Vendula Pachlová

The effect of ripening and storage conditions on the distribution of tyramine, putrescine and cadaverine in Edam-cheese.

The aim of the work was to describe the development of selected biogenic amines (histamine, tyramine, putrescine and cadaverine) in 4 layers of Dutch-type cheese (Edam-cheese) depending on 3 ripening/storage regimes during a 98-day period. Biogenic amines were analysed by means of ion-exchange chromatography. A further goal was to identify microbial sources of biogenic amines in the material analysed. Phenotype characterization and repetitive sequence-based PCR fingerprinting were used to identify the isolated bacteria. The highest content of tyramine, putrescine and cadaverine was determined in cheeses stored in a ripening cellar at a temperature of 10 degrees C during the whole observation period. Lower biogenic amines content was determined in samples which were moved into a cold storage device (5 degrees C) after 38 days of storage in a ripening cellar (10 degrees C). The lowest concentrations of biogenic amines were detected in cheeses which were moved into a cold storage device (5 degrees C) after 23 days of storage in a ripening cellar (10 degrees C). During the 98-day period, histamine was not detected in any of the regimes. Within the cheeses analysed, non-starter lactic acid bacteria Lactobacillus curvatus, Lactobacillus casei/paracasei and Lactobacillus plantarum were detected as the main producers of the biogenic amines tested. In starter bacteria Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris the decarboxylase activity tested was not detected.

Monitoring of biogenic amines in cheeses manufactured at small-scale farms and in fermented dairy products in the Czech Republic

The aim of the study was the monitoring of six biogenic amines (histamine, tyramine, phenylethylamine, tryptamine, putrescine, and cadaverine) and two polyamines (spermidine and spermine) in 112 samples of dairy products purchased in the Czech Republic, namely in 55 cheeses made in small-scale farms and in 57 fermented dairy products. The products were tested at the end of their shelf-life period. Neither tryptamine nor phenylethylamine was detected in the monitored samples; histamine was found only in four cheese samples containing up to 25mg/kg. The contents of spermine and spermidine were low and did not exceed the values of 35 mg/kg. Significant amounts of tyramine, putrescine, and cadaverine occurred especially in cheeses produced from ewes milk or in long-term ripened cheeses. In about 10% of the tested cheeses, the total concentration of all the monitored biogenic amines and polyamines exceeded the level of 200mg/kg, which can be considered toxicologically significant. In fermented dairy products, the tested biogenic amines occurred in relatively low amounts (generally up to 30 mg/kg) that are regarded safe for the consumers health.

Biogenic amine production by Lactococcus lactis subsp. cremoris strains in the model system of Dutch-type cheese

The aim of this study was to compare the biogenic amine production of two starter strains of Lactococcus lactis subsp. cremoris (strains from the Culture Collection of Dairy Microorganisms - CCDM 824 and CCDM 946) with decarboxylase positive activity in a model system of Dutch-type cheese during a 90-day ripening period at 10°C. During ripening, biogenic amine and free amino acid content, microbiological characteristics and proximate chemical properties were observed. By the end of the ripening period, the putrescine content in both samples with the addition of the biogenic amine producing strain almost evened out and the concentration of putrescine was >800mg/kg. The amount of tyramine in the cheeses with the addition of the strain of CCDM 824 approached the limit of 400mg/kg by the end of ripening. In the cheeses with the addition of the strain of CCDM 946 it even exceeded 500mg/kg. In the control samples, the amount of biogenic amines was insignificant.

Effects of different strains Penicillium nalgiovense in the Nalžovy cheese during ripening

BACKGROUND The present study examined the influence of eight selected strains of Penicillium nalgiovense as secondary culture on the ripening of soft mould cheese. Ion-exchange chromatography, SDS-PAGE and sensory analysis were used for comparison of P. nalgiovense with common secondary mould culture (Penicillium camemberti). RESULTS Proteolytic activity was more intensive in the case of the strains of P. nalgiovense in comparison with the control strains of P. camemberti. Some differences in the proportion and amount of free amino acids were observed between the strains of P. nalgiovense during ripening. Lower proteolytic activity of P. nalgiovense was more desirable for sensory properties of cheese, especially in case sample N2. CONCLUSION This study provides information on the usability of selected strains of P. nalgiovense that could support the development of sensory properties of mould-ripened soft cheese. The cheese with the culture N2 had the best flavour after 35 days of storage. Moreover, this strain showed the lowest bitterness in comparison with the other used P. nalgiovense cultures. The intensity of bitterness of sample N2 was comparable to that of the control sample with P. camemberti.

Texture Properties of Dutch-Type Cheese as a Function of Its Location and Ripening

The aim of the study was to explore texture changes of Dutch-type cheese at its different locations during 126-day ripening at the temperature common for maturation of this type of cheese (10°C). Each block of cheese was divided into 3 slices and texture properties were studied in 13 segments evenly distributed in each slice. Due to cheese brining, a significant increase of hardness and elastic component was reported especially in the edge segments. During the subsequent ripening, both hardness and elastic component of natural cheese decreased gradually in all segments and slices. Studied parameters of individual parts of cheese did not demonstrate uniform rate of changes during the ripening period. In the whole experiment (even after 126-day ripening), hardness and elastic component of the cheese in core showed lower values compared to those obtained in the edge of all slices.

Biogenic amines content in the fermented asian food in the Czech Republic

Normal 0 21 false false false EN-GB X-NONE X-NONE The aim of this work was to study the typical fermented Asian food (miso paste, soy sauce, rice vinegar, kimchi and tempeh) to monitor their microbial quality and presence of biogenic amines in relation to time and temperature of storage. This study is focused on microbiological research in order to determinate presence of selected indicator groups of microorganisms during storage of individual products at three different temperatures, 8 °C, 23 °C, 30 °C. It was found that the highest increase of total viable counts was observed in products stored in 23 °C and 30 °C, especially in tempeh and miso paste. In soy sauce and rice vinegar were observed only very low amounts of microorganisms through the storage period. In the second part of the experiment, the biogenic amines were analyzed using high performance liquid chromatography. It was found that the levels of biogenic amines in tested products were low and does not affect human health.

Contaminating microorganisms in quark-type cheese and their capability of biogenic amine production

Ministry of Agriculture of the Czech Republic; National Agency for Agriculture Research [QK1710156]; Tomas Bata University in Zlin, Internal Grant Agencies [IGA/FT/2017/003]

Effect of milk origin on proteolysis and accumulation of biogenic amine during ripening of Dutch-type cheese

Dairy products from goats milk are characterized by their distinctive aroma and their specific taste. However, the strong aroma can discourage some consumers. Properties of cheese can be modified by the combination of goats and cows milk. On the other hand, chemical diversity from different milk origin may affect the changes during ripening. The aim of the study was to compare the intensity of changes during ripening of model cheese samples produced with various ratios of goats and cows milk. The combinations 100:0 (100% goats milk), 75:25, 50:50, 25:75 and 0:100 (100% cows milk) were used for the manufacture of Dutch-type cheeses, which were ripened during a period of 84 days. Protein profile, free amino acid content and biogenic amine content were used for the description of cheese properties during storage. Cluster analysis showed different changes in the protein matrix of the examined samples. The results indicated that even low addition of cows milk significantly affected the protein profile. However, the homology of protein profiles rose with the increasing ripening time. More intensive proteolysis occured in the samples with predominance of goats milk. Moreover, cheese samples produced only from goats milk presented a significant increase inthe amount of free amino acids after 14 days of ripening. The effect of milk origin on the production of biogenic amines was also examined. However, higher concentrations of biogenic amines were detected in samples manufactured from goats milk. Tyramine, putrescine, histamine and phenylethylamine were detected during the storage of the samples. The total biogenic amine content exceeded 100 mg/kg in samples with predominance of goats milk.