Microwave‐synthesized magnetic chitosan microparticles for the immobilization of yeast cells

An extremely simple procedure has been developed for the immobilization of Saccharomyces cerevisiae cells on magnetic chitosan microparticles. The magnetic carrier was prepared using an inexpensive, simple, rapid, one‐pot process, based on the microwave irradiation of chitosan and ferrous sulphate at high pH. Immobilized yeast cells have been used for sucrose hydrolysis, hydrogen peroxide decomposition and the adsorption of selected dyes. Copyright © 2014 John Wiley & Sons, Ltd.     

Cross-national differences in consumer responses to savoury crackers containing blackcurrant pomace

Juice-pressing residues, among them blackcurrant pomace, are valuable materials for being upgraded in food products. Their excellent nutritional profiles in line with their functional properties allow a wide range of applications. The current study was performed to evaluate the overall liking of a pomace-enriched thin crispy-baked bread product in five European countries, and to obtain suggestions for improvements. Moreover, data on the frequency of snack consumption, openness to new foods and an opinion on residues in food applications were acquired. Four hundred and sixty-six consumers from United Kingdom, Spain, Sweden, Italy and Germany were involved. On a 9-point hedonic scale, the pomace cracker was rated towards the direction of liking with 5.94 ± 1.90 on average. Contingency tables showed that the overall-liking correlated highly significant (p < 0.01) with the country of origin and sex of the respondents and their openness to new products. Significantly higher liking scores were provided by British and Spanish consumers and, among these respondents, savoury snacks were stated to be consumed most frequently. Therefore, the snack consumption frequency also appeared to be a driver for cross-national differences in hedonic responses. The consent for using pomace in food products was remarkably high (>90%) in all countries and stresses consumer awareness in terms of healthy longevity and sustainability.     

Direct analysis of dithiocarbamate fungicides in fruit by ambient mass spectrometry

Dithiocarbamates (DTCs) are fungicides that require a specific single-residue method for detection and verification of compliance with maximum residue limits (MRLs) as established for fruit and vegetables in the EU. In this study, the use of ambient mass spectrometry was investigated for specific determination of individual DTCs (thiram, ziram) in fruit. Two complementary approaches have been investigated for their rapid analysis: (i) direct analysis in real time (DART) combined with medium-high resolution/accurate mass time-of-flight mass spectrometry (TOFMS) and high-resolution/accurate mass Orbitrap MS, and (ii) desorption electrospray ionization (DESI) combined with tandem-in-time mass spectrometry (MS(2)). With both techniques, thiram deposited on a glass surface (DART) or Teflon (DESI) could be directly detected. With DART, this was also possible for ziram. Before the instrumental analysis of fruit matrix, an extract had to be prepared following a straightforward procedure. The raw extracts were deposited on a slide (DESI), or rods were dipped into the extracts (DART), after which thiram and ziram could be rapidly detected (typically 10 samples in a few minutes). In the case of thiram, the lowest calibration levels were 1?mg?kg(-1) (DART-TOFMS, DESI-MS(2)) and 0.1?mg?kg(-1) (DART-Orbitrap MS). For ziram, the achieved lowest calibration levels were 0.5?mg?kg(-1) (DART-TOFMS) and 1?mg?kg(-1) (DART-Orbitrap MS). In all cases, this was sufficiently low to test samples against EU-MRLs for a number of fruit crops. Using an internal standard, (semi)quantitative results could be obtained.     

Transverse mechanical properties of collagen fibers from nanoindentation

The mechanical properties of collagenous tissues, such as tendon and ligaments, are of particular interest as they are found extensively in the human body. In the present study the transverse mechanical properties of collagen fibers are reported for the first time. The elastic modulus was found to be 63 ± 4 MPa, while the viscosity was estimated to be 14  \textGPa ￡ h ￡ 56  \textGPa  \texts 14\;{\text{GPa}} \le \eta \le 56\;{\text{GPa}}\;{\text{s}} . Comparison with similar data in the literature, for bulk tendon and collagen fibrils, suggests that the apparent modulus of a network of interconnected building blocks is reduced as compared to the modulus of the individual building blocks; in particular E _tendon < E _fiber < E _fibril; this is due to the fact that as the scale of the microstructure increases (i) slippage and sliding between the respective building blocks (fibrils or fibers) increases, (ii) the volume fraction of the stiff collagen proteins decreases.     

Polar compounds dominate in vitro effects of sediment extracts

Sediment extracts from three polluted sites of the river Elbe basin were fractionated using a novel online fractionation procedure. Resulting fractions were screened for mutagenic, aryl hydrocarbon receptor (AhR)-mediated, transthyretin (TTR)-binding, and estrogenic activities and their potency to inhibit gap junctional intercellular communication (GJIC) to compare toxicity patterns and identify priority fractions. Additionally, more than 200 compounds and compound classes were identified using GC-MS/MS, LC-MS/MS, and HPLC-DAD methods. For all investigated end points, major activities were found in polar fractions, which are defined here as fractions containing dominantly compounds with at least one polar functional group. Nonpolar PAH fractions contributed to mutagenic and AhR-mediated activities while inhibition of GJIC and estrogenic and TTR-binding activities were exclusively observed in the polar fractions. Known mutagens in polar fractions included nitro- and dinitro-PAHs, azaarenes, and keto-PAHs, while parent and monomethylated PAHs such as benzo[a]pyrene and benzofluoranthenes were identified in nonpolar fractions. Additionally, for one sample, high AhR-mediated activities were determined in one fraction characterized by PCDD/Fs, PCBs, and PCNs. Estrone, 17β-estradiol, 9H-benz[de]anthracen-7-one, and 4-nonylphenol were identified as possible estrogenic and TTR-binding compounds. Thus, not only nonpolar compounds such as PAHs, PCBs, and PCDD/Fs but also the less characterized and investigated more polar substances should be considered as potent mutagenic, estrogenic, AhR-inducing, TTR-binding, and GJIC-inhibiting components for future studies.     

Removal of Pseudomonas putida biofilm and associated extracellular polymeric substances from stainless steel by alkali cleaning

Alkali (NaOH)-based compounds are commonly used in the food industry to clean food contact surfaces. However, little information is available on the ability of alkali and alkali-based cleaning compounds to remove extracellular polymeric substances (EPS) produced by biofilm bacteria. The objectives of this study were to determine the temperature and NaOH concentration necessary to remove biofilm EPS from stainless steel under turbulent flow conditions (clean-in-place simulation) and to determine the ability of a commercial alkaline cleaner to remove biofilm EPS from stainless steel when applied under static conditions without heat. Biofilms were produced by growing Pseudomonas putida on stainless steel for 72 h at 25 degrees C in a 1:10 dilution of Trypticase soy broth. The biofilms were treated using NaOH at concentrations of 1.28 to 6.0% and temperatures ranging from 66 to 70 degrees C. Other biofilms were treated with commercial alkaline cleaner at 25 or 4 degrees C for 1 to 30 min. Removal of EPS was determined by direct microscopic observation of samples stained with fluorescent-labeled peanut agglutinin lectin. Treatment with 1.2% NaOH at 66 degrees C for 3 min was insufficient to remove biofilm EPS. A minimum of 2.5% NaOH at 66 degrees C and 2.0% NaOH at 68 degrees C for 3 min were both effective for EPS removal. Commercial alkaline cleaner removed over 99% of biofilm EPS within 1 min at 4 and 25 degrees C under static conditions. Selection of appropriated cleaning agent formulation and use at recommended concentrations and temperatures is critical for removal of biofilm EPS from stainless steel.     

Timing of ICSI with Respect to Meiotic Spindle Status

The aim of this study was to evaluate the efficiency of using meiotic spindle (MS) visibility and relative position to the polar body (PB) as indicators of oocyte maturation in order to optimize intracytoplasmic sperm injection (ICSI) timing. This was a cohort study of patients younger than 40 years with planned ICSI, the timing of which was determined by MS status, compared with those without MS evaluation. The angle between PB and MS and MS visibility were evaluated by optical microscope with polarizing filter. Oocytes with MS evaluation were fertilized according to MS status either 5–6 h after ovum pick-up (OPU) or 7–8 h after OPU. Oocytes without MS evaluation were all fertilized 5–6 h after OPU. For patients over 35 years visualization of MS influenced pregnancy rate (PR): 182 patients with MS visualization had 32% PR (58/182); while 195 patients without MS visualization had 24% PR (47/195). For patients under 35 years, visualization of MS did not influence PR: 140 patients with MS visualization had 41% PR (58/140), while 162 patients without MS visualization had 41% PR (66/162). Visualization of MS therefore appears to be a useful parameter for assessment of oocyte maturity and ICSI timing for patients older than 35.     

Reduction in alphabet priming with delay and degradation.

Phonologically ambiguous Serbo-Croatian words are named more slowly than their phonologically unique partners. This difference is reduced by nonword primes containing consonants unique to one or the other alphabet. In 2 experiments the hypothesis was investigated that alphabet priming is the inhibition of unique and ambiguous letter units of one alphabet by the unique letter units of the other alphabet. In Exp 1, ambiguous and unique words followed alphabet-specific nonwords at lags between 100 msec and 1,550 msec. The ambiguous–unique difference increased from 1 msec to 45 msec, consistent with a relaxing inhibitory process. Exp 2 compared priming of ambiguous words with and without visual noise. Priming was less for noisy than for intact stimuli, as would be expected if noise slows processing and if the inhibition responsible for priming weakens further during the additional processing time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)