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The aim of the study was to examine the contents of nitrates and nitrites in raw beef coming from cattle of the Polish Holstein-Friesian breed, black-and-white type, originating from different parts of Poland. The research material comprised semitendinosus and longissimus thoracis muscles obtained from 176 heads of cattle. The content of nitrites in the examined muscles ranged from 0.6 to 13.3 mg kg^-1 in rump muscles and from 0.8 to 13.7 mg kg^-1 in muscles of the back. The most samples were characterised by the presence of nitrites in the range from 1 to 5 mg kg^-1, and the least samples from 11 to 14 mg kg^-1. The contents of nitrates were significantly higher, ranging from 10.2 to 73.5 mg kg^-1 in the semitendinosus muscle and from 10.4 to 74.3 mg kg^-1 in the thoracis longissimus muscle. Such and higher level of contamination may be the cause of meat discolouration after heat treatment despite the absence of curing ingredients. It is necessary to continuously monitor the concentration of nitrates in raw materials, water and feed to ensure the complete safety of food of animal origin.

We evaluated changes in the content of total polyphenols and antioxidant activity of frozen spinach, peas, and sweet corn in relation to the storage period. Total polyphenol content and antioxidant activity in analysed samples were determined by colorimetric methods. Both parameters were analysed in frozen samples monthly and the changes were monitored during storage in a freezing box at a temperature of -18°C for 10 months. Freezing had a different influence on the levels of total polyphenol content and antioxidant activity in individual analysed samples. The greatest decrease in antioxidant activity during the entire period of freezing was recorded in spinach (79.4%), while the lowest decrease was observed in peas (26.8%). A relatively significant decrease in antioxidant activity was also found in sweet corn (62.7%). On the contrary, the greatest decrease of total polyphenol content throughout the period of freezing was found in peas (62.0%), and lowest decrease was recorded in sweet corn (only 5.0%). The total polyphenol content in spinach decreased by 43.1% after 10 months of storage.

Propolis is a popular subject of research worldwide due to its therapeutic potential. The antimicrobial activity of propolis appears to be promising but depends on many variables related to its origin such as the content of phenolics and flavonoids. To address this issue with Croatian propolis, which has two major origins (Mediterranean and continental), we exposed bacteria (Escherichia coli and Staphylococcus aureus) and yeasts (Candida albicans and Aspergillus niger) to different propolis concentrations (two-fold microdilution method with TCC/formazan endpoint). Total phenolic and flavonoid content and chromatographic profile along with antioxidant activity were assessed. The majority of the 24 propolis samples tested exhibited potent antimicrobial activity against S. aureus bacteria and the yeast C. albicans. Most propolis samples also exhibited robust antioxidative capacity which correlated polyphenol and flavonoid content. To the best of our knowledge this is the first study in which the antimicrobial activity of Croatian propolis is correlated with its constituents.

Contents of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine and phenylethylamine) were determined in vacuum-packed fillets of rainbow trout (Oncorhynchus mykiss). Fish flesh was treated using a solution of chitosan (2%, w/v) or monoacylglycerols (monocaprylin C8, monocaprin C10, 5%, w/v). The control and treated packs were stored at 3.5 °C for up to 25 days. Samples of good quality did not contain more than 30 mg kg-1 of either putrescine or cadaverine. Exceeding this limit was usually followed by a worsening of the sensory properties of samples. Chitosan was found to be the most potent additive, prolonging the storage time of fillets by approximately four times, compared to control samples. Histamine was not found in any sample treated with chitosan. of the monoacylglycerols, C8 was more efficient compared to C10. All additives are easily applicable to the surface of fish flesh.

Several toxicological centres have reported ailments, mainly digestive inconveniences, following the intake of provably edible mushroom species. The causes of such complaints have not been explained yet. We, therefore, tested levels of biogenic amines (BAs). Fruit bodies of widely consumed wild-growing species, Imleria badia and Suillus variegatus were stewed, then preserved by freezing or canning and stored for up to 12 months. Contents of six amines were determined in the fresh matter, in each step of preservation and during storage. Histamine (HIM) and cadaverine (CAD) were not detected at all. Putrescine (PUT) occurred in fresh fruit bodies at levels of 700-1 500 mg kg^-1 dry matter (DM), however, its contents considerably decreased, particularly during stewing. Undesirable phenylethylamine (PEA) and tyramine (TYM) occurred at lower levels. Stewing, the technological step necessary in both the tested preservation treatments, reduced the contents of all the amines alike as sterilisation, whereas following storage showed a limited effect. PUT seems to be the only amine that could participate in the reported ailments.

in recent years, great attention has been paid to the quality of eaten meat and its products. There have been launched a lot of promotional campaigns aimed at providing opportunities for the consumption of traditional products. Based on the experiment, a significantly higher protein content was found in sausages produced by large producers (24.73 ± 1.98%). The fat content was significantly higher in traditional ham (16.25 ± 14.47%), compared with local ham (4.38 ± 2.26%) and the mass (9.29 ± 5.25%). The samples of traditional and local ham had a significantly higher salt content (3.31 ± 0.72 and 2.90 ± 0.54%, respectively). No dye compounds were detected in any of the tested samples. There were no statistically significant differences in hydroxyproline and l‑glutamic acid content between traditional and conventional samples of meat products. Analysis of nitrate (V and III) showed a statistically significant difference in the average contents of these compounds. Significantly higher levels of nitrates were revealed only in traditional ham samples (12.60 ± 8.08 mg NaNO(V)/kg and 17.53 ± 27.91 mg NaNO(III)/kg of the product, respectively), wherein there was a large variation in the content of these compounds in the samples.

The aim of this study was to evaluate the distribution of essential and toxic elements between the orange juice and orange flesh of various orange cultivars. Different orange cultivars, such as Abousorah [Citrus sinensis (L.)], Aseear (Citrus aurantium), Afandi (Citrus reticulata Blanco), Helo (Citrus sinensis), and grapefruit (Citrus paradisi), were collected from local markets. Elemental analysis was carried out after microwave-assisted digestion using inductively coupled plasma mass spectrometry (ICP-MS) in 18 samples. Eleven elements (V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Cd, and Pb) were analysed. Their average concentrations ranged from 0.006 µg g^-1 to 7.13 µg g^-1 in both orange juice and flesh (wet weight). There was a high increase in the average concentrations of all elements in the juice compared to the flesh of up to 40-fold.

This study aimed to develop a bamboo culm flour (BCF) to be used in the formulation of cookies, replacing 15% and 30% of wheat flour (WF). The parameters analysed for bamboo flour and cookies were moisture, ash, protein, fat, fibre and carbohydrates. For the flour, the water absorption index (WAI) and water solubility index (WSI) were also determined. BCF is a good source of protein, with a low lipid content and high fibre content, presenting the potential to be used in several food products. For the cookies produced, hardness, sensory analysis and purchase intent were analysed. In the sensory analysis of acceptability, the samples that showed better acceptance were the control formulation and the 15% BCF cookie; in the same sample, crude fibre increased from 5.92 g (100 g)^-1 to 11.64 g (100 g)^-1 compared to the control, and the intention to purchase the 15% sample was worse than for the control but still good: the majority of tasters said they certainly or maybe would buy. Thus, it is possible to conclude that the use of BCF is considered an excellent option to enrich cookies while keeping them acceptable nutritionally.

Honey is an important functional food for human health and nutrition that is collected by honey bees and stored in the honeycombs. In this study, total phenolic content, antioxidant activity and volatile compounds of 13 different honey samples collected from various districts of Malatya province were investigated. As a result of this study, it was determined that the total phenolic content varied between 8.50 mg GAE 100 g^-1 and 73.90 mg GAE 100 g^-1 and it was observed that the honey samples were rich in aldehydes, aliphatic acid and esters, alcohols, hydrocarbons, carboxylic acid esters, ketones, terpenes, fatty acids and esters. In addition, the antibacterial effects of honey samples were determined against 18 different pathogenic bacteria using agar well diffusion (AWD) method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). In AWD assay, it was recorded that inhibition zone diameters varied between 9 mm and 14 mm and honey samples were found to have a partial inhibitory effect against selected target pathogens.

To investigate a comparative evaluation of the gluten polymerization properties at different oil contents during the extrusion processing, the electrophoretic profiles of the gluten, free sulfhydryl (SH) compounds, the secondary structure of gluten, glutenin macropolymer contents and gluten network were measured. Five gluten samples were formulated by adding different oil contents. The low molecular weight contents of gluten decreased as well as the high molecular weight contents increased during the extrusion processing. The free SH of gluten at 8 or 10% oil content drops significantly to a minimum. The β-sheets contents of gluten have significantly difference between the treatments and control, except for 15 and 20% oil content treatments. Confocal laser scanning microscopy of mixed glutens correlated to the degree of oil contents with the gluten in the bi-continuous gluten network.

The gluten content in oat products on the market in the Czech Republic was monitored. The ELISA kit Ridascreen gliadin from R-Biopharm based on the R5 antibody was used for the gliadin determination. Oat products (41 samples), including 21 samples of oat flakes, were tested. Only 6 samples were labelled as gluten-free and it was confirmed that these samples meet the criteria for gluten-free foods. The total of 29 oat products, of which 15 were samples of oat flakes, contained more than 20 mg/kg of gluten. This means that 71% of oat cereal products were contaminated with cereals toxic for people with celiac disease. It was shown that most oat products on the Czech market are not safe for people with gluten intolerance.

The investigation determined the influence of Lactobacillus helveticus strains (T80, T105, B734 and DSMZ 20075) and Lactobacillus acidophilus La-05 (probiotic strain) on the antioxidant activity of whey and milk protein preparations. In order to indicate possible mechanism of antioxidant activity of the obtained hydrolysates, the reducing power (RP) assay, ability to neutralize free radicals and Fe2+ chelating activity analysis were employed. The results suggest that antioxidant activity of tested hydrolysates depends on the type of protein preparation (substrate) and the applied bacterial strain. The strongest antioxidant activity was exhibited by whey protein isolate hydrolysate obtained by using L. helveticus T80. A majority of fermented products obtained with the use of the probiotic strain were characterized by higher antioxidant properties than those obtained by application of L. helveticus. The solution of caseinoglicomacropeptide fermented by strain T105 exhibited the highest RP values, while α-lactalbumin hydrolysed by probiotic strain (La-5) was characterized by the strongest Fe2+ chelating activity. The analysed protein preparations and their hydrolysates obtained with using tested bacteria might potentially be applied in food products in order to inhibit oxidation processes.

Ten beaver (Castor fiber) females were used in the experiment. The samples were excised from a different anatomical location of each beaver carcass used in the study: m. longissimus dorsi (LD), m. triceps brachii (shoulder), m. biceps femoris (thigh). Thigh muscles were characterized by the highest percentage of free fat followed by longissimus muscle and shoulder. The total proportions of saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA), including many individual fatty acids, were affected by the muscle anatomical location. The fattiest thigh had the most favourable and highest PUFA/SFA, hypocholesterolemic/hypercholesterolemic (h/H) and lowest n-6/n-3 PUFA ratios, and the lowest thrombogenic index. Despite the fact that the leanest m. triceps brachii had the highest proportions of total polyunsaturated fatty acids, the n-6/n-3PUFA ratio was the lowest compared with the muscles from other anatomical locations and showed lower atherogenic index compared with a more fatty longissimus muscle.

The diet based on gluten free products is characterised by a low content of some nutritional components such as proteins and mineral components, as well as non-nutritional but physiologically important components like dietary fibre. Buckwheat grains are a rich source of proteins, which have a high biological value due to the well-balanced amino-acids composition, although its digestibility is relatively low. The aim of the present research was to investigate the influence of buckwheat flour addition on gluten free bread quality and their antioxidant capacity. In this study, own gluten free bread formula, composed of corn starch, potato starch, salt, yeast, pectin, sugar and sunflower oil was investigated. The buckwheat flour substituted corn starch at final amount of 10, 20, 30, 40% w/w of total ingredients in gluten free bread formula. The breads were baked in electric oven at 200°C for 25 min. The bread samples were freeze-dried, ground and sieved. The sensory quality of buckwheat enhanced gluten free breads was analysed using sensory profiling (QDA) and hedonic tests. The measurement of macroelements content in the crumb was carried out using the atomic absorption spectroscopy (AAS) method (SORAL-SMIETANA et al. 2001). The antioxidant capacity (AC) of the breads was evaluated by cyclic voltammetry (CV) method and free radical scavenging activities of 67% methanol extracts against 2,2-diphenyl-1-picryhydrazyl radical (DPPH.) as DPPH Radical Scavenging Activity (DPPH RSA). All breads were analysed for their total phenolics content. The buckwheat enhancing gluten free breads were in accordance to the requirements of Polish Standards (PN-A-74123) for gluten-free bread. The sensory profiles of gluten-free breads were dependant on the amount of buckwheat flour added. The overall quality of breads was the highest for bread with 40% buckwheat flour addition. The positive correlation between macroelements content and increasing amount of buckwheat flour was observed in breads. The antioxidant capacity of buckwheat enhanced gluten free breads determined by CV and DPPH RSA was related to the amount of added buckwheat flour. The total phenolics content was positively correlated with antioxidant capacity of the breads. In summary, buckwheat flour as a natural source of minerals and antioxidant activity, and also as a structure-forming factor improving the sensory quality, can be used for preparation of new buckwheat enhanced gluten free breads.

Spoilage bacteria were isolated from spoiled fruit-flavoured bottled water with a visual defect in the form of floating flocks. The bacteria were identified as Asaia lannensis using the PCR technique. The efficacy of five chemical agents commonly used in the beverage industry and of power ultrasound (PUS) on Asaia biofilms was studied. A static cultivation procedure on stainless steel plates was used and the efficacy of the chemical agents was tested in two stages. First, only the chemical agents were used. Second, the effect of the application of PUS for 1 min prior to the application of the chemical agents was tested. The most effective chemical agent was the one based on peracetic acid. Its use without PUS proved to be more effective than a combination of any of the other chemical agents with PUS. The least effective methods included the physical sanitation by PUS, the chemical agent based on a 10% solution of sodium hypochlorite and sodium hydroxide, and the chemical agent containing a 0.3% solution of chlorine dioxide.

We characterised 12 wines (10 red, 1 sweet red, and 1 white) from different Cypriot cultivars in terms of their phenolic, anthocyanin composition, and antioxidant capacity as determined by two activities: radical scavenging and ferric reducing ability. Two different phenolic fractions (tannin-free and 1-kDa permeate) were also isolated from Cypriot wines with an ultimate goal of investigating their role in the overall antioxidant capacity of wines. The results indicated that Maratheftiko and Lefkada cultivars had higher concentrations of o-diphenols, hydroxycinnamic acid derivatives, flavonols and anthocyanins compared to other Cypriot cultivars like Ofthalmo, Mavro, and Giannoudi. The higher concentrations of phenols did not always correspond to a higher antioxidant capacity, probably due to the antagonistic action observed between hydroxycinnamic acid derivatives, flavonols, and anthocyanins. The latest interactions restricted the release of flavonols' advanced antiradical activity in wines.

The characteristic features of traditional cottage sausage were analysed. In addition, the extent to which manufacturers create product diversity on the market was investigated, along with potential health risks of the product to consumers. The samples had high overall sensory scores. The average level of fat slightly exceeded 28%, cholesterol content was in the range of 435.4-1220.3 mg/kg and salt content was 1.53-2.77%. Some manufacturers do not cure their product, but about 20% of them apply nitrites above the level of 150 mg/kg. Due to their relatively high pH level (5.76-6.60) and water activity (0.95-0.98), Polish cottage sausage can be a medium which encourages the growth of microorganisms; however, pathogenic bacteria were not found. Histamine was detected in only 42% of the samples, at the low level of 2.6 to 34.2 mg/kg. Principal Component Analysis (PCA) was applied and the dominant variables were specified for particular PCs.

The evolution of volatile organic compounds during the production process of Mozzarella di Gioia del Colle (traditional type) was investigated in comparison with citric mozzarella (industrial type). The total volatile concentration in the traditional curd was ten times higher than milk, versus only twice as much in the industrial type. In both technologies, the concentrations decreased from curd to mozzarella at the same rate, due to losses during the stretching phase. The higher microbial activity in the traditional product was responsible for a much more complex profile, characterised by 2- and 3-methylbutanal, acetoin, ethanol, 3-methyl-1-butanol, acetic acid and ethyl-acetate. In contrast, the industrial mozzarella had a very simple profile, with the most important compounds being directly derived from the milk, the oxidation reactions, or the activity of the adventitious microflora such as acetone, hexanal, nonanal, and hexanoic acid. According to the discriminant analysis, Mozzarella di Gioia del Colle had a very different profile than the milk used, whereas the industrial mozzarella was more similar to the milk.

The aim of the study was to elaborate a universal calibration for the near infrared (NIR) spectrophotometer to determine the moisture of various kinds of vegetable seeds. The research was conducted on the seeds of 5 types of vegetables - carrot, parsley, lettuce, radish and beetroot. For the spectra correlation with moisture values, the method of partial least squares regression (PLS) was used. The resulting qualitative indicators of a calibration model (R = 0.9968, Q = 0.8904) confirmed an excellent fit of the obtained calibration to the experimental data. As a result of the study, the possibilities of creating a calibration model for NIR spectrophotometer for non-destructive moisture analysis of various kinds of vegetable seeds was confirmed.

The processing of chocolate bars is influenced by cocoa beans used. Chocolate bar is one of the downstream products with a simple processing process. The taste and aroma in candy comes from chocolate bars. Fermentation is an important activity in the formation of cocoa flavour. This study aims to determine the panellists' acceptance of chocolate bars produced from various fermentation treatments of sun-dried cocoa beans. The materials used in this study were cocoa beans of varieties of Lindak. The fermentation variation consisted of two treatments, namely, the addition of the inoculum gradually (A1) and the addition of the inoculum simultaneously at the beginning of fermentation (A2). The inocula added were Sacharomyces cerevisiae (FNCC 3056), Lactococcus lactis (FNC 0086) and Acetobacter aceti (FNCC 0016). The control treatment was dry cocoa beans without fermentation (A0). The fermentation time was 120 h, then the fermented cocoa beans were processed into chocolate bars. The resulting chocolate bars were subjected to sensory analysis including evaluation of the taste of sepia, bitter, and sour taste and in the test the polyphenol content of chocolate bars was used. The results showed that there was a decrease in the septic, bitter and sour taste from treatment A0, A2 and A1, respectively. The highest polyphenol content was in A0, A2, and A1, respectively. Panellists stated that the preferred chocolate bar was made from cocoa beans with A1 treatment.

The relationship between body weight and total mercury content in the muscle of common carp (Cyprinus carpio) from 13 uncontaminated ponds in South and West Bohemia was investigated. In total, 215 three-years-old marketable carps and 26 samples of bottom sediment were analysed. Total mercury contents (THg) in muscle and sediments were determined using an single-purpose atomic absorption spectrophotometer. The correlation between body weight and mercury content in muscle was found to be negative and statistically significant (Pearson correlation: r_p = -0.269, P < 0.001). THg content in muscle significantly decreased as the body weight of carp from uncontaminated ponds increased. This is likely due to the intensive weight gain of marketable carp.

Filamentous fungi were isolated from ten spices collected from markets in Indonesia. The aim was to enumerate fungal contamination and to determine the toxigenicity of Aspergillus flavus strains on each of the spices. Viable fungal populations were determined using a dilution method. Toxigenicity of Aspergillus flavus was determined by culture on a quick screening coconut agar and by PCR using four sets of primers specific for aflatoxin pathway genes. All the tested spices were contaminated by storage fungi, Species of Aspergillus was the most commonly isolated moulds followed by species of Fusarium, Mucor, Penicillium and Rhizopus. The greatest number of Aspergillus flavus isolates were found on white pepper, followed by nutmeg, cardamom, and black pepper. The greatest number of Aspergillus chevalieri isolates were found on coriander, followed by nutmeg. Fifty strains of A. flavus were isolated, all of the strains produced large sclerotia and biseriate conidiophores. Their toxigenicity was assayed by the presence of yellow pigment on a quick screening coconut agar medium and PCR amplification of regulatory and structural genes in the aflatoxin pathway.

Aiming to reduce the sodium content in saltine crackers, the present study employed a methodology of salt coating that provided an inhomogeneous distribution of salt so that the salt perception was not altered. To this end, three cracker recipes were prepared and compared. Recipe 1 (F1) was the standard, Recipe 2 (F2) had a 33.3% reduction in salt in the dough, and Recipe 3 (F3) had no salt in the dough but instead a salty coating with the same amount of salt as F2. Physicochemical and sensory analyses revealed that F1 and F3 were not statistically different in salt perception, whereas F2 differed from the others. From these results, it was concluded that the methodology of covering crackers with a salty coating with a 42.5% salt reduction could be an alternative to achieving salt reduction.

In order to study the formation and conversion of the most important flavour compounds, the real wort used in alcohol-free beer fermentation was mimicked by a complex model medium containing glucose, yeast extract, and selected aldehydes. The fermentation experiments were carried out in a continuously operating gas-lift reactor with brewing yeast immobilised on spent grains (brewing by-product). During the continuous experiment, parameters such as oxygen supply, residence time (Rt), and temperature (T) were varied to find the optimal conditions for the alcohol-free beer production. The formation of ethanol, higher alcohols (HA), esters (ES), as well as the reduction of aldehydes and consumption of glucose were observed. The results suggest that the process parameters represent a powerful tool in controlling the degree of fermentation and flavour formation brought about by immobilised biocatalyst. Subsequently, the optimised process parameters were used to produce real alcohol-free beer during continuous fermentation. The final product was compared with batch fermented alcohol-free beers using the methods of instrumental and sensorial analysis.

The changes in total phenolics, hydroxycinammic acid derivatives, and antioxidant properties of spearmint after five drying treatments (convection oven drying, freeze-drying, microwave drying, and air drying with the sun exposure and without the sun exposure) were investigated. Phenolic composition of dried spearmint was analysed by spectrophotometric assays, while DPPH radical scavenging activity and Ferric reducing/Antioxidant power (FRAP) assay was used to measure the antioxidant properties. The results showed that freeze drying produced dried spearmint that had the highest total phenolics (34.6 ± 1.9 mg/g) content and the most potent antioxidant capacity (126.2 ± 0.4 mg/g for FRAP and 88.1 ± 5.9 mg/g for DPPH, respectively). On the other hand, spearmint that was dried by convection oven and microwave drying presented the lowest amount of phenolic compounds (12.0 ± 0.5 mg/g) and antioxidant potency (49.3 ± 0.7 mg/g for FRAP and 26.9 ± 1.6 mg/g for DPPH, respectively). This might be attributed to the fact that heat-sensitive phenolics were degraded or biotransformed at high temperatures. The loss of phenolic compounds and antioxidant activity reached up to 60% compared to freeze drying.

Hepatitis A and E viruses (HAV and HEV) are recognised as food- and water-borne infections and shellfish are a well-documented source of these viruses. The presence of HAV and HEV in mussels has not previously been investigated in Bosphorus, Istanbul, Turkey, and therefore the aim of this study was to investigate the frequency of HAV and HEV in mussels collected from this location. A total of 92 pooled samples representing 736 mussels originating along the Bosphorus coast were collected from fish distributors. RNA was extracted using the RNeasy Plant Mini Kit and a TaqMan real-time RT-PCR was performed using primers specific to HAV and HEV. Amongst the 92 pooled samples tested, 3 (3.3%) were found to be positive for HAV by the TaqMan real-time RT-PCR. No HEV was detected in any of the mussels tested. A 174 bp product was observed on gel electrophoresis with HAV positive samples detected by SYBR Green real-time PCR after reverse transcription. This product was sequenced and confirmed to contain HAV sequences by alignment using the data in GenBank. This is the first report describing the presence of HAV in mussels harvested in the Bosphorus, Istanbul, Turkey, indicating the potential contamination of aquatic environment and risk to public health.

The antioxidant properties of cool-climate Regent wines from Podkarpacie region, Poland were investigated. Total polyphenols, total flavonoids, total monomeric anthocyanins, trans-resveratrol concentration, radical scavenging ability using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and total antioxidant capacity with TEAC and FRAP methods were measured. The average contents of the compounds determined for Regent wines were comparable to the respective data available in literature found for warm-climate wines. Correspondence Analysis of the data revealed the relation of total polyphenols content and antioxidant capacity and radical scavenging ability of studied wines, and in lesser extent correlation with total flavonoids content. The total monomeric anthocyanins content and resveratrol concentration were poorly related to the total polyphenols content and antioxidant capacity.

DNA extraction is a crucial step in PCR analysis especially when analysing food samples that can be degraded and can potentially contain PCR-inhibiting substances. In this study, we compared the suitability of three DNA extraction methods - two kits: DNeasy^® Plant Mini Kit and NucleoSpin^® Food, and the CTAB method - for DNA extraction from commercial fruit jams. Fourteen jams with different contents of fruit, sugar and other additives were extracted in triplicate using the above-mentioned methods directly and after a washing step. The concentration and optical density were analysed using UV spectrophotometry and the amplifiability of the obtained DNA was evaluated using a PCR assay targeting a sequence coding for chloroplast tRNA-Leu. Samples isolated using the NucleoSpin^® Food kit contained non-amplifiable DNA in eight cases, and samples isolated using the CTAB method could not be quantified. The DNeasy^® Plant Mini Kit thus proved to be the most suitable method, since well-amplifiable DNA was obtained for all the analysed samples.

The paper pertains to the issue of quality assurance methods. Particular emphasis is placed upon the examination of hazards and possible product defects in food processing. At present, Polish regulations oblige any food processing entity to implement HACCP system. The system is perceived as a universal vaccine preventing the emergence of possible hazards or reducing the risk to an acceptable level. As far as defects are concerned, these are either disregarded altogether or do not occur at all. Meanwhile, the practice proves the case is not so. The research aspect of the paper revolves around an attempt to transplant solutions primarily applied in the automotive sector onto food processing industry. The practical aspect of the paper is manifested in the analysis of causes behind defects and hazards conducted on the basis of bakery industry. Potential hazards and product defects emerging from the process were identified in the course of the study. In addition, in order to eliminate these, their level was established with the application of various methods.

Production development for asparagus has become an important research subject due to its low shelf life. In order to determine the content of flavonoids in asparagus tips and shoots, LC-MS-based method was performed for a targeted analysis of flavonoids in asparagus, and 34 peaks attributed to the targeted flavonoids were characterised. Twelve peaks corresponding to rutin, isoquercitrin, quercetin, naringin, taxifolin, vitexin, genistin, daidzein, luteolin, chrysin, and kaempferide were identified and quantified from the asparagus tips and shoots by the LC-MS-based detection with monitoring of parent/daughter ions. The results showed that rutin (> 99%) was the main flavonoid present in the asparagus tips and shoots. Although the tips and shoots contained almost similar compounds, the content of the major compounds, especially rutin, was significantly different. Therefore, the method established through this study could be used for quantitative analysis of flavonoids, especially rutins, in asparagus. The result will provide a theoretical basis for food development in asparagus.