was the highest (p <0.05) in rabbit meat from butcher shops (5.34 log CFU.g-1). The counts of lactic acid bacteria (LAB) in rabbit meat originating from domestic breeding was 2.58 log CFU.g-1, in vacuum-packaged rabbits 3.18 log CFU.g-1, in frozen rabbits 2.29 log CFU.g-1, and in rabbit meat purchased from butcher shops 3.58 log CFU.g-1. The highest count (p <0.05) of Enterobacteriaceae was observed in samples from butcher shops, namely 2.91 log CFU.g-1. In contrast the lowest count (p <0.05) was in rabbit meat from home slaughtering at 1.47 log CFU.g-1 and in frozen ones at 1.36 log CFU.g-1. The lowest counts (p <0.05) of moulds and yeasts were observed in rabbit meat from domestic slaughter, namely 1.12 log CFU.g-1. The highest counts (p <0.05) were in rabbit meat from butcher shops 2.97 log CFU.g-1. The highest counts (p <0.05) of psychrotrophic microorganisms were detected in rabbit meat from butcher shops, namely 4.98 log CFU g-1 and the lowest ones (p <0.05) in the meat of domestically slaughtered rabbits at 2.52 log CFU.g-1. In all monitored microbiological indicators, we have found differences (p <0.05) in their counts on the surface and inside the muscle tissue, both on the front and rear parts of the rabbit carcass.O

Evaluation of quality of wine in the Czech republic

The work is focused on a review of quality wines produced and sold in the CR in the period 2004 to 2007, from the perspective of CAFIA inspections. A description of the quality of individual groups of wines based on the percentage of unsatisfactory samples. Background for the development work was completed the surveillance activities diplomanty in a position to control the State Department inspector, agricultural and food inspections and other activities CAFIA inspectors in the CR. The inspection found that a large proportion of food enterprises still disregards the requirements laid down by law č.321/2004 Coll. about viticulture and wine-making and EU legislation in force and its implementing regulations, as evidenced by the number of unsatisfactory samples.

Detection of honey adulteration using HPLC method

This work deals with the determination of undeclared or illicitly added sugar content in honey samples evaluated using the High-Performance Liquid Chromatography or HPLC with refractive index detection. Labelling of samples was also evaluated in accordance with current legislation. In a total of 21 samples of honey purchased in the fall of 2013, 13 samples were obtained from the regular shopping network, 2 samples were purchase in Health Food stores and 6 samples came directly from local beekeepers and were purchased at the Christmas Markets in Brno.We have determined the contents of fructose, glucose, sucrose, and oligosaccharides using the HPLC method. We have calculated the basic statistics such as the mean and standard deviation for each sample. Samples have been evaluated according to the Council Directive 2001/110/EC, which lays down limit values for the parameters of honey.Only four out of 21 honey samples complied with the requirements of Council Directive 2001/110/EC. These were three samples obtained from the regular shopping network and one obtained directly from the local beekeeper. Six samples did not meet the requirements for the sum of fructose and glucose, two samples could not be determined due to the failure to specify the honey type, and fourteen samples failed the requirement of sucrose content.We have further assessed whether honey samples comply with legislative requirements relating to this product or consumer misleading practices take place. Our analysed samples often lacked indication whether it is a floral honey or honeydew honey; this information was missing in eight out of 21 samples. Samples 5 and 9 did not mention the name of manufacturer. Sample 10 did not mention the country of origin

Effect of different storage times on Japanese quail egg quality characteristics

The aim of this research was to monitor selected quality parameters of Japanese quails (Coturnix coturnix japonica) - the loss of egg weight, changing yolk and white index, Haugh units, egg yolks color. Quail eggs were stored for 0, 1, 2, 4, 6 and 8 weeks at 4 oC. The weight of the quail eggs ranged from 11.67 to 12.27 g. The ratio of the shell range 7.60 to 8.16 % (resp. 0.89 - 0.96 g), ratio of egg white from 59.33 to 62.10 % (resp. 6.31 - 6.66 g) and a ratio yolk of 30.13 - 32.88 % (resp. 3.68 - 3.91 g). The lost of egg weight ranged from 0.47 to 2.93 % during the quail eggs storage, corresponding to a weight loss of 0.26 - 0.58 g of the total weight of the eggs. The average values of the yolk index ranged from 42.67 - 48.53 % and the average values of the quail egg white index ranged from 6.77 to 11.35 %. The average Haugh units were set between 56.93 and 73.72. The color of quail egg yolk was determined using the La Roche scale with the most frequent value 3. During the quail eggs storage, a statistically significant difference was found with most of the quality traits observed.O

Effect of additives to microbiological quality of yogurts

The objective of this work was to study the effect of addition chia flour, quinoa flour, nopal powder, apple fibre and bamboo fibre BAF 40 in yogurt to microbiological quality. Yogurts were made with 1, 3 and 5% of addition of these additives. The milk used for manufacturing was heated up to 85oC for 5 min and flour, powder and fiber were irradiated for 20 min in three replicates. It was monitored: Lactic acid bacteria (LAB) - 72 hours at 30oC (ISO 13721:1998) and yeasts and moulds - 5 days at 25oC (ISO 21527-1:2009). During storage, the number of LAB was increased to match the initial concentration of yogurt with addition chia flour (concentration 1, 3, 5%) and quinoa flour (1%). The addition of nopal powder, apple or bamboo fiber to yogurt showed a tendency to decrease the number of LAB compared with its initial concentration. All samples were compared with the control yogurt without addition whatever flour, powder or fiber. The amount of yeasts and moulds was increased with the increasing addition of fiber in yogurts. The lowest amount of yeasts and moulds was in yogurt with the bamboo fiber. On the other hand the highest amount was in yogurt with chia flour.O

Effect of milking method and season on phthalate content in cow milk from organic production

Dibutyl phthalate (DBP) and diethylhexyl phthalate (DEHP) content was determined by the high-performance liquid chromatography in the milk samples either mechanically or manually taken from 10 dairy cows in January, April, July and October (altogether 344 milk samples were collected). Milking method and season accounted for 23 and 77%, and 33 and 36% of the explained variability of DBP and DEHP content, respectively. Content of DBP in mechanically collected samples was higher in comparison with manually collected milk: 10.0 vs. 6.7 mg kg-1 milk (P < 0.05). Irrespective of the milking method, DBP content differed significantly (P < 0.05) between samples collected in January (6.6 mg kg-1), July (4.2 mg kg-1) and October (20.0 mg kg-1). In the case of DEHP, only differences between April and October milk were found out (0.03 vs. 0.96 mg kg-1; P < 0.05). Concentration of DBP in both mechanically and manually collected milk increased according to a polynomial function from spring to autumn (P < 0.01). Thirty times higher average DBP content than DEHP content was contrary to expectation. A migration of DBP in milk apart from the milking equipment (probably by contaminated silage) was more important in comparison with DEHP.OA-hybri

Monitoring of Acrylamide Content in Selected Foods

Acrylamide is a toxic substance occurring in foods. It is formed at temperatures higher than 120 °C, the highest acrylamide amount is produced within the temperature range of 150–180 °C. High acrylamide content occurs namely in starch rich foods that are thermally processed. The quantification of acrylamide in various groups of foods was investigated using the GC/MSD method. No acrylamide was detected in instant coffee and sunflower bread. The lowest acrylamide quantity was detected in pre-fried potato chips (66 μg.kg-1); acrylamide content in wholesome bread, biscuits, crackers and roasted coffee varied in the range from 78–470 μg.kg-1. The acrylamide value in potato crisps was higher (160–1530 μg.kg-1), the highest acrylamide level was measured in potato chips after frying (1588 μg.kg-1)