Investigations of the natural microflora of poppy seeds (<Emphasis Type="Italic">Papaver somniferum</Emphasis>) and hazelnut kernels (<Emphasis Type="Italic">Corylus avellana</Emphasis>) including microbiological decomposition

Fatty seeds of Papaver somniferum and Corylus avellana undergo a rapid microbial degradation after being ground. Those bacteria and fungi which are mainly responsible for the microbial decay were identified, and the most important growth and death processes were documented using crucial indicator-organisms. Additionally, an aflatoxin-screening was carried out in order to assess the possible risk-potential of food intoxication. The acid value (indicator for free fatty acids) of poppy seeds and hazelnut kernels was determined during their fermentation in order to document the decomposition of triglycerides.In this study it could be proved that initially a natural decay of oil seeds is caused by bacteria, yeasts and mould fungi. After the bacteria died in the course of time, yeasts and mould fungi dominated the germ spectrum. Bacteria taking part in the degradation were identified as varieties of Staphylococcus xylosus, Enterobacteriaceae and coliforms. Yeasts were identified as Pichia burtonii, and the mould fungi are associated with the genus Alternaria.On account of the absence of the genus Aspergillus in the spectrum of mould fungi, no aflatoxin was produced.     

Effect of ungutting on microbiological, chemical and sensory properties of aquacultured sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) stored in ice

The effect of ungutting on microbiological, chemical and sensory properties of aquacultured sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) stored in ice were studied. The total viable mesophilic and psychrophilic bacterial counts increased throughout the storage period of ungutted sea bream and sea bass. Mesophilic counts of ungutted sea bream and sea bass reached 7.39 log cfu/g and 7.26 log cfu/g after 9 days. At the end of the storage period of 14 days; TVB-N, TBA, TMA-N values of ungutted sea bream were determined as 37.5±0.51 mg/100 g, 3.82±0.03 mg MA/kg, 7.73±0.25 mg/100 g, respectively. TVB-N, TBA, TMA-N values of ungutted sea bass were reached 35.4±0.9 mg/100 g, 3.75±0.81 mg MA/kg, 6.94±0.08 mg/100 g on day 14th, respectively. Result of this study indicates that the shelf life of whole ungutted sea bream stored in ice as determined by the overall acceptability sensory scores, chemical quality and microbiological data is 12, 9 and 9 days, respectively. Each chemical, sensory and microbiological results for sea bream showed us that there was a correlation and similarity, and day 9 was the beginning of spoilage. Whole ungutted sea bass stored in ice as chemical results for sea bass showed us that day 7 was the beginning of spoilage and for sea bream day 9 was the beginning of spoilage.     

Production of biogenic amines by<Emphasis Type="Italic"> Morganella morganii</Emphasis>,<Emphasis Type="Italic"> Klebsiella pneumoniae</Emphasis> and<Emphasis Type="Italic"> Hafnia alvei</Emphasis> using a rapid HPLC method

The histidine decarboxylating activity and production of biogenic amines by Morganella morganii (NCIMB, 10466), Klebsiella pneumoniae (NCIMB, 673) and Hafnia alvei (NCIMB, 11999) were investigated using a rapid HPLC method. Derivatisation of the bacterial samples was carried out using benzoyl chloride. A gradient elution system was used for analysis with a mixture of acetonitrile and HPLC grade water. Bacterial strains not only produce histamine in histidine-enriched broth but also the other biogenic amines. The chromatographic results show that bacterial strains are also capable of producing spermine and spermidine in histidine-enriched broth. Bacterial ammonia production by all three strains was clearly detected since ammonia is generated during the degradation of histidine. The study demonstrates that the highest histamine production was obtained by Morganella morganii, followed by Klebsiella pneumoniae, and the lowest with the Hafnia alvei. Therefore, Morganella morganii and Klebsiella pneumoniae have strong histidine decarboxylase activity since they are prolific histamine-forming bacteria     

Effects of slaughtering methods on sensory,chemical and microbiological quality of rainbow trout (<Emphasis Type="Italic">Onchorynchus mykiss</Emphasis>) stored in ice and MAP

The effects of slaughtering methods (percussive stunning and death in ice slurry) on the quality of rainbow trout stored in ice and modified atmosphere packing (MAP) (40% CO₂, 30% N₂ and 30% O₂) were investigated in terms of sensory, chemical and microbiological analysis. Sensory analysis showed that the demerit points of fish slaughtered by percussive stunning were higher than those slaughtered by the ice slurry method, but there were no significant differences in demerit points (P>0.05). In addition, the rate of increase in demerit points in fish in MAP was significantly (P>0.05) higher at 6 and 10 days of storage than that in fish in ice for each slaughter method, which was due to increased drip, the appearance of slime and the odour of the fish in MAP packing. The mean K values of rainbow trout slaughtered by percussive stunning in this study were significantly lower (P<0.05) than those of trout slaughtered according to the ice slurry method. The level of biogenic amines, regardless of the slaughter method, showed a similar trend (P>0.05), but higher concentrations of biogenic amines were found for the ice slurry slaughter method and for fish stored in ice. There were no significant differences (P>0.05) in total viable count of fish stored in ice and MAP, regardless of the different slaughter methods used. However, fish packed in MAP showed reduction in bacterial counts compared to fish held in ice throughout study. The results of this study showed that slaughter by percussive stunning improved the quality of trout compared to the ice slurry method.     

Antitumor activities of liposome-incorporated aqueous extracts of <Emphasis Type="Italic">Anodonta </Emphasis><Emphasis Type="Italic">woodiana</Emphasis> (Lea, 1834)

To acquire the effectiveness of oral treatments, aqueous extracts of Anodonta woodiana (HB) were incorporated into liposome and its antitumor activities evaluated in vivo. The HB-loaded liposomes (HBL) were prepared at a mean size of 14.85 μm by reverse-phase evaporation method. Referring to the maximum tolerated doses test, mice with orally administrated HBL, at a 3 g/kg body weight dosage, showed no obvious acute toxic sign. Furthermore, the tumoricidal activities of HBL against C26 murine colon carcinoma, Lewis lung tumor, human QGY hepatic carcinoma and MKN-45 gastric tumor were examined, respectively. In contrast to free HB, HBL possessed remarkable antitumor activity. Simultaneously, the effect of HBL was observed in a dose-dependent manner. For C26 murine colon carcinoma and Lewis lung tumor, the inhibitory ratios of HBL were 54.36 and 51.97% at a dose of 400 mg/kg, respectively. The suppression of tumor growth and the reduction in body weight were more pronounced in human QGY hepatic carcinoma and MKN-45 gastric tumors inoculated mice by treatment of HBL during 30 days. All these promising results implied that liposome-incorporated aqueous extracts of Anodonta woodiana had a more potential application as a natural antitumor and immunomodulator formulation.     

Seasonal changes in the fatty acids of gilthead sea bream (<Emphasis Type="Italic">Sparus aurata</Emphasis>) and white sea bream (<Emphasis Type="Italic">Diplodus sargus</Emphasis>) captured in Iskenderun Bay,eastern Mediterranean coast of Turkey

Seasonal variations in the fatty acid compositions of gilthead sea bream (Sparus aurata) and white sea bream (Diplodus sargus), captured in Iskenderun Bay, Eastern Mediterranean of Turkey, were investigated. Results from studying the composition over all seasons showed that the basic saturated, monounsaturated and polyunsaturated fatty acids for gilthead sea bream and white sea bream were palmitic acid (16:0), oleic acid (18:1) and docosahexaenoic acid (DHA, 22:63). The other main fatty acids for both species were myristic acid (14:0), stearic acid (18:0), palmitoleic acid (16:1), linoleic acid (18:26) (especially in autumn and winter for gilthead sea bream), and eicosapentaenoic acid (EPA, 20:53). Gilthead sea bream and white sea bream exhibited seasonal fluctuations in their fatty acid contents. EPA ratios in gilthead sea bream in the autumn, winter, spring and summer were 5.42%, 4.69%, 5.20% and 4.27%, whereas the ratios in white sea bream in autumn, spring and summer were found to be 5.03%, 4.53% and 6.97%, respectively. DHA ratios in gilthead sea bream in autumn, winter, spring and summer were 15.37%, 14.16%, 9.51% and 7.07%, whereas the ratios in white sea bream in autumn, spring and summer were found to be 11.49%, 20.17% and 7.74%, respectively. The present study suggests that the daily consumption of either 100 g of gilthead sea bream captured in any season or 100 g white sea bream captured in spring or summer could meet peoples needs for EPA+DHA fatty acids.     

Effects of using slurry ice on the microbiological, chemical and sensory assessments of aquacultured sea bass (Dicentrarchus labrax) stored at 4 °C

Slurry ice, a biphasic system consisting of small spherical ice crystals surrounded by seawater at subzero temperature, was evaluated as a new chilled storage method for whole sea bass (Dicentrarchus labrax) a sparidae fish species of remarkable commercial interests. Four different group of chilling methods were used in this study; in slurry ice packaged on board (group A), in slurry ice packaged on company after 2 h (group B), slurry + flake ice packaged on board (group C) and only flake ice packaged on board (group D). The effect of this advanced system at the beginning of storage on quality losses and the shelf-life of aquacultured sea bass was evaluated. Mesophilic counts for sea bass exceeded 7 log cfu/g, which is considered the maximum level for acceptability for freshwater and marine fish after 13 days for groups C and D, and 15 days for groups A and B. At day 15; total volatile basic nitrogen (TVB-N) values of groups A–D reached the legal limits (35 mg/100 g set for TVB-N) for consumption. According to the results of sensory analyses, up to day 11, all the groups were determined as ‘acceptable’ but on day 13, the groups A–D were no longer acceptable. The main negative aspect related to quality loss in slurry ice group corresponded to the appearance of eyes and gills. Using slurry ice at the beginning of packaging did not affect the shelf-life of sea bass stored at 4 °C.     

Effects of process parameters on growth and metabolism of<Emphasis Type="Italic"> Lactobacillus sanfranciscensis</Emphasis> and<Emphasis Type="Italic"> Candida humilis</Emphasis> during rye sourdough fermentation

The effects of temperature, pH, inoculum level, and NaCl on the growth and metabolism of Lactobacillus sanfranciscensis and Candida humilis in rye sourdough were determined. The temperature optima for growth of C. humilis and L. sanfranciscensis were 28 and 32 °C, respectively. Yeast growth was inhibited at 35 °C. The pH did not affect yeast growth in the range 3.5–5.5, whereas growth of L. sanfranciscensis was inhibited at pH 4.0. A NaCl concentration of 4% (flour base) inhibited growth of L. sanfranciscensis but not C. humilis. The effects of the process parameters on the formation of lactate, acetate, ethanol, and CO₂ by the organisms were generally in agreement with their effects on growth. However, decreased formation of acetate by L. sanfranciscensis was observed at 35 °C although lactate and ethanol formation were not affected. In conclusion, the study provides a rationale for the stable persistence of L. sanfranciscensis and C. humilis in traditional sourdoughs and will facilitate the optimisation of sourdough fermentations in traditional and new applications.     

Modeling high pressure inactivation of <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Listeria innocua</Emphasis> in whole milk

The survival curves of Escherichia coli and Listeria innocua inactivated by high hydrostatic pressure (HHP) were obtained at room temperature (∼22 °C) and at five pressure levels (400, 450, 500, 550 and 600 MPa) in whole milk. These curves were described by the Weibull model and parameters of this model were reduced from two to one with slight loss of goodness-of-fit. The logarithm of the time constant parameter (δ) of the reduced Weibull model was described with respect to high pressure (P). This approach can be used to define a z _p value analogous to the modeling of the classical D value (increase in pressure that results in one log unit decrease of δ values). The development of accurate survival models under high pressure, as presented here, can be very beneficial to food industry for designing, evaluating and optimizing HHP processes as a new preservation technology.     

Lactic acid fermentation of<Emphasis Type="Italic"> Brassica rapa</Emphasis>: chemical and microbial evaluation of a typical Italian product (<Emphasis Type="Italic">brovada</Emphasis>)

Brovada is an ancient traditional product from the northeast Italian region, included in any list of typical Italian products, which is obtained by natural fermentation of turnips (Brassica rapa). Turnips are cleaned and put in vats, alternating them with a layer of grape skins. Before covering the vat a mix of water and salt or water only is added. The vegetable fermentation is a spontaneous process caused by the microorganisms present on the various components (turnip and grape skins). A total 225 lactic acid bacteria (LAB) and 63 yeasts were isolated during this natural fermentation process. The main heterofermentative population was identified as Lactobacillus spp. while the major homofermentative LAB were Pediococcus spp., Candida spp. was the main yeast present. During the first 24 h of fermentation, the pH decreased rapidly to 3.7. At different steps of fermentation the headspace aroma compounds of brovada were analyzed by solid-phase-micro-extraction/gas chromatography/flame ionization detection to define the characteristic aroma profile of this particular product.     

Efficiency of pulse pressure treatment for inactivation of <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Listeria innocua</Emphasis> in whole milk

Escherichia coli ATCC 11775 and Listeria innocua ATCC 33090 in whole milk were inactivated by single- and multi-pulsed (up to 10 pulses) high hydrostatic pressure (HHP) treatments. Both bacteria showed similar resistance to single- and multi-pulsed HHP. The efficiency of pulsed pressure treatment depends on the combination of holding time of each pulse and number of pulses. It was observed that multi-pulsed pressure treatment instead of traditional single-pulsed HHP could be used to pasteurize milk at a lower pressure level. Nevertheless, an optimization is necessary between the pulse holding time, number of pulses, and pressure levels to reach the desirable log-reduction of microorganisms compatible with industrial application. This study was partly presented in Joint 21st AIRAPT and 45th EHPRG International Conference on High Pressure Science and Technology held September 17–21, 2007 in Catania (Italy).     

Antioxidant activity of <Emphasis Type="Italic">Dioscorea batatas</Emphasis> Decne glycoprotein

Dioscorea batatas Decne (DBD) has been traditionally used as folk medicine and health food in Korea. One glycoprotein was isolated from DBD and confirmed to have 30 kDa molecular weight. The DBD glycoprotein was tested its antioxidative activity and characterized in various chemical conditions. The DBD glycoprotein has the optimal free radical scavenging activities in acidic and neutral pH and up to 85 °C. In the M²⁺ ions (Ca²⁺, Mn²⁺, and Mg²⁺) in the presence of EDTA, the activities of DBD glycoprotein reduced, compared to DBD glycoprotein alone without metal ion. Interestingly, the results in this study indicated that the activities of DBD glycoprotein do not depend on the presence of EDTA. Interestingly, when DBD glycoprotein was treated with deactivation agents (pronase E or NaIO₄), scavenging activity of DBD glycoprotein was decreased. The anti-oxidative effects of DBD glycoprotein on hydroxyl radicals in cell-free system revealed, and the DBD glycoprotein has remarkable scavenging effects on hydroxyl radicals generated by G/GO. Furthermore, the results in this study showed that the DBD glycoprotein (200 μg/ml) significantly inhibits intracellular ROS amounts and protects from cytotoxicity in primary mouse splenocyte culture treated with GO (30 mU/ml). Therefore, we speculate that DBD glycoprotein has an antioxidative potential as one of natural antioxidants.     

Novel anticoagulant compound from fermented red alga <Emphasis Type="Italic">Pachymeniopsis elliptica</Emphasis>

Natural fermentation was tested as a method of releasing active compounds during screening for potential anticoagulant activity in three types of algae (Pachymeniopsis elliptica, Sargassum horneri, and Ulva pertusa). Freeze dried algae samples (2.5 g) were fermented by adding 75 g of sugar and 500 mL of water and thereafter kept at room temperature (25 °C) for 3 months. Activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) were measured every 2 weeks for 3 months to determine the optimum time for the highest activity. Fermented P. elliptica, (which had the highest activity) was subjected to anion exchange chromatography (DEAE-cellulose) and sepharose 4B gel permeation chromatography. The purified sample was analyzed by agarose-gel electrophoresis and polyacrylamide gel electrophoresis (PAGE) to confirm the purification and to determine the molecular mass, respectively. The 360 μg/mL of purified compound (Mwt > 500,000 Da) had both APTT and PT activities (>1,000 s). However, at the concentrations of 180 μg/mL, purified compound and heparin showed 540 and >1,000 s APTT activity, respectively. Though, the purified compound of P. elliptica considered as a weaker anticoagulant than heparin, this purified anticoagulant polysaccharide could be considered as a good alternative source as an anticoagulant. Moreover, the technique of fermentation is an inexpensive and feasible, this purified anticoagulant polysaccharide compound could be used in pharmaceutical and biomedical industry. Further investigations need to be performed to determine the mechanism of this novel anticoagulant compound. The authors Prashani Mudika Ekanayake and Chamilani Nikapitiya contributed equally to this work.     

Influence of<Emphasis Type="Italic"> Lactobacillus plantarum</Emphasis> on<Emphasis Type="Italic"> Staphylococcus aureus</Emphasis> growth in a fresh vegetable model system

The influence of a Lactobacillus plantarum (B₄) on the growth of Staphylococcus aureus (Sa₄) was verified by impedometric methods in a suitable model reproducing the characteristics of fresh vegetables. The inoculum size of the single strains and their growth temperature were varied according to a Central Composite Design. The results obtained via statistical analysis showed that the temperature affected the growth of both S. aureus and L. plantarum strains. The pathogenic strain, independently of its inoculum size, was inhibited by L. plantarum at all the tested temperatures. A proper combination of specific lactic acid bacteria and storage temperature should improve the safety of the vegetable products.     

Extracts of plant cell cultures of <Emphasis Type="Italic">Lavandula vera</Emphasis> and <Emphasis Type="Italic">Rosa damascena</Emphasis> as sources of phenolic antioxidants for use in foods

Ethanolic extracts of plant cell cultures of lavender (Lavandula vera) and rose (Rosa damascena) have been examined as potential food antioxidants. The L. vera cell extract quenched the radicals Fremy’s salt, DPPH (2,2-diphenyl-1-picrylhydrazyl radical), and ABTS^·+ (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic) radical) more efficiently than the R. damascena extract. Also the L. vera extract inhibited lipid oxidation in a methyl linoleate emulsion more efficiently than the R. damascena extract. However, the L. vera extract had a prooxidative effect on the iron-based Fenton reaction in an aqueous model system. A similar effect was observed for pure rosmarinic acid, but not for the R. damascena extract. The addition of L. vera extract to minced chicken meat reduced lipid oxidation (measured as thiobarbituric acid reactive species) and the loss of α-tocopherol during cold storage after the meat was cooked. This suggests the antioxidative properties of L. vera extracts dominate in a real food system.     

Supercritical fluid extraction of<Emphasis Type="Italic"> Cucurbita ficifolia</Emphasis> seed oil

Pumpkin, Cucurbita ficifolia, seed oil was extracted with supercritical carbon dioxide (SC-CO₂) in the temperature range of 308–318 K and in the pressure range of 18–20 MPa. In addition, the influence of the superficial velocity within a tubular extractor was studied. The oil content determined by a Soxhlet apparatus was 43.5%. Physical and chemical characteristics of the oil were obtained. The results in terms of free fatty acids contents were compared with those obtained when n-hexane was used as the solvent, and no significant differences between the oils extracted by both methods were found. The main fatty acid was 6-linoleic acid (about 60%), followed by palmitic acid (about 15%) and oleic acid (about 14%). Oxidative stability was studied by using the induction time determined by the Rancimat method. The oil obtained by supercritical fluid extraction (SFE) was less protected against oxidation (4.2 h for SFE-extracted oil and 8.3 h for the pumpkin seed oil extracted with n-hexane). The oil extracted by SC-CO₂ was clearer than that extracted by n-hexane, showing some refining. The acidity index was 5.5 for the n-hexane extracted oil. For the oils extracted by SC-CO₂, two analyses were made: for the oils obtained at 15 min of extraction time, for which the acidity indices varied from about 15 to 20, and for the remaining oils (extracted until 150 min), for which the acidity indices varied from about 2 to 2.6. The central composite nonfactorial design was used to optimise the extraction conditions, using the Statistica, version 5, software (Statsoft). The best results, in terms of oil recovered by SC-CO₂, were found at 19 MPa, 308 K and a superficial velocity of 6.0×10^–4 ms^–1.     

Genetic typification by pulsed-field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA (RAPD) of wild <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> and <Emphasis Type="Italic">Oenococcus oeni</Emphasis> wine strains

Genetic typification of 120 bacterial isolates of Lactobacillus plantarum and Oenococcus oeni from different Rioja musts and wines was performed by numerical analysis of pulsed-field gel electrophoresis (PFGE) patterns with endonuclease SfiI, and 46 of them were also studied by randomly amplified polymorphic DNA (RAPD)-PCR. A comparative study of both typification methods applied to L. plantarum and O. oeni oenological strains was performed. Bacterial species was determined both by biochemical identification methods and by specific PCR analysis. A wide variety of restriction digest patterns were detected by PFGE among L. plantarum strains (36 unrelated patterns and one closely related pattern, out of 48 isolates), as well as among O. oeni strains (18 unrelated patterns out of 72 isolates). PFGE was shown to be a suitable method for strain differentiation and to determine which strains are present in wine fermentations, with a discriminatory power to type L. plantarum and O. oeni strains higher than that of RAPD-PCR.     

Effect of soybean substitution on some physical,compositional and sensory properties of<Emphasis Type="Italic"> kokoro</Emphasis> (a local maize snack)

Kokoro was prepared from maize–soybean flour mixtures in ratios of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50. The physical, compositional, and sensory characteristics of kokoro were evaluated. Protein and fat contents increased, while carbohydrate content decreased as the soy flour proportion of the flour mixture used in the kokoro was increased. The bulk density and water-holding capacity increased with increasing proportion of soybean flour, while the swelling capacity was found to decrease. High soy-substitution significantly reduced the sensory acceptance of kokoro. Sensory evaluation indicated that maize:soybean flour mixture ratios of 100:0 and 90:0 were the most acceptable to the panellists.     

<Emphasis Type="Italic">Aronia melanocarpa</Emphasis> phenolics and their antioxidant activity

The purpose of the present study was to evaluate small and high molecular phenolics (tannins) and antioxidant activity of Aronia melanocarpa berries, juice and pomace in order to find new potential sources of natural antioxidants. The fruits of Aronia melanocarpa Elliot were collected in the middle of October at a plantation near Wroclaw, Poland. The pomace has a much higher content of phenolics in comparision to juice and fruits. Results showed that polymeric proanthocyanins, predominantly of (−)epicatechin, are the major class of polyphenolic compounds in chokeberry, represent 66% of fruits polyphenols. The average concentration ranged from 1578.79 mg/100 g of DW for chokeberry juice up to 8191.58 mg/100 g in pomace. The concentration of phenolic acids (chlorogenic and neochlorogenic acids) in juice was higher than in pomace. Anthocyanins in Aronia melanocarpa are second phenolic compound group and represent about 25% of total polyphenols, mixture of four different cyanidin glycosides: 3-galactoside, 3-glucoside, 3-arabinoside and 3-xyloside. The higher antioxidant activity expressed as TEAC was measured in pomace >fruit >juice.