Carbohydrate constituents of some nigerian maize varieties grown at three soil nitrogen levels

Of eight varieties of maize analysed, average values for constituent carbohydrates in g/100g dry matter were: soluble sugars, 1·61; starch, 62·04; water-soluble polysaccharides, 2·60; alkali-soluble polysaccharides, 6·85 and cellulose, 1·08. Lignin varied from 1·18 to 1·86%. Significant varietal differences (P < 0·05) were found for the carbohydrate fractions, although differences within varieties due to nitrogen fertilisation were not significant. Soluble sugars and starch, which contribute appreciably to the energy value of the maize, ranged between 56·68% for WCUI and 67·12% for Lag ABCD. Predicted digestible energy (DE) and metabolisable energy (ME) values for pigs were in the range 4005–4073 kcal/kg and 3881–3947 kcal/kg, respectively whilst metabolisable energy for poultry varied between 3692 and 4007 kcal/kg.     

Preparation of a hydroxypropyl Ganoderma lucidum polysaccharide and its physicochemical properties

A hydroxypropyl Ganoderma lucidum polysaccharide (H-GLP) was prepared from a low-value water-insoluble polysaccharide from G. lucidum (GLP) using propylene oxide under an alkaline condition. The H-GLP was characterised for its chemical structure with IR and ¹³C NMR spectra and analysed for its mono-sugar composition, molecular weight, and hydroxypropyl content. H-GLP contained mannose, glucose, and galactose in a mole ratio of 1.0:36.5:3.59, respectively, with an average molecular weight of 788 kDa and a hydroxypropyl content of 12.05%. H-GLP also had an excellent water solubility of more than 50 mg/mL, suggesting that hydroxypropylation might serve as an effective approach to enhance water solubility of GLP. H-GLP was also compared to the original GLP and ascorbic acid for antioxidant properties. H-GLP showed much stronger free radical scavenging capacity against hydroxyl and superoxide anion radicals and hydrogen peroxide than GLP. These results suggested the potential of hydroxypropylation in developing water-soluble antioxidative polysaccharides from GLP to enhance the profitability of G. lucidum production and processing industries.     

Separation and quantification of component monosaccharides of the tea polysaccharides from Gynostemma pentaphyllum by HPLC with indirect UV detection

A reversed-phase high-performance liquid chromatographic (HPLC) method is described for the simultaneous determination of aldoses and uronic acids. The separation was carried out on a RP-C₁₈ column (4.6 mm i.d. × 250 mm, 5 μm, Venusil, USA) using precolumn derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP) and UV detection at 250 nm, and the 10 PMP derivatives of mannose, ribose, rhamnose, glucuronic acid, galacturonic acid, glucose, xylose, galactose, arabinose and fucose were baseline separated within 40 min. Furthermore, the described method was applied to the quantitative analysis of component monosaccharides in the water-soluble polysaccharides extracted from Gynostemma pentaphyllum Makino tea and the result showed that the tea polysaccharide was a typical heteropolysaccharide and consisted of mannose, ribose, rhamnose, glucuronic acid, galacturonic acid, glucose, xylose, galactose and arabinose in the molar contents of 16.3, 10.3, 47.1, 5.6, 24.0, 128.4, 25.0, 101.4 and 71.1 μM, respectively. Quantitative recoveries of the component monosaccharides in the tea polysaccharide were in the range of 94.6–108.0% and the RSD values were lower than 4.9%. The results demonstrated that the proposed HPLC method was precise and practical for the analysis of the G. pentaphyllum tea polysaccharide.     

Quantitative determination of wine polysaccharides by gas chromatography-mass spectrometry (GC-MS) and size exclusion chromatography (SEC)

Wine polysaccharides play an important role on a number of technological and quality properties of wines and thus several methods have been proposed for their quantification. The present study evaluates the suitability of gas chromatography with mass spectrometry detector (GC-MS) for determining the content of wine monosaccharides and thus polysaccharide families. Factors affecting the yield of polysaccharide precipitation were firstly evaluated and the GC-MS method was characterised and compared with the previously reported GC-FID method. Repeatability and reproducibility values were similar in both methods, with values ranging from 1% to 14%. LODs obtained by MS were below 1.0 μg for all monosaccharides and LOQs were below 1.8 μg. Moreover, a recovery study of the whole method was carried out and it provided absolute recoveries between 81% and 116% for different wine samples, very good values taking into account the multi-step procedure. Both GC-MS and GC-FID were applied to determine the content of wine polysaccharide families in three wine samples and no significant differences were observed. Finally, high-resolution size exclusion chromatography with refractive index detector (HRSEC-RID) was applied to obtain the molecular weight distributions of the wine polysaccharides and to estimate their global content. The correlation observed between the polysaccharide values obtained with the GC method and the HRSEC-RID method (r = 0.746, p < 0.05) indicated that the latter could serve as a rapid and simple method to give an estimation of total wine polysaccharides although it can not be used to quantify in a precise way.     

Improvement in intestinal function of hamsters as influenced by consumption of polysaccharide-rich sage weed extracts

The purpose of this study was to investigate the effect of the water-soluble polysaccharide-rich sage weed (Salvia plebeia) extracts on intestinal function. The results showed that the extract is rich in water-soluble polysaccharides (60.5/100 g extract), which are mainly composed of pectic polysaccharides and hemicellulose. The inclusion of sage weed extract in the control diet at a level of 0.5/100 g diet resulted in significantly (P < 0.05) improved effects on intestinal and faecal parameters of the hamsters, such as shortened gastrointestinal transit time, reduced caecal ammonia, decreased daily faecal ammonia output, increased short-chain fatty acid concentrations in caecal content, and lowered activities of β-d-glucuronidase, β-d-glucosidase, mucinase, and urease. These findings suggest that an adequate intake of sage weed extracts (0.5/100 g diet) may play a role in the maintenance of intestinal health by reducing the exposure of intestinal mucosa to toxic materials and other harmful compounds.     

Structural characterisation of acid- and alkali-soluble polysaccharides in the fruiting body of Dictyophora indusiata and their immunomodulatory activities

The acid- and alkali-soluble polysaccharides (DIPs I and II) were extracted from the fruiting body of Dictyophora indusiata in this work. DIP I comprised of Glc (glucose), Fru (fructose) and Man (mannose), whereas DIP II was of Glc and Fru. Glc was the dominant monosaccharide in both DIPs with relatively molar percentage of >60%, which constructed the backbone of polysaccharide chain. The analysis of the glycosidic linkages indicated that Glc occurred as Glc 1 → 6 in DIP II. The immunological assays showed that both DIPs I and II had a noticeable effect on the hemolysis antibody level in the tested dosage range. However, DIP I could improve the weight of thymus organ and phagocytosis of monocyte. DIP II could restore delayed-type hypersensitivity reaction to dinitrofluorobenzene (DNFB), improving the activity of natural killer cells and the proliferation of splenocytes at high dose.     

Antioxidant activities of different fractions of polysaccharide conjugates from green tea (Camellia Sinensis)

Three fractions of water-soluble polysaccharide conjugates, coded as TPC-1, TPC-2, and TPC-3, were isolated and purified from low-grade green tea (Camellia sinensis) by absorbent chromatography and ion exchange chromatography. Their chemical and physical characteristics were determined by chemical methods, gas chromatography and size exclusion chromatography with laser light scattering. Deoxyribose assay, photoreduction of Nitro Blue Tetrazolium (NBT) assay and lipid peroxidation inhibition assay were applied to test the antioxidant activities of tea polysaccharide conjugates in vitro. The results indicated that the three polysaccharide conjugates were heteropolysaccharides bounded with protein. TPC-1 was composed of l-arabinose (Ara), d-ribose (Rib), d-xylose (Xyl), d-glucose (Glc), d-galactose (Gal) and d-mannose (Man). TPC-2 was only composed of four monosaccharides: Ara, Rib, Glc and Man. There was no Man detected in TPC-3. The protein contents of TPC-1, TPC-2, and TPC-3 were 2.8%, 3.8% and 4.0% and the molecular weights were 26.8 × 10⁴, 11.8 × 10⁴, 4.2 × 10⁴, respectively. TPC-3 showed the highest antioxidant activities among the three fractions of polysaccharide conjugates, with an IC₅₀ of 182 μg/ml for the deoxyribose assay, and 93 μg/ml for the photoreduction of NBT assay, values which were lower than those of TPC-1 and TPC-2 (P < 0.01). The effects of the molecular weight and protein content of the polysaccharide conjugates on the improvement of the bioactivities appeared to be significant.     

Purification and identification of polysaccharide derived from Chlorella pyrenoidosa

The conditions for extracting and purifying polysaccharides from Chlorella pyrenoidosa, including intensity and duration of ultrasound, the temperature and incubation time, and ethanol concentration, were investigated through an orthogonal design of L₁₆(4⁵) in this work. High performance liquid chromatography (HPLC) and gas chromatography (GC) were used to characterize the compounds in C. pyrenoidosa. The highest yield of 44.8 g kg⁻¹ was achieved at 400 W of ultrasound for 800 s and then followed by incubation in water bath at 100 °C for 4 h in 80% ethanol. Two polysaccharide fractions (S1 and S2) were separated from the extracts of C. pyrenoidosa using Sepharose 4B column chromatography. The average molecular weights (M_w) of S1 and S2 were 81,877 Da and 1749 Da, respectively. Gas chromatographic (GC) traces of the hydrolyzed polysaccharides showed that most of the majority of monosaccharide in both fractions was mannose (78.0% and 76.5% of relative mass from S1 and S2, respectively) with low levels of glucose (13.2% and 8.4% of relative mass from S1 and S2, respectively). The Fourier-transform infrared spectra (FT-IR) of S1 and S2 revealed typical characteristics of polysaccharides. Both samples had the characteristics of hydroxyl groups, weak C–H band and α-pyranoses; however, only S2 had a carboxyl group.     

Sustainable production of pectin from lime peel by high hydrostatic pressure treatment

The application of high hydrostatic pressure technology for enzymatic extraction of pectin was evaluated. Cellulase and xylanase under five different combinations (cellulase/xylanase: 50/0, 50/25, 50/50, 25/50, and 0/50 U/g lime peel) at ambient pressure, 100 and 200 MPa were used to extract pectin from dried lime peel. Extraction yield, galacturonic acid (GalA) content, average molecular weight (M_w,ave), intrinsic viscosity [η]_w, and degree of esterification (DE) were compared to those parameters obtained for pectins extracted using acid and aqueous processes. Pressure level, type and concentration of enzyme significantly (p < 0.05) influenced yield and DE of pectin. Enzyme and high pressure extraction resulted in yields which were significantly (p < 0.05) higher than those using acid and aqueous extraction. Although pressure-induced enzymatic treatment improves pectin yield, it does not have any significant effect on M_w,ave and [η]_w of pectin extracts indicating the potential of high pressure treatment for enzymatic pectin production as a novel and sustainable process.     

Submerged culture conditions for mycelial yield and polysaccharides production by Lyophyllum decastes

The effects of various carbon and nitrogen sources, their concentrations, initial pH and fermentation duration on the production of mycelia in terms of dry weight, exo-polysaccharide (EPS) and inner polysaccharide (IPS) by Lyophyllum decastes, a culinary-medicinal mushroom, were investigated in shake-flask cultures. Lactose, glucose and fructose were the top three best carbon sources for mycelial growth with corresponding yields of 6.73 g/l, 6.36 g/l and 6.10 g/l, respectively. Glucose was the best for production of EPS and IPS with 1.65 g/l and 317 mg/g dry mycelia, respectively. Maltose also performed well for EPS production. Yeast extract was the best nitrogen source for the production of mycelia (7.03 g/l) and IPS (325 mg/g dry mycelia), whereas EPS was improved further by increasing the yeast extract concentration (2.46 g/l at 2%). Similarly, initial pH 7 and 8 were best for polysaccharides production (EPS 1.73 g/l and IPS 320 mg/g) and mycelial growth (7.10 g/l), respectively. Maximum mycelial growth peaked at 15 days of cultivation whereas polysaccharides peaked at 10 days, and then tapered off. A concentration of glucose 3% and yeast extract 1% (mycelial yield and IPS) were found to be a suitable condition for submerged culture.     

Composition,characteristics, and in-vitro physiological effects of the water-soluble polysaccharides from Cassia seed

The popular beverage ingredients Cassia obtusifolia and Cassia tora were found to have considerable amounts of water-soluble polysaccharides (WSPs) (58.5 and 55.9/100 g of dried extract). The composition, characteristics, and in-vitro physiological effects of these polysaccharides and their possible health benefits were investigated. The major polysaccharide components in the WSP of C. obtusifolia were possibly pectic polysaccharides and hemicellulose, while C. tora WSP was mainly composed of arabinoglucan and pectic polysaccharides. These WSPs had inhibitory effects on the activities of α-amylase and pancreatic lipase, while they rendered an increase in protease activity. These WSPs also had the ability to bind bile acids and reduce the amount of cholesterol available for absorption. This suggested that these WSPs had potential application as herbal ingredients in beverages. Further investigations on their in-vivo hypocholesterolaemic effects and intestinal functions using animal-feeding experiments are under way.     

Effects of ovariectomization and ractopamine hydrochloride inclusion on heifer feedlot performance,meat yield,and tenderness of select muscles

Forty-eight British cross heifers were used to examine the effects of ovariectomization (OVX v. intact; INT) and ractopamine-HCl inclusion (0 or 0.41 mg/kg of BW day^− 1; NORAC or RAC) for the final 31 days on performance, meat yield, and tenderness of select muscles. Ractopamine supplemented heifers had heavier BW (P ≤ 0.05) and greater dressing percent than NORAC. Dressing percent was also greater (P < 0.01) for INT v. OVX. LM area tended to be larger for RAC (P = 0.07) and was larger for INT (P = 0.05). Neither ractopamine inclusion nor sex class affected (P > 0.08) organ weights or percent intramuscular fat. Ractopamine inclusion increased (P ≤ 0.05) subprimal weight for the shoulder clod and bottom round. However, ractopamine inclusion and sex class had minimal effects on subprimal yields or slice shear force. Heifers receiving ractopamine had increased BW, DP, carcass weight and select subprimal weights without impacting meat quality. Ovariectomization did not influence the affects of ractopamine supplementation.     

The comparison of three β-agonists for growth performance,carcass characteristics and meat quality of feedlot cattle

Forty-eight Bonsmara steers were assigned to three treatment groups and one control group consisting of 12 animals each. The control (C) received no β-agonist, while the three treatment groups received zilpaterol (6 ppm) (Z), ractopamine (30 ppm) (R) or clenbuterol (2 ppm) (Cl) for the last thirty days on feed. Growth performance (final 30 days), USDA quality and yield grades and meat quality (shear force, chemical, histological and biochemical) were compared for the three β-agonist and control groups. Animals responded negatively to Cl treatment during initial stages of supplementation, which was evident in lower feed consumption and initial growth rates. For carcass growth and yield, Cl had greater and more efficient growth rates, higher dressed out yields (proportional), lower USDA yield grades, and reduced marbling compared with C (P < 0.05). For meat quality measurements, the M. longissimus (LL) and M. semitendinosus (ST) were sampled. Cl had the greatest effect (P < 0.05) on WBSF, especially on the LL, followed by Z. Variation in tenderness and ageing effects corresponded with variation in calpastatin activity and myofibrillar fragmentation between treatment groups. While zilpaterol and ractopamine are currently the only products registered for cattle in different countries, it seems that zilpaterol has an advantage in carcass growth efficiency and yield without showing any adaptation problems for animals such as experienced by the more aggressive β-agonist clenbuterol.     

Three sulphated polysaccharides isolated from the mucilage of mud snail, Bullacta exarata philippi: Characterization and antitumour activity

Three sulphated polysaccharides, coded as BEMPA, BEMPB₁, BEMPB₂, were extracted from the mucilage of mud snail of Bullacta exarata and purified by DEAE-cellulose ion-exchange and size-exclusion chromatography. Structural analysis of purified polysaccharides by chemical and biochemical methods revealed BEMPA was a high (1→3,4)-linked mannose-containing polysaccharide with molecular weight of 22,977 Da. BEMPB₁, with molecular weight of 64,117 Da, was a high (1→3)-linked arabinose-containing polysaccharide. BEMPB₂ was mainly composed of (1→3,4)-linked mannose with molecular weight of 47,507 Da. The comparison between sulphated polysaccharides and their desulphated products showed that sulphate substitutions of BEMPB₁ were deduced to be at the C-3 of (1→4)-linked mannose, while sulphate substitutions of BEMPA and BEMPB₂ were at C-4 of (1→3)-linked mannose. Furthermore, BEMPA exhibited highest inhibitory effects on growth of B-16 melanoma cells, and IC₅₀ were 31.1 μg/mL.     

Chemical characterization and antioxidant activity of sulfated polysaccharide from the red seaweed Gracilaria birdiae

Hydrocolloids from seaweeds have interesting functional properties, such as antioxidant activity and gelling ability. A polysaccharide was isolated by aqueous extraction at 90 °C from the red seaweed Gracilaria birdiae (Gb), with a yield of 27.2% of the seaweed dry weight. The sulfate content of the polysaccharide was 8.4% and the main sugars present were galactose (65.4 mol%), 3,6-anhydrogalactose (25.1 mol%) and 6-O-methylgalactose (9.2 mol%). Gel permeation chromatography showed that Gb polysaccharide is a heterogeneous system, with molar mass at the main peak of 3.7 × 10⁵ g mol⁻¹ and a shoulder of 2.6 × 10⁶ g mol⁻¹. The sulfated polysaccharide of Gb characterized by FTIR exhibits the characteristic bands of agarocolloids (at 1375 and 770 cm⁻¹).     

Effects of supercritical fluid extraction parameters on lycopene yield and antioxidant activity

The effects of various parameters of supercritical carbon dioxide (SC-CO₂) fluid extractions of tomato skins on the extraction yields and antioxidant activities of lycopene-rich extracts were investigated. A Box–Behnken design was applied to study the effects of three independent variables (temperature ranging from 40 to 100 °C, pressure ranging from 20 to 40 MPa, and flow rate ranging from 1.0 to 2.0 mL/min) on lycopene yield. The model showed good agreement with the experimental results, by the coefficient of determination (r² = 0.9834). Temperature, pressure, and the quadratic term for the temperature of SC-CO₂ extraction were large significantly positive factors affecting lycopene yield (P < 0.05). The maximum total lycopene content of 31.25 μg/g of raw tomato was extracted at the highest temperature of 100 °C, 40 MPa and 1.5 mL/min. TEAC assay was applied to assess the antioxidant activity of lycopene-rich extracts from SC-CO₂ fluid extraction. The effects of SC-CO₂ fluid extraction parameters on the antioxidant activities of the extracts differed with the yield. For each unit of lycopene extract, the antioxidant activity level was constant below 70 °C, but then gradually decreased above 70 °C due to isomerization occurring as a result of the higher temperature. The ratio of all-trans-lycopene to the cis-isomers changed from 1.70 to 1.32 when the operating temperature was adjusted from 40 to 100 °C, indicating an increased bioavailability due to the generation of the cis-isomers. No significant effects of pressure or flow rate of SC-CO₂ fluid extraction on the antioxidant activity were observed.     

Comparison of the characteristics, functional properties, and in vitro hypoglycemic effects of various carrot insoluble fiber-rich fractions

Fiber-rich fractions (FRFs) including insoluble dietary fiber (IDF), alcohol-insoluble solid (AIS), and water-insoluble solid (WIS) were isolated from carrot pomace via different methods. This study revealed that carrot pomace was rich in insoluble FRFs (50.1-67.4 g/100 g), which were mainly composed of pectic polysaccharides, hemicellulose, and cellulose. These insoluble FRFs, especially WIS, were found to have significantly (P<0.05) higher functional properties, glucose-adsorption capacity, and amylase-inhibition activity than those of cellulose. The ability of these FRFs to adsorb glucose and reduce amylase activity implied that they might help control post-prandial serum glucose level. Moreover, it was shown that the yield, composition, functional properties, and in vitro hypoglycemic effects among the three FRFs would be affected by their preparation methods. Our results recommended the consumption of these insoluble FRFs, especially WIS, as sources of food fibers or low calorie bulk ingredients in food applications requiring oil and moisture retention.     

Isolation, characterization and immunological activity of a polysaccharide from the fruit bodies of an edible mushroom, Sarcodon aspratus (Berk.) S. Ito.

A water-soluble polysaccharide (HCP) with a molecular mass of 6.7 × 10⁵ Da determined by high performance size-exclusion chromatography (HPSEC), was isolated from the fruit bodies of Sarcodon aspratus (Berk.) S. Ito., an edible mushroom. HCP was elucidated as a liner glucan with a backbone structure of (1 → 6)-linked-??-d-glucopyranosyl residues by interpretation of the composition analysis, methylation analysis, periodate oxidation experiment, FT-IR, and NMR spectroscopy. Immunological activity evaluation using H³-thymidine incorporation method revealed that HCP could significantly stimulate the proliferation of the cultured mice spleen lymphocyte in a dose-dependent manner. HCP might be a potential immunomodulator which can be used against pathogens and tumors in health-care food or medicine. This is the first report on the detailed structure elucidation of the polysaccharide from S. aspratus.     

Effects of composition and oxidation of proteins on their solubility,aggregation and proteolytic susceptibility during processing of Cantonese sausage

Cantonese sausage proteins were classified into five fractions based on solubility. The alkali-soluble protein was the major protein component of Cantonese sausage and increased during the process. The salt- (myofibrillar proteins) and water-soluble protein fractions (sarcoplasmic proteins), which decreased throughout the process, played an important role in the proteolysis. The total carbonyl content was found to significantly increase (p < 0.05) in sarcoplasmic, myofibrillar and alkali-soluble proteins. The SH group level decreased, whereas S–S group level increased gradually. The protein solubility determinations suggested that hydrogen bonds, hydrophobic interactions, disulphide bonds and ionic bonds gave rise to a three-dimensional network structure of Cantonese sausage proteins. Average particle size and specific surface area of Cantonese sausage proteins were affected by the changes in composition and oxidation of proteins. Results of proteolysis suggested that proteolytic susceptibility was influenced by the degree of protein oxidation.