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Abstract: Inactivated mycobacterium phlei (M. phlei) is well known for its immune‐stimulatory functions in humans and livestock, but less information is available about the influence on meat quality of pigs when used as a feed additive. This study was designed to evaluate the effects of inactivated M. phlei on growth performance as well as meat quality of fattening pigs. A total of 240 cross‐bred pigs ([Landrace × Yorkshire] × Duroc) with initial body weight of 80.14 ± 0.29 kg were randomly allocated to five treatments, each of which consisted of eight replicates with 6six pigs per replicate. The basal diet supplemented with five levels of inactivated M. phlei preparations (0, 3.5 × 109 [0.1% w/w], 7 × 109 [0.2%], 1.4 × 1010 [0.4%] or 2.1 × 1010 [0.6%] colony‐forming units/kg) was respectively fed to the control group and four treatment groups for 30 days. Adding 0.4% of inactivated M. phlei to diet increased the average daily feed intake and average daily gain of pigs. Importantly, intramuscular fat percentage in the Longissimus dorsi (LD) was increased by feeding diet containing 0.2%, 0.4% and 0.6% of inactivated M. phlei, despite the pH value, drip loss, cooking loss and filter paper fluid uptake not being influenced. Analysis of the fatty acid components showed that some saturated fatty acids were decreased in LD after feeding inactivated M. phlei, but some monounsaturated fat acids (MUFAs) and polyunsaturated fatty acids were increased (PUFAs), which induced the total contents of MUFAs and PUFAs were improved. RT‐PCR assay revealed that feeding inactivated M. phlei up‐regulated genes implicated in fat metabolism in muscle, including ELOVL6, FASN, SCD1 and H‐FABP. This study revealed that feeding inactivated M. phlei not only increased growth performance of fattening pigs, but also improved the meat quality by increasing intramuscular fat content, thus inactivated M. phlei probably has high utilization value in modern pig production. [ABSTRACT FROM AUTHOR]

The contradiction between high susceptibility of early weaned piglets to enteric pathogens and rigid restriction of antibiotic use in the diet is still prominent in the livestock production industry. To address this issue, the study was designed to replace dietary antibiotics partly or completely by an immunostimulant, namely heat-killedMycobacterium phlei(M. phlei). Piglets (n = 192) were randomly assigned to one of the four groups: (1) basal diet (Group A), (2) basal diet + a mixture of antibiotics (80 mg/kg diet, Group B), (3) basal diet + a mixture of antibiotics (same as in Group B, but 40 mg/kg diet) + heat-killedM. phlei(1.5 g/kg diet) (Group C) and (4) basal diet + heat-killedM. phlei(3 g/kg diet) (Group D). All piglets received the respective diets from days 21 to 51 of age and were weaned at the age of 28 d. Compared with the Control (Group A), in all other groups the average daily gain, average daily feed intake, small intestinal villus height:crypt depth ratio and protein levels of occludin and ZO-1 in the jejunal mucosa were increased. A decreased incidence of diarrhoea in conjunction with an increased sIgA concentration in the intestinal mucosa and serum IL-12 and IFN-γ concentrations was found in groups supplemented with heat-killedM. phlei(Groups C and D), but not in Group B. Groups C and D also showed decreased IL-2 concentrations in the intestinal mucosa with lower TLR4 and phosphor-IκB protein levels. The antioxidant capacity was reinforced in Groups C and D, as evidenced by the reduction in malondialdehyde and enhanced activities of antioxidant enzymes in serum. These data indicate that heat-killedM. phleiis a promising alternative to antibiotic use for early weaned piglets via induction of protective immune responses. [ABSTRACT FROM PUBLISHER]

Lignin was used as a template for the first time to in situ synthesize lignin-based silver nanoparticles composites using sodium borohydride or ascorbic acid as a reducing agent. The lignin-based silver nanoparticles composites were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis. The scanning electron microscopy and transmission electron microscopy studies confirmed that silver nanoparticles with good dispersibility were well anchored onto the surface of lignin and the nanoparticles had pseudospherical shape with size mostly in 45–55 nm. Moreover, the antibacterial activity of the composites was studied against E. coli. A headspace gas chromatographic technique was used to monitor the bacterial growth by measuring the CO2 released by the bacteria. The results showed that the lignin-based silver nanoparticles composites can be used as potential antimicrobial agents. [ABSTRACT FROM AUTHOR]

BACKGROUND T1 lipase has received considerable attention due to its thermostability. Fatty acid specificity of T1 lipase (crude and purified) was investigated, and its potential in the synthesis of acylglycerols was also evaluated. RESULTS Fatty acid specificity of T1 lipase (crude and purified) was investigated in the esterification of fatty acids ( C6:0 to C18:3), suggesting that crude and purified T1 lipase had the lowest preference for C18:0 [specificity constant (1/ α) = 0.08] followed by C18:1 (1/ α = 0.12) and showed the highest preference for C8:0 (1/ α = 1). A structural model was constructed to briefly explore interactions between the lipase and its substrate. Furthermore, crude T1 lipase-catalysed synthesis of diacylglycerols ( DAGs) and monoacylglycerols ( MAGs) by esterification of glycerol with C18:1 was studied for evaluating its potential in acylglycerols synthesis. The optimal conditions were glycerol/oleic acid molar ratio 5:1, the lipase concentration 9.7 U g−1 of substrates, water content 50 g kg−1 of substrates and temperature 50 °C, which yielded 42.25% DAGs, 26.34% MAGs and 9.18% triacylglycerols at 2 h. CONCLUSION DAGs and MAGs were synthesised in good yields although C18:1 (a much poorer substrate) was used. Our work demonstrates that T1 lipase, which was discovered to show 1,3-regio-selectivity, is a promising biocatalyst for lipids modification. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Human milk fat substitutes (HMFS) were prepared by enzymatic synthesis combined with physical blending methods. As the main constituents in HMFS, 1,3-dioleoyl-2-palmitoylglycerol-rich TAGs (OPO-rich TAGs) were synthesized in one step by Lipozyme RM IM-catalyzed acidolysis of 34L-leaf lard and then purified by molecular distillation. The results showed that OPO-rich TAGs with purity of 91.39wt% were obtained at evaporation temperature of 180°C and a pressure of 6.7-7.5 Pa. Furthermore, a mathematical model was established for formulating HMFS by blending OPO-rich TAGs product with the selected vegetable oils. Under the blending ratio of 0.6700:0.1638:0.1627:0.0035:0.0000 (OPO-rich TAGs product/coconut oil/soybean oil/flaxseed oil/sunflower seed oil), the HMFS had fatty acids levels similar to those of human milk fat (HMF), and kept a high proportion (about 70%) of C16:0 at the sn-2 position. Based on the fatty acid composition and distribution of HMF and 'deducting score' principle, the similarity of HMFS to HMF was assessed by the related model, and the score for the similarity of HMFS to HMF was 85.54 points, indicating that this HMFS can be used as a fat substitute in infant formula. This study can provide valuable information on preparing HMFS and will be helpful for the infant formula industry. Practical applications: The information on the whole process of the production of HMFS, including one-step enzymatic synthesis, purification, quality evaluation and physical blending, is important for the development of infant formula with high quality. The enzymatic synthesis combined with physical blending methods enable a high similarity of HMFS to human milk fat and the HMFS can be used a potential fat substitute in infant formula. [ABSTRACT FROM AUTHOR]

This article reports an improved headspace gas chromatographic (HS-GC) technique for the determination of monomers in polymer latex. The method is based on a HS-GC technique reported previously (Chai et al., J Appl Polym Sci 2006, 99, 392) but includes a major modification in the method of sample preparation. By using a weight-based sampling method, coupled with initial dissolution in dimethyl sulfoxide (DMSO), followed by water dilution, the uncertainty in the sample preparation associated with previous method can be significantly reduced. The improved method is reliable, practical, and suitable for use in the kinetic study during emulsion polymerization. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

Abstract: Methyl methacrylate (MMA) was homogeneous-grafted on a cellulose based macro-initiator, cellulose chloroacetyl chloride by the atom transfer radical polymerization (ATRP) at a mild reaction temperature. The synthesized cellulose graft copolymers were characterized by FT-IR, 1H NMR and 13C NMR spectroscopies. The linear first-order kinetics of monomer conversion was determined by headspace gas chromatography. The molecular weights and their distributions of the poly (methyl methacrylate) (PMMA) grafted onto the cellulose backbone were determined by gel permeation chromatography. The results confirmed that the generation of the cellulose grafted PMMA at 50°C in the given solvent system was a controlled/living ATRP process. [Copyright &y& Elsevier]

Abstract: This paper reports on a full evaporation headspace gas chromatographic method for rapid determination of monomeric methyl methacrylate (MMA) in the cellulose graft poly-methyl methacrylate (PMMA) via an atom transfer radical polymerization process. The data show that a near-complete mass transfer of MMA from the very small liquid sample size (<30mg) to the vapor phase (headspace) was achieved within 5min at 105°C. The present method has excellent precision (RSD<0.3%) and accuracy (recovery=97%) for the quantification of the residual MMA in cellulose graft PMMA liquid samples. [Copyright &y& Elsevier]

Abstract: This paper reports on a headspace gas chromatographic method (HS-GC) for rapid determination of degree of substitution in succinic anhydride (SA) modified celluloses. The method is based on the reaction between the carboxyl groups in SA modified cellulose and bicarbonate solution in a closed headspace sample vial. The CO2 released from the reaction was measured by HS-GC. The completion of the reaction was achieved within 25min at 80°C when a small sample size (<20mg) was used. The relative standard deviation (RSD) measurement of precision was less than 4.1%, and the results were within 8.0% of those obtained with the traditional titration for determining the degree of substitution. The present method is simple, practical, automated, and suitable for use in anhydride modified cellulose research. [Copyright &y& Elsevier]