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SYBR Green real-time or quantitative PCR (Q-PCR) is a suitable system in which to establish a multiplex method to detect allergenic ingredients in food. In this study, a triplex Q-PCR method was developed to detect trace amounts of peanut, soybean and sesame in processed food. Specific PCR primer sets were designed and the concentration of the primers used in the triplex PCR was optimised. The triplex method showed high specificity and sensitivity which were similar to those of the simplex method, and it was applied for the detection of allergenic ingredients in commercially available processed food. The results demonstrate that the developed triplex Q-PCR is a quick, reliable and efficient method for the detection of allergenic ingredients in processed food.

Off-flavour in soft drinks is one of the main threats to manufacturers, which can result in expensive recalls, and discredit the brand. Off-flavours can occur for a variety of reasons (e.g . chemical contamination of raw material). The presented case study has proved there is a relationship between the identification of biphenyl and its derivatives in the used preser vative (benzoate) and off-flavours in the drink . The project consisted of three phases: (1) the assessment of the probable cause of off-f lavours based on sensor y evaluation and GC-MS -Olfactometr y profiling of volatiles; (2) the quantification of biphenyls and the characterisation of their sensor y properties; (3) the screening of commercially available benzoates for the presence of biphenyls. Based on the odour threshold obtained by GC-O (0.03 mg/l for 4-methyl-1,1'-biphenyl and 0.02 mg/l for biphenyl in an aqueous solution) and the common benzoate content in soft drinks (0.14 g/l), the 'non-obser vable sensory' levels of contamination were determined to be maximally 0.143 mg/g of benzoate for biphenyl and 0.214 mg/g of benzoate for 4-methyl-1,1 '-biphenyl .

Industrial wine yeasts Saccharomyces bayanus and two interspecies hybrids (S. cerevisiae × S. bayanus) were checked for their suitability for fermentation of apple musts with different L-malic acid content (4, 7 and 11 g/l). The fermentation profiles including main organic acids, acetaldehyde, diacetyl, glycerol, esters and polyphenols were presented. The results were obtained by HPLC method (organic acids, acetaldehyde, glycerol, diacetyl), GC (esters), colorimetrically (polyphenols) and enzymatically (L-malic acid, ethanol). Although the fermentation profiles of wines were characteristic for specific yeast strains, similarities in organic acid profiles of wines fermented by S. bayanus and its hybrid S-779/25 were noted. In all the tested wines L-malic, pyruvic and citric acids were dominant. Statistical analysis of all wine parameters indicates that yeast strains respond individually to different acidities of the fermentation environment. In order to choose the right yeast strain for the fermentation of acidic musts, information about fermentation profiles should be included in the collection certificate of yeast strains.

The manufacturers have to provide modern and safe packaging due to the growing consumer interest in the consumption of fresh products with extended shelf-life and controlled quality. It is a challenge to the food packaging industry and it also acts as a driving force for the development of new and improved concepts of packaging technology. It is in order to meet these needs that intelligent packaging can be applied. This article presents a generation of packaging which allows maintaining and even improving the quality of the packaged product, which is an essential advantage particularly in the food industry. The most important advantage resulting from their use is a reduction in the loss of food products due to the extension of their shelf life.

Many studies show that the consumption of juices rich in polyphenols may increase serum antioxidant capacity, improve blood lipid profile, and endothelial function. The relation between the consumption of chokeberry juice and changes in the antioxidant capacity, blood lipid profile, and endothelial function as important indicators in the assessment of cardiovascular risk were determined. The study was conducted on a group of 11 healthy volunteers, who consumed chokeberry juice for three weeks. The research included determination of serum antioxidant capacity, blood lipid profile analysis, and measurements of endothelial function. The 3-week consumption of chokeberry juice significantly increased serum antioxidant capacity, and the best results were observed just after one week of the experiment. However, there was no significant change in the blood lipid profile, except for the persons with a higher level of triglycerides, in whom the consumption of chokeberry juice reduced these compounds to normal values. The endothelial function was normal in all patients and did not significantly change during the study.

The effect of malolactic fermentation (MLF) on the flavour quality of cider was examined. Leuconostoc mesenteroides subsp. mesenteroides Z25 was used to start MLF taking place at 25°C for 12 days after the completion of alcoholic fermentation (AF) by Saccharomyces cerevisiae. Strain Z25 showed good activity in starting MLF of cider with 10% alcoholic concentration. The content of malic acid, whose high concentration gives negative organoleptic characteristics to the cider, dropped significantly from 4.0 g/l to 0.25 g/l via MLF. The concentration of lactic acid increased significantly from 0.99 g/l to 3.50 g/l, contributing to volatile acidity. The acetic acid content of the ciders was 0.74 g/l. Among 51 volatile compounds detected by GC-MS, higher alcohols, esters, and carbonyl compounds were formed in ciders through MLF. The total concentration of aromatic substances doubled compared to the controls. The occurrence of MLF started by strain Z25 enabled the cider containing more volatile compounds and an acceptable adjustment of organic acids. This is the first report on using L. mesenteroides subsp. mesenteroides strain Z25 to start the MLF of apple wine improving the flavour quality of the cider produced.

Fennel, mint (peppermint), and sage herbal teas and apple, lemon, and rosehip fruit teas were selected for the determination of the following risk elements contents: aluminium (Al), arsenic (As), barium (Ba), cadmium (Cd), nickel (Ni), lead (Pb), and antimony (Sb). Moreover, the effect of lemon on these elements contents was also examined. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) was used for these experiments on selected teas (2 g of tea infused in 100 ml of water). The maximum changes of elements concentrations after the lemon addition were as follows: Al 1077 µg/l in lemon tea; Ba 12560 µg/l in rosehip tea; Cd 183 µg/l in sage tea; Ni 1136 µg/l in fennel tea; and Pb 238 µg/l in lemon tea. Both As and Sb were below the detection limits in pure tea and lemon-infused teas. This study indicated that after the lemon addition, rosehip tea had a hazard index (HI) value of 10827 × 10^-4 for 200 ml/day (2 cups/day), which represents a high risk for human health. If lemon is added to rosehip tea for consumption, 100 ml/day is recommended according to the calculated HI values.

Increased detection records of Listeria monocytogenes in foods have been recently observed. Standard methods of L. monocytogenes elimination from food products including pasteurisation or acidification may, however, be unreliable. The elimination of L. monocytogenes using specific bacteriophages which are natural antagonists of these pathogenic bacteria has become an innovative method that does not affect the taste, smell or appearance of the product. The use of phage preparations in food production is becoming an increasingly popular method for the effective and safe elimination of L. monocytogenes from food products.

Disinfectant or card-board off-flavour formation was observed in the batch of pasteurised reconstituted apple juice. Aroma profile of products was analysed using SPME and GC/MS, guaiacol was detected in the apple juice sample as well as apple concentrate. Sporulating bacteria Alicyclobacillus acidoterrestris, which are able to growth in acidic conditions were isolated and identified as the cause of the off flavour formation. The possibilities of flavour formation inhibition using various additives were evaluated. The inhibitory effect of nisin, sulphur dioxide, benzoic acid and EDTA was followed. The best way of prevention is the sufficient washing and disinfection of apples prior the processing e.g. using chlorine dioxide. But when the treatment is insufficient and contaminated apples are to be processed the tested additives can prolong the lag phase and increase product stability. The inhibitory effect of the tested additives decreased in the order: benzoic acid, EDTA, nisin and sulphur dioxide.

The effect of wort filling time on the process of fermentation, maturation, and acetaldehyde content in beer was determined. The experiments were performed on an industrial scale, the fermentation and maturation took place in fermentation tanks. Three tanks were filled using three different intervals. Worts were aerated with sterile air and yeast was added after the second fermentation (third passage). During fermentation and maturation, changes in the content of the apparent extract and the amount of acetaldehyde were investigated. Experiments have shown that different filling times have a significant impact on the course of fermentation and the amount of acetaldehyde. With the increase of wort filling time, fermentation speed improved and acetaldehyde content decreased.

In order to develop environmentally sound, energy inexpensive and well scalable drying techniques that maintain high quality of dried fruit, optimisation of integrated process (ultrasound and air-drying) in the production of dried apples was conducted. Selected quality parameters of fresh and dried apples (variety Goldparmâne) resulting from different duration of ultrasonic pre-treatment and air-drying were compared. Sugars were determined spectrophotometrically using an enzymatic method. Content of total phenols and flavonoids was determined spectrophotometrically with the Folin-Ciocalteau assay, while the antioxidant capacity was evaluated by using ABTS (2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and FRAP (Ferric Reducing/Antioxidant Power) assays. Sensory properties of dried apples were investigated according to the Quantitative Descriptive Analysis. In combination with the same air-drying conditions, prolonged ultrasound pre-treatment led to a decrease in total phenols and flavonoids, as well as in the antioxidant capacity of dried apples. Difference in drying time had no significant effect on the content of total phenols and flavonoids, as well as antioxidant capacity. The sample dried without the ultrasound pre-treatment was evaluated as the most sensory acceptable. The content of glucose and fructose correlated well with total phenols and flavonoids, as well as with antioxidant capacity of apple samples.

Macrocybe gigantea (Massee) Pegler & Lodge is a species of edible mushrooms which has important nutritional, medicinal, and economic values. Discrimination of M. gigantea with different storage periods is helpful to guarantee the authenticity and to promote marketing of this species. We focused on the establishment of the fingerprints based on UV spectroscopy to discriminate the wild-grown M. gigantea samples stored for different years and to distinguish the wild-grown and cultured samples which were stored for the same years. The analyses of the data were performed by multivariate analyses such as principal component analysis (PCA) and cluster analysis (CA). UV spectral fingerprints showed that the major composition and content of the main components were significantly variable over time. All the M. gigantea samples which were stored for different years could be successfully grouped by PCA and CA. The results demonstrated that this qualitative assessment could be regarded as a rapid and reliable method for discrimination of M. gigantea with different storage times.

The influence of yeast strain on the volatile profile of meads fermented from blossom honey using three different Saccharomyces cerevisiae var. bayanus strains was evaluated. Meads were analysed by methods of basic chemical analysis and gas chromatography after 15 days of fermentation. Individual yeast strains produced various metabolites in different concentrations under the same fermentation conditions which significantly influenced the final secondary aroma of mead. Higher concentrations of acetaldehyde and 1-propanol, associated with S. cerevisiae var. bayanus MM-R2 considerably distinguished this strain from the others, whereas the difference between strains S. cerevisiae var. bayanus FM-R-Fix1 and MT-R1B was characterised by the production of ethyl hexanoate, ethyl octanoate (FM-R-Fix1), and isobutyl alcohol (MT-R1B).

The water of the breads was replaced with phenolic aqueous extracts from chicory, cabbage, celery, fennel, olive leaf, or grape marc wastes obtained through microwave-assisted extraction. The highest phenolic concentrations were found in the grape marc and in the bread enriched with it. The highest antioxidant activity values were measured in the crust of bread produced with the grape marc extract and in the crumb of bread with olive leaf extract. Generally, the replacement of water caused significant decreases of the specific volume, the shift of the crumb colour towards redder and yellower tones, and modification of gustatory and tactile attributes.

Consumption of minimally processed fruits has been increased lately mainly due to their fresh-like quality characteristics. One of the major alterations that limit the shelf-life of these products is browning caused by polyphenol oxidase (PPO) activity on phenolic compounds. Six yellow-flesh peach cultivars, Spring Lady, Royal Glory, Ruby Rich, Summer Rich, Ryan Sun, and O'Henry, were selected. Peaches were hygienised and then samples were processed in a clean room. Slices were washed in cold tap water, dried, packaged in modified atmosphere, and stored at 4°C during 9 days; physicochemical and other quality parameters were studied. Principal Component Analysis (PCA) and correlation study were carried out in order to evaluate the relation between variables and cultivars. In conclusion, Spring Lady, Royal Glory, and Ruby Rich cultivars were the cultivars that offered the most suitable fruits for fresh-cut processing, mainly due to their low BP and PPO activity.

The effect of temperature on the kinetics of pigment extraction during the maceration of different fruits (raspberry, blackberry, and cranberry) into a commercially available hard spirit (orujo, with 42% v/v ethanol) was evaluated. The analytical method used was UV-Vis spectrophotometry. The initial extraction rate showed an Arrhenius-type dependence with apparent energy activation of 28.8, 69.8, and 55.6 kJ/mol, respectively. Furthermore, a study about the evolution of the colour (from colourless to reddish colour appearance) during the soaking process was done by calculating the CIE tristimulus values (X, Y, Z) for illuminant C, until reaching the apparent stabilisation of colour, which occurs after about two to four weeks for the studied temperatures (5, 23, and 40°C). Studies about the evolution of colour in the soaking process of this kind of fruit liquors can lead to a better understanding of this process, and thus to a better control over the mechanisms underlying it.

The effects of refrigerated storage on the microstructure and physicochemical properties of high hydrostatic pressure (HHP) treated onion were evaluated. Onion was submitted to 100 MPa at 50°C or 400 MPa at 25°C for 5 min, and stored for 28 days at 4°C. Electron microscopy techniques and light microscopy were used for the microstructural study. Total soluble phenolics, soluble protein percentage, and shear force were also studied. HHP treatments affected the cell wall and membrane permeability, favouring the diffusion of soluble material to the apoplast. Storage at 4°C also caused important structural degradation in the HHP-treated samples, which was higher when 400 MPa at 25°C were applied and led to physico-chemical changes during the first week of storage. Interactions between phenolics and solubilised cell wall material or proteins could explain the decrease in soluble phenolics and proteins during storage.

Potential application of a metal oxide semiconductor based electronic nose (e-nose) as a non-destructive instrument for monitoring the change in volatile production of banana during the ripening process was studied. The proposed e-nose does not need any advanced or expensive laboratory equipment and proved to be reliable in recording meaningful differences between ripening stages. Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), Soft Independent Modelling of Class Analogy (SIMCA) and Support Vector Machines (SVM) techniques were used for this purpose. Results showed that the proposed e-nose can distinguish between different ripening stages. The e-nose was able to detect a clear difference in the aroma fingerprint of banana when using SVM analysis compared with PCA and LDA, SIMCA analysis. Using SVM analysis, it was possible to differentiate and to classify the different banana ripening stages, and this method was able to classify 98.66% of the total samples in each respective group. Sensor array capabilities in the classification of ripening stages using loading analysis and SVM and SIMCA were also investigated, which leads to develop the application of a specific e-nose system by applying the most effective sensors or ignoring the redundant sensors.

The basic chemical characteristics of 22 quince (Cydonia oblonga Mill.) genotypes and cultivars were determined: dry matter content, soluble solid content, the contents of organic acids, pectins, and mineral elements (nitrogen, phosphorus, potassium, calcium, and sodium). Quince fruits were harvested in the course of October and thereafter analysed at the stage of consumption ripeness after storage at the temperature of +2°C and a relative air humidity of 85%. The contents of pectins in fruits were high - the cultivar Hruškovitá contained 3.51 ± 0.19 g/100 g FW. The contents of vitamin C were also high, the cultivar Muškatová containing as much as 79.31 ± 2.01 g/100 g FW. The affinity of chemical properties of the individual cultivars was expressed by means of cluster analysis and it was found out that there were no marked differences between pear-shaped (Cydonia oblonga subsp. pyriformis) and apple-shaped (Cydonia oblonga subsp. maliformis) forms of fruit.

Caciottina massaggiata di Amaseno, a typical dairy product of the Lazio Region prepared from buffalo milk, was analysed for moisture, fat, protein, pH, and acidity content at different storage (0, 3, 6, and 9 months after production). Cheeses were also evaluated for various sensory attributes (taste, flavour, texture, and overall acceptability) during storage. We evaluated the flavour profile and acceptability of Caciottina cheeses of varying maturity using a descriptive analysis. Descriptive sensory profiles of selected cheeses were determined using a trained panel (n = 12) and an established cheese flavour sensory language. In quantitative descriptive analysis a trained panel rated the cheeses for colour, odour, taste and texture. In the affective tests the panellists evaluated the samples for overall quality. The results proved that months of production had significant effects on the sensory quality of the cheeses.

The dehydration kinetics of the fruits with special geometries, i.e. spherical and cylindrical (e.g. apple, peach, banana, pineapple, etc.), were studied based on mathematical methods. The influence of the size reduction (slicing) of these fruits into smaller rings was also investigated. The mathematical modelling was performed based on the Fick's second law. The results showed that increasing the value of the water diffusion coefficient in fruit (for instance, via increasing the process temperature) promotes faster water migration from the fruit. Mathematical modelling also showed that the characteristic length of fruits (radius) is in an inverse relation to the dehydration kinetics. Comparing the results obtained with both the sphere- and cylinder-shaped fruits revealed that slicing the fruit into more thin rings makes a better condition for operating the osmotic dehydration process with a higher efficiency and a shorter duration.

The impacts of chemical treatment and modified atmosphere on enzymatic changes in minimally processed apples were evaluated. Slices of apple cultivars Golden Delicious and Red Delicious were packed in plastic bags with modified atmospheres: 85% N₂, 5% O₂, 10% CO₂ (MA) and 78% N₂, 21% O₂, 1% other gases (NA). The changes in colour, firmness, polyphenoloxidase activity, total phenols content and concentration of single phenols during storage were measured. It has been found that the effects of storage atmosphere and antioxidant treatment were not as important as the choice of apple cultivar. Red Delicious is a cultivar with high concentration of phenolic compounds and high activity of polyphenoloxidase; therefore it is difficult to limit the very fast enzymatic changes and subsequent discoloration.

The gas chromatographic (GC) determination of volatile constituents and the determination of ¹³C/¹²C isotope ratios by isotope ratio mass spectrometry - IRMS analysis as well as SNIF-NMR analysis of (D/H)I and (D/H)II ratios in ethanol are prospective analytical methods which can be used for checking the authenticity of fruit spirits and for detecting their adulteration. Different concentrations of volatile compounds such as acetaldehyde, ethyl acetate, diethyl acetal, methanol, 1-butanol, 2-butanol, 1-propanol, 2-methyl-1-propanol, 2- and 3-methyl-1-butanol, volatile fatty acids and isotopic data were demonstrated using discriminant analysis. The results show that the determination of isotope ratios can be used especially for distinguishing between fruit spirits and others spirits, i.e. those made from beet sugar, maize, cane sugar, grain, potato, or synthetic alcohol. Gas chromatography also makes it possible to discriminate between respective spirits derived from one kind of fruit such as sweet cherry brandy, sour cherry brandy, pear brandy, apple brandy, apricot brandy, or plum brandy.

Antioxidant capacity of foods and food supplements based on berries and flowers of medicinal plant elderberry (Sambucus nigra L.) was assessed. Reducing properties of the samples and extracts were evaluated using amperometric detection at working electrode potential -0.8 V after HPLC separation. Moreover, antiradical activity of selected samples was determined by the means of spectrophotometric DPPH radical scavenging method. Electrochemical activity (EA) of fresh juice pressed from elder fruits amounted to 0.71 g AAE/l with anthocyanins as minor contributors (10.2%). Catechins and phenolic acids were the major active groups. During production of elder berry spread, even more than 90% of the EA compounds found in raw elder berry material can be destroyed. Comparable activity may be found also in the products from elder flowers. Although elder blossom syrups possessed similar EA regardless of the technology used (0.033-0.054 g AAE/kg), their chromatographic patterns were often very different. For example, no flavonols were present in the syrups, if traditional preparation comprising 24-h maceration with citric acid was applied. Analyzing the chromatographic patterns, one can distinguish different base materials and technology, which can be used for the authenticity confirmation. Herbal infusions from elder flowers, which contain more flavonols than are in syrups, were 16-27 times richer in EA than drinks prepared from the syrups after recommended dilution. Only the syrup designed for preventing and treating upper-respiratory viral infections showed the EA (0.09 g AAE/kg) comparable to that of herbal infusion (0.13 g AAE/l).

In this work preliminary studies on application of immunochromatographic method to detection of pesticides in food samples, in particular fruit juices, are presented. The aim was to develop immunochromatographic technique on a porous membrane for rapid detection of the pesticides thiabendazole and methiocarb in fruit juices. For detection colloidal carbon conjugated with secondary antibody was used. The tests were evaluated visually. Our results show that in the fruit juices samples examined the detection limit for thiabendazole covered the MRL (maximum residue limit) for food of plant origin established by the legislative and for methiocarb the method has to be further optimised in order to decrease the detection limit below the MRL.

Pears cv. Pituralka are autochthon old cultivar from west Slovenian region and northern part of Italy, that were traditionally consumed as cooked or baked meals. In our study we developed new products and defined their nutritional value. Different thermical treatments (cooking and baking) were used for preservation of these products in sugar solution with or without an ascorbic or citric acid and packed in vacuum in a thermostable polyamide/polypropylene (PA/PP) foil. The products made from pears cv. Pituralka were sensory evaluated. The results show that Pituralka pears can be consumed only if they are thermally processed. Containing high amount of total fiber (6-7 g/100 g) products have functional perspective as prebiotics. Having low acidity level (total amount of acids 12.9-15.3 mg/100 g) products from pears cv. Pituralka have very acceptable sensory properties, especially for people with dyspepsia. However low amount of vitamin C (0.5 mg/100 g) has affect on higher sensitivity to oxidation, that needs to be taken into consideration during processing and storage.

The absence of good agricultural and manufacturing practices in the production and postharvest handling of fresh produce, such as green asparagus or green onions increase the contamination risk by biological hazards like Salmonella. The objective of this work was to investigate the efficacy of chlorine (200 and 250 ppm), hydrogen peroxide (1.5% and 2%), and lactic acid (1.5% and 2%) sanitisers during different exposure times (40, 60, and 90 s) on the reduction of Salmonella enterica subspecie enterica serovar Typhimurium in inoculated fresh green asparagus and green onions. Washing with clean water only reduced < 1 log10 CFU/g in both vegetables. The most effective sanitiser evaluated for fresh green asparagus and green onions disinfection appeared to be 2% lactic acid reducing Salmonella growth close to 3 log₁₀ CFU/g. Hydrogen peroxide was the least effective agent for Salmonella Typhimurium reduction. No effect was observed of the exposure time of inoculated product to sanitiser up to 90 seconds. These results confirm that lactic acid could be used as an alternative for fresh green asparagus and green onions sanitation.

Colour and texture are very important quality properties of all foods. In this work, the influence was investigated of different types of pectin on colour and textural properties in strawberry jams and low-calorie strawberry jams containing fructose and aspartame or fructose syrup and aspartame. The highest anthocyanin content and total phenol content were detected in strawberry jam samples prepared with low methoxy amidated pectin. During storage, after 4 and 6 weeks at both storage temperatures, room temperature and 4°C, anthocyanin content and total phenol content decreased. Also, free radical scavenging activity decreased during storage. As far as the texture parameters are concerned, namely firmness, consistency and cohesiveness, the highest values were found in strawberry jam samples prepared with high methoxyl pectin.

Furan and its derivatives were identified in a small number of heat-treated foods back in the 60's and 70's. In May 2004, US Food and Drug Administration published a report on the occurrence of parent furan in a number of thermally treated foods. Since furan has been classified as "possibly carcinogenic to human" by IARC, a great concern has been addressed to the analysis of this substance naturally-occurring in food. This paper gives a short overview on the mechanistic pathways of the parent furan formation in food by degradation of amino acids and/or reducing sugars, and oxidation of ascorbic acid and poly-unsaturated acids which can be induced by thermal or irradiation treatments; further, it deals with the metabolism and toxicology of furan as well as with the comparison of the methods of furan determination.

There is a basic lack of information about the presence of pesticide residues in apples obtained from farms in Slovakia collaborating with baby food producer. Residues of several pesticides (widely used for the protection on apple trees) have been determined in apples (a common raw material for the baby food production and baby food) from Slovakia (agricultural area in the South of Slovakia). The analysis of the pesticides was performed by gas chromatography on CP-Sil 5 CB (15 m long, 0.15 mm I.D., film thickness 0.15 μm) with normal bore retention gap (1 m long, 0.32 mm I.D.) using the subsequent determination with MS detector in SIM mode, after the acetonitrile extraction of the pesticide residues from apples, the clean-up and preconcentration steps of samples with SPE-NH₂. For the study pesticides belonging to various groups were selected, such as organophosporus pesticides, oximinoacetates, anilinopyrimidines, triazoles, and triazines pyrethroids. The GC-MS analysis of pesticide residues in all samples searched showed that most of the detected and quantified residues were below 10 μg/kg which corresponds to the maximum residual limit for pesticide residues in baby food.