Machine strength grading of Argentinean<Emphasis Type="Italic"> Eucalyptus grandis</Emphasis>

The present paper reports the results of an investigation regarding the possibility of machine strength grading sawn timber of Argentinean Eucalyptus grandis. In order to assess the usefulness of each parameter for predicting the mechanical properties of this timber species, and to propose strength, stiffness and density profiles, an empirical research project with four samples of beams and one sample of boards subjected to bending, and another sample of boards subjected to tension parallel to the grain, was carried out. The results obtained with specimens in structural sizes reveal the more important single and combined parameters for machine strength grading this timber species, and allow to analyse strength, stiffness and density profiles in comparison with the international strength class system established in the European standard EN 338.     

Mixed glued laminated timber of poplar and<Emphasis Type="Italic"> Eucalyptus grandis</Emphasis> clones

The authors investigated the properties of small-sized joint-free laminated beams (80 mm in width, 115 mm in height and 2 m in length) composed of 7 mechanically graded laminations of poplar (Populus x euramericana, 'Neva' clone) and eucalyptus (Eucalyptus grandis, '7', '329', '330' and '358' clones) in different combinations. Tests were carried out in order to determine their modulus of elasticity, bending strength and shear modulus; the bonding reliability was also evaluated by means of delamination and shear tests in the glue lines. The beams composed using the '330' eucalyptus clone, by its own or in combination with poplar, showed outstanding mechanical performance and the best structural efficiency. In addition the bonding quality, also at the interface between the two species, proved to be excellent. The results, separately for each clone of E. grandis, in terms of absolute values and structural efficiency, are shown and discussed.

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Schichtverklebtes Holz mit einer Mischung von Pappel und Eucalyptus grandis Klonen

Zusammenfassung Die Autoren untersuchten die Eigenschaften von kleinen verbindungsfreien Brettschichtträgern (von 80 mm Breite, 115 mm in Höhe and 2 m Höhe) zusammengesetzt aus 7 mechanisch sortierten Brettschichthölzern von Pappel (Populus x euramericana, 'Neva' clone) und Eucalyptus (Eucalyptus grandis, '7', '329', '330' und '358' Klonen) in unterschiedlichen Kombinationen. Tests wurden durchgeführt, um ihr Elastizitätsmodul, ihre Biegefestigkeit und Scherfestigkeit zu bestimmen; die Haftverläßlichkeit wurde ebenfalls abgeschätzt durch Delaminierung und Schertests in den Klebefugen. Die zusammengestellten Balken, bei denen man den 330 Eukalyptusklon verwendete, entweder allein oder in Kombination mit Pappel, zeigten herausragende mechanische Qualität und die beste strukturelle Leistungsfähigkeit. Zusätzlich erwies sich die Bindefestigkeit, auch an den Grenzflächen zwischen den beiden Arten als exzellent. Es werden die Ergebnisse separat für jeden Klon von E. grandis, als absolute Werte und als strukturelle Leistungsfähigkeit dargestellt und diskutiert.

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Tyramine production of technological important strains of <Emphasis Type="Italic">Lactobacillus</Emphasis>, <Emphasis Type="Italic">Lactococcus</Emphasis> and <Emphasis Type="Italic">Streptococcus</Emphasis>

The aim of this paper was to study the biogenic amines (histamine, tyramine, putrescine, cadaverine, agmatine, spermine and spermidine) production of selected technological important lactic acid bacteria (strains of the genera Lactococcus, Lactobacillus and Streptococcus). Three methods (ion-exchange chromatography (IEC), PCR and cultivation method with pH indicator) were used. Within the 39 strains of lactic acid bacteria tested, the production of tyramine (formed by tyrosine decarboxylase) was detected in eight strains (3 strains of Lactococcus lactis subsp. lactis, three strains of Lactococcus lactis subsp. cremoris, 1 strain of Streptococcus thermophilus and 1 strain of Lactobacillus delbrueckii subsp. bulgaricus). The other tested biogenic amines were not detected. Cultivation in decarboxylation broth seems to be the least accurate method for the detection of biogenic amines due to enhanced risk of false-positive reactions. Therefore, in order to detect bacteria producing biogenic amines, the combination of PCR and chromatographic methods (e.g. IEC) can be recommended.     

Estrogenic effects of various extracts from <Emphasis Type="Italic">Chamdanggui</Emphasis> (<Emphasis Type="Italic">Angelica gigas</Emphasis> Nakai) and <Emphasis Type="Italic">sogdan</Emphasis> (<Emphasis Type="Italic">Phlomis umbrosa</Emphasis> Turcz)

The various extracts from chamdanggui (Angelica gigas Nakai) and sogdan (Phlomis umbrosa Turcz) were evaluated for estrogenic activity and characterized according to HPLC profile. Chamdanggui and sogdan were individually extracted with 4 solvents (hot water, 70% ethanol, n-butanol, and dichloromethane) of differing polarities. Estrogenic activity was determined by E-screen using an estrogen-dependent MCF-7 BUS cell. Although almost all extracts showed estrogenic effects in a concentrationdependent manner, the hot water extract from chamdanggui (250 μg/mL) had the higher effect (138%). Among 90 fractions using HPLC separation of the hot water extract from chamdanggui, fraction 21 and 28 produced the highest estrogenic effects of 178 and 163% at 10 μg/mL, respectively. The results imply that the hot water extract from chamdanggui could be useful as an alternative hormone replacement therapy.     

Thermal inactivation kinetics of quality-related enzymes in cauliflower (<Emphasis Type="Italic">Brassica oleracea</Emphasis> var. <Emphasis Type="Italic">botrytis</Emphasis><Emphasis Type="Bold">)</Emphasis>

Thermal inactivation of quality-related enzymes in both cauliflower crude enzyme extracts and fresh tissue samples was studied in temperature range 50–100 °C. For crude enzyme extracts, several parameters, reaction rate constants (k) and activation energy (E _a) as well as decimal reduction time (D) and (z) values, were used to characterize the thermal stability. The rates of inactivation were found to follow first-order inactivation kinetics. Activation energies varied between 101.18 and 208.42 kJ mol⁻¹ with z values of 10.59–24.09 °C. The examined kinetics indicated that lipoxygenase was the most heat resistant followed by peroxidase, polyphenol oxidase, pectin methyl esterase and ascorbic acid oxidase. Furthermore, the obtained results from the blanched fresh tissues indicated that inactivation of lipoxygenase secured disappearing of any other enzyme activities. Therefore, this study recommends using lipoxygenase as an indicator enzyme to optimize the thermal treatments of cauliflower products.     

A New Multiplexed Real-Time PCR Assay to Detect <Emphasis Type="Italic">Campylobacter jejuni</Emphasis>, <Emphasis Type="Italic">C. coli</Emphasis>, <Emphasis Type="Italic">C. lari</Emphasis>, and <Emphasis Type="Italic">C. upsaliensis</Emphasis>

A new rapid method based on real-time PCR was developed to detect four thermophilic Campylobacter species (Campylobacter jejuni, Campylobacter coli, Campylobacter lari, and Campylobacter upsaliensis) in food samples. The assay targeted the bipA gene for C. upsaliensis and C. lari, whereas the gene encoding the ATP-binding protein CJE0832 was used to detect C. coli and C. jejuni. These genes were chosen for this assay due to their low variability and mutation rate at a species level. The multiplex PCR showed 100% inclusivity for all 25 thermophilic Campylobacter strains tested and 100% exclusivity for 38 non-targeted strains belonging to closely related species. The newly developed real-time PCR could detect down to 10² genomes/reaction and displayed efficiency above 97% for all species except for C. upsaliensis (90.1%). The method proved to be a reliable tool for food analysis, showing 100% sensitivity, 96% efficiency, and 92.45% specificity when validated against the gold standard method UNE-EN ISO 10272:2006 using 200 diverse food samples (meat, fish, fruits and vegetables, and raw milk). In artificially spiked samples, the detection limit of the method was 10 cfu/g in salad, 5 cfu/g in turkey meat, and 1 cfu/g in the rest of meat samples tested. Consequently, the newly designed molecular tool represents a quick and safe alternative to obtain reliable results concerning the presence/absence of the main thermophilic Campylobacter in any food sample.     

In vivo study of antiallergenicity of ethanol extracts from <Emphasis Type="Italic">Sargassum tenerrimum</Emphasis>, <Emphasis Type="Italic">Sargassum cervicorne</Emphasis> and <Emphasis Type="Italic">Sargassum graminifolium turn</Emphasis>

Food allergy has becoming the serious threat in the world for which the search of an effective anti-allergic drug is the demand of time. Keeping in view of the potentiality of seaweeds, the ethanol extracts from Sargassum tenerrimum (ST), Sargassum cervicorne (SC), and Sargassum graminifolium turn (SG) have been studied in vivo for its antiallergenicity through passive cutaneous anaphylaxis (PCA) and active cutaneous anaphylaxis (ACA) in female BALB/c mice. Intraperitoneal administration of these ethanol extracts inhibit mouse PCA and ACA in a dose-dependent manner using ovalbumin (OVA) and shrimp allergen as triggering agents to induce allergenicity over mice. The extract of ST containing phlorotannin has been found most active over the suppression of PCA triggered by OVA and shrimp with IC₅₀ values of 25.64 and 40.98 mg/kg, respectively and an efficacy comparable to that of an anti-allergic drug disodiumcromoglycate. Similarly, ST inhibits ACA triggered by ova and shrimp allergen in the mouse, with 50% suppression at 25.5 and 43.53 mg/kg, respectively. The results presented here show that these extracts are active on the studied models among which ethanol extract of ST was the most potent, leading toward the promising development of a new class of anti-allergic drugs.     

Molecular diversity among natural populations of <Emphasis Type="Italic">Lactobacillus paracasei</Emphasis> and <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis>/<Emphasis Type="Italic">paraplantarum</Emphasis> strains isolated from autochthonous dairy products

The diversity of 87 Lactobacillus paracasei and Lactobacillus plantarum/paraplantarum strains, previously identified from different autochthonous dairy products, was investigated by phenotypic and genotypic approaches. The increased resolution obtained using phenotypic and genotypic characterization allowed the level of strain heterogeneity detection to be widened. Phenotypic diversity was evaluated by studying biochemical characteristics of technological interest, including antimicrobial and proteinase activities, resistance to nisin, aggregation ability, production of exopolysaccharides, acetoin and diacetyl, citrate utilization, and antibiotic susceptibility. Genotypic diversity was generally evaluated by PCR amplification of repetitive bacterial DNA element fingerprinting using the (GTG)₅ primer [(GTG)₅-PCR]. Moreover, in cases where strains were not discriminated by (GTG)₅-PCR combined with phenotypic analysis, pulsed-field gel electrophoresis (PFGE) analysis was performed. The results indicate that L. plantarum/paraplantarum and L. paracasei natural isolates from artisanal dairy products are a gold mine in terms of diversity of strains and could be potentially interesting to dairy companies for the formulation of functional starter cultures in the production of innovative foods.     

Antioxidant and emulsion properties of freshwater carps (<Emphasis Type="Italic">Catla catla</Emphasis>, <Emphasis Type="Italic">Labeo rohita</Emphasis>, <Emphasis Type="Italic">Cirrhinus mrigala</Emphasis>) protein hydrolysates prepared using flavorzyme

Fish protein hydrolysates (FPHs) were prepared from freshwater carps (Catla catla, Labeo rohita, and Cirrhinus mrigala) using flavorzyme at different degrees of hydrolysis (DHs) ranging from 5 to 20%. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging activity of the FPHs prepared from the three species were in the range of 50–82%; the ferric reducing power of the FPHs prepared from catla was the highest. The linoleic acid peroxidation inhibition activity of the prepared FPHs varied from 71 to 91%. The emulsion activity index of the FPHs prepared from catla and rohu decreased significantly with an increase in the DH (p < 0.05). The emulsion stability index of the FPHs prepared from the three species was the highest at 20% DH. FPHs prepared from freshwater carps possess good antioxidant and surface-active properties and are therefore suitable to be used as natural antioxidants in health-food formulation and as water-soluble antioxidants in the food-processing industry.     

Exposure assessment of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> in <Emphasis Type="Italic">Kimbab</Emphasis>, a ready-to-eat Korean food

The exposure assessment was carried out for Staphylococcus aureus in kimbab by predicting growth of S. aureus and the production of enterotoxin using Food MicroModel® program. Environmental parameters selected were pH 5.5, Aw 0.999, and storage temperatures in the range of 10 to 30°C. It was predicted that 6.3 hr could be a critical time for enterotoxin production while kimbab was stored at 30°C. Mild case scenario analysis showed that enterotoxin could not be produced if kimbab was kept at 10°C during preparation and distribution and then left at 25°C for 4 hr before consumption. In the worst case scenario, the keeping time at 25°C was assumed to be 7.0 hr. The level of S. aureus in the worst case was predicted to be 6.8×10⁶ CFU/g which is lower than the critical level (7.8×10⁶ CFU/g) for toxin production.     

Nutritional properties of mussels <Emphasis Type="Italic">Mytilus galloprovincialis</Emphasis>

The aim of this study was to determine the quality indices and assess the influence of diets supplemented with mussels from contaminated (MCont) and non-contaminated areas (MNCont) on some indices of protein and lipid metabolism in rats fed with cholesterol. A wide range of in vitro tests demonstrated that mussels from contaminated area have a higher content of proteins, lipids and higher antioxidant capability. In the in vivo experiment, 28 male Wistar rats were divided into 4 diet groups each of 7 and named Control, Cholesterol (Chol), Chol/MCont and Chol/MNCont. During 30 days of the experiment rats of all four groups were fed basal diet (BD), supplemented with 1% of Chol, 1% of Chol and 5.6% of mussel’s dry matter (DM) from contaminated and 1% Chol and 5.6% of mussel DM from non-contaminated areas for Chol/MCont and Chol/MNCont groups, respectively. At the end of the experiment, a high digestibility coefficient of DM and crude protein in the Chol/MCont and Chol/MNCont groups of rats was found: 93.56 and 93.87% and 91.64 and 91.36%, respectively, and the differences were not significant (P > 0.05). However, the protein efficiency ratio was significantly higher in the Chol/MCont and Chol/MNCont than in the Control and Chol diet groups. Also the level of nitrogen retention as shown by feces and urine examination was higher in the Chol/MCont and Chol/MNCont groups. Diet, supplemented with mussel dry matter from both contaminated and non-contaminated areas significantly hindered the rise in plasma lipids and also hindered the decrease in plasma antioxidant activity. Minor changes were fixed in the protein profile of rat’s plasma after both mussels’ diet. In conclusion, supplementation of diets, containing cholesterol with mussels’ DM from both contaminated and non-contaminated areas improves animals’ protein metabolism and positively affects plasma lipid profile and plasma antioxidant activity. Antioxidant tests can be used as an additional index for the quality of mussels.     

Effect of <Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> Bauer and <Emphasis Type="Italic">Bifidobacterium animalis</Emphasis> ssp. <Emphasis Type="Italic">lactis</Emphasis> BB12 on proteolytic changes in dry-cured loins

The effect of the potentially probiotic bacteria strain of Lactobacillus acidophilus Bauer and probiotic bacteria Bifidobacterium animalis ssp. lactis BB12 on proteolytic changes of proteins in dry-cured loins during fermentation and cold storage was studied. Results of the conducted tests demonstrated that the use of probiotic bacteria for the production of dry-cured meats impacts the generation of products of protein proteolysis with high antioxidant activity. The highest antioxidant activity of peptides after fermentation and cold storage was observed in the loin with the strain B. animalis ssp. lactis BB12 and the loin with the mixture of strains L. acidophilus Bauer and B. animalis ssp. lactis BB12. Qualitative analysis of peptides demonstrated that peptides with weight below 3.5 kDa are characterized by the highest capacity of quenching the ABTS cation radical, including the peptides in loins with the strain B. animalis ssp. lactis BB12.     

Pressurized acidified water extraction of black carrot [<Emphasis Type="Italic">Daucus carota</Emphasis> ssp. <Emphasis Type="Italic">sativus</Emphasis> var. <Emphasis Type="Italic">atrorubens</Emphasis> Alef.] anthocyanins

The anthocyanins present in black carrot were extracted with pressurized water acidified with sulfuric, citric and lactic acids. Anthocyanin degradation became significant above 100 °C and there was no improvement when extraction pressure was increased to 100 bar. Therefore, the extraction from black carrot was carried out at temperatures 50, 75 and 100 °C under 50 bar pressure. The extraction efficiencies in terms of acylated and non-acylated anthocyanins were comparable for all three acids used to acidify water at 50 °C, while similar results were observed at 75 °C for both citric and lactic acids. Water acidified with lactic acid showed significantly higher extraction efficiency at 100 °C compared to water acidified with sulfuric and citric acids. Highest degree of polymerization together with increasing degree of browning was observed within extracts when sulfuric acid was used. On the other hand, when organic acids were used to acidify water, a higher extraction efficiency of anthocyanins, accompanied with a relatively low polymerization and browning was observed, with lactic acid giving the best results.     

Optimization for encapsulation of green tea (<Emphasis Type="Italic">Camellia</Emphasis><Emphasis Type="Italic">sinensis</Emphasis> L.) extract by spray drying technology

Green tea has been credited with providing a wide variety of health benefits like higher total antioxidant, cancer prevention, and anti-irritant etc. Microencapsulation technology is used to prevent antioxidant loss during processing which involves entrapment of active material into carrier material. The experiments were designed using response surface methodology based on three level two factor (green tea extract, 10–25 % and drying inlet air temperature, 120, 130 and 140°C) central composite design. The feed emulsion was prepared with green tea extract as core material and 40 % maltodextrin concentration as wall material with the ratio of core to wall (1:2) and it was fed into the spray dryer at varied drying inlet air temperature to get encapsulated green tea extract powder. The quality characteristics were analysed such as moisture content, total antioxidant activity and total phenolic content and the process conditions were optimized using desirability function methodology. At optimum spray drying condition moisture content, total antioxidant activity and total phenolic content were found to be 3.1 % w.b., 72.91 % free radical scavenging activity by DPPH method, 57.81 mg/g of dry matter, expressed as gallic acid equivalent respectively with desirability value of 0.92.     

Effect of heat-treated <Emphasis Type="Italic">Nuruk</Emphasis> on the quality characteristics of aged <Emphasis Type="Italic">Yakju</Emphasis>

Long-term aging of Yakju, a traditional Korean liquor made of rice and Nuruk (a fermentation agent), causes browning and odor and flavor development. This study investigated the effects of heat-treated Nuruk (50–80 °C, 30 min) on Yakju quality. The saccharogenic powers and glucoamylase, α-amylase, and carboxypeptidase activities were similar in non-heat-treated Nuruk and that treated at 50 °C. However, acidic protease and alcohol dehydrogenase decreased above 50 °C. The content of nitrogen-containing compounds was inversely proportional to the heat-treatment temperature. Compounds that cause off-flavors decreased at 50–60 °C, but increased at 70–80 °C, whereas compounds that provide fragrance increased at 50–60 °C. Sensory evaluation indicated that bad taste attributes were higher in Yakju produced using non-heat-treated Nuruk. Therefore, heat treatment of Nuruk at 50 °C can be adopted as a method for improving Yakju quality, as enzymatic activities that affect color, aroma, and taste are regulated.     

Development of a nucleic acid lateral flow immunoassay for simultaneous detection of <Emphasis Type="Italic">Listeria</Emphasis> spp. and <Emphasis Type="Italic">Listeria</Emphasis><Emphasis Type="Italic">monocytogenes</Emphasis> in food

We present a new nucleic acid lateral flow immunoassay (NALFIA) for the assessment of listeria contamination. The detection procedure starts with enrichment of sample in Half Fraser broth (24 h). Following isolation of DNA, a duplex PCR is performed with two labelled primer sets, one generic and directed to a specific sequence of the gene encoding 16S rRNA from Listeria spp. and the other specific and directed to a part of the prfA gene encoding the central virulence gene regulator from the food pathogen Listeria monocytogenes (3.5 h). The PCR solution is directly added to the one-step assay device and the appearance of a grey/black line is indicative of the presence of specific amplicons (max 15 min). In all tests performed, the method correctly identified L. monocytogenes and strains of Listeria spp. PCR material of over 20 food samples was tested by NALFIA. The method proved to be useful for the detection of L. monocytogenes in different kinds of food samples.     

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     

Differences of Bactericidal Efficacy on <Emphasis Type="Italic">Escherichia coli</Emphasis>, <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>, and <Emphasis Type="Italic">Bacillus subtilis</Emphasis> of Slightly and Strongly Acidic Electrolyzed Water

In the present study, the disinfection efficacy of slightly acidic electrolyzed water (SAEW) and strongly acidic electrolyzed water (AEW) was tested on three bacteria, Escherichia coli, Staphylococcus aureus, and Bacillus subtilis and the disinfection mechanism was discussed. The results showed that SAEW had a stronger antibacterial efficacy against these tested bacteria in comparison with AEW. The results also showed that both SAEW and AEW treatments could damage the cell membrane, which was demonstrated microcosmically by scanning electron microscopy (SEM), thus causing leakages of protein, DNA, RNA, and ATP, resulting in the death of microbes. Moreover, AEW treatment could not cause the degradations of DNA and RNA, and nucleic acids including DNA and RNA are not the target point of its bactericidal efficacy. However, SAEW could maybe cause the degradation of RNA, and RNA may be the target in its antibacterial activity. We suggested that the differences in antibacterial efficacy between SAEW and AEW could be explained by the different impacts on RNA of tested strains.     

Spray Chilling Microencapsulation of <Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> and <Emphasis Type="Italic">Bifidobacterium animalis</Emphasis> subsp. <Emphasis Type="Italic">lactis</Emphasis> and Its Use in the Preparation of Savory Probiotic Cereal Bars

The use of probiotic microorganisms has been limited by the difficulty of maintaining their viability during processing and throughout the product’s shelf life. This study evaluated the viability of microencapsulating Lactobacillus acidophilus (LA) and Bifidobacterium animalis subsp. lactis (BL) using the spray chilling technique to add them to savory cereal bars. The results showed that spray chilling generated a powder that was composed of smooth and continuous spheres with low moisture content and low water activity. The microencapsulated microorganisms exhibited a storage viability at least of 90 days as microparticles and in savory cereal bars, and their counts were superior to those resulting from other methods of adding activated and lyophilized probiotics to savory cereal bars. Thus, microparticles prepared by spray chilling are good vehicles for incorporating probiotics into cereal bars and have the potential to release the probiotics in the consumers’ intestines by means of fat digestion. Savory cereal bars that did and did not contain probiotics exhibited no differences in sensorial acceptance or commercial potential.