Lipany

monografi

Modelling biogenic amines in fish meat in Central Europe using censored distributions

The aim of the study is to model concentrations of selected biogenic amines in various fish species (Atlantic salmon, Atlantic cod, striped catfish) bought in retail stores in Central Europe. Since the data contains non-detectable values, statistical methods for left-censored values from the exponential and Weibull distributions are applied and used to evaluate and compare the amount of biogenic amines in fish samples. Moreover, a risk of exceeding certain limits of biogenic amine concentrations to protect human health is determined. There are relatively high concentrations of putrescine, cadaverine and histamine in almost all fish species. Moreover, there was a significant difference in mean concentrations (distributions of concentrations, respectively) of histamine, tyramine and spermidine among the species. © 2020 Elsevier LtdCzech Science FoundationGrant Agency of the Czech Republic [GACR 17-09594 S

Statistical analysis of biogenic amines formation process under different levels of selected factors

Some bacterial strains of enterococci are commonly used in food industry and therefore their ability of biogenic amine formation should be investigated. This enables to indicate decarboxylase-positive strains. Within the process of decarboxylation, these strains produce high amount of biogenic amine, which is a toxicologically important compound. Biogenic amines are present in certain foodstuffs (cheese, meat, wine.) and at high concentrations they are considered risk factors for human health. The aim of this contribution was to explore production of eight chosen biogenic amines by Enterococcus faecium (DPE 002) from rabbit meat (Oryctolagus cuniculus f. domesticus) and to evaluate the effect of selected factors on the production. To fit the data subsets involving different conditions of the experiment, appropriate regression models were used. Some of the growth curves such as Gompertz, logistic, and Richards are found to be very useful in many areas. The most suitable models for our data appeared to be Gompertz and logistic. Their three regression parameters, which are of biological interest, are an asymptotic value of concentration, a maximum production rate and a lag time. Model parameters were estimated and tested. The effect of different factor levels on the parameter values is studied

Fuzzy and regression approach to estimating the cheese consistency changes influenced by a substitution of emulsifying agents in the mixture

This paper aims to study the dependence of the hardness of processed cheese spreads on the composition of binary mixtures of phosphate emulsifying salts consisting of disodium hydrogenphosphate, tetrasodium diphosphate, pentasodium triphosphate, and/or sodium salt of polyphosphate and on the number of days of storage. The main goal was to find suitable statistical models in order to describe the dependence of the hardness examined on the composition of binary mixtures. Polynomial regression proved to be suitable for the global behaviour of the statistical relationship observed. Detailed observation of local changes was made by means of a fuzzy inference system. In binary mixtures of polyphosphate combined with monophosphate, diphosphate or triphosphate, hardness was gradually increasing with rising amount of polyphosphate in the mixture. In binary mixtures of monophosphate combined with diphosphate or triphosphate, a rapid increase in the hardness of the samples was determined when the proportion of diphosphate or triphosphate in the mixture was rising up to 50-60 %. A further increase in diphosphate or triphosphate content in the binary mixture (above 60 %) resulted in a similarly rapid decrease in the hardness of the processed cheeses

Risk analysis of tyramine concentration in food production

The contribution is focused on risk analysis in food microbiology. This paper evaluates the effect of selected factors on tyramine production in bacterial strains of Lactococcus genus which were assigned as tyramine producers. Tyramine is a biogenic amine sythesized from an amino acid called tyrosine. It can be found in certain foodstuffs (often in cheese), and can cause a pseudo-response in sensitive individuals. The above-mentioned bacteria are commonly used in the biotechnological process of cheese production as starter cultures. The levels of factors were chosen with respect to the conditions which can occur in this technological process. To describe and compare tyramine production in chosen microorganisms, generalized regression models were applied. Tyramine production was modelled by Gompertz curves according to the selected factors (the lactose concentration of 0-1% w/v, NaCl 0-2% w/v and aero/anaerobiosis) for 3 different types of bacterial cultivation. Moreover, estimates of model parameters were calculated and tested; multiple comparisons were discussed as well. The aim of this paper is to find a combination of factors leading to a similar tyramine production level. © 2013 AIP Publishing LLC

Estimation of the effect of the combinations of sodium phosphates on hardness of the model processed cheese by fuzzy logics

The aim of this work was to study the dependence of hardness of processed cheese spreads on the composition of binary mixtures containing disodium hydrogenphosphate, tetrasodium diphosphate, pentasodium triphosphate, and/or sodium salt of polyphosphate using advanced statistical models. Eleven percentage ratios were applied in each of the 6 types of binary mixtures. The study was focused on finding of suitable models in order to describe the dependence of hardness on the composition of binary mixtures. These models use fuzzy sets - especially as Fuzzy Inference System. Fuzzy inference system is able to identify possible nonlinear dependence between input variables and output variables in process. It can also work with data described in vague terms. In mixtures of polyphosphate with the other phosphates studied, hardness was increasing with the rising amount of polyphosphates within the mixture. In binary mixtures of monophosphate with diphosphate or triphosphate, a rapid grow in sample rigidity was determined when the amount of diphosphate or triphosphate in the mixture was rising (up to 40-60%). A further increase in diphosphate or triphosphate concentration (above 50 - 60%) resulted in a drop in rigidity of processed cheeses. Hardness of samples was increased during 30-day storage

The effect of different ternary mixtures of sodium phosphates on hardness of processed cheese spreads

The aim of this study was to describe the dependence of hardness of processed cheeses on the proportion of disodium hydrogenphosphate (DSP), tetrasodium diphosphate (TSPP) and/or sodium salts of polyphosphate (POLY) in ternary mixtures of emulsifying salts. The samples were observed during a 30-day storage period (at 6°C). On the second day of storage, hardness of the samples with the individual DSP, TSPP or POLY were in the range of 1.65-1.83N, 2.42-2.81N and 5.98-6.53N, respectively. Within zero or a very low proportion of POLY in the mixture, hardness of the processed cheeses increased rapidly (up to 14N) at a specific ratio of DSP to TSPP in range of 1:1-3:4. Hardness of the samples containing the above-mentioned specific ratio was decreasing with the rising content of POLY (up to 60%) in the ternary mixtures. Within the prevailing content of POLY in the ternary mixtures (more than 60%), the phenomenon of a specific ratio of DSP to TSPP was no longer observed. With the increasing storage period (up to 30days), hardness of the processed cheeses was slightly rising (in range of 2-4N)

The effect of combinations of sodium phosphates in binary mixtures on selected texture parameters of processed cheese spreads

The dependence of hardness, adhesiveness and cohesiveness of processed cheese spreads on the composition of binary mixtures of disodium hydrogen phosphate, tetrasodium diphosphate, pentasodium triphosphate, and/or sodium salt of polyphosphate was studied. Suitable statistical models to describe the dependence of the texture parameters examined on the composition of binary mixtures were investigated. Each of the 6 types of binary mixtures was applied in 11 percentage ratios of each component. In binary mixtures of polyphosphate combined with monophosphate, diphosphate or triphosphate, hardness gradually rose with the increasing proportion of polyphosphates within the mixture. In binary mixtures of monophosphate combined with diphosphate or triphosphate, a rapid growth in hardness of the samples was observed when the proportion of diphosphate or triphosphate in the mixture increased (up to 50-60%). A further increase in diphosphate or triphosphate content (above 60%) resulted in a rapid decrease in hardness of the processed cheeses. © 2011 Elsevier Ltd

The effect of ternary emulsifying salt composition and cheese maturity on the textural properties of processed cheese

The dependence of textural parameters of processed cheeses (40%, w/w, dry matter content, 50%, w/w, fat in dry matter content) on the composition of ternary mixtures of phosphate emulsifying salts (disodium hydrogen phosphate - DSP; tetrasodium diphosphate - TSPP; sodium salt of polyphosphate - POLY) was modelled. The effects were studied in samples from cheeses with different maturity (2, 4 and 8 weeks) over a 30-day storage period at 6 degrees C. With a constant POLY content (below 60%) in the ternary mixtures, a rapid increase in hardness and a decrease in cohesiveness and relative adhesiveness was observed in products with a ratio of DSP to TSPP ranging in the instance of 1:1-3:4. The effect of a specific ratio of DSP to TSPP on the texture parameters decreased with increasing content of POLY in the mixtures. Neither the degree of maturity of the cheese nor a 30-day storage period affected these general trends. (C) 2012 Elsevier Ltd. All rights reserved