Alteration of biomass toxicity in torrefaction - A XDS-CALUX bioassay study.

Torrefaction constitutes one of the promising technologies for the management of waste biomass and the production of high-carbon products for combustion, gasification, adsorption of pollutants or soil treatment. Unfortunately, waste biomass may be contaminated with toxic persistent organic pollutants, such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) and dioxin-like biphenyls (dl-PCB). Literature does not provide consistent measurements on how the low-temperature thermochemical processing, such as torrefaction, affects the toxicity of biomass. This contribution assesses how a torrefaction treatment, conducted at 200 °C, modifies the toxicity due to PCDD/PCDF/dl-PCB in biomass. We deploy the XDS-CALUX biotest on five types of waste biomass (sewage sludge, tree bark, cattle manure, spent coffee ground, common reed), before and after treatment. The content of total dioxin- & biphenyl fraction compounds in the raw biomass, investigated in this study, varies from 0.14 to 3.67 pg BEQ·g-1d.m., and in the torrefied biomass between 0.17 and 6.00 pg BEQ·g-1d.m.; BEQ stands for bioanalytical equivalent. This increase is statistically insignificant at p = 0.05, taking into account all types of examined biomass. This proves that low-temperature torrefaction cannot detoxify biomass, i.e., chars, produced from biomass characterized by elevated concentration of PCDD/PCDF/dl-PCB, will reflect the contamination of the feedstocks. With respect to heavy metals, we conclude that only the content of Cd in biomass, and, to a lesser extent, the abundance of Cu and Fe, modify the toxicity of this material during its thermochemical treatment at low temperature.

Mercury Content in Impacted Wisdom Teeth from Patients of the Legnica-Glogów Copper Area-An In Vitro Pilot Study.

The aim of this study was to determine the content of mercury in impacted third molars from Legnica-Glogów Copper Area residents to emphasize the effects of environmental pollution on the human body. A group of 72 patients with an average age of 27.3 ± 6.9 years participated in the study. Within this study, the research group (Legnica-Glogów Copper Area residents) comprised 51 individuals, while the control group (residents of Wroclaw) consisted of 21 participants. A higher number of female individuals participated in the research (55). The amount of mercury present in the samples was determined through atomic absorption spectrometry with the use of a SpectraAA atomic absorption spectrometer and a V2 AA240FS flame attachment that utilized an air-acetylene flame. The accumulation of Hg in the teeth of members of the control group residing in Wroclaw was studied, with a focus on identifying the risk factors that contribute to this phenomenon. The final model analyzed the presence of various factors, including thyroid and parathyroid gland diseases, cardiac diseases, and interval-scale Vit. D3 concentration. Among these factors, the presence of cardiac diseases was deemed statistically significant in relation to an increase in Hg concentration in third molars (rate ratio = 2.27, p < 0.0001). The concentration of mercury increased with the age and time of residence in the L-G Copper District.

Some Immune Parameters of Term Newborns at Birth Are Associated with the Concentration of Iron, Copper and Magnesium in Maternal Serum.

The nutritional status of pregnant women is considered to affect fetal development and the health condition of newborns, including their immune system. We investigated the relationship between the concentrations of magnesium (Mg), calcium (Ca), zinc (Zn), iron (Fe) and copper (Cu) in maternal serum (MS) and the concentrations of IgG antibodies and antineutrophil cytoplasmatic auto-antibodies against lactoferrin (Lf-ANCA) in umbilical cord serum (UCS). IgG was considered as a promoter of immunity, and Lf-ANCA as an inhibitor. The examined group consisted of 98 pregnant women and their healthy term newborn children. The concentrations of mineral elements were measured by FAAS/FAES, while the concentrations of antibodies were determined by ELISA. Excessive MS Fe and insufficient MS Cu were related to insufficient UCS IgG and excessive UCS Lf-ANCA. The correlation analysis showed confirming results. Adequate UCS IgG and Lf-ANCA were related to MS Mg at the strictly lower limit of the reference values. The results obtained seem to suggest that an excess of Fe and a deficiency of Cu in pregnancy may adversely affect some immune parameters of newborns. Reference values for MS Mg are likely to require reconsideration. It would be advisable to monitor the nutritional status of pregnant women with minerals in order to support the immune capacity of newborns.

Physical Properties of Starches Modified by Phosphorylation and High-Voltage Electrical Discharge (HVED).

High-voltage electrical discharge (HVED) is considered as a novel, non-thermal process and is currently being researched regarding its effect on microorganisms (decontamination of food), waste water treatment, and modification of different compounds and food components. In this paper, four native starches (maize, wheat, potato, and tapioca) were treated with HVED, phosphorylated with Na2HPO4 and Na5P3O10, and modified by a combination of HVED with each phosphorylation reaction both prior and after chemical modification. Pasting properties, swelling power, solubility, gel texture, and particle size were analyzed. Although HVED induced lower contents of P in modified starches, it had an effect on analyzed properties. The results revealed that HVED treatment alone had a limited effect on pasting properties of starches, but it had an effect on properties of phosphorylated starches, both when it was conducted prior and after the chemical modification, reducing the influence of Na5P3O10 and Na2HPO4 on the decrease of pasting temperature. With minor exceptions, the gel strength of starches increased, and the rupture strength decreased by all modifications. HVED treatment resulted in a decrease of the particle size after the modification of maize and wheat starches, while potato and tapioca starches were not significantly influenced by the treatment.

Assessment of Selected Morphological, Physical and Chemical Parameters of the Teeth of the Offspring of Female Rats Exposed to 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), Taking into Account the Protective Role of Selected Antioxidants-Preliminary Study.

The studies conducted so far indicate a negative effect of dioxins on the structure of the alveolar bone and teeth, especially in the developmental period in rats. The research aimed to analyze the indirect effect of dioxins contained in the body of female rats on the structure of the dental organ in their offspring in the neonatal period and to determine the possibility of reducing potential dioxin disorders of the structure of hard tissues in the offspring of intoxicated mothers by simultaneous administration of vitamin E or acetylsalicylic acid (ASA). Another goal of the research was to determine the level of magnesium, calcium and phosphorus contained in bone tissue as indicators of the mineralization process of hard tissues in rats, in the case of using 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and acetylsalicylic acid or α-tocopherol. The experiment was carried out on eight female rats of the Buffalo strain divided into four groups. From the offspring of eight females, the mandibles were removed from the mandibular joints, and then, after the removal of soft tissues, they were prepared for individual tests. Selected morphological, chemical and physical parameters of the teeth of the offspring of female rats from the experimental groups were analyzed. The analysis showed the effect of vitamin E and ASA on the content of Mg, Ca and P. In combination with TCDD, vitamin E and ASA, they positively inhibit the inflammatory process, preventing the leaching of Ca and Mg from the bones. ASA counteracted this phenomenon much more effectively than vitamin E. Detailed analysis of the tooth morphology showed that the molars' crowns exhibit shape disturbances under the influence of TCDD. Individual nodules in teeth T1, T2, T3 did not fuse, and the roots showed signs of hypertrophy. The study confirmed the negative effect of TCDD on tooth development. Teeth arising early in development are the most sensitive to the disorders, while the later ones are less exposed to the toxic effects of TCDD transmitted by the mother.

Chokeberry Pomace as a Component Shaping the Content of Bioactive Compounds and Nutritional, Health-Promoting (Anti-Diabetic and Antioxidant) and Sensory Properties of Shortcrust Pastries Sweetened with Sucrose and Erythritol.

In this study, an attempt was made to develop shortcrust pastries containing different amounts of chokeberry pomace (0%, 10%, 30%, 50%), modulating their degree of sweetness via the application of sucrose or erythritol. The obtained products were assessed for their nutritional value (energy value, protein, fats, dietary fibre, sugars, minerals). Bioactive compounds, as well as antioxidant and anti-diabetic properties in an in vitro model and sensory attributes, were also analysed. Increasing the proportion of chokeberry pomace in shortcrust pastries improved their nutritional value, especially their energy value (reduction of nearly 30% for shortcrust pastries with 50% pomace sweetened with erythritol), nutritional fibre content (10-fold higher in shortcrust pastries with the highest proportion of pomace) and potassium, calcium, magnesium, and iron content. Chokeberry pomace was also a carrier of 14 bioactive compounds. The most beneficial antioxidant and anti-diabetic effect was shown for shortcrust pastries containing 50% chokeberry pomace. In addition, it was shown that the use of erythritol as a sweetener has a beneficial effect on the perception of sensory attributes. Finally, it was shown that the developed products could be excellent alternatives to traditional shortcrust pastries and, at the same time, be a good way to utilize waste from the fruit industry.

Food Insecurity in the Households of Polish Elderly: Diversity in the Perception of Its Causes by Demographic and Socioeconomic Characteristics.

The aging of societies and the quality of life of the elderly may be accompanied by food insecurity. The aim of the study was to find the relationships between the perceptions of various causes of food insecurity, i.e., financial, social, health, and spatial, and then between those and the selected sociodemographic characteristics. The survey was conducted in late 2018 and early 2019 among 760 people aged 65 and older in two regions of Poland. Factor analysis with the use of principal component analysis (PCA) was used to identify the main causes of the prevalence of food insecurity. Cluster analysis using Ward's hierarchical classification and logistic regression analysis were used to assess the relationship between the identified reasons for food insecurity, demographic characteristics, and socioeconomic status (SES). Two groups of causes that favor the experience of food insecurity among the elderly were identified, i.e., economic-social reasons and spatial-health reasons. They relate to such situations of food insecurity as concerns about food shortages, lack of staple foods, limited size or frequency of meals, and skipping meals. The high importance of economic-social (HE-S) reasons was associated with the low importance of spatial-health (LS-H) reasons, and conversely, the high importance of spatial-health (HS-H) causes was associated with the low importance of economic-social (LE-S) causes. HE-S and LS-H reasons were combined with low SES and residence in a city of more than 100,000 inhabitants. HS-H causes, on the other hand, were associated with LE-S causes and living in rural areas or towns of fewer than 100,000 inhabitants, as well as high SES. This specificity should be considered in the development of strategies and interventions aimed at reducing the phenomenon of experiencing food insecurity in the elderly population.

Oxidative Stress at Birth Is Associated with the Concentration of Iron and Copper in Maternal Serum.

Oxidative stress (OS) in the foetal and neonatal periods leads to many disorders in newborns and in later life. The nutritional status of pregnant women is considered to be one of the key factors that triggers OS. We investigated the relationship between the concentration of selected mineral elements in the blood of pregnant women and the concentration of 3'nitrotyrosine (3'NT) as a marker of OS in the umbilical cord blood of newborns. The study group consisted of 57 pregnant women and their newborn children. The concentrations of magnesium (Mg), calcium (Ca), iron (Fe), zinc (Zn) and copper (Cu) in maternal serum (MS) were measured by the flame atomic absorption/emission spectrometry (FAAS/FAES) method. The concentration of 3'NT in umbilical cord serum (UCS) of newborns was determined by the ELISA method. A positive correlation between MS Fe and UCS 3'NT in male newborns was shown (rho = 0.392, p = 0.053). Significantly higher UCS 3'NT was demonstrated in newborns, especially males, whose mothers were characterized by MS Fe higher than 400 µg/dL compared to those of mothers with MS Fe up to 300 µg/dL (p < 0.01). Moreover, a negative correlation between the MS Cu and UCS 3'NT in male newborns was observed (rho = -0.509, p = 0.008). Results of the study showed the need to develop strategies to optimize the nutritional status of pregnant women. Implementation of these strategies could contribute to reducing the risk of pre- and neonatal OS and its adverse health effects in the offspring.

Toxic Metals Content in Impacted Third Molars and Adjacent Bone Tissue in Different Groups of Patients.

The aim of the study was to determine the content of: Pb, Cd, Cr, Ni, Fe, Mn, Cu, Zn in the impacted third molars and a fragment of covering bone. Patients were divided according to following criteria: place of residence, age, gender, anatomical location of the removed tooth. Content of Cd, Pb, and Mn in the samples increases with age of the patient. The content of Cd and Pb in the tooth and bone was higher in patients living in Wroclaw. Residents of the Wroclaw had higher Cu content in the teeth, while they had a lower content in the jawbone. In contrast to Cd and Pb, an average of 68% higher concentration of Zn in the jawbone than in the tooth was noted. The content of Cr in tooth was lower by 33% than in the mandible bone and, similarly to the content of Ni, it decreased with age. In women, the Fe content in bone of the jaw was higher than in the removed tooth. The presence of Pb and Cd aggregates is confirmed in all hard tissues of the tooth and bone, in contrast to bioelements which show a stronger tendency to aggregate, essentially within the dentine.

Is Biochar from the Torrefaction of Sewage Sludge Hazardous Waste?

Improved technologies are needed for sustainable management of sewage sludge (SS). The torrefaction (also known as biomass "roasting") is considered a pretreatment of SS before use in agriculture. However, it is not known whether the torrefaction has the potential to decrease heavy metals' (HMs) leachability and the SS toxicity. Thus, the aim of the study was to evaluate the influences of the SS torrefaction parameters (temperature and process time) on HM contents in biochar, HM leachability, and biochar toxicity, and compare them with raw SS. The experiments were designed in 18 combinations (six temperatures, 200, 220, 240, 260, 280, and 300 °C; and three process times-20, 40, 60 min). Standard tests were used to determine HMs content, leachability, and toxicity. Results indicated that the torrefaction did not increase (p < 0.05) the HM content in comparison to the raw SS. The leachability of Zn, Ni, Cu, Cr, and Mn from SS biochars was similar to raw SS. However, the degree of leachability varied significantly (p < 0.05) from as low as 0.1% for Cu to high as 16.7% for Cd. The leachability of Cd (<16.7%) and Pb (<11.9%) from biochars was higher than from raw SS (<6.1% and <2.4%, respectively). The leachability of Cd from SS biochar, in five torrefaction combinations, was higher than the threshold value for hazardous waste. It is recommended that site-specific decisions are made for torrefaction of SS with respect to its HM content, as the resulting biochar could be considered as hazardous waste, depending on the feedstock. Moreover, the biochar produced under the whole range of temperatures during 20 min retention time significantly (p < 0.05) increased the Daphnia magna Straus mobility inhibition by up to 100% in comparison to the biochar obtained during 40 and 60 min torrefaction. Taking into account the increased leachability of specific HMs and D. magna Straus mobility inhibition, biochar should be considered a potentially hazardous material. Future research should focus on biochar dosage as a fertilizer in relation to its toxicity. Additional research is warranted to focus on the optimization of SS torrefaction process parameters affecting the toxicity.

Waste-to-Carbon: Is the Torrefied Sewage Sludge with High Ash Content a Better Fuel or Fertilizer?

Sewage sludge (SS) recycling is an important part of the proposed 'circular economy' concept. SS can be valorized via torrefaction (also known as 'low-temperature pyrolysis' or 'roasting'). SS can, therefore, be considered a low-quality fuel or a source of nutrients essential for plant growth. Biochar produced by torrefaction of SS is a form of carbonized fuel or fertilizer. In this research, for the first time, we tested the feasibility of torrefaction of SS with high ash content for either fuel or organic fertilizer production. The research was conducted in 18 variants (six torrefaction temperatures between 200~300 °C, and three process residence times of 20, 40, 60 min) in 5 repetitions. Fuel and fertilizer properties and multiple regression analysis of produced biochar were conducted. The higher heating value (HHV) of raw SS was 21.2 MJ·kg-1. Produced biochar was characterized by HHV up to 12.85 MJ·kg-1 and lower H/C and O/C molar ratio. Therefore, torrefaction of SS with high ash content should not be considered as a method for improving the fuel properties. Instead, the production of fertilizer appears to be favorable. The torrefaction increased C, N, Mg, Ca, K, Na concentration in relation to raw SS. No significant (p < 0.05) influence of the increase of temperature and residence time on the increase of biogenic elements in biochar was found, however the highest biogenic element content, were found in biochar produced for 60 min, under the temperature ranging from 200 to 240 °C. Obtained biochars met the Polish regulatory criteria for mineral-organic fertilizer. Therefore SS torrefaction may be considered a feasible waste recycling technology. The calculation of torrefaction energy and the mass balance shows energy demand <2.5 GJ∙Mg-1 w.m., and the expected mass yield of the product, organic fertilizer, is ~178 kg∙Mg-1 w.m of SS. Further investigation should consider the scaling-up of the SS torrefaction process, with the application of other types of SSs.

The The influence of high doses of α-tocopherol on the content of selected trace elements in the liver of developing chicken embryos in experimentally induced 2,3,7,8-tetrachlorodibenzo-p-dioxin intoxication.

A chicken embryo develops in ovo without access to a constant circulating maternal nutrient supply, and therefore all necessary nutrients are initially stored in the yolk, and with progressive development are transferred to the liver, where they are taken up in response to various needs. Fluctuations in hepatic trace elements correlate with their mobilization from egg stores. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) intoxication causes liver damage by production of free radicals, while α-tocopherol is a well-known antioxidant and may play a protective role. In the experiment presented here, a solution containing only TCDD, TCDD and α-tocopherol, as well as α-tocopherol exclusively, was administrated into the yolk sac. The iron, zinc, copper and magnesium distribution was evaluated using histological and chemical methods. It has been found that α-tocopherol has no influence on magnesium and zinc content in the liver. The observed increase in iron content may be caused by antagonistic action of iron and α-tocopherol. On the other hand, synergistic action of α-tocopherol and TCDD has been noted with respect to the copper content.

Indirect study of the effect of α-tocopherol and acetylsalicylic acid on the mineral composition of bone tissue in the offspring of female rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin: long-term observations.

This paper discusses problems related to the influence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the mineral composition of the calvaria in the offspring of female rats. The female rats were administered with a single dose of TCDD and subsequently, after three-weeks, with α-tocopherol or acetylsalicylic acid. The research focused on analysis of the main mineral elements (Ca, Mg, Fe, Zn). The aim of the study was to determine the effect of dioxins and various doses of drugs on bone mineral composition in a six-month observation period. The mineral composition was analyzed using an atomic spectrometry method. Data were statistically analyzed and verified at a significance level of p = 0.05. The use of α-tocopherol normalizes bone resorption and formation disturbed by TCDD, maintaining the content of the studied elements at the physiological level. In turn, administration of acetylsalicylic acid limits the bone resorption process, which affects the element content.

The Protective Effect of α-Tocopherol on the Content of Selected Elements in the Calvaria for Exposed Hens to TCDD in the Early Embryonic Period.

This paper focuses on negative effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on element content in male chicken calvaria and α-tocopherol (vitamin E) ability to reduce its toxic potential on bone mineralization in offspring. In the experiment carried out once, a solution containing only DMSO, TCDD, TCDD + α-tocopherol, and exclusively α-tocopherol was administrated. Subsequently, on the 5th day after hatching, the mineral composition of the chicken calvaria was evaluated. The results obtained suggest that the use of α-tocopherol contributes to the maintenance of the concentration of calcium, magnesium, and manganese in the chicken calvaria treated with TCDD in the embryonic period. In turn, vitamin E increases the level of zinc. It has been found that α-tocopherol in chicken embryos has a protective effect against disturbance of level of chosen trace elements in the bones of offspring caused by the TCDD.

Modulating effect of selected pharmaceuticals on bone in female rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

This paper discusses the problems connected with the influence of TCDD on the mechanical properties and structure of the bone tissue in female rats treated with the dioxin. Moreover an analysis of the protective role of tocopherol, acetylsalicylic acid, dexamethazone and levamisol was performed. Rat tibiae were assessed by mechanical testing, and histological and trace element analysis. It was proved that TCDD has negative effect on bone mechanical properties, histological microstructure and trace element content. The results indicate that usage of both steroid and non-steroid anti-inflammatory medicaments, along with tocopherol and levamisol, modulating their activity, can reduce the negative effect of dioxin activity on the bone tissue of female rats intoxicated with TCDD.

Influence of arsenic on selected biochemical blood parameters in rats fed diet with different fat and protein content.

BACKGROUND: Arsenic is widely distributed in the environment. The main routes of absorption of inorganic arsenic compounds are the lungs and the gastrointestinal tract. Arsenates both (III) and (V) are absorbed from the gastrointestinal tract in 55-95%, while the organic arsenic compounds in 75-85%. Arsenic poisoning leads to damage the activities and morphological changes in the stomach and intestines, causing the occurrence of nausea, vomiting and diarrhoea. Arsenic compounds may also be the cause of the development of certain cancers (lung, skin and liver). The first changes caused by arsenic poisoning usually remain unnoticed. Arsenic affects haematological and both lipid and carbohydrate metabolism. It also causes changes in the organs involved in metabolism, so biochemical parameters or enzymes activity are therefore a good indicator of poisoning changes. OBJECTIVE: The aim of this study was to examine the influence of protein and fat content in diet on selected biochemical blood parameters in rats. MATERIAL AND METHODS: Rats (11 groups n = 88) were fed with 5 types of diet: control, low-protein, high-protein, low-fat and high-fat. Animals received water without arsenic (control group) or water with 10 or 20 µg As/mL. RESULTS: In animals fed a low protein diets, regardless of the dose of arsenic, it was a decreasing of total cholesterol, triglycerides, and glucose in serum observed, compared to the control group. In the groups fed with low-protein diet revealed a significantly less damage in the liver as compared to the control group. In animals fed high-protein diets and with varying addition of arsenic a significant higher concentration of various biochemical parameters were found, in comparison to the respective control groups. In animals fed the high protein diet and poisoned with 20 µg As/mL of the arsenic significantly higher liver damage were found, compared to control group. CONCLUSIONS: Symptoms of arsenic hepatotoxicity measured with enzyme activity were highest in the groups of animals fed with low-protein diet. The parameters of lipid and carbohydrate metabolism depended mostly on diet than the dose of arsenic.

Arsenic contents in rats' fur as an indicator of exposure to arsenic. Preliminary studies.

BACKGROUND: Since arsenic compounds have an affinity to thiol groups their greatest amounts can then be found in the tissues containing sulphur-rich proteins, like beta-keratin in skin, hair and nails. Accumulation of arsenic also depends on the macronutrient content in daily food ration. The deficiency and excess of both the protein and fat may contribute to a higher content of arsenic in the organism, including hair in human or fur in animals. OBJECTIVE: Hair and fur is a good indicator of population exposure to many toxic substances, including arsenic. The degree of arsenic accumulation may depend on the diet and nutritional status. The aim of this study was to determine the effect of protein and fat in diet on the accumulation of arsenic in rats' fur. MATERIALS AND METHODS: A total number of 70 male Buffalo rats (body weight 200 - 220 g, age - 6 weeks) were divided into 10 groups. Rats were housed in plastic cages (4 per cage) in a 12h light/dark cycle for 6 weeks. The diets of different protein and fat contents ware administered to the animals. Five of ten groups of rats received throughout the whole period 10 ppm sodium arsenite dissolved in distilled drinking water (about 250 µg As/animal/day). The arsenic were determined with the method of atomic adsorption spectrometry in conjunction with a graphite-furnace atomize using a Varian AA240FS apparatus. RESULTS: The highest arsenic concentrations were found in fur of rats which were given low protein diet and water with arsenic. The lowest arsenic contents were found in fur of rats, which were given control diet and high protein diet with arsenic in water. CONCLUSIONS: Balanced control diet or high protein diet protected organism from arsenic accumulation, only small increase of arsenic content in rats' fur, compared to the control group, was observed. KEY WORDS: arsenic, rats' fur, protein and fat in diet, exposure to arsenic.

Effect of resistant starch RS4 added to the high-fat diets on selected biochemical parameters in Wistar rats.

BACKGROUND: Resistant starch (RS) is part of potato starch that is not digested in the gastrointestinal tract. RS4 is a chemically modified starch (for example by oxidation and esterification) and physically (by heating). OBJECTIVE: The study was aimed at determining the effect of resistant starch on lipid metabolism and activity of hepatic enzymes in Wistar strain rats fed high-fat diets containing 15% of lard or 15% of soybean oil. MATERIAL AND METHODS: Four types of diets were administered to the animals (4 groups of males, n = 32): control diet (K1) containing 15% of soybean oil; control diet (K2) containing 15% of lard as well as two groups receiving the same diets with 10% addition of resistant starch RS4 (K1S and K2S). RESULTS: The mean concentration of total cholesterol was lower in the group of animals fed a diet with vegetable oil (39.9 mg/dl) as compared to that reported in the group of rats fed the lard-supplemented diet (55.2 mg/dl). Compared to the control groups in both groups of animals receiving the diet supplemented with resistant starch RS4 the total cholesterol concentration in serum decreased by ca. 25% (differences were statistically significant). In groups of rats receiving oil- or lard-containing diets with the addition of the resistant starch preparation the concentration of triglycerides in serum decreased by ca. 47% and 10%, respectively. CONCLUSIONS: A beneficial effect of the resistant starch RS4 added to Wistar rats diets on the lipid metabolism has been shown. The concentrations of total cholesterol and triglycerides in the serum were lower and concentration of HDL-cholesterol was higher in the rats fed with the diets containing the addition of the RS4 preparation as compared to the control groups. Based on the activity of hepatic enzymes the degree of liver damage was lower in groups of rats fed with diets containing resistant starch RS4 as compared to the control groups.

Evaluation of plant products from the Legnicko-Glogowski region for their contamination with arsenic.

Contents of arsenic were determined in plant products originating from the region of two copperworks, Glogów and Legnica. Analyses were carried out by means of atomic absorption spectrometry, using an MHS-10 unit for hydride generation (acetylene/argon), after wet mineralisation of samples. The maximum permissible level of arsenic was not exceeded in any of the examined samples of cereals, potatoes, carrots, beetroots, cabbages, tomatoes, apples and pears, originating from the regions under scrutiny.

[The influence of RS4 resistant starch on wistar rats metabolism. Biochemical and lipid indices]. / Wplyw skrobi opornej RS4 na metabolizm szczurów rasy Wistar. Wskazniki biochemiczne i lipidowe.

The influence of resistant starch RS4 on total cholesterol (TC), HDL cholesterol, triacyloglycerols (TAG) composition in blood serum and liver of rats was determined. 4 week experiment involved 32 males and 40 females laboratory Wistar rats allotted in 4 groups in each sex. Control rats were feed ad libitum with standarised synthetic diet AIN-93. In experimental groups animals were given modified feed enriched with 5% of resistant starch. monophosphate of potato starch, monophosphate of soluble potato starch and monophosphate of potato starch heated with glycne and microwaved were examined. Diet enrichment with resistant starch decerased triacyloglycerol level (TAG) while the total cholesterol (TC) level, in serum was not affected.