Renata Pietrzak-Fiećko

University of Warmia and Mazury in Olsztyn · Department of Commodities and Food Analysis

The quality of fat in infant milk is determined by the fatty acid profile and selected indices describing nutritional value. The aim of this study was to analyze the fatty acid profile and lipid quality indices of infant formulas and compare these data with breast milk. The study material included seven types of cow's milk-based follow-on infant fo...

The aim of the present study was to determine the effect of concentrating skim milk (10–50 g 100 g−1) on changes in contents of minerals as well as values of physicochemical and structural parameters (pH, total protein, micro- and macro-mineral content, viscosity, particle diameter, micrographs by fractal dimension), electrical parameters: conducti...

Organic waste can provide an alternative to synthetic fertilisers for maintaining productivity with limited environmental impact. Our research evaluates the potential use of processed animal waste in corn fertilisation, which may represent a partially closed nutrient cycle of importance in a sustainable agricultural system. The objective of this st...

This study aimed to determine the physicochemical, nutritional, antioxidant, and sensory properties of crackers with the addition of edible insects. The analyses covered the contents of total dry matter, crude protein, fat and ash; amino acid composition and antioxidant activity (DPPH method); total polyphenol content; mineral compound composition...

(1) Background: This study investigated the effect of the lactation period and the type of infant formula on the content of amino acids and selected minerals in an infant’s food; (2) Methods: The study material consisted of breast milk (colostrum, n = 38; transitional milk, mature milk, n = 38) and three types of infant formulas (for first and foll...

The aim of the study was to determine the influence of diets (factor D) and the time period (factor T) during which they were applied on the growth performance and physiological condition (blood plasma hematological and biochemical indicators of stress and immunity) in juvenile sea trout ( Salmo trutta ; initial body weight approximately 73 g). The...

The aim of the study was to compare the effects of microwave and sous-vide cooking on chemical composition, including fatty acid composition, colour, and microbial and eating quality of fillets produced from wild-living pikeperch. Skinned fillets were sous-vide (SV)-cooked at 65 °C for 40 min. or cooked in a microwave oven (M) at 539 W for 3 min. G...

The aim of the study was to compare the chemical and fatty acid composition, colour, and sensory quality of wild and farmed pikeperch. Raw wild pikeperch had a higher moisture and ash contents, as well as pH value, but lower fat and protein contents than farmed pikeperch. In sous-vide fillets, a higher fat and a lower protein content were noted in...

1) Background: The aim of the conducted research was to analyze the squalene content in infants' food. (2) Methods: The experimental material included human milk collected from 100 women from Poland and three different infant formulas. The breast milk fat was extracted according to the Rose-Gottlieb method (AOAC), while the squalene content was det...

Imleria badia, Boletus edulis, and Cantharellus cibarius are popular mushrooms of economic importance in Poland. Since physical and mental development of a person and the maintenance of good health entail providing the body with adequate nutrients, including plant and animal fats, the aim of this study was to determine the fatty acid profiles of th...

The aim of the study was to investigate the influence of temperature and time combination on the quality of pikeperch fillets and to propose settings which allow high nutritional quality fish fillets to be obtained. The material for the study consisted of 24 farmed pikeperch (Sander lucioperca) fillets, which were evaluated raw and after sous vide...

This study aimed to assess the content of caffeine and its metabolites—paraxanthine, theophylline, and theobromine—in breast milk according to selected factors. Samples of human milk were collected from 100 women living in the east–northeast region of Poland. Information on the consumption of beverages and foods containing caffeine was collected us...

The aim of the study was to evaluate the effect of two commercial oil marinades on marinated bovine semimembranosus muscles’ (n = 12) fatty acid composition. Fatty acids were determined in unmarinated raw and sous-vide beef and marinated muscles with two different marinades. The application of marinating changed the fatty acid composition in sous-v...

The aim of this study was to estimate the fish quality in terms of the Cu, Fe, Mn and Zn contents. The research material was the muscle tissue of the fish crucian carp (Carassius carassius Linnaeus, 1758), flounder (Platichthys flesus Linnaeus, 1758), Gilthead seabream (Sparus aurata Linnaeus, 1758), mackerel (Scomber scombrus Linnaeus, 1758), Blue...

Methylxanthines, including caffeine and its metabolites - paraxanthine, theophylline, theobromine, accumulate in breast milk when consumed with food by the nursing mother. The aim of the study was to assess the content of caffeine and its metabolites in breast milk depending on the lactation period. Samples of human milk were collected from 100 wom...

Validated extraction methods from in vitro digestion phases are necessary to obtain a suitable bioaccessibility study of mycotoxins in bakery products. The bakery industry produces bread with different ingredients to enrich the nutritional properties of this product and protect it from fungal growth. This bread can be contaminated by AFB1, AFB2, AF...

Mushrooms are able to accumulate toxic trace elements. This study investigates the content of cadmium (Cd) and lead (Pb) in selected species of fungi (Boletus badius, Boletus edulis, and Cantharellus cibarius) from the northeastern part of Poland and estimates their edible safety. The amount of Cd and Pb was determined by flameless atomic spectrome...

Animal-based foods such as meat, fish, milk and dairy products as well as eggs are considered typical protein sources for the hydrolysis and production of bioactive peptides on an industrial scale. During the hydrolysis of animal proteins, numerous peptides characterized by high biological activity are generated. Bioactive peptides are protein frag...

1) Background: The integrated approach to the prevention and treatment of eating disorders (EDs) requires knowledge and can be used only when specific risk factors are known. The aim of this study was to examine the differences in food choices and eating behavior between males and females; (2) Methods: This study comprised 148 females and 27 males...

The study assesses the antioxidant activity, total phenolic content, total flavonoids content and lipophilic pigments (β-carotene, chlorophyll a, chlorophyll b) content in homemade and marketed fruit and vegetable whey beverages and fruit and vegetable mousses. All of the tests were performed using spectrophotometric methods. The highest polyphenol...

Although DDT, γ-HCH and PCBs have been almost completely withdrawn from world production and use, they are still present in the environment. Mushrooms are eagerly collected and consumed local raw material in north-eastern part of Poland. The aim of the study was to determine the content of DDT, γ-HCH and PCB residues in popular species (Boletus bad...

The initial experiment of this study was conducted to determine whether sex steroid concentrations varied before, during and after the reproductive season of European grayling (Thymallus thymallus L.) farmed broodstock confined in a recirculation aquaculture system (RAS). The results indicated that the plasma sex steroid (testosterone - T, progeste...

The region of Warmia and Mazury is characterized by the special diversity and richness of its natural environment, including large forest complexes, where wild mushrooms are commonly collected and consumed. This study aimed to examine the differences in mineral content (calcium, magnesium, sodium, potassium, iron, zinc, copper, manganese) of three...

One of main nutritional components in milk are fat. Fats are the main source of energy used by the body. The most important components are fatty acids (FA), which have important biological functions e.g. anti-inflammatory, anti-atherosclerotic, reducing blood pressure. What is more, milk fat in human diet shows health-promoting properties (1, 2). T...

Meat, including beef, is a rich source of minerals in the human diet (1,2) . However, different thermal treatments might affect minerals concentration in beef and thus its nutritional value. The aim of the study was to determine the degree of coverage of the demand for minerals by consuming 100 g of steam-cooked and sous-vide beef. Material for the...

Meat semi-finished products that are portioned or not, meat with the addition of a different composition of spices and oil are a common element of the commercial offer in the convenient ready to cook food segment. During the refrigeration storage in this complex system of meat, oil and spices, there is a number of physicochemical changes, including...

Meat and meat products are one of the most relevant food groups in the human diet due to high content of protein. Meat from wild animals is considered a delicacy and commands a high price compared to other sorts of meat. Due to the characteristic sensory properties (taste), lower fat and cholesterol contents and higher share of polyunsaturated fatt...

This study focused on comparing slaughter yield, proximate composition, and fatty acid profiles of meat from wild vendace, Coregonus albula L. caught in natural conditions (lakes; group W) and from cultured vendace reared on formulated feed in recirculating systems (group C). The slaughter yield of gutted vendace (group C) was approximately 2% high...

1) Background: The variation in the concentration of different components found in milk depends on mammalian species, genetic, physiological, nutritional factors, and environmental conditions. Here, we analyse, for the first time, the content of different components (cholesterol concentration and fatty acids composition as well as the overall fat a...

The aim of the study was to indicate potential differences in composition of fatty acids between two mushroom species as well as to examine the impact of mushrooms’ vegetative places and morphological parts of a fruiting body on the fatty acids profile. The research material consisted of 72 samples of wild Leccinum aurantiacum and Leccinum versipel...

Nitrogen fertilization combined with microelements is an effective way to provide nutrients to plants, which are essential for obtaining high-value crops. The aim of this study was to evaluate two N fertilizer rates (150 and 200 kg ha-1) and four Mn fertilizer rates (0.0, 0.5, 1.0, and 1.5 kg Mn ha-1) on the N, Mn, Zn, Cu, and Fe content and compos...

The quality of rapeseed seeds is determined by the content of mineral components, protein and fat with favourable fatty acid composition. The aim of the study was to assess leaf gas exchange as well as the yielding and quality of seeds of two varieties of rapeseed cultivated in various crop rotation systems and at different levels of agrotechnology...

Twenty four Holstein-Friesian bulls were randomly assigned to one of three dietary treatments: a control diet, diet O (supplemented with Optirum herbal extracts improving the functioning of the gastrointestinal tract of cattle), and diet OS (containing two herbal preparation: Optirum and Stresomix, used to reduce stress). The quality of longissimus...

Introduction Reports that the presence of persistent organic pollutants in fat may affect fatty acid metabolism prompted this research aiming to study the relationship between the contents of γ-HCH and DDT, DDE, DDD, and ΣDDT, and fatty acid composition of milk fat. Material and Methods The material consisted of 50 samples of cow and mare milk, co...

Introduction: Reports that the presence of persistent organic pollutants in fat may affect fatty acid metabolism prompted this research aiming to study the relationship between the contents of γ-HCH and DDT, DDE, DDD, and ΣDDT, and fatty acid composition of milk fat. Material and Methods: The material consisted of 50 samples of cow and mare milk, c...

The nutritional and technological value of grains is determined mostly by genetic traits of crops, and also by environmental conditions, such as the weather, soil conditions and applied crop production technology. The aim of the study was to assess the effects of nitrogen fertilisation on the yield components, the yield of grains, grain mineral con...

Recent interest in mare’s milk is associated with the fact that it contains a wide variety of valuable nutrients with health-promoting properties. Among milks of many mammal species, it is the mare’s milk that is highly appreciated for similarity to human milk in terms of chemical composition allowing its use as a substitute for mother’s milk in in...

The aim of the study was to investigate the effects of northern pike origin (wild vs. farmed) and sex (female vs. male) on chemical composition, including fatty acids, and technological properties of fresh fillets. Fish origin influenced moisture, protein, fat, and ash contents, pH and color of the fillets, and the proportion of 22 out of 25 determ...

The aim of the present study was to investigate the effect of thermal treatment methods, such as microwave cooking, steaming, and shallow pan-frying, on fatty acids composition in northern pike fillets. All methods of thermal treatment increased fat content in the fillets. Microwave cooking decreased the proportion of saturated fatty acids and incr...

Quality features of rapeseeds (Brassica napus L.) and potential for high yielding to a major extent may be defined by improvements in agricultural engineering methods that encompass biological progress. However, this is associated with fertilization and application of pesticides, which may negatively impact on environment and quality. It is thus es...

The aim of this study was to determine the level of chlorinated hydrocarbon residues in selected edible mushrooms from north-eastern Poland. The experiment was carried out on 45 samples consisting of 15 fruiting bodies each of the following species: Boletus edulis, Imleria badia and Cantharellus cibarius. Dried samples were subjected to extraction...

The aim of this study was to determine the fatty acid profile of cheese and tvorog milk fat obtained from the local producers from the region of north-eastern Poland. The material consisted of tvorog and cheese samples made from cow, goat and sheep's milk. Methyl esters of fatty acids in milk fat was prepared with the use of IDF Standard 1999 and w...

The grain of winter rye (Secale cereale L.) originated from a field experiment conducted in the years 2011-2013 at the Didactic-Experimental Centre of the University of Warmia and Mazury in Tomaszkowo (53°72 N; 20°42 E) in Poland. The aim of the study was to determine the yield of winter rye and its components and the content of proteins, starch an...

The aim of this study was to determine the content of fat and fatty acids profile in wild Boletus edulis. The research material consisted of 33 samples of wild Boletus edulis in the form of caps and stems, collected from selected regions of Poland. Methyl esters of fatty acids were prepared by Peisker's method. Separation of the examined compounds...

The aim of the study was to determine the impact pike fishing season (before spawning in fall (group A) and after spawning in spring (group B)) had on the slaughter yield and fillet fatty acid profile. The slaughter yield of fillets with skin and skinned fillets from the group B fish was significantly lower (by approximately 7.5% of body weight). T...

The aim of this study was to compare the content of chosen PAHs (benzo[a]pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene) in meat of different freshwater fish species that were traditionally (directly) smoked. The survey covered 16 freshwater fish samples of four species: rainbow trout (Oncorhynchus mykiss), carp (Cyprinus carpio), venda...

The aim of the study was to determine the content of chlorinated hydrocarbon residues in fat of different assortment of rainbow trout (Oncorhynchus mykiss). The research material consisted of 108 fish from six different producers. Thirty-six fish were analysed as fresh, 36 fish as frozen after six months storage, and 36 fish as traditionally smoked...

The aim of this study was to determine the effect of cattle breed (Holstein-Friesian-HF, Jersey-JE, HF x JE) and lactation stage (days 160, 220 and 280) on nutrient concentrations in milk and the fatty acid profile of milk fat. An analysis of lactation stage on the chemical composition of milk revealed that the concentrations of dry matter, protein...

The aim of the study was to determine and compare the concentrations of chlorinated hydrocarbons residues (DDT, DDE, DDD, gamma-HCH) in the milk fat of selected species of farm animals. The experiment was carried out on cow's, sheep's, goat's, and mare's milk samples originating from different parts of north-eastern Poland. The samples were prepare...

The objective of the study was to compare the content of eight selected polycyclic aromatic hydrocarbons in the meat of traditionally (directly) smoked rainbow trout (Oncorhynchus mykiss) from a fresh and a frozen fish, with the content of the same in the market trout fish smoked using different methods (in a smokehouse with an external smoke gener...

The aim of the study was to determine and compare the fatty acid composition of minced meat, smoked cooked hams and smoked dry pork sausages available on the Polish market. The fatty acid profile was determined using gas chromatography. Among all fatty acids found in the meat products the highest share had C18:1 n-9, C16:0, C18:0, C18:2 n-6, and C1...

Results of an inexpensive and rapid evaluation of the cholesterol concentration in human milk using ATR-FTIR techniques are presented. The FTIR spectrum of pure cholesterol was characterized and quantitatively estimated in the region between 2800 and 3200 cm−1. 125 samples at different stages of lactation were analyzed. There were no differences be...

Analyses were carried out on the fatty acid composition of milk fat originating from mares of three breeds: Polish Cold-Blooded, Wielkopolski and Konik Polski. Milk was collected from mares in the early, mid and late lactation. Determination of fatty acids was conducted with the gas chromatography method. The analysis of the fatty acid composition...

This experiment was designed to study the effects of supplementing laying hens’ diets with vermiculite (V) and vermiculite mixed with fishmeal (FM) on productivity, morphometric para-meters, chemical composition and fatty acid profile of eggs as well as on some blood plasma indicators of laying hens. Hajseks White birds were randomly divided into 5...

The aim of the study was to determine the content of chlorinated hydrocarbon residues in edible mushrooms from the north-eastern part of Poland. Material consisted of two species of fungi: Xerocomus mushrooms (Xerocomus badius), Boletus mushrooms (Boletus edulis). The dried samples (cups and cut-up material) were extracted with Soxhlet method in or...

More and more research is done concerning nutritional programming. Human milk nutrients which are consumed by infants can influence their health in later life. High level of cholesterol in human milk paradoxically lowers the cholesterol concentration in blood in adults. During the course of human lactation the cholesterol concentration decreases fr...

Polychlorinated biphenyls (PCBs) form a group of synthetic aromatic chemical compounds, commonly occurring in the environment as a result of industrialisation. Despite the ban on PCBs production, their wide application in the past resulted in their common occurrence in all elements of the environment. The lipophilic nature of the compounds resultin...

The composition and quality of milk depend on various factors, among other things, on genetic and environmental conditions, physiological status of animals, and season of the year. The effect of season of the year is reflected by the seasonality of milk production (winter season: indoor feeding; summer season: pasture feeding). However, in recent y...

The aim of the study was to evaluate the fatty acids composition of storage fat of slaughter horses. Samples of cervical and peri-intestinal fat taken from horses of different genders and weights in a slaughterhouse were used as the study material. The fat was esterified by the method described by Peisker. Separation and analysis of the fatty acids...

The aim of the study was to determine the content of chlorinated hydrocarbons (DDT, DDE, DDD and γ-HCH) in different tissues of turkeys from a reproductive flock. Linear correlation coefficients between the contents of chlorinated hydrocarbons in blood of the turkey hens and their concentrations in egg yolks; in egg yolk and their concentrations in...

The objective of the study was to determine the levels of congeners (28, 52, 101, 118, 153, 180, 138) of polychlorinated biphenyls in edible mushrooms available at the market in the region of Warmia and Masuria. The research material constituted 15 samples of edible mushrooms available at the market in Warmia and Masuria, including: five species of...

In the life of a foal, mare's milk is the most valuable food source, barely replaceable with any other prod-uct. Milk of this origin has also been used in human nutrition (Drogoul et al., 1992). Mongolians inhabit-ing steppes of Central Asia are known to consume a variety of mare's milk based products as well as to be perfect in their acquisition....

This study presents the results of determinations of Cs-137 in full-fat cow milk powder originating from four regions of Poland. The assays performed demonstrated differences in the content of Cs-137 in milk powder depending on the region. The higher content of Cs-137 was found in powdered milk samples collected from Opole (3.50 Bq/dm3́). The lowes...

Milk samples were collected from 2000 to 2001, between 7th to 180th d of lactation from mares differing in age and the number of lactations. The content of DDT and HCH was determined by gas chromatography with electron capture detection. It was confirmed that mare's milk was contaminated with various amounts of hazardous residues of DDT and its met...

The growing demand for turkey meat causes an intensification of studies on factors that determine the reproductive performance of these birds. Results of numerous studies indicate that extremely stable chlorinated hydrocarbons negatively affect the reproductivity of animals. It therefore seems reasonable to perform studies on the content of DDT, DD...

An increasing demand for turkey meat requires intensification of rearing, while almost permanent presence of stable chlorinated hydrocarbons in the environment, feeds, living organisms, including humans, to force undertaking studies on the wholesome safety of food of animal origin. The objective of the present study was therefore to evaluate select...

The fatty acid composition of human milk, UHT cow's milk and the infant formulas Nan and Bebiko were assayed in the study. Human milk samples were collected in the years of 1999-2000 from 130 breastfeeding mothers, on day 3 to 5 postpartum and analysed by IDF Standard method (1999) with gas chromatograph HP 6890. The sum of saturated fatty acids in...

The content of polychlorinated biphenyls was determined in human milk collected from four regions of Poland, as well as in cow's milk and infant formulas. Significant statistical differences in PCB levels were determined in human milk depending on the re- gion. The highest PCB mean concentration (0.351 mg . kg -1 milk fat) was determined in human m...

The contents of polychlorinated biphenyls in human milk were determined. The PCB levels in human milk were determined in relation to factors such as: age and weight of women, birthweight of the baby, smoking, period of breast-feeding (3-5 days, 2-4 weeks, 6-8 month) and seasons of the year. It was found that level of PCB in human milk have been dec...

Residual amounts of organochlorine insecticides: gamma-HCH, DDT and its metabolites DDE and DDD were determined by gas chromatography in human milk collected in Olsztyn in 1996. The results were compared with the results obtained earlier in 1976 and 1986 in the same region of Poland. It was observed that with time the amount of chlorinated hydrocar...

A study was conducted on the residues of γ-HCH and DDT and their metabolites in the milk of women, cows and mares from the province of Warmia and Mazury, obtained in the years 1996-1999. Residues of chlorinated carbohydrates were determined by gas chromatography performed after extraction of fat from the milk. Residues of γ-HCH were detected in all...

The GC-MS method was applied to determine residues of growth hormones in muscle tissue. Following the analysis of the results of the method it was found out that only 42% of internal standard added to the sample remained in the silisnised extract. The low recovery of the substances analysed might have led to a wrong conclusion regarding the absence...