The impact of the various chemical and physical factors on the degradation rate of bronopol

Bronopol (2‐bromo‐2‐nitropropane‐1,3‐diol) is used as preservative in cosmetic industry. Its main role in commercial products consists in protection of the cosmetic composition stability by inhibiting the development of micro‐organisms. Unfortunately, preservatives can also undergo the degradation processes. The aim of examinations was to prove that bronopol decomposes in aqueous solutions and storage conditions have a significance influence on its degradation rate. High‐performance liquid chromatography method (methanol/water with hydrochloric acid 5:95 v/v) with spectrophotometric detection (210 nm) was used for examining the decomposition rate of bronopol. The impact of chemical (addition of cosmetics components: citric acid and/or sodium dodecylsulfate) and physical (elevated and ambient temperature, sunlight or ultraviolet radiation and air access) factors has been elaborated. Bronopol decomposes most rapidly (independently on the sample surrounding conditions) when it is in solution with sodium dodecylsulfate, the inverse dependence is observed in the presence of two compounds – citric acid and sodium dodecylsulfate. Additionally, the elevated temperature causes the acceleration of decomposition. Bronopol degradation by‐products were also identified as methanol, formic acid, tris(hydroxymethyl)methane and 2‐bromo‐2‐nitroethanol.     

Impact of the synbiotic combination of Lactobacillus casei shirota and oligofructose-enriched inulin on the fecal volatile metabolite profile in healthy subjects

Scope: Hypothesis‐driven approaches have mainly focused on the quantification of SCFAs as mediators of beneficial effects of synbiotics. However, the emergence of metabolite profiling strategies allows to evaluate the colonic metabolism from a top‐down approach. In the present study, we evaluated the impact of a synbiotic combination on fecal metabolite profiles. Methods and results: A synbiotic combination (Lactobacillus casei Shirota cells+oligofructose‐enriched inulin) was evaluated in nine healthy volunteers. Before the start, during and after 4‐wk treatment, fecal samples were obtained. GC‐MS technology was applied to analyze the volatile metabolites. Application of a Type III test revealed that the metabolite profiles from the three conditions were significantly different. We identified three volatile organic compounds, acetate, dimethyl trisulfide and ethyl benzene, which were significantly affected. The acetate levels increased, whereas the dimethyl trisulfide levels decreased during and after the intervention. For ethyl benzene only an effect during the synbiotic intervention period was observed. Conclusion: We report a detailed analysis of the influence of L. casei Shirota combined with oligofructose‐enriched inulin on fermentation metabolites. Our results indicated a stimulation of saccharolytic fermentation and, importantly, a reduction of potentially toxic protein fermentation metabolites dimethyl trisulfide and ethyl benzene attended these effects.     

Polymorphism of the MPR1 gene required for toxic proline analogue resistance in the Saccharomyces cerevisiae complex species

We recently discovered, on the chromosome of Saccharomyces cerevisiae sigma 1278b, novel MPR1 and MPR2 genes required for resistance to a toxic analogue of L-proline, L-azetidine-2-carboxylic acid. The MPR genes, which were absent in the S. cerevisiae genome project strain S288C, encoded a novel acetyltransferase of 229 amino acids that detoxifies the analogue by acetylating it. The MPR1 gene homologue found in Schizosaccharomyces pombe was also shown to encode a similar acetyltransferase. To further analyse the origin and the physiological role of the yeast novel gene, we report here the comparative analysis of the MPR1 gene in the S. cerevisiae complex spp. which belong to the Saccharomyces sensu stricto group. Only the type strain of S. paradoxus exhibited resistance and acetyltransferase activity to L-azetidine-2-carboxylic acid. PCR was then used to isolate the new MPR1 homologue (Spa MPR1) from S. paradoxus with the primers based on the sequence of the MPR1 gene. Gene expression and enzymatic analysis showed that the cloned Spa MPR1 gene encodes an L-azetidine-2-carboxylic acid acetyltransferase of 231 amino acids, which has 87% identity to the MPR1 protein. We also found in the protein databases that S. bayanus contains a DNA fragment that is partly homologous to the MPR1 gene. However, the gene product was considered to lose the enzymatic activity, possibly due to the gene truncation or the base substitution(s) at the important region for catalysis. Further, genomic PCR analysis showed that most of the S. cerevisiae complex spp. have the sequence highly homologous to the MPR1 gene.     

Changes on free amino acids during the alcoholic fermentation of strawberry and persimmon

Changes in amino acids and ammonium were monitored during the alcoholic fermentation of strawberry and persimmon purees. Fermentations were carried out either by autochthonous or by commercial yeasts. The amino acid content in strawberry and persimmon was lower than that of grapes but enough to successfully perform the alcoholic fermentation, showing a different consumption pattern. Arginine, although is not present in the most strawberry substrates, appears in strawberry wines (2.75–3.36 mg L^?1). Additionally, as opposed to grape wine, an exceptional high consumption of proline was observed during the alcoholic fermentation of strawberry purees. The consumption of amino acids was highly influenced by the substrate and the S. cerevisiae strain used for the fermentation process. These results were confirmed by principal component analysis, which was able to group the samples based on substrate, harvest or yeast strain, considering the amino acids as variables.     

Proteomic analysis of the distribution of the major seed allergens in wild,landrace, ancestral,and modern soybean genotypes

BACKGROUND: A comparative analysis of seed allergens from various soybean genotypes is crucial for identifying and eliminating potential allergens. We have investigated the distribution of three major allergens (Gly m Bd 60K, Gly m Bd 30K and Gly m Bd 28K) in wild, landrace, ancestral and modern soybean genotypes. RESULTS: Gly m Bd 60K allergens consist of α subunits of β‐conglycinin and G2 subunits of glycinin. In wild genotypes, α subunits of β‐conglycinin separated into six to seven protein spots whereas five to seven spots were observed in the landraces. All genotypes of modern and ancestral groups showed 3–5 protein spots of α subunits of β‐conglycinin. All genotypes showed eight spots of glycinin G2 subunits except one ancestral genotype which had seven spots. Two protein spots were detected for Gly m Bd 30K in 14 genotypes but one spot was detected in two wild genotypes. Two protein spots were detected for Gly m Bd 28K in all genotypes. CONCLUSION: Considerable heterogeneity of the α subunit of β‐conglycinin distribution exists among these 16 soybean genotypes. Significant proteomic variation was observed between different soybean groups rather than among genotypes in the same group. This investigation would be valuable to researchers working with soybean and nutrition. Copyright © 2007 Society of Chemical Industry     

Influence of the emulsion components and preparation method on the laboratory‐scale preparation of o/w emulsions containing different types of dispersed phases and/or emulsifiers

Emulsification is a complex process, strongly influenced by emulsion composition as well as by preparation procedure, and the characterisation of emulsions with regard to their structure and stability can be carried out with many different methods. To evaluate the influences of emulsion composition and preparation procedure on the structure and properties, oil‐in‐water emulsions were prepared using the model dispersed phase dodecane and the surfactant Tween on the one hand and the real food components sunflower oil (dispersed phase) and casein (emulsifier) on the other hand. The emulsions were prepared in a small laboratory‐scale with a turbo‐mixer alone and in combination with ultrasonic treatment. The emulsion activity was measured by photometry, the emulsion stability was evaluated visually and the droplet size was determined by laser particle analysis. The results of the investigations made with the model substances agreed only partly with those made with the real food substances. For the model emulsions strong correlation were found between the emulsion activity and the particle sizer data because of the high purity and the defined structure of the model substances. On the contrary, for the emulsions made with the real food components sunflower oil and sodium caseinate the correlation were much weaker. Therefore, a proper characterisation of the structure and properties of food emulsions requires examinations with several methods which are independent from each other. Furthermore, for laboratory‐scale emulsification the combination of turbo‐mixer and ultrasonic treatment is suitable to obtain small droplets and a narrow droplet distribution also for very small emulsion volumes.     

Influence of eye make-up on the perception of gaze direction

Make‐up has a beautifying effect on facial attractiveness. However, little is known about the role of make‐up in other than social perception. Does eye make‐up applied to a gazing face influence the perception of this gaze by others? Eye make‐up might make an individual’s gaze more recognizable by emphasizing the contrast of the eyes. Or make‐up might make gaze less recognizable by transforming eyes to unnatural shapes. There were two stimulus conditions: eye make‐up (no‐eyeliner, thin‐eyeliner and thick‐eyeliner) and gaze direction (same gaze direction and different gaze directions). Participants had to make a recognition response indicating whether the gaze directions were the same or different. Results indicated that in the same gaze‐direction condition, thin and thick‐eyeliner made recognition of a persisting gaze direction easier, whereas in the different gaze‐direction condition thick‐eyeliner made it more difficult to recognize the changes in gaze direction. These findings suggested a significant role of make‐up in facial processing.     

Development of made‐in‐transit set culture yoghurt: effect of increasing the concentration of reconstituted skim milk as the milk base

The fermentation time, yoghurt acidity expressed as lactic acid, starter culture growth, viscosity and firmness of made‐in‐transit (MIT) set culture yoghurt produced using different concentrations of reconstituted skim milk powder (SMP) from 12% to 20% (w/v) as the milk base were investigated. All milk base formulations were ultra‐high temperature sterilised at 138 °C for 6 s. The results revealed that increasing the SMP concentration increased the viscosity and firmness of MIT set culture yoghurt. At 20% SMP, viscosity and firmness were 4650.8 cP and 1.266 N, respectively. Fermentation of MIT set culture yoghurt with 20% SMP was observed to be faster than with the other conditions. The fermentation time for a medium containing from 14% to 20% SMP could be extended to 168 h, reaching a final pH of 4.50–4.37 and at the same time improving the texture of the MIT set culture yoghurt. The SMP concentration had no influence on the total viable counts of starter bacteria in the yoghurt. The texture of MIT set culture yoghurt may be improved by increasing the concentration of SMP.     

The effect of salinity on the growth,yield and essential oils of turnip‐rooted and leaf parsley cultivated within the Mediterranean region

BACKGROUND: Turnip‐rooted parsley, a field‐crop of northern Europe, has recently been introduced to the Mediterranean region for fresh consumption or production of essential oil. Because of soil salinity within this area, the sensitivity of turnip‐rooted and two other parsley subspecies (plain‐ and curly‐leafed) to salt was studied. RESULTS: NaCl or CaCl₂ additions to the irrigation water raised the electrical conductivity (EC) in increments from 0.5 dS m^?1 to 4.5 dS m^?1 (year 1) or 6.0 dS m^?1 (year 2), reducing parsley foliage weight in year 2, but increasing the root weight of turnip‐rooted parsley in year 1. Raising the EC with NaCl increased the yield of foliar essential oil from curly‐leafed parsley (both years), but not from the other cultivars. CaCl₂ had less effect on oil yield. The relative concentrations of the principal aroma constituents (β‐phellandrene, myristicin, β‐myrcene and apiole) of the foliar essential oil were affected by NaCl or CaCl₂ in a way that differed between cultivars. Oil yield from parsley roots was very low and apparently unaffected by salinity. CONCLUSION: All three parsley subspecies are moderately sensitive to salinity, but may be cultivated at <4.5 dS m^?1 EC. Salinity may assist oil production by increasing oil yield (curly‐leafed parsley) and positively affecting certain aroma constituents. Copyright © 2009 Society of Chemical Industry