Fruit drinks containing probiotics are gaining interest in the global marketplace. For example, longan juice, containing carbohydrate and various bioactive components, is a potentially health-promoting beverage as well as probiotic carrier for human consumption. In this study, high-pressure and thermal processes were applied to eliminate competitive micro-organisms in longan juice prior to the addition of Lactobacillus acidophilus LA5 or Lactobacillus casei 01. The activities of these probiotics in a simulated gastrointestinal tract were also investigated.
Encapsulated probiotics could survive in the acidic environment of the stomach and small intestine, while the free cells were completely eliminated. In the colon experiment, the influence of encapsulated L. casei 01 on colon lactobacilli was significantly greater than that of encapsulated L. acidophilus LA5. Both encapsulated probiotics suspended in processed longan juices led to extensive increases in the formation of lactic acid and short-chain fatty acids (SCFA). Acetate was the major SCFA produced by colon bacteria, followed by propionate and butyrate. The discernible clear zone suggested that L. casei 01 provided greater antibacterial activity than L. acidophilus LA5.
Both encapsulated probiotics along with processed longan juice led to significant increases in colon lactobacilli, lactic acid and SCFA formation.
Edible fungi polysaccharides usually exhibited antioxidant activity, and zinc has been shown to have antioxidant properties. In the present work, Pholiota nameko SW-03 was used as a vector of zinc biotransformation in order to obtain mycelia zinc polysaccharide (MZPS), and the structural characterization and anti-ageing activity of MZPS were investigated.
P. nameko SW-03 could accumulate zinc in the form of zinc-riched polysaccharide, and the zinc content in MZPS was 16.39 ± 0.72 mg g(-1) . Three fractions (MZPS-1, MZPS-2 and MZPS-3) were successfully isolated. The main fraction (MZPS-2) with the highest antioxidant activity in vitro was composed of glucose, mannose, glucuronic acid, galactose, galacturonic acid and arabinose in a molar ratio of 172.59:5.29:4.61:4.20:1.01:1.00, with the weight-average molecular weight of 13.63 kDa. The anti-ageing capability has been measured by building the D-galactose-induced ageing mice, and the results showed that MZPS could improve antioxidant status (SOD, T-AOC, MDA and LPO), indicating that MZPS had strong anti-ageing capability in vivo.
This study suggested that organification of zinc through edible fungi liquid fermentation provided a novel method to produce mycelia zinc polysaccharide, which might be used as natural antioxidant to slow the progression of ageing.
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The synergism of carbaryl (1-naphthyl-N-methyl carbamate) with 26 derivatives of 1,3-benzodioxole and naphtho-1,3-dioxole was examined by topical dosage of female houseflies, Musca domestica, which, though of a strain not selected with insecticides, were completely tolerant to carbaryl. The synergists also were non-toxic when applied alone. The doses of carbaryl and synergist in different combinations that gave 50 % mortality (LD50) were estimated. A simple form of graphical analysis revealed a common pattern in the results for 18 of the synergists. This indicated that if the mechanism that detoxifies carbaryl and that was depressed by these synergists was completely inhibited, the LD50 for carbaryl would be about 0.06 μg per fly. Moreover, the analysis enabled relative potencies for these synergists to be estimated on a simple and rational basis, and showed a 700-fold difference between the most and the least active. The significance of these and the remaining results is discussed in the light of the probable factors affecting the mode of action of the synergists.
Pork meat rejected by consumers because of a nauseating taint was analysed by gas chromatography and mass spectrometry (g.c.-m.s.) and found to contain 5–20 mg kg−1 of 1,4-dichlorobenzene. Trace amounts (10–35 μg kg−1) of 1,4-dichlorobenzene were found in wood-shavings used as litter materials and in the feedstuffs, but were considered insufficient to be the main cause of contamination. Meat from the following batch of pigs from the same source contained only very small amounts, similar to those present in normal pork obtained elsewhere (<25 μg kg−1). Examination of data recorded by g.c.-m.s. in the previous 2 years showed that 1,4-dichlorobenzene was present in trace quantity (>10μg kg−1) in several samples of normal meat, and appeared to be widespread in its occurrence.
L(+)-Lactic acid is used in the pharmaceutical, textile and food industries as well as in the synthesis of biodegradable plastics. The aim of this study was to investigate the effects of different medium components added in cassava wastewater for the production of L(+)-lactic acid by Lactobacillus rhamnosus B 103.
The use of cassava wastewater (50 g L(-1) of reducing sugar) with Tween 80 and corn steep liquor, at concentrations (v/v) of 1.27 mL L(-1) and 65.4 mL L(-1) respectively led to a lactic acid concentration of 41.65 g L(-1) after 48 h of fermentation. The maximum lactic acid concentration produced in the reactor after 36 h of fermentation was 39.00 g L(-1) using the same medium, but the pH was controlled by addition of 10 mol L(-1) NaOH.
The use of cassava wastewater for cultivation of L. rhamnosus is feasible, with a considerable production of lactic acid. Furthermore, it is an innovative proposal, as no references were found in the scientific literature on the use of this substrate for lactic acid production.
Effects of the individual variation among dairy cows on the cis-9, trans-11 CLA synthesis are still not well characterized. Therefore, the protein expression profiles of isolated milk epithelial cells (MECs) were detected by 2-DE and their correlation with the various proportion of cis-9, trans-11 CLA were evaluated.
Although animals were offered the same diet, the proportion of cis-9, trans-11 CLA in group High (1.02 ± 0.10 %) was twice as high as that in group Low (0.59 ± 0.14 %) (p < 0.05). MECs owned the characteristics of native epithelial cells were successfully isolated from the milk and these cells had no obvious RNA degradation or hardly contaminated with leucocytes or blood red cells. Moreover, the protein expression pattern of Cathelicidin 5 in isolated MECs was positively, whereas Annexin I (confirmed by real time PCR), ZW10 interactor and Kappa casein were negatively related to the cis-9, trans-11 CLA proportion in the milk fat.
The varied individual content of cis-9, trans-11 CLA in cows may associate with Annexin I. These findings may provide some theoretical basements for the studies about effects of the individual variation among dairy cows on the cis-9, trans-11 CLA synthesis.
Xylanases have attracted much attention because of their potential applications. Unfortunately, the commercialization of xylanases was limited by their low catalytic activities. The purpose of this work was to improve the activity of a xylanase by optimization of the expression conditions, and investigate its characterization.
The activity of recombinant AuXyn11A (reAuXyn11A), a family 11 xylanase from Aspergillus usamii E001 expressed in Pichia pastoris GS115, reached 912.6 U mL(-1) under the optimized conditions, which was 2.14 times as high as that expressed using the standard protocol. After the endogenous 18-aa propeptide was processed in P. pastoris, the reAuXyn11A (188-aa mature peptide) was secreted and purified with a specific activity of 22,714 U mg(-1) . It displayed the maximum activity at pH 5.0 and 50 °C, and was stable at a pH range of 4.0-8.0 and at a temperature of 46 °C or below. Its activity was not significantly affected by most of metal ions tested and EDTA. The xylooligosaccharides of xylobiose (X2) to xylohexaose (X6) were produced from insoluble corncob xylan by reAuXyn11A.
The high specific activity and good enzymatic properties suggested that the reAuXyn11A was a potential candidate for applications in industrial processes.
BACKGROUND: γ-Glutamyltranspeptidase (GGT; EC 188.8.131.52) is a widely distributed enzyme that is of interest in the food industry. In this study the effects of pH and dissolved oxygen (DO) on GGT synthesis from Bacillus subtilis SK 11.004 were investigated.
RESULTS: GGT production increased to 0.5 U mL−1 when the pH value was controlled at 6.5. The control of a single DO level revealed that the highest specific growth rate (3.42 h−1) and GGT production rate (0.40 U g−1 mL−1) were obtained at DO levels of 40 and 10% respectively. To satisfy the different oxygen demands at different stages of cell growth and GGT synthesis, a stage DO level control strategy was designed as follows: 40% from 0 to 4 h, 30% from 4 to 6 h and 10% from 6 to 18 h. Furthermore, the maximum biomass (2.27 g L−1) and GGT production (3.05 U mL−1) could be obtained using a fermentation strategy combining a constant pH value with stage DO level control.
CONCLUSION: The proposed fermentation strategy resulted in a 13.7-fold increase in GGT production. This finding should be of great importance for the industrial production of GGT. Copyright
D-Tagatose, as one of the rare sugars, has been found to be a natural and safe low-calorie sweetener in food products and is classified as a GRAS substance. L-Arabinose isomerase (L-AI, EC 184.108.40.206), catalysing the isomerisations of L-arabinose and D-galactose to L-ribulose and D-tagatose respectively, is considered to be the most promising enzyme for the production of D-tagatose.
The araA gene encoding an L-AI from Bacillus stearothermophilus IAM 11001 was cloned, sequenced and overexpressed in Escherichia coli. The gene is composed of 1491 bp nucleotides and codes for a protein of 496 amino acid residues. The recombinant L-AI was purified to electrophoretical homogeneity by affinity chromatography. The purified enzyme was optimally active at 65 degrees C and pH 7.5 and had an absolute requirement for the divalent metal ion Mn(2+) for both catalytic activity and thermostability. The enzyme was relatively active and stable at acidic pH of 6. The bioconversion yield of D-galactose to D-tagatose by the purified L-AI after 12 h at 65 degrees C reached 36%.
The purified L-AI from B. stearothermophilus IAM 11001 was characterised and shown to be a good candidate for potential application in D-tagatose production.
Propolis is a complex resinous sticky substance that honeybees collect from buds and exudates of various plants. Owing to its versatile biological and pharmacological activities, propolis is widely used in medicines, cosmetics and foods. The aim of this study was to evaluate the cytotoxic and antioxidative effects of various ethanolic extracts of propolis (EEPs) on human colon cancer cell line HCT-116 and compare them with their composition determined by HPLC-DAD.
The most abundant flavonoids in all samples were chrysin, pinocembrin and galangin (12.697–40.811 µg mg−1), while the main phenolic acids were caffeic acid, ferulic acid and isoferulic acid. Dose- and time-dependent inhibition of growth of HCT-116 cells was observed for all propolis samples, with IC50 values ranging from 26.33 to 143.09 µg mL−1. Differences in cytotoxic activity of propolis samples were associated with differences in their composition. All EEP samples reduced both superoxide anion radical and nitrite levels and also had strong DPPH-scavenging activity.
All tested propolis samples had pronounced cytotoxic and antioxidative activities.
The 7S and 11S fractions from soybean proteins have interesting high nutritional and excellent functional properties. The aim of this research was to improve the functional properties of soy proteins by studying the effect of bis(2-ethylhexyl) sodium sulfosuccinate (AOT) reverse micelles on the conformation of the 7S and 11S globulins using Fourier transform infrared and X-ray diffraction spectroscopy.
Fourier transform infrared revealed that the intensity of the 7S and 11S globulin bands from AOT reverse micelle extraction at 1600–1700, 1480–1575, 1220–1300, 3330, 1448 and 1395 cm−1 was higher than from aqueous buffer. X-ray diffraction data showed that the intensities of 7S globulin using two extraction methods at 2θ about 10° were significantly different (P < 0.05), about 22° slightly increased. The intensities of 11S globulin at 2θ about 10° and 22° were similar. The average distance between particles (dhkl) for 7S globulin with aqueous buffer extraction at 2θ about 10° was greater than AOT reverse micelle extraction.
This study showed the potential of reverse micelles as a protocol for extracting the 7S and 11S globulins for analytical purposes. The results represent a new avenue for determining the structures of the 7S and 11S globulins.
The production of rapidly acidifying laboratory silage provides support for the hypothesis that rate of fall of pH in the early stages is the vital factor in the preservation of free arginine and lysine produced in ensilage, inhibiting the extensive decarboxylation which occurs under conditions of more gradual production of acid and of high pH.
Herbhoneys, relatively new bee products, are expected to have interesting medicinal properties. However, there is still a lack of data concerning their composition and antioxidant properties. H-1 and C-13 NMR spectroscopy coupled with chemometric analysis (PCA and PLS-DA) and antioxidant assays (DPPH-ESR and ORAC-FL) were used to study 25 samples of Polish herbhoneys and honeys. RESULTSAntioxidant activity varied among the samples. The best properties were exhibited by cocoa and instant coffee herbhoneys. The contents of total polyphenols and total carotenoids in the studied samples were found to be 70-1340mg GAE kg(-1) and 0-28.05mgkg(-1) respectively. No significant differences between herbhoney and honey samples were found in their sugar profiles. The PCA of C-13 NMR spectra of the samples in DMSO-d(6) resulted in sample clustering due to sucrose content. CONCLUSION
Herbhoneys have similar antioxidant properties to traditional honeys, being therefore of equal nutritional value. There was a noticeable influence of the extract concentration on the observed antioxidant effect. For samples with high antioxidant activity, polyphenols were responsible for the observed effect. Sample clustering due to sucrose content in the NMR-PCA study allowed effortless detection of adulteration. (c) 2013 Society of Chemical Industry
BACKGROUND: Lignification-associated phenolic acids are widely distributed in graminaceous plant cell walls. This study developed a rapid and sensitive reversed-phase method for the simultaneous quantification of protocatechuic (PRA), vanillic (VA), ferulic (FA) and p-coumaric (PCA) acids and investigated the relationship between these compounds and lignin contents in 13 fibrous feeds.
RESULTS: The phenolic acids were identified at a column temperature of 15 °C in a single run, in which the wavelength was programmed at 260 nm for PRA and VA, then switched to 310 nm for FA and PCA determinations. Satisfactory precision, recovery, and linearity were obtained with this method. Among 13 feeds, PCA was most abundant, followed by FA, VA and PRA. Great variations in phenolic acid and lignin contents were found. FA content was much richer than PCA content in maize and wheat brans, and the highest PCA content occurred in maize stalks. Lignin content was correlated with proportions of FA (r = − 0.95) and PCA (r = 0.90) in the summed phenolic acids and the PCA:FA ratio (r = 0.91).
CONCLUSION: The improved method appears to be useful for simultaneous quantification of target phenolic compounds. Both FA and PCA may be good indicators for plant cell wall lignification associated with feed digestibility. Copyright
Ochratoxin A (OTA) is a mycotoxin produced by some Aspergillus and Penicillium species. In this study, a strain of Bacillus subtilis was studied for its action against OTA-producing Aspergillus and degradation. At the same time, the mechanisms were investigated.
A strain of Bacillus spp. isolated from fresh elk droppings was screened out using the methods described by Guan Shun(1) . The 16S rRNA gene sequence suggested that it was Bacillus subtilis (CW 14). It could inhibit the growth of the OTA-producing species, Aspergillus ochraceus 3.4412 and Aspergillus carbonarius , with inhibition rates of 33.0% and 33.3%, respectively. At 6 µg mL(-1) of OTA, both viable and autoclaved (121 °C, 20 min) cells of CW 14 bound more than 60% of OTA. In addition, OTA was degraded by the cell-free supernatant of CW 14. By high performance liquid chromatography (HPLC), the cell-free supernatant degraded 97.6% of OTA after 24 h incubation at 30 °C, and no degradation products were produced. The fastest degradation occurred during the first 2 h. In 3-grams samples of contaminated maize, 47.1% of OTA was degraded by 50-mL inocula of overnight cultures of CW 14.
These findings indicated that B. subtilis CW 14 could both prevent OTA contamination and degrade OTA in crops.
Sensory analysis is a crucial tool for evaluating the quality of extra virgin olive oils. One aim of such an investigation is to verify if the sensory attributes themselves - which are strictly related to volatile and phenolic compounds - may permit to discriminate high-quality products obtained by olives of different cultivar and/or grown in various regions. Moreover, a crucial topic is to investigate the interdependency between relevant parameters determining consumer acceptance and objective sensory characteristics evaluated by Panel test.
By statistically analyzing the sensory results, a grouping - but not discriminatory - effect was evidenced for some cultivars and some producing areas. The preference map shows that the most appreciated samples by consumers were situated in the direction of the "ripe fruity" and "sweet" axis and opposite to the "bitter" and "other attributes" (pungent, green fruity, freshly cut grass, green tomato, harmony, persistency) axis.
Extra virgin olive oils produced from olives of the same cultivars and grown in the same areas shared similar sensorial attributes. Some differences in terms of expectation and interpretation of sensory characteristics of EVOOs might be present for consumers and panellists: most of the consumers appear unfamiliar with positive sensorial attributes, like bitterness and pungency.
Organic substrates and calcium are important factors controlling organic matter turnover in Karst soils. To understand their effects on soil organic carbon (SOC) mineralization, an incubation experiment was conducted involving a control treatment (CK), the addition of a (14)C-labeled rice straw (T1), CaCO(3) (T2), and both (14)C-labeled rice straw and CaCO(3) (T3) to two types of Karst soils (terra fusca and rendzina) and a red soil from southwestern China.
Cumulative mineralization of the rice straw over 100 days in rendzina (22.96 mg kg(-1)) and terra fusca (23.19 mg kg(-1)) was higher than in the red soil (15.48 mg kg(-1); P < 0.05). Cumulative mineralization of native SOC decreased following addition of (14)C-labeled rice straw in the rendzina and terra fusca but increased in the red soil (negative and positive priming effects on native SOC). The turnover times of (14)C-labeled microbial biomass C (MBC) in the red soil, terra fusca and rendzina were 71 ± 2, 243 ± 20 and 254 ± 45 days, respectively. By adding CaCO(3), the accumulation of SOC was greater in the Karst soils than in the red soil.
Although the interactions between rice straw decomposition and priming effects on native SOC are not yet understood, there was considerable variation between Karst and red soils. Soil calcium was a positive factor in maintaining SOC stability. MBC from rice straws was stable in terra fusca and rendzina, whereas it was active in the red soil. The Karst soils (terra fusca and rendzina) used in this study benefited SOC accumulation.