Showing papers in "Polish Journal of Food and Nutrition Sciences in 2004"

Characteristics of students eating habits with the separation of the nutritional models using advanced statistical analysis methods.

Abstract: An overview of lipids oxidation in foods, its main aspects and implications for the customer has been outlined in a concise form. Three different mechanisms of fatty acid oxidation yielding different products are described: autoxidation, photo-oxidation and lipooxygenase action. Oxidation of sterols and fat-soluble vitamins (named A, D, E and K), all isoprenoic compounds, as a part of unsaponificable fraction of lipid are included to review. It is indicated that relatively little information exists on oxyphytosterols. The contents of these compounds in food products are presented. The crucial significance for the sensory aspect of food quality is ascribed to volatiles from lipid oxidation products. Some volatiles with low odour threshold are characterized. Nutritional problem of lipid oxidation products and products obtained by interactions with other food components is discussed. Use of antioxidants as important factors in reducing the risk of chronic diseases and its economical aspects is discussed. The need for search of natural antioxidant, commonly perceived as safe is stressed. Last part of review covers the methods for the assessment of lipid oxidation. Classic methods for the determination of lipid stability, for the measurement of lipid oxidation are described. Also chromatographic analyses of volatile compounds generated in the lipid oxidation process included static, dynamic head space and SPME are discussed. The novel approaches to the analysis of these volatiles such as chemometrical methods and electronic noses are also presented.

Resistant starch: Classification, structure, production

Abstract: Starch is a high-molecular carbohydrate composed of linear (amylose) and branched (amylopectin) chains of glucose residues. In water, at increased temperatures, it undergoes gelatinisation followed by amylase-induced hydrolysis. Owing to this, it is completely digested in the gastrointestinal tract of humans. Also raw starch of some plant species, e.g. cereals, is subject to complete but slow digestion. In addition, starch may occur in the form incapable of enzymatic hydrolysis, referred to as “resistant starch” (RS). Resistant starch is a sum of starch and products of its degradation undigested in the small intestine of humans. There are four types of resistant starch. Type I RS – physically unavailable starch. Amylolytic enzymes have no access to starch accumulated in undamaged plant cells as the gastrointestinal tract lacks enzymes capable of degrading the components of plant cell walls. Type II RS – raw starch of some plant species, e.g. potato. Type III RS – retrograded starch, i.e. spontaneously- or artificially-precipitated from starch paste, occurring in the form of water-insoluble semi-crystalline structures. As a result of retrogradation, more thermostable structures are formed by amylose rather than by amylopectin. The amount of resistant starch produced this way increases along with the increasing amylose content of starch. Type IV RS – chemically- or physically-modified starch. Resistant starch has been reported to reduce the caloric value of food products and to decrease glucose level in blood. In the large intestine, it is fermented by gut-colonising bacteria. Products of its fermentation include gases and short-chain fatty acids – acetic, propionic and butyric, which are responsible for favourable selection of intestinal microflora, reduce the levels of cholesterol, triglycerides, and urea in blood, as well as prevent the formation of gut cancer. Commercial preparations of resistant starch are also produced to be used as food additives. Their resistance to the activity of enzymes, as well as physiological effects of their application, are determined with in vitro and in vivo methods. Results of those analyses are not always unequivocal, especially with the application of resistant starch with artificially-increased resistance. Resistant starch may serve as dietary fibre and exert a health-promoting effect on the human organism. Therefore further studies into its formation and results of its application in food production are still necessary.

In vivo evaluation of antioxidant and anti-inflammatory activity of different extracts of date fruits in adjuvant arthritis.

Abstract: )This study was carried out to evaluate the antioxidant and anti-inflammatory activity of methanolic and water extracts of the edible portion of date fruits (Phoenix dactylifera of date fruits (Phoenix dactylifera of date fruits ( L., Family Palmae) and methanolic extract of date seeds in adjuvant arthritis in rats, a model of chronic inflammation. Acute oral toxicity of the different extracts was carried out to determine their safety as functional foods. The results revealed that oral administration of the methanolic and aqueous extracts of edible portion of date fruits suppressed the swelling in the foot significantly by 67.8 and 61.3% respectively, while the methanolic extract of date seeds showed significant reduction by 35.5%. Antioxidant state (plasma vitamin C, E and A and β-carotene) increased significantly on administration of different extracts, while plasma level of MDA reduced significantly. Methanolic extract of edible portion of the fruit was the best in reducing foot swelling, ESR and plasma fibrinogen and in normalizing the plasma level of antioxidants. Adjuvant arthritic rats showed significant reduction in body weight gain and food efficiency ratio. Administration of any of the extracts produced significant increase in body weight gain and food efficiency ratio. Acute lethal toxicity test showed that the safest extract was the methanolic of edible portion of the fruit followed by the water extract that showed complete safety up to 6 g/kg mice weight. Methanolic extract of the seed showed LD50 equal to 6.75 g/kg mice.

Opioid peptides derived from milk proteins

Abstract: This paper is devoted to opioid peptides derived from milk proteins. The evolutionary aspect of the biological activity of proteins and peptides, protein precursors, amino acid sequences of opioid peptides, and their biological activity are presented herein. Attention was also paid to the relationship between the conformation of b-casomorphins, their hydrophobicity and their ability to interact with opioid receptors. The biological function of opioid peptides derived from milk proteins was shown from the nutritional and pharmaceutical points of view. In this context, the gastrointestinal, analgesic, tolerance and dependence, respiratory, cardiovascular, immunomodulatory and allergic effects of opioid peptides are discussed. Finally, the perspectives of the application of opioid peptides derived from milk proteins in nutrition and pharmacy are also presented. EVOLUTIONARY ASPECT OF THE BIOLOGICAL ACTIVITY OF PEPTIDES DERIVED FROM FOOD PROTEINS Nutrition is an attribute of man’s life determining his phylo- and ontogenetic development. However, before life could evolve on Earth as biologically-active forms of organic molecules, compounds with specific physicochemical properties first had to develop. These were amino acids which led to proteins. Hence, amino acids can be considered as one of the primary nutrients for living organisms which were only later to come into existence. It seems logical that in the primary mixture of organic substances there were no proteins, but only various amino acid polymers which did not show any sense of purpose in their intermolecular structure; moreover, they lacked any functional properties. It was only in the course of evolution that amino acid polymers, phase-liberated from the environment, could interact in a manner that directed their structure to perform biological functions. The course of organic-molecule evolution towards biological activity was determined first by the appearance of the crystalline structure and the optical properties in the amorphic and racemic mixture of the organic compounds, a fact which is also confirmed by the structure of the amino acids themselves. The importance of amino acids in the evolution of biologically-active systems is partly supported by their geological supremacy over carbohydrates. Regarding evolution, it is worth mentioning that in the beginning a predominance developed of aliphatic amino acids over aromatic amino acids containing comparatively high quantities of sulphur. This is interesting, because the biological properties of peptides are mainly affected by their hydrophobic character and the presence of aromatic acids. As aliphatic amino acids predominated in the Precambrian era, it can be presumed that the biological activity of peptides occurred at a later stage. This biochemical evolution of peptides towards protein structures has been confirmed in research results from the areas of molecular biology, palaeobiochemistry and bioelectronics, which allow us to presume that the evolution of protein molecules was aimed at elongating the polypeptide chain, expanding the side chains, as well as developing aromatization, including closing the chain into a ring, and a secondary structure. However, not only was the chemical structure of the protein important in the evolution of life, but also the proteins’ electrical states, which determine their conformation. The phenomenon of protein amphotericity proves their adaptation for oxidoreductive fluctuations in the environment, while on the other hand, the cyclic structure of protein molecules enables them to save the so-called “delocalized electrons”. The cyclization of protein is considered to be another remarkable concept regarding life’s appearance, i.e. the closing of the polypeptide chain into a ring. The formation of such a protein structure offered the possibility of producing metal complexes, the so-called “chelate compounds”. Such a degree of protein molecule configuration could in some cases be sufficient to transfer enzymatic properties, which are the basis of biological activity in living organisms, to a protein. Hence, a question arises of the relationship between the structure of food proteins and their biological functions. It seems barely probable that the food proteins

Evaluation of chemical composition of some Silphium L. species seeds as alternative foodstuff raw materials.

Abstract: The studied seeds of three Silphium species (Silphium perfoliatum L., Silphium trifoliatum L. and Silphium integrifolium Michx.) contained (recalculating onto dry matter): up to 33.5% of protein, up to 24.1% of fat, up to 9.58% of water-soluble sugars, and up to 25.4% of cellulose. Ash was up to 6.8% of seeds dry matter. Mean energetic value of the analysed raw materials ranged from 1076 kJ/100 g (S. trifoliatum) to about 1530 kJ/100 g DM (S. perfoliatum). Mineral element content, particularly K (from about 1.6 g/100 g to about 1.8 g/100 g DM), Ca (from about 1.0 g/100 g to about 2.1 g/100 g DM) or Mg (from 651 mg/100 g to 672 mg/100 g DM) as well as that of trace elements, e.g. Fe (from about 28 mg/100 g to about 38 mg/100 g DM) in Silphium seeds is one of the most important traits affecting their nutritional value. Moreover, the experiment revealed that S. perfoliatum was the most valuable plant referring to seed yielding (about 185 g seeds from a single plant, on average). Glutamic acid (up to 23%) and leucine (7.76%) were found dominating among all amino acids in protein of Silphium seeds. An analysis of lipid fraction showed that linoleic (44.4%) and oleic (13.2%) acids were the main fatty acids contained in the oil made from seeds. The achieved data point out that the analysed raw materials were characterized with a valuable chemical composition and may he used in the food industry.

Influence of kernel size on grinding process of wheat at respective grinding stages.

Abstract: The aim of the present work was to determine the influence of kernel size on wheat grinding properties. The samples of kernel were divided into three fractions according to different thickness: small (2.0–2.5 mm), medium (2.7–2.9 mm) and large (3.1–3.5 mm). The results showed that the kernels size had an influence on bulk density, PSI hardness index and ash content. As kernel size increased, the bulk density also increased. The large kernels (fraction 3.1–3.5 mm) had the lowest values of PSI hardness index and ash content. Laboratory milling results showed that the kernel size had the largest influence on grinding process at the first grinding stage. After the first grinding stage of small kernels (fraction 2.0–2.5 mm), the highest values of average particle size, grinding ability index and grinding efficiency index and the lowest values of total flour yield were observed. The flour obtained from fraction 2.0–2.5 mm also had the highest ash content. This shows that the energy-consuming indices can be a useful tool for describing the grinding process.

The effect of beta-1.3/1.6: Glucan in diets on the effectiveness of anti-Yersinia Ruckeri vaccine: An experimental study in rainbow trout (Oncorhynchus mykiss)

Abstract: In the present study, the influence of beta-1.3/1.6 - glucan, a natural product, on the antibody secreting cells (ASC) and specific Ig levels after immunization of rainbow trout (Oncorhynchus mykiss) with the anti-Yersinia ruckeri vaccine was studied. Fish were fed pellets containing beta-1.3/1.6 - glucan (Macrogard) at a dose of 0.5 g/100 g of pellets (0.5%) per day. After one week of beta-1.3/1.6 - glucan supplementation, the fish were immunized by immersion of the vaccine. At 7, 14, 21, 28 and 40 days after the immunization, blood and pronephros were taken from 20 fish in each group for immunological study. When analyzed by the ELISPOT assay, beta-1.3/1.6 - glucan (Macrogard) was found to increase the number of specific antibody secreting cells (ASC) and specific Ig levels in serum. In conclusion, the results of the present study showed that beta-1.3/1.6 - glucan (Macrogard) increased the effectiveness of anti-Yersinia ruckeri vaccine in fish.

Structure and allergenicity of wheat gluten proteins - a review

Abstract: In persons showing gluten intolerance, wheat storage proteins (gliadins and glutenins) cause IgE-mediated allergies and coeliac disease. Because both of these protein fractions play a significant role in the human diet, intensive research has been carried out to explore the biochemical and molecular reasons for their allergenicity, and the possibilities for eliminating or limiting it. In spite of much progress, this problem has not been solved yet. This paper reviews important information on the structure and conformation of gluten proteins in the context of their allergenicity. Three significant protein structure elements are emphasized. The first is short (“toxic”) amino acid sequences that probably function as antibody-binding epitopes in immunological reactions. Other structural elements considered are beta turns, giving allergen particles a specific conformation, and disulphide (SS) bonds which stabilize that structure. Attempts to modify gluten proteins, using various enzyme systems and a thioredoxin reducing system, are also discussed. Such modifications may considerably decrease allergen immunoreactivity. Finally, an interdisciplinary strategy, using methods from genetics, plant breeding, food technology and medicine, is proposed which may aid in developing wheat having decreased allergenicity.

Perspectives of linseed utilisation in baking

Abstract: The aim of the study was to show the nutritional and health benefits implied by consumption of bread and pastry supplemented with linseed meal. Bread with 10 and 13% share of linseeds was characterised by higher amounts of protein, fat, dietary fibre, macro- and microelements in comparison to standard one. In the experiments on rats, a spectacular hypocholesteric effect of such bread was observed. Linseed pastry obtained high quality scores, irrespective of the linseed cultivar. A 3% increase in linseed in the recipe for flax hermit cookies and a 5% rise in flax muffins resulted in an increase in the amounts of proteins, dietary fibre, micro- and macroelements.

Sensory quality of eggplant fruits (solanum melongena l.) as affected by cultivar and maturity stage

Abstract: Sensory quality of eggplant fruits harvested at three stages of maturity was examined. Eggplant cultivars: ‘Impulse’ F1, ‘Epic’ F1 and ‘Cubanita’ F1, which differ in fruit shape, were chosen for the experiment. The quality of the fruits was evaluated by the panel of trained assessors and a quantitative descriptive analysis (QDA) was used for that assessment. Nineteen descriptors for fruit quality were chosen in an expert panel. Consumer preference test was also performed. Results showed that both cultivar and maturity stage significantly affected some sensory properties of fruits – sharp odour, odour of steamed potatoes, flesh colour, number of seeds, flesh firmness, flesh fibrousness, skin hardness, bitter taste, pungent flavour and overall quality. Overall sensory quality score was the highest for cv. ‘Impulse’ F1 and for the fruits harvested at the earliest maturity stage. The correlation between consumer preference and QDA results was significant. Linear multiple regression models were constructed for the prediction of overall quality scores and overall preference.

Epithelial cell cultures in vitro as a model to study functional properties of food

Abstract: This review presents the applications of the in vitro cultures of human epithelial cells as a model for the study on functional properties of probiotic bacteria and bioactive food compounds. The main cell lines used in the research are Caco-2 as a model of small intestine and HT-29, as a model of large intestine. The structure, monolayer formation and physiology of epithelial cells are described. The commonly used growth media, culture vessels and growth conditions of the in vitro epithelial cultures are discussed. One of the most important applications of epithelial cell cultures are the studies on adhesion of probiotic bacteria and invasion of human pathogens. It was shown that Caco-2 and HT-29 cultures are suitable models for determination bacteria adherence. The mechanisms of adhesion and the role of environmental factors in bacteria attachment are discussed. The comparative studies on the bacteria adhesion to epithelial cells and solid substrates are described. The cell lines are also used in the studies on the trans-epithelial transport of different food compounds. In the review the results of experiments on the food compounds bioavailability are presented. Enterocyte-like cells from the in vitro cultures are also used to study carcinogenesis process caused by some chemical substances and free radicals from food products. The biological effects of the DNA damage on intestinal cell necrosis and apoptosis are discussed. Further research should confirm that epithelial cell cultures cultivated in laboratory conditions have qualities similar to those present under natural conditions in the human alimentary tract.

Resistant starch - nutritional and biological activity.

Abstract: This paper presents different nutritional and biological activities of resistant starch in human organism. Resistant starch fractions may indicate some physiological functions remaining in relation with their physical and physico-chemical properties, including water holding capacity, intestinal transit time, potential glycaemic index, insulin action, induction of thermogenesis (gases, ammonia, phenols), mineral absorption, intestinal pH. Colonic function, especially bowel habit, short-chain fatty acids production, N-metabolism, bacterial activity and epithelial cell function, are largely controlled by carbohydrates that enter the colon as well as, the resistant starch (RS), non-starch polysaccharides (NSP) and oligosaccharides. The relationship between diet, microflora and colorectal cancer is complex and intimate. Substances entering the colon from ileum and the resident microflora are major determinants of colonic physiology. These, together with the innate biology of the colon, are pertinent to the initiation and promotion of colorectal cancer. The biological activity of resistant starch, as it results from the recent literature data, can also positively influence the prevention of gastrointestinal disease.

An introduction to chemometrics for food science

Abstract: The texture and histology of selected muscles (m. longissimus dorsi, m. quadriceps femoris, m. biceps femoris, and m. semimembranosus) of piglets and wild boar juveniles were compared. The muscle texture was determined with the TPA test performed with an Instron 1140 apparatus. Structural elements (muscle fibre cross-section area, peri- and endomysium thickness, area of intramuscular fatty tissue) were measured in muscle samples using a computer image analysis program. The young wild boar muscles showed higher values of textural parameters. The muscle fibre cross-section area and the area of intramuscular fatty tissue of the juvenile wild boar muscles were lower than those in the piglet meat, while the peri- and endomysium were thicker. Of the piglet and young wild boar muscles tested, the highest hardness, springiness, and chewiness were found in BF which, at the same time, showed the highest fibre cross-section area and the thickest peri- and endomysium. The highest thermal drip loss was typical of BF, both in piglets and wild boars, the lowest thermal drip being found in LD, a muscle with the most delicate histological structure. The juvenile wild boar muscles showed a higher thermal drip loss than the piglet muscles.

Physiological effect of low digestible oligosaccharides in diets for animals and humans

Abstract: The article reviews literature data and results of own investigations concerning biological properties of low digestible carbohydrates (LOOs): lactulose, inulin and different type of oligosaccharides. The following problems: (1) sources of oligosaccharides in animal and human diets, (2) behaviour of oligosaccharides in the gastrointestinal tract, (3) physiological effect of LOOs in diets for laboratory rodents, (4) physiological effect of LOOs in diets for non-ruminat livestock and (5) nutritional advances of LOOs in diets for humans were presented. The above-mentioned reports indicate that oligosaccharide preparations can be considered as feed additives in pigs and poultry feeding, e.g. being as effective as antibiotics in the control of pathogens and enhancement of growth performance. However much more research are needed to determine the appropriate role of these oligosaccharides in animal feeding. LDOs may influence animals and humans in various ways: improve intestinal health, modify lipid metabolism, modulate the immune response, and decrease the risk of intestinal and systemic diseases. The present state of knowledge on the mechanism of dietary action of prebiotic LDOs and physiological effects of different types and doses of low-digestible carbohydrates is not sufficient.

Non-nutrient bioactive substances in food of plant origin causing bitterness and astringency

Abstract: of 200 mg/kg of mixture for the experimental group were used. The addition of vitamin E to the diet caused a significant decrease in MUFA level in longissimus and semimembranosus muscles (p<0.05) along with an increase in the PUFA level in the ham and the loin respectively from 20.34% and 14.84% to 22.98% and 16.48%. The differences were not significant. The addition of α-tocopherol acetate to the diet fattened with the corn oil caused an increase in unsaturated fatty acids from the n-6 family, mainly the linoleic (C18:2) and arachidonic (C20:4) acids. A significant decrease of the oleic acid (C18:1) in the semimembranosus muscle of fatteners from the experimental group from 39.4% to 35.2% (p<0.01) was found. A tendency to reduce the CLA level in the semimembranosus muscle of pigs obtaining higher doses of α-tocopherol acetate was observed. A significant decrease in the total cholesterol level in the semimembranosus muscle from 68.4 to 52.8 (mg/100g) and a tendency to reduce its content in the longissimus muscle were found in this study. It was observed that the addition of the α-tocopherol acetate in the amount of 200 mg/kg of mixture significantly increased the α-tocopherol level (p<0.01) in longissimus and semimebranosus muscles respectively from 1.58 and 1.56 to 3.37 and 3.33 (µg/g of fresh meat). The effect of vitamin E on the derivative metabolites of lipid oxidation (TBARS) after 60 days of storage at -19°C was not observed. The positive influence of the α-tocopherol acetate in the diet on the improvement of the palatability and the flavour of the semimembranosus muscle of ham was observed in this study.

The application of lipases in modifying the composition, structure and properties of lipids - a review

Abstract: Structured triacylglycerols (sTAG), not so long ago called “lipids of the future”, have become functional food available on the market. In the nearest future, some fatty products designed for infant and children nutrition in the USA will contain increased concentrations of arachidonic (AA) and docosahexaenoic (DHA) acids. Many formulae and dietetic products containing triacylglycerols with modified chemical structure and composition – structured triacylglycerols (sTAG) – are available as supplements to human nutrition. This paper reports on the directions and possibilities of lipid modification catalyzed by lipases. Two basic methods for the synthesis and modification of triacylglycerols to obtain sTAG are characterized. The main properties of sTAG are also discussed.

Microstructure, thermal properties and susceptibility of the high amylose wheat starch to enzymatic hydrolysis: a new material for resistant starch (RSIII) production

Abstract: Differential scanning calorimetry, optical (LM) and scanning electron (SEM) microscopy methods were used for studying the properties and structure of type III resistant starches obtained from high amylose (39.5% amylose) wheat starch. The susceptibility of RSIII starch to enzymatic hydrolysis was also studied. This study has shown that the structure of the investigated, laboratory-obtained preparation was highly influenced by the processing parameters - indicating changes typical of a repeated heating-cooling process. Thermal properties connected with the presence of amylose-lipid complexes, as well as ordered structure fragments in the preparations, were in high accordance to those reported in literature for RSIII preparations from normal wheat, high amylose barley and pea starches as well as commercial types - Novelose 330 or CrystaLean. It was shown that high amylose wheat is a promising raw material for processing bakery and extrusion food products with a reasonably high content of resistant starches without the addition of commercial resistant starches to meal or extrusion mixture.

Antagonistic activity of Lactobacillus acidophilus bacteria towards selected food-contaminating bacteria.

Abstract: The aim of this study was to determine the antibacterial properties of 20 Lactobacillus acidophilus strains against spoilage or pathogenic bacteria. The relationship between contents of various metabolites and the inhibitory activity of Lb. acidophilus against Escherichia coli, Pseudomonas fluorescens, Pseudomonas aeruginosa, Staphylococcus aureus and vegetative cells and spores of Bacillus mycoides and Bacillus subtilis was studied. The antibacterial activity was determined by measuring zones of growth inhibition on agar media. The antibacterial activity was markedly diversified. Some Lb. acidophilus strains also inhibited the germination of Bacillus spp. spores. Lactic and acetic acids as well as hydrogen peroxide were the most potent inhibitory agents produced by the Lb. acidophilus studied. However, some strains of Lb. acidophilus producing relatively small amounts of lactic acid in milk had a higher inhibitory activity than those producing a large quantity of lactic acid.

Preserving Domiati cheese using metabolites of Propionibacterium thoenii P-127

Abstract: In many developed and developing countries, sedulous trails are running for achieving high quality dairy products without using chemical preservatives. Microbial metabolites, such as that produced by Propionibacteria are coming in need to achieve such an aim. Therefore, utilization of permeate supplemented with different nutrients to improve production of metabolites under controlled conditions in a fermentor was studied. Metabolites of Propionibacterium thoenii P-127 proved to have an antimicrobial activity against the tested microorganisms. Permeate supplemented with casein hydrolysate supported maximum production of antimicrobial substances by P. thoenii. Antifungal activity of lyophilized metabolites stored at 25°C showed a drop of activity (approximately 25%) compared to metabolites stored at 4°C. The addition of lyophilized P. thoenii P-127 metabolites by 1.5% to Domiati cheese milk obviously prolonged the shelf-life of soft cheese. The investigators proposed the name “Propiogard” for the product, to differentiate it from commercial name “Microgard”.

Application of pea hulls for extrudate production

Abstract: 2 A research was undertaken to determine the effect of the concentration of pea hulls (a by-product of the industrial dehulling of pea seeds) and parameters of extrusion-cooking process on the chemical composition of extrudates obtained with the use of a twin-screw extrusion-cooker (extruder). It was shown that the concentration of pea hulls in extrudates can reach up to 80%. The extrusion-cooking process resulted in a decrease in the contents of lipid, protein, dietary fibre (TDF) and its insoluble fraction (IDF) as well as caused an increase in the content of the soluble fraction of fiber (SDF). These changes depended on the composition of the mixture subjected to the extrusion-cooking process and on the following process parameters: temperature and moisture content of raw material.

Qualitative and quantitative analysis of filamentous fungi in air, food and ochratoxin A in human milk

Abstract: This work was based on a research of filamentous fungi in the air of kitchens of domestic households, the contamination of cereal products by fungi and the presence of ochratoxin A (OA) in human milk. The highest contamination by spores of filamentous fungi in 23 domestic households was recorded in bread bins. In 104 tested samples of cereal products, the most commonly isolated fungi were those from Penicillium and Aspergillus genera. The presence of ochratoxin A was recorded using ELISA method in 51% of tested human milk samples. The concentration of OA was higher in colostrums samples than in term and mature samples from the same women, which can result from the accumulation of mycotoxins in tissue and their gradual release through the breast gland.

Assessment of n-3 and n-6 polyunsaturated fatty acid intake in the average polish diet

Abstract: The aim of the study was to establish the intake level of n-3 and n-6 polyunsaturated fatty acids intake in the average Polish diet. The intake of fatty acids n-3 and n-6 in an average Polish diet was estimated using data gathered by the Central Statistical Office in 1998 using food composition tables. The consumption of polyunsaturated fatty acids n-6 constituted 5.21% of the total energy in the diet (13.10 g/day), while n-3 only 0.95% of energy (2.40 g/day). The intake of PUFA n-3 alpha-linolenic acid was 0.9% of energy and was close to recommended levels (1%), but the intake of long-chain forms PUFA n-3 DHA and EPA amounted to 0.04% of energy and was much too low (recommended 0.3%). The intake of PUFA n-6 linoleic acid equalled 5% of energy and was much higher than the recommended upper limit (3% of energy). The results indicate that it is necessary to increase the intake of long chain PUFA n-3 by greater consumption of fish and fish products or EPA and DHA-enriched foods or supplements.

Influence of PH1 of fatteners' Musculus longissimus lumborum on the changes of its quality

Abstract: Depending on initial pH, the physicochemical properties of fatteners' musculus longissimus lumbonun (electric conductivity, colour - CIE Lab values, cooking and drip loss as well as the crude protein content) were investigated, distinguishing 3 groups, i.e. I - to 5.8 (n=16), II - from 5.8 to 6.3 (n=28), and III - over 6.3 (n=20). The range of the initial pH had no significant influence on the physicochemical properties of pork musculus longissimus lumborum, with the exception of electrical conductivity 45 min post mortem as well as lightness. On the basis on established critical values for the pork quality standards, the results indicate that meat with pH 1 >6.3 (group III) met requirements for normal meat, meat with pH 1 <5.8 (group 1) - for PSE, and meat with pH 1 5.8-6.3 (group II) - for RSE defect. Significant and negative correlations were found between the pH 1 value and the electric conductivity value 45 min and 24 h post mortem (r=-0.488 and r=-0.326, respectively), lightness L* (r=-0.562) as well as drip loss (r=-0.494) and b* value (r=-0.376).

Association between retinol metabolism and diabetic retinopathy

Abstract: The purpose of this article was to study the possible interaction and relation between vitamin A status in diabetic retinopathy and the state of proliferative changes occurring in these cases. Twenty five healthy and sixty diabetic retinopathy patients were included in this study. Diabetic patients were classified into four groups according to the type of diabetic retinopathy. Group 1: normal fundus; Group 2: proliferative; Group 3: non-proliferative, and Group 4: hard with exudate. Groups were further classified into 3 subgroups according to the route of treatment; whether receiving insulin therapy alone or oral hypoglycemic tablets or both. The level of serum glucose, insulin, retinol binding protein (RBP), vitamin A and β-carotene were estimated for all groups. The fasting blood glucose and glycosylated hemoglobin levels of patients suffering from diabetic retinopathy were high in all diabetic groups. The highest levels were noticed among proliferative group. Cases with normal fundus receiving insulin therapy had the lowest levels of blood sugar. Serum insulin level was markedly high in all diabetic groups when compared within control values, markedly higher among those who received oral hypoglycemic tablets alone. Serum vitamin A and β-carotene levels were significantly decreased in all groups of patients, the lowest was attained for proliferative group receiving insulin. The level of RBP was significantly high in all diabetic groups. Serum RBP was markedly low in the subgroup of patients under insulin therapy. It was concluded that the patients with diabetic retinopathy included in this study suffer from a state of non controlled hyperglycemia which induces the generation of free radicals. This state together with decreased level of the antioxidant, β-carotene or vitamin A results in a state of retinal damage. The deficiency of vitamin A is believed to participate in the phenomena of retinal cell proliferation.

Family environment as a predictor of selected food habits among adolescents from warsaw

Abstract: The aim of the study was to assess the role of family environment in shaping food habits among adolescents. The questionnaire research was conducted in autumn 2002 among 2179 teenagers aged 13 to 15 living in Warsaw. The correct nutritional habits within family, hospitality, and ' openness to nutritional information contributed to the occurrence of more correct food habits among adolescents. Bringing pressure to bear on children increased the frequency of consumption of food important for their health, and also increased the number of meals eaten a day.

Application of artificial neural networks for modelling pea protein hydrolysis by trypsin

Abstract: The experimentally-determined degrees of hydrolysis (DH) for different enzyme/substrate (E/S) ratios were used for training the artificial neural network (ANN) to predict the trypsin hydrolysis reaction of pea protein for E/S=15, 25 and 35 mAU/g based on measurements carried out for E/S=5 mAU/g only. The analysis was performed on a personal computer using a Statistica Neural Networks v. 6.0 PL (StatSoft, Tulsa, OK, USA). The input data were randomized into three sets: learning, validating and testing. Good agreement between the calculated DH values with the use of the ANN designed and the experimentally obtained values was achieved with all three sets of data. The correlation coefficient R 2 ranged from 0.978 to 0.999. The differences between the experimental and the calculated data of DH% were very low and ranged from 0.07% to 0.26%. The results obtained show that the ANN method can be useful for the design of the enzymatic processes.

Yeast cell biomass as a potential source of magnesium bioplexes - a review.

Abstract: The capability of yeasts for binding magnesium in the amounts exceeding its physiological demand affords an opportunity for exploiting those organisms as a natural source of a deficient bio-compound in a diet of contemporary humans. The mechanism of cation binding with yeast cells demonstrating first the character of chemisorption followed by intracellular bioaccummulation, may lead to the formation of organic linkages called bioplexes. Magnesium ions bound with proteins in the form of the so-called bioplexes are very well assimilated by human and animal organisms, thus they may be an alternative to pharmacological supplementation at increasingly observed magnesium deficiency. After appropriate treatment, reducing the content of nucleic acids, cellular biomass of yeasts may not only be a valuable source of protein and vitamins but also of magnesium, especially when used in the form of protein-mineral preparations.

Juices and beverages with a controlled phenolic content and antioxidant capacity

Abstract: The aim of the study was to design sensory-attractive beverages containing a significant but naturally occurring level of total phenolics and with a potentially high antioxidant effect. The concentrated fruit juices (cranberry, raspberry, black currant and others as references) and herbs (tea and dried elderberry fruits) were selected as raw materials. The study was realised in three steps: (1) development of the sensory-accepted herbal extracts and fruit beverages – characterised as phenolic sources, (2) development of the fruit-herbal beverages based on the pattern formulae of the selected fruit products, (3) determination of the total phenolics, antioxidant capacity and sensory properties of newly developed fresh compositions, and after six months of storage. It was found out that the total phenolics of fruit-tea beverages exceeded significantly those of their fruit counterparts and, except for one, those of the reference red grape juice. The fruit-tea drinks and red grape juice were recognised among all products tested as revealing comparable and the highest antioxidant capacities. The antioxidant capacity of the fruit and fruit-herbal beverages analysed correlated with their total phenolic content (r=0.85; p£0.02), which could be accepted as the basic characteristic of the antioxidant properties of the products declared as functional. Fruit and mixed beverages were categorised in accordance with both of these characteristics. The total phenolics, antioxidant and sensory properties of developed fruit-herbal beverages stored did not undergo substantial changes during six months. So, the products could be proposed as good sources of antioxidants supporting the organism defence system against oxidative stress.

Tannins from different foodstuffs as trypsin inhibitors.

Abstract: The trypsin inhibitory effect of phenolic extracts from different plant foodstuffs: two bean varieties, black and green tea and quince fruits as well as of standard phenolic compounds: (+)catechin, (-)epicatechin, gallic acid and tannic acid, was investigated. Monomeric tannin precursors exhibited 1000-times lower activity in the trypsin inhibition than high-molecular tannic acid. All of the plant phenolic extracts used in the experiments showed high level of the trypsin inhibition except for white bean one. Black tea polyphenols exhibited the highest inhibitory potency. The salting out of high molecular polyphenols reduced trypsin inhibiting effect of the examined extracts by 14-68%.

Effect of emulsifiers addition on dough properties, backing quality and microstructure of biscuits

Abstract: 2The effect of emulsifiers, e.g. Monoglyceride and Flavo 1500, and their levels (from 0.1 to 0.4% and 1.0, 1.5, 2.0%, respectively) on dough properties and baking quality of biscuits was studied. The addition of Flavo 1500 at the concentrations from 1.0 to 2.0% resulted in an increase in dough water absorption. Monoglyceride-supplemented dough did not show significant differences in water absorption compared to that of the control dough. Only in the case of dough supplemented with Flavo 1500 at highest concentration (2%), an improvement in dough stability and consistency was observed. The Monoglyceride supplementation caused a significant improvement of dough stability compared to that of control samples already at 0.1% level. The weight and volume of biscuits significantly decreased with an increasing level of Flavo 1500. The biscuits containing Flavo 1500 and Monoglyceride at the levels of 1.0% and 0.4%, respectively, were characterised by the highest value of relative shape factor (SFR). A higher level of Monoglyceride improved all baking characteristics of the biscuits. The Monoglyceride-supplemented biscuits were characterised by crunchy-like structure. Contrary, the biscuits containing Flavo 1500 had a more rigid and open structure.