Influence of high-dose gamma radiation and particle size on antioxidant properties of Maize ( Zea mays L.) flour

ABSTRACT Influence of high-dose gamma radiation and particle size on antioxidant properties of maize (Zea mays L.) flour was studied using response surface methodology. A central composite design based on three levels of each of particle size, in terms of mesh number (40, 60 and 80 meshes), and gamma radiation dose (25, 50 and 75 kGy) was constructed. A statistically significant dose-dependent decrease (p<0.05) in antioxidant properties of gamma irradiated flour was observed. However, an increase in the mesh number (decrease in particle size of flour) resulted in an increase in antioxidant properties. The optimum level of radiation dose to achieve maximum value of responses was found to be 50 kGy for Trolox equivalent total antioxidant activity (TETAOA), 25 kGy for iron chelating ability (ICA), 25 kGy for reducing power (RP) and 75 kGy for linoleic acid reduction capacity (LARC). However, the optimum level of mesh number to achieve desired levels of TETAOA, ICA, RP and LARC was found to be 80 meshes

Ameliorative potential of gemfibrozil and silymarin on experimentally induced nephrotoxicity in rats

Introduction: Acute nephrotoxicity is a frequent complication of critical illness especially in the inpatient setting. Cisplatin is one of the most active anticancer drugs. Nephrotoxicity is the most common side effect associated with cisplatin treatment. Silymarin is widely used for hepatic disorders due to its antioxidant and anti-inflammatory properties. Gemfibrozil, a hypolipidemic drug, has also antioxidant and anti-inflammatory properties. Objective: To detect the effect of gemfibrozil and silymarin either alone or in combination on cisplatin-induced nephrotoxicity in rats. Subjects and methods: Fifty albino rats were divided into 5 equal groups: Control untreated group, cisplatin treated group, gemfibrozil + cisplatin treated group, silymarin + cisplatin treated group, gemfibrozil + silymarin + cisplatin treated group. Blood urea, serum creatinine, creatinine clearance, urinary N-acetyl beta-d-glucosaminidase, urinary protein, tissue superoxide dismutase, malondialdehyde, reduced glutathione, tumour necrosis factor alpha and mitochondrial complex I activity were determined. Kidneys were excised for histopathological examination. Results: Gemfibrozil and/or silymarin efficiently attenuated cisplatin-induced nephrotoxicity evidenced by significant decrease in blood urea, serum creatinine, urinary N-acetyl beta-d-glucosaminidase, urinary protein, tissue malondialdehyde and tissue tumour necrosis factor alpha with significant increase in creatinine clearance, tissue reduced glutathione, tissue superoxide dismutase and mitochondrial complex I activity simultaneous with reduction of the necrotic damage and progressively increasing apoptotic index assessed by renal histopathological examination compared to the cisplatin treated group. Conclusion: The combination of gemfibrozil and silymarin has protective effects against cisplatin-induced nephrotoxicity in rats better than each of these drugs alone due to anti-inflammatory and antioxidant properties of the used drugs

Laccase catalyzed grafting of-N-OH type mediators to lignin via radical-radical coupling

Lignin is an underexploited resource in biomass refining. Laccases (EC 1.10.3.2) catalyze oxidation of phenolic hydroxyls using O2 as electron acceptor and may facilitate lignin modification in the presence of mediators. This study assessed the reactivity of four different synthetic mediators by laccases from Trametes versicolor and Pleurotus ostreatus by quantitative analysis of the reaction outcome by pyrolysis gas chromatography mass spectroscopy. The two laccases were equally efficient in catalyzing grafting, but only-N-OH type mediators grafted. HPI (N-hydroxyacetanilide) grafted 7-10 times better than HBT (1-hydroxybenzotriazole). Three different mechanisms are suggested to explain the grafting of HPI and HBT, all involving radical-radical coupling to produce covalent bonding to lignin. Lignin from exhaustive cellulase treatment of wheat straw was more susceptible to grafting than beech organosolv lignin with the relative abundance of grafting being 35% vs. 11% for HPI and 5% vs. 1% for HBT on these lignin substrates. The data imply that lignin can be functionalized via laccase catalysis with-N-OH type mediators

Characterisation of cell wall polysaccharides from rapeseed (Brassica napus) meal

To enable structural characteristics of individual cell wall polysaccharides from rapeseed (Brassica napus) meal (RSM) to be studied, polysaccharide fractions were sequentially extracted. Fractions were analysed for their carbohydrate (linkage) composition and polysaccharide structures were also studied by enzymatic fingerprinting. The RSM fractions analysed contained pectic polysaccharides: homogalacturonan in which 60% of the galacturonic acid residues are methyl-esterified, arabinan branched at the O-2 position and arabinogalactan mainly type II. This differs from characteristics previously reported for Brassica campestris meal, another rapeseed cultivar. Also, in the alkali extracts hemicelluloses were analysed as xyloglucan both of the XXGG- and XXXG-type decorated with galactosyl, fucosyl and arabinosyl residues, and as xylan with O-methyl-uronic acid attached. The final residue after extraction still contained xyloglucan and remaining (pectic) polysaccharides next to cellulose, showing that the cell wall matrix of RSM is very strongly interconnecte

Understanding carbohydrate structures fermented or resistant to fermentation in broilers fed rapeseed (Brassica napus) meal to evaluate the effect of acid treatment and enzyme addition

Unprocessed and acid-extruded rapeseed meal (RSM) was fed to broiler chickens, with and without addition of commercial pectolytic enzymes. Nonstarch polysaccharide (NSP) fermentability and unfermented NSP structures from RSM were studied in the excreta in detail. From unprocessed RSM, 24% of the nonglucose polysaccharides could be fermented. Acid treatment did not have a significant effect, but enzyme addition did improve fermentability to 38%. Most likely, the significant increase in NSP fermentability can be ascribed to the addition of pectolytic enzymes, which decreased branchiness of the water-soluble arabinan. Mainly xyloglucan, (glucurono-)xylan, (branched) arabinan, and cellulose remained in the excreta. The proportion of unextractable carbohydrates increased in excreta from broilers fed acid-extruded RSM. Probably, acid extrusion resulted in a less accessible NSP matrix, also decreasing the accessibility for pectolytic enzymes added in the diet. During alkaline extraction of the excreta, 39 to 52% (wt/wt) of the insoluble carbohydrates was released as glucosyl- and uronyl-rich carbohydrates, probably originally present via ester linkages or hydrogen bonding within the cellulose-lignin network. These linkages are expected to hinder complete NSP fermentation and indicate that digestibility of RSM may benefit substantially from an alkaline treatment or addition of esterases

Effects of processing technologies and pectolytic enzymes on degradability of nonstarch polysaccharides from rapeseed meal in broilers

Rapeseed meal (RSM) contains a high level of nonstarch polysaccharides (NSP) that are not well degraded in poultry and interfere with digestion of other nutrients as protein, starch, and fat. By altering physicochemical properties of NSP from RSM, processing and enzyme technologies might improve digestive utilization of RSM, enhancing its potential as a source of nutrients in poultry diets. The effects of wet milling and extrusion in combination with pectolytic enzymes on the degradability of RSM in broilers were investigated in a 3 × 2 factorial arrangement. Wet milling and extrusion did not affect total tract apparent digestibility of DM, CP, crude fat, and nonglucose polysaccharides (NGP). Addition of pectolytic enzymes did not affect total tract apparent digestibility of CP and crude fat, but improved degradability of NGP by 9 to 20% units (P <0.001), independent of prior technological processing of RSM. This coincided with an increased NGP concentration in the ceca (4 to 7 g/g of cobalt, P <0.001), indicating that more NGP were solubilized such that they could enter the ceca and become available for fermentation. Particle size reduction facilitated solubilization of polysaccharides from RSM, increasing the concentration of NGP found in the ceca (4 g/g of cobalt, P = 0.008). Without help of additional pectolytic enzymes, those solubilized structures could, however, still not be degraded by the cecal microbiota. Feed intake, BW gain, and feed conversion ratio were not affected. No interaction between processing technologies and enzyme addition was found. Apparently, the processing technologies studied were not facilitating accessibility of NSP to pectolytic enzymes added to the feed in vivo

Synthesis of polyalkylacrylate nanolatexes by microemulsion polymerization method

The paper concerns with the radical polymerization of [octadecyl acrylate (ODA), isooctyl acrylate (iso-OA) and α-olefins 1-Octene (n-O)]. These microemulsions were stabilized by sodium dodecyl sulfate (SDS) and initiated by water-soluble initiator potassium persulfate (KPS). The nanolatex particle sizes were determined by transmission electron microscope (TEM). They were situated between 10 and 100 nm. The microstructures were confirmed by FT-IR and molecular weights determined by Gel permeation chromatography (GPC). The obtained M. wt. were (≈70 × 103, 101 × 103 and 153 × 103 g/mol). The polydispersity, molecular weights, and particle sizes were discussed in the light of micelle formation and shape of the alkyl group via emulsion polymerization

Separation of digesta fractions complicates estimation of ileal digestibility using marker methods with Cr2O3 and Co-EDTA in broiler chickens

Marker methodologies to measure ileal and total tract digestibilities of diets varying in content and degradability of dietary fiber in broiler chickens were evaluated. Chromium sesquioxide (Cr2O3) and cobalt-ethylenediamine tetraacetic acid (Co-EDTA) were used as markers of solid and soluble fractions, respectively, and compared with digestibility values obtained with the total collection method. Groups of broilers (n = 17, 11 broilers/group) were assigned to a low-fiber diet or 1 of 2 high-fiber diets, the latter 2 containing 35% rapeseed meal (RSM). Pectolytic enzymes were added to one RSM diet to improve degradability of the fiber fraction. Excreta were quantitatively collected for 96 h, and contents from ileum and ceca were collected at slaughter at 29, 30, or 31 d of age. Chromium recovery in excreta ranged between 86 and 95%, whereas cobalt recovery was considerably lower (66 to 70%). Chromium:cobalt ratio was higher in ileal digesta than in feed. Hardly any chromium was found in the ceca, indicating that separation of the marker and specific digesta fractions occurs. Estimates of apparent total tract digestibility (ATTD) were lower when calculated using the marker method compared with the total collection method, particularly in high-fiber diets. Using Cr2O3 as a marker, differences were relatively small and effects due to enzyme addition were generally similar. Using Co-EDTA as a marker, ATTD of all components were lower compared with values obtained using the collection method (3 to 45 percentage units, P <0.001), likely related to the low Co recovery. When estimating apparent ileal digestibility (AID), separation of marker and digesta resulted in unrealistically high estimates for the digestibility of nonglucose polysaccharides (54 to 66%), exceeding ATTD values by 16 to 42 percentage units. Moreover, the effect of pectolytic enzyme addition on the AID of nonglucose polysaccharides was in the opposite direction when compared with total collection. The data illustrate that fractionation of digesta, particularly in high-fiber diets, complicates accurate AID measurements in broilers, regardless of the choice of markers used

Residual Carbohydrates from in Vitro Digested Processed Rapeseed (Brassica napus) Meal

Rapeseed meal (RSM) was subjected to different physical or chemical pretreatments to decrease residual, hard to degrade carbohydrates and to improve fermentability of RSM polysaccharides. Next, these pretreated samples were in vitro digested and fermented, with or without the addition of commercial pectinolytic enzymes. Remaining carbohydrates were quantified, and two physical characteristics were analyzed: (1) water-binding capacity (WBC) of the insoluble residue and (2) viscosity of the soluble fraction. Mild acid pretreatment in combination with commercial pectinolytic enzyme mixtures showed best digestion of RSM carbohydrates; only 32% of the total carbohydrate content remained. For most pretreatments, addition of commercial pectinolytic enzymes had the strongest effect on lowering the WBC of the in vitro incubated RSM. In the cases that less carbohydrate remained after in vitro digestion, the WBC of the residue decreased, and less gas seems to be produced during fermentation

Effects of acid-extrusion on the degradability of maize distillers dried grain with solubles in pigs

Commonly used feed processing technologies are not sufficient to affect recalcitrant non-starch polysaccharides (NSP) such as arabinoxylans present in maize distillers dried grain with solubles (DDGS). Instead, hydrothermal treatments combined with acid catalysts might be more effective to modify these NSP. The objective of this experiment was to investigate the effects of hydrothermal maleic acid treatment (acid-extrusion) on the degradability of maize DDGS in growing pigs. It was hypothesized that acid-extrusion modifies DDGS cell wall architecture and, thereby, increases fermentability of NSP. Two diets, containing either 40% (wt/wt) unprocessed or acid-extruded DDGS, were restrictedly fed to groups of gilts (n = 11, with 4 pigs per group; initial mean BW: 20.8 ± 0.2 kg) for 18 d and performance and digestibility were analyzed. Acid-extrusion tended to decrease apparent ileal digestibility (AID) of CP (~3 percentage units, P = 0.063) and starch (~1 percentage unit, P = 0.096). Apparent digestibility of CP and starch measured at the mid colon (2 percentage units, P = 0.030 for CP and 0.3 percentage units, P <0.01 for starch) and total tract (ATTD; 3 percentage units, P <0.01 for CP and 0.2 percentage units, P = 0.024 for starch) were lower for the acid-extruded diet compared with the control diet. Hindgut disappearance was, however, not different between diets indicating that reduced CP and starch digestibility were mainly due to decreased AID. Acid-extrusion tended to increase AID of NSP (6 percentage units, P = 0.092) and increased digestibility of NSP measured at the mid colon (6 percentage units, P <0.01), whereas, hindgut disappearance and ATTD of NSP did not differ between diets. Greater NSP digestibility was mainly due to greater digestibility of arabinosyl, xylosyl, and glucosyl residues, indicating that both arabinoxylan and cellulose degradability were affected by acid-extrusion. In conclusion, these results show that acid-extrusion did not improve degradation of DDGS for growing pigs. Although acid-extrusion seemed to facilitate more rapid degradation of NSP and shifted fermentation to more proximal gastrointestinal segments, total extent of NSP degradation was not affected. More than 35% of the NSP from DDGS remained undegraded, independent of technological processing. Enzyme technologies that specifically target ester-linked acetyl, feroloyl, or coumaroyl groups were identified to be of interest for future research