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Thermal characterization of partially hydrolyzed cassava (Manihot esculenta) starch granules
Lacerda, Luiz Gustavo;Azevedo, Jayme Augusto Menegassi;Carvalho Filho, Marco Aurélio da Silva;Demiate, Ivo Mottin;Schnitzler, Egon;Vandenberghe, Luciana Porto de Souza;Soccol, Carlos Ricardo;
Brazilian Archives of Biology and Technology , 2008, DOI: 10.1590/S1516-89132008000600016
Abstract: cassava starch, partially hydrolyzed by fungal á-amylase, was characterized using thermal analysis, light microscopy and x-ray diffraction. thermal degradation was initiated at lower degradation temperatures after enzymatic treatment and the dsc (differential scanning calorimetry) analysis showed almost similar range of gelatinization temperature, but the enthalpies of gelatinization were quite increased for the partially hydrolyzed starch granules. the results suggested that the partial degradation of the starch granules was concentrated in the amorphous regions.
Arraste via fecal de nutrientes da ingest?o produzido por baga?o de mandioca hidrolisado
Raupp, Dorivaldo da Silva;Marques, Silvia Helena de Paula;Rosa, Danielle Amorim;Caldi, Carla Marielle;Cremasco, Ana Candida Vivan;Banzatto, David Ariovaldo;
Scientia Agricola , 2002, DOI: 10.1590/S0103-90162002000200005
Abstract: dietary fiber can drag nutrients in faeces. cassava waste from starch industry can be hydrolyzed by an enzymatic process and give origin to a food with high content of insoluble dietary fibers, named partially hydrolyzed cassava waste (hcw). hcw or standard wheat bran (wb) were fed to model growing rats in order to assess their dragging skill of nutrients from the intake of faeces. addition of 5%, 15% or 25% hcw, in replacement of starch, promoted a significant dragging proportion for the overall minerals or proteins; addition of 15% or 25% hcw dragged a significant proportion of lipids and the addition of 25% hcw dragged a significant proportion of digestible carbohydrates. adding 25% wb caused significant dragging of total minerals, protein and digestible carbohydrates, lipids were, however, not dragged with wb treatment. hcw promoted a more pronounced effect as compared to wb in regard to the dragging process of total minerals or proteins for 5% or 15% additions. nervertheless, for high rates, such as 25% additions, both fibrous sources produced similar effects on the dragging of protein, but wb promoted the greatest dragging process of total minerals. no differences between both fiber sources were observed as to their abilities of dragging lipids or digestible carbohydrates into faeces. with high rates (25%) hcw promoted effects similar to wb, allowing to conclude that hcw might be used as an important alternative source of insoluble dietary fiber for the formulation of digestive-functional feeds.
Bioconversion of cassava starch by-product into Bacillus and related bacteria polyhydroxyalkanoates
Krueger,Cristhiane L; Radetski,Claudemir M; Bendia,Amanda G; Oliveira,Ida M; Castro-Silva,Marcus A; Rambo,Carlos R; Antonio,Regina V; Lima,André O.S.;
Electronic Journal of Biotechnology , 2012,
Abstract: background: unlike petroleum-based synthetic plastics, biodegradable biopolymer generation from industrial residue is a key strategy to reduce costs in the production process, as well as in the waste management, since efficient industrial wastewater treatment could be costly. in this context, the present work describes the prospection and use of bacterial strains capable to bioconvert cassava starch by-product into biodegradable polyhydroxyalkanoates (phas). results: the first step of this study was the bacterial competence screening which was conducted with 72 strains covering 21 bacillus and related species. the microorganism growth in a medium with a starch substrate was measured by an innovative mtt assay, while the ability of the bacteria to secrete amylase and produce pha was evaluated by the nile red dye method. based on growth and potential for pha production, four isolates were selected and identified as bacillus megaterium by 16s rrna sequencing. when cultivated in hydrolyzed cassava starch by-product, maximum production reached 4.97 g dry biomass/l with 29.7% of poly-(3-hydroxybutyrate) (characterized by ftir). conclusions: mtt assay proved to be a reliable methodology for monitoring bacterial growth in insoluble media. selected amylolytic strains could be used as an alternative industrial process for biodegradable plastics production from starchy residues, reducing costs for biodegradable biopolymer production and wastewater treatment operations.
Viscosity of partially hydrolyzed polyacrylamide under shearing and heat
Changhong Gao
Journal of Petroleum Exploration and Production Technologies , 2013, DOI: 10.1007/s13202-013-0051-4
Abstract: Polymer flooding is the most successful chemical method to enhance oil recovery. This technique has achieved large-scale field application in China. Polymer flooding is also being tested in several heavy oil fields. For oil field applications, partially hydrolyzed polyacrylamide (HPAM) is the most widely used polymer. HPAM must maintain high viscosity to achieve good oil recovery. In reality, however, polymers can be severely degraded by shearing and heat in the underground environment. This phenomenon is studied in this paper. The two HPAM test samples have molecular weight of 10 million and 20 million. The samples were added to water to achieve concentrations of 500 to 3,000 ppm. The first group of tests was conducted to study the effect of shearing on HPAM viscosity. The second group of tests was carried out to evaluate the effect of high temperature up to 90 °C on HPAM viscosity. It was discovered that both shearing and high temperature can severely reduce polymer viscosity. Data analysis shows that the empirical power law parameters are strong functions of polymer concentration and temperature. Simple formulas are proposed to correlate HPAM viscosity with shearing rate, polymer concentration and temperature. These formulas are useful tools for predicting HPAM viscosity in field applications.
Partially hydrolyzed guar gum in pediatric functional abdominal pain  [cached]
Claudio Romano,Donatella Comito,Annalisa Famiani,Sabrina Calamarà
World Journal of Gastroenterology , 2013, DOI: 10.3748/wjg.v19.i2.235
Abstract: AIM: To assess the effects of partially hydrolyzed guar gum (PHGG) diet supplement in pediatric chronic abdominal pain (CAP) and irritable bowel syndrome (IBS). METHODS: A randomized, double-blind pilot study was performed in sixty children (8-16 years) with functional bowel disorders, such as CAP or IBS, diagnosed according to Rome III criteria. All patients underwent ultrasound, blood and stool examinations to rule out any organic disease. Patients were allocated to receive PHGG at dosage of 5 g/d (n = 30) or placebo (fruit-juice n = 30) for 4 wk. The evaluation of the efficacy of fiber supplement included IBS symptom severity score (Birmingham IBS Questionnaire), severity of abdominal pain (Wong-Baker Face Pain Rating Score) and bowel habit (Bristol Stool Scale). Symptom scores were completed at 2, 4, and 8 wk. The change from baseline in the symptom severity scale at the end of treatment and at 4 wk follow-up after treatment was the primary endpoint. The secondary endpoint was to evaluate compliance to supplementation with the PHGG in the pediatric population. Differences within groups during the treatment period and follow-up were evaluated by the Wilcoxon signed-rank test. RESULTS: The results of the study were assessed considering some variables, such as frequency and intensity of symptoms with modifications of the bowel habit. Both groups were balanced for baseline characteristics and all patients completed the study. Group A (PHGG group) presented a higher level of efficacy compared to group B (control group), (43% vs 5%, P = 0.025) in reducing clinical symptoms with modification of Birmingham IBS score (median 0 ± 1 vs 4 ± 1, P = 0.025), in intensity of CAP assessed with the Wong-Baker Face Pain Rating Score and in normalization of bowel habit evaluated with the Bristol Stool Scale (40% vs 13.3%, P = 0.025). In IBS subgroups, statistical analysis shown a tendency toward normalization of bowel movements, but there was no difference in the prevalence of improvement in two bowel habit subsets. PHGG was therefore better tolerated without any adverse effects. CONCLUSION: Although the cause of pediatric functional gastrointestinal disorders is not known, the results show that complementary therapy with PHGG may have beneficial effects on symptom control.
Quality Evaluation of Glucose Syrup from Sweet Cassava Hydrolyzed by Rice Malt Crude Enzymes Extract
D. Ahure,C.C. Ariahu
Journal of Food Technology , 2013, DOI: 10.3923/jftech.2013.1.3
Abstract: The quality of glucose syrup from cassava hydrolysis by rice malt crude enzymes extract was evaluated. Four syrups were produced using 5% rice malt 95% cassava flour, 10% rice malt 90% cassava flour, 15% rice malt 85% cassava flour and 20% rice malt 80% cassava flour, respectively. The viscosity, brix, refractive index, flavour, colour, taste and overall acceptability of the syrups were determined. The use of the crude enzyme extract for cassava starch hydrolysis resulted in significant (p≤0.05) decrease in viscosities which is advantageous in relation to flow and pumping requirements. The brix and refractive indices values were 65.5° and 1.454° (5% of rice malt 95% cassava flour), 61.0° and 1.445° (10% of rice malt 90% cassava flour), 58.5° and 1.439° (15% of rice malt 85% cassava flour) and 55.5° and 1.432° (20% of rice malt 80% cassava flour), respectively indicating that the substrate concentration was the limiting factor in enzyme hydrolysis of cassava starch. The mean sensory scores were 2.50-4.25 for 5% of rice malt 95% cassava flour, 2.75-3.58 for 10% of rice malt 90% cassava flour, 2.00-4.08 for 15% of rice malt 85% cassava flour and 3.08-4.08 for 20% of rice malt 80% cassava flour, respectively on a 5-point Hedonic scale.
Tolerance of a standard intact protein formula versus a partially hydrolyzed formula in healthy, term infants
Carol Berseth, Susan Mitmesser, Ekhard E Ziegler, John D Marunycz, Jon Vanderhoof
Nutrition Journal , 2009, DOI: 10.1186/1475-2891-8-27
Abstract: The objective of this study was to assess discontinuance due to study physician-assessed formula intolerance in healthy, term infants. Infants (335) were randomized to receive either a standard intact cow milk protein formula (INTACT) or a partially hydrolyzed cow milk protein formula (PH) in a 60 day non-inferiority trial. Discontinuance due to study physician-assessed formula intolerance was the primary outcome. Secondary outcomes included number of infants who discontinued for any reason, including parent-assessed.Formula intolerance between groups (INTACT, 12.3% vs. PH, 13.7%) was similar for infants who completed the study or discontinued due to study physician-assessed formula intolerance. Overall study discontinuance based on parent- vs. study physician-assessed intolerance for all infants (14.4 vs.11.1%) was significantly different (P = 0.001).This study demonstrated no difference in infant tolerance of intact vs. partially hydrolyzed cow milk protein formulas for healthy, term infants over a 60-day feeding trial, suggesting nonstandard partially hydrolyzed formulas are not necessary as a first-choice for healthy infants. Parents frequently perceived infant behavior as formula intolerance, paralleling previous reports of unnecessary formula changes.clinicaltrials.gov: NCT00666120Breastfeeding is the ideal source of nutrition for infants, but standard cow milk-based formulas (CMBF) are an appropriate source of nutrition for most infants who are not breastfed [1]. Some nonstandard formulas, such as soy-based or partially or extensively hydrolyzed protein cow milk-based formulas (CMBF), may be indicated for select groups of infants [2-4]. Partially hydrolyzed formulas are marketed as easier to digest although no evidence supports the physical need for these formulas in healthy infants. In addition, healthy infants who receive a CMBF with intact protein are often unnecessarily switched to a nonstandard formula or alternate CMBF [5-7]. Although published estimate
Modeling of Partially Hydrolyzed Polyacrylamide-Hexamine-Hydroquinone Gel System Used for Profile Modification Jobs in the Oil Field  [PDF]
Upendra Singh Yadav,Vikas Mahto
Journal of Petroleum Engineering , 2013, DOI: 10.1155/2013/709248
Abstract: The cross-linked polymer gel systems are being used increasingly to redirect or modify reservoir fluid movement in the vicinity of injection wells for the purpose of permeability/profile modification job in the oil field due to their high temperature stability and capability to provide rigid gel having high mechanical strength. In this study, a partially hydrolyzed polyacrylamide-hexamine-hydroquinonegel is used for the development of polymer gel system. The experimental investigation demonstrates that the gelation time varies with polymer and crosslinker concentration and the temperature. The mathematical model is developed with the help of gelation kinetics of polymer gel and using Arrhenius equation, which relates the gelation time with polymer, crosslinker concentrations, and temperature. The developed model is solved with the help of multivariate regression method. It is observed in this study that the theoretical values of gelation time have good agreement with the experimental values. 1. Introduction The reservoir heterogeneity, permeability variations, and presence of fractures and fracture network in the reservoir are the main hurdles of the water flooding operations used to enhance the oil recovery from matured oil fields. Normally during water flooding, water sweeps through more permeable sections of the reservoir leaving back oil in low permeability channels leading to low oil recovery and early water breakthrough. This excessive water production from the producers leads to rise in handling and disposal costs and reduces the economic life of the well. The polymer gels block or reduce the permeability in high permeability channels and divert the injected water through the low permeability sections, which were not flooded or swept earlier, leading to improvement in oil recovery. This technique is known as profile modification or permeability modification technique and the proper application of this technique is essential for the success of water flooding projects in the oil fields [1–3]. Basically two types of polymers have been used for profile modification jobs. These are polyacrylamides with different degrees of hydrolysis and polysaccharide such as xanthan biopolymer. These are cross linked with inorganic and organic crosslinkers to produce a three-dimensional polymer structure of the gel [4–7]. The inorganic gel system based on the crosslinking of the carboxylate groups on the partially hydrolyzed polyacrylamide chain (PHPA) with a trivalent cation like Cr (III). This crosslinking is believed to rely on coordination covalent bonding. It
Short Term (14 Days) Consumption of Insoluble Wheat Bran Fibre-Containing Breakfast Cereals Improves Subjective Digestive Feelings, General Wellbeing and Bowel Function in a Dose Dependent Manner  [PDF]
Clare L. Lawton,Jenny Walton,Alexa Hoyland,Elaine Howarth,Peter Allan,David Chesters,Louise Dye
Nutrients , 2013, DOI: 10.3390/nu5041436
Abstract: This study investigated whether increasing insoluble (predominantly wheat bran) fibre over 14 days improves subjective digestive feelings, general wellbeing and bowel function. A single centre, multi-site, open, within subjects design with a 14 day non-intervention (baseline) monitoring period followed by a 14 day fibre consumption (intervention) period was performed. 153 low fibre consumers (<15 g/day AOAC 985.29) completed a daily symptom diary for 14 days after which they consumed one bowl of ready-to-eat breakfast cereal containing at least 5.4 g fibre (3.5 g from wheat bran) for 14 days and completed a daily symptom diary. Significant improvements were demonstrated in subjective perception of bowel function (e.g., ease of defecation) and digestive feelings (bloating, constipation, feeling sluggish and digestive discomfort). Significant improvements were also found in subjective perception of general wellbeing (feeling less fat, more mentally alert, slim, happy and energetic whilst experiencing less stress, mental and physical tiredness, difficulty concentrating and fewer headaches). In general, improvements in study outcomes increased with increasing cereal/fibre consumption. However, consuming an additional minimum 5.4 g of fibre (3.5 g wheat bran) per day was shown to deliver measurable and significant benefits for digestive health, comfort and wellbeing. Encouraging consumption of relatively small amounts of wheat bran could also provide an effective method of increasing overall fibre consumption.
The hydrothermal synthesis of hydrotalcite by using different partially soluble and insoluble in water mangesium and aluminium components  [PDF]
Bankauskaite A.,Baltakys K.
Science of Sintering , 2011, DOI: 10.2298/sos1103261b
Abstract: In this work, the influence of different partially soluble and insoluble in water Mg and Al components on the formation of hydrotalcite by using only hydrothermal synthesis was examined. Hydrothermal synthesis duration was 4, 24 and 72 h at 200°C and Mg/Al ratio was equal to 3:1. The starting materials were: 4MgCO3 Mg(OH)2 5H2O, Mg5(CO3)4 (OH)2 4H2O, Al(OH)3 and γ-Al2O3. It was determined that Mg and Al containing compounds have most important influence on the formation of hydrotalcite by hydrothermal conditions. 4MgCO3 Mg(OH)2 5H2O as raw material is not recommendable for the synthesis of hydrotalcite, because even after 24 h of isothermal curing at 200°C temperature hydrotalcite is not formed and magnesium aluminum hydroxide hydrate is dominant in the synthesis products. Besides, initial magnesium containing component is decomposed into magnesium carbonate and hydroxide. It was examined that hydrotalcite is formed already after 4 h of hydrothermal synthesis at 200°C temperature when Mg/Al molar ratio is equal to 3:1 in the Mg5(CO3)4 (OH)2 4H2O - γ-Al2O3/ Al(OH)3 - H2O system. However, together with this compound a fair amount of an intermediate compounds (boehmite and magnesium carbonate) are formed. The duration of isothermal curing determines the formation of a hexagonal plates which are characteristic to hydrotalcite.
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