Addition Of Corn Starch Research Articles

Cornstarch and tannin in phenol–formaldehyde resins for plywood production

The aim of this work is to demonstrate the performances of cornstarch–quebracho tannin-based resins designed as adhesive in the plywood production. In this way, the cornstarch and quebracho tannin was introduced in the classic adhesive formulation in order to supply a part of phenol–formaldehyde (PF). The physical properties (rheological characterization, thermogravimetric analysis and solid phase 13C NMR analysis) of the formulated resins were measured. In order to evaluate the mechanical performances of optimal cornstarch–quebracho tannin-based resins, plywood panels were produced and mechanical properties were investigated. These mechanical properties included tensile strength, wood failure and 3-point bending strength. The performance of these panels is comparable to those of plywood panels commercial PF made. The results showed that plywood panels bonded with cornstarch–quebracho tannin–PF resins (15:5:80, w/w/w) exhibited better mechanical properties than plywood panels commercial PF made. The introduction of small proportions of cornstarch and quebracho tannin in PF resins contributes to the improvement of the boiling water performance of these adhesives. The formaldehyde emission levels obtained from panels bonded with cornstarch–quebracho tannin–PF were lower to those obtained from panels bonded with control PF. Solid state CPMAS NMR spectra indicates that no reaction at all between PF resins and cornstarch and quebracho tannin. Even when reaction does evidently not occur, the addition of cornstarch and quebracho tannin improves markedly the water resistance of PF resins.

Effect of stabilizers on the physico-chemical and sensory attributes of thermized yoghurt

Stabilized thermized yoghurt was produced by the addition of gelatin, carboxyl methyl cellulose (CMC) and corn starch, into yoghurt mix as stabilizers, each at 0, 0.5, 0.75 and 1.0% concentrations. The yoghurt samples produced after pasteurization of the mix, cooling, inoculation of starter culture and incubation for about 16 h were thermized at 75oC for 60 s followed by immediate cooling. Results show that titratable acidity value of the control samples (0% stabilizer) was 0.92 ± 0.03. CMC, when added to yoghurt mix at levels of 0.5% and above, depressed lactic acid production (compare 0.92 ± 0.03 of the control with 0.90 ± 0.01 of samples containing 0.5 and 0.75% CMC). This observation is in contrast to effects of corn starch and gelatin which enhanced lactic acid production (at least up to 0.75% concentration). This was also mirrored (in reverse order) in the pH values; as samples with higher titratable acidity had, expectedly, lower pH values. Addition of stabilizers decreased percent protein and ash contents due to dilution effect but increased total solids and specific gravity of the thermized yoghurt samples. Sensory results showed that addition of corn starch produced the most desirable flavour and taste which differed significantly (p < 0.05) from flavour and taste produced by gelatin but did not differ significantly (p ≥ 0.050) from that produced by CMC at 0.5 and 0.75% concentrations. Yoghurt containing CMC had the best mouth feel/consistency as well as appearance which did not differ significantly (p ≥ 0.05) from the mouth feel and appearance of yoghurt containing corn starch but differed significantly from yoghurt containing gelatin. Yoghurt containing CMC at 0.75% concentration was the most generally accepted. Key words: Stabilizers, thermized yoghurt, sensory attribute, physco-chemical.

Effect of stabilizers on the physico-chemical and sensory attributes of thermized yoghurt

Stabilized thermized yoghurt was produced by the addition of gelatin, carboxyl methyl cellulose (CMC) and corn starch, into yoghurt mix as stabilizers, each at 0, 0.5, 0.75 and 1.0% concentrations. The yoghurt samples produced after pasteurization of the mix, cooling, inoculation of starter culture and incubation for about 16 h were thermized at 75oC for 60 s followed by immediate cooling. Results show that titratable acidity value of the control samples (0% stabilizer) was 0.92 ± 0.03. CMC, when added to yoghurt mix at levels of 0.5% and above, depressed lactic acid production (compare 0.92 ± 0.03 of the control with 0.90 ± 0.01 of samples containing 0.5 and 0.75% CMC). This observation is in contrast to effects of corn starch and gelatin which enhanced lactic acid production (at least up to 0.75% concentration). This was also mirrored (in reverse order) in the pH values; as samples with higher titratable acidity had, expectedly, lower pH values. Addition of stabilizers decreased percent protein and ash contents due to dilution effect but increased total solids and specific gravity of the thermized yoghurt samples. Sensory results showed that addition of corn starch produced the most desirable flavour and taste which differed significantly (p Yoghurt containing CMC had the best mouth feel/consistency as well as appearance which did not differ significantly (p
0.05) from the mouth feel and appearance of yoghurt containing corn starch but differed significantly from yoghurt containing gelatin. Yoghurt containing CMC at 0.75% concentration was the most generally accepted.

Evaluation of the efficacy of vacuum cleaners for the integrated control of brown spider Loxosceles intermedia

Some venomous spiders of the genus Loxosceles can reach high population densities inside and around houses. In Brazil, most spider accidents are related to Loxosceles intermedia. Control of loxoscelism should utilize integrated pest management tools, such as vacuum cleaners, to eliminate egg sacs, webs and spiders. The present study tested the efficacy of one type of vacuum cleaner (for professional and domestic use) in the control of L. intermedia populations. Cockroaches (Pycnoscelus surinamensis) were used in some tests for comparison. Vacuuming using standard accessories or a paper tube resulted in the death of all female (n=60), male (n=60), young (n=60) and just-hatched (n=60) L. intermedia, and all egg sacs (n=5) were destroyed. The removal of the plastic plate present at the bottom of the vacuuming tube inside the machine allowed some spiders to survive the vacuuming process. When kept inside a vacuum bag full of dust and debris, adult females (n=10) survived for 10 days; however, significant mortality was observed among male (n=10) and young individuals (n=10). Addition of cornstarch to the vacuum bag did not affect the spiders (n=20). Vacuum cleaners, such as the one used in the present investigation, are promising tools for integrated management of L. intermedia and other spiders in domestic environments.

Development and in vitro evaluation of chitosan–polysaccharides composite wound dressings

This study focuses on the design and evaluation of chitosan-based films intended for wound dressing application. Films of chitosan and their blends with cornstarch and dextran were developed to improve the films’ physical strength. Polypropylene glycol at concentrations of 0.5, 1.0 and 1.5% (w/v) was added to improve the films’ flexibility. Some properties required for successful wound dressing, such as liquid adsorption, vapor and oxygen penetration, bioadhesiveness, and film elasticity, were examined. Chitosan films showed the highest liquid adsorption and the adsorption tended to decrease with addition of cornstarch and dextran. Moisture vapor and oxygen were found to be able to penetrate through all film formulations, and those films with cornstarch and dextran showed increased penetration rates through the films. The bioadhesiveness test using a pig gut model did not show significantly different bioadhesive properties with the addition of cornstarch and dextran. The film elasticity of the formulation containing only chitosan exhibited the lowest elongation of the film at a force of 2 N, but increased with the addition of cornstarch and dextran, respectively. In conclusion, the design and development of chitosan as a wound dressing can be improved by the addition of cornstarch or dextran, and propylene glycol to obtain the films with optimal properties for wound management.

옥수수 전분을 첨가한 스폰지 케이크의 품질특성

본 연구에서는 옥수수 전분의 첨가량을 0, 10, 20, 30, 40%로 달리하였을 때의 반죽의 특성과 스폰지 케이크의 물리적 및 관능적 특성을 조사하여 스폰지 케이크 제조 시 옥수수 전분의 첨가량에 따른 영향을 알아보고자 하였고, 그 결과는 다음과 같다. 옥수수 전분 첨가량을 달리하여 첨가한 스폰지 케이크 반죽의 비중은 전분 첨가량이 증가할수록 감소하였고, 반죽의 점도는 전분 첨가량이 증가할수록 점도가 증가하였다. 스폰지 케이크의 부피는 전분을 30% 첨가할 때까지는 부피가 증가하다 그 이상 첨가할 경우 부피가 오히려 감소하는 것을 알 수 있었다. 색도를 측정한 결과 L값은 옥수수 전분의 첨가량이 증가함에 따라 높은 값을 보였고, 전분 첨가량이 증가할수록 점점 황금 갈색을 나타내었다. 30% 처리구가 저장기간 동안 색의 변화가 적음을 알 수 있었다. 텍스쳐 실험 결과는 경도와 씹힘성은 옥수수 전분 첨가량이 증가할수록 낮은 값을 보였고, 저장기간이 증가함에 따라 모든 처리구의 경도는 증가하였다. 저장 기간동안 전분을 30% 첨가한 처리구의 경도 증가율이 다른 케이크에 비하여 가장 낮았다. 부착성의 경우 옥수수 전분의 첨가량이 증가할수록 높았고, 저장 기간이 길어질수록 증가하였다. 30% 처리구의 경우 부착성이 완만하게 증가하였다. 응집성은 옥수수 전분 첨가량이 증가할수록 감소하였고, 저장 기간이 길어질수록 다소 감소하였다. 20%와 30% 처리구는 완만하게 감소하여 저장 3일에도 크게 변화가 없는 것을 알 수 있었다. 관능검사 결과 모든 항목에서 전분을 첨가하지 않은 0% 처리구보다 전분을 첨가한 10%, 20%와 30% 처리구의 점수가 높았다. 반면 40% 처리구는 저장기간 동안 가장 낮은 점수를 받아 전분을 많이 첨가한 케이크는 오히려 좋아하지 않음을 알수 있었다. 저장기간 전반에 걸쳐 20%와 30%의 처리구의 점수가 높아 스폰지 케이크에 옥수수 전분은 20~30% 정도 첨가한 것을 가장 좋아하였다. 이상의 결과로 볼 때 스폰지 케이크를 만들 때 물리적 특성에서는 옥수수 전분을 30% 첨가할 경우 부피를 증가시키고 저장하는 동안 색과 텍스쳐를 잘 유지하여 좋은 상태의 케이크로 보관할 수 있을 것으로 보이며, 관능검사 결과에서도 전분을 20~30% 첨가한 것을 선호하는 것으로 보아 스폰지 케이크 제조 시 옥수수 전분을 30% 정도 첨가할 경우 바람직한 결과를 줄 것으로 기대된다.

Changes in in vitro digestibility and available lysine of soy protein isolate after formation of film

The effect of different pH and addition of ferulic acid, tannin, cornstarch and hydrogen peroxide into the film forming solutions on in vitro protein digestibility, content of available lysine, and mechanical and water vapor barrier properties of films made of soy protein isolate were investigated in our experiment. The results showed that protein digestibility and content of available lysine decreased after film formation. Moderately higher pH, addition of cornstarch, ferulic acid and tannin improved mechanical and water barrier properties. However, except for the addition of cornstarch, these substances further decreased protein digestibility and the content of available lysine compared with the same pH treatment. Addition of hydrogen peroxide decreased protein digestibility but did not greatly improve the mechanical and water vapor barrier properties of film. It seemed that a full estimation of the nutritional properties of protein based edible films is necessary before they launch into industrial application as edible films rather than as general packaging materials.

Preparation of porous (Ba,Sr)TiO3 by adding corn-starch

A new method of preparing porous (Ba,Sr)TiO3 ceramics has been introduced, using an ordinary ceramics processing technique. The effect of corn-starch on the positive temperature coefficient of resistivity characteristics and microstructure of the porous (Ba,Sr)TiO3 ceramics has been investigated. When the corn-starch addition was 1–20wt%, the PTCR jump was over 106 and 1–2 orders higher than that of samples without corn-starch. Also, it was found that the (Ba,Sr)TiO3 ceramics had porous microstructure by the addition of corn-starch. The porosity of the ceramics with 20wt% corn-starch was 44%. The electrical properties of the (Ba,Sr)TiO3 ceramics have been discussed, based on the microstructure, resistivity of grain boundaries, donor concentration of grains and the electrical potential barrier of grain boundaries.

Microstructure and CO gas sensing properties of porous ZnO produced by starch addition

Abstract Effects of corn starch addition on the microstructure and CO gas response were studied by sintering ZnO at 600∼900°C for 3 h in air. The addition of 5 wt% corn starch as the fugitive phase decreased both the grain size and the sintered density of ZnO at all sintering temperatures and thus increased the sensitivity to 200 ppm CO. The increasing relative density and grain size with sintering temperature was accompanied by a decreasing CO gas sensitivity after maximum at 700°C. The temperature showing the maximum CO gas sensitivity decreased with decreasing grain size. Humidity decreased both the hysteresis of electrical conductivity and CO gas sensitivity.

Viscoelastic Characterization of Surimi Gel: Effects of Setting and Starch

ABSTRACTRheological properties of Alaska pollock surimi gels were affected by setting and addition of corn starch. Setting increased (p &lt; 0.05) both elastic and loss moduli of gel in the absence of starch. However, in the presence of corn starch, setting decreased (p &lt; 0.05) the elastic and loss moduli of the gels. In stress relaxation, the residual forces increased from 37.1 Newton (N) (nonsetting) to 51.8N (setting) in the absence of starch. However, in the presence of starch, the residual force decreased from 49.1N (nonsetting) to 39.0N (setting) which indicated an antagonistic effect between corn starch and setting. A Maxwell model was useful to quantify relaxation behavior of surimi gel and to evaluate the effects of changes in processing conditions.

Effects of increased dietary energy after mating on developmental uniformity and survival of porcine conceptuses.

Two experiments were conducted to examine the effect of the feeding of a high-energy diet during early gestation on survival of porcine conceptuses. In the first, 91 second-estrus gilts were inseminated 24 h after detection of standing estrus and randomly assigned to a recommended energy (RE: 22.2 MJ of DE/d) or high-energy diet (HE: 36.0 MJ of DE/d) obtained by addition of cornstarch to RE. Gilts were slaughtered 9, 10, or 11 d later, and numbers of corpora lutea (n = 1,268) and recovered conceptuses (n = 977) were recorded. Conceptuses were photographed, and surface areas were measured using an image analysis system. Standard deviations (SD) for mean areas from 82 litters with 899 embryos were used as a measure of size variability within and between litters, and 472 of these were cultured for measurement of estrogen (E) concentrations by enzymeimmunoassay. Conceptus survival was similar for RE and HE groups (76.2 +/- 21 vs 78.8 +/- 17.5%; P > .05). Mean surface areas and SD increased (P < .05) between d 9 and 11, but they were the same for both diets (P > .1). No difference was detected between diets in E produced by d 9 and 10 blastocysts after 24 h in vitro (P > .1). In contrast, d-11 RE embryos produced more E than did HE embryos after 3 h (.77 +/- .11 vs .37 +/- .11 ng/mL; P < .01) and 24 h (3.02 +/- .40 vs 1.29 +/- .39 ng/mL; P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Spectroscopic and mechanical changes in irradiated starch-filled LDPE

LDPE containing corn starch (3·9%, 5·8% and 7·9% by weight) without further additives and corn starch in a pro-oxidant formulation (= masterbatch (MB): 10%, 15% and 20% by weight), were analysed by FTIR and drawtesting after irradiation for periods of up to 500 h. The carbonyl index for LDPE-20% MB after 500 h irradiation was 2·5 times the value obtained in pure LDPE and in LDPE-starch. The hydroperoxide index for the same material was three times the value obtained in pure LDPE and in LDPE-starch. During irradiation the tensile strength decreased to almost the same extent for all three materials—a mean value of 70% of the initial value was obtained after irradiation. The elongation at break for pure LDPE decreased during irradiation from 650 to 500%. The addition of starch and MB decreased the initial value from 650 to 500%. After irradiation the decrease was considerable—a mean value of 60% being recorded for the elongation at break of LDPE-MB. A material susceptible to photolysis is thus obtained by the addition of corn starch and a master batch containing LLDPE, styrene-butadiene copolymer (SBS) and manganese stearate. Incorporating only starch into LDPE did not significantly change the susceptibility of the material to photolysis. LDPE-MB is thought to degrade by an initial photo-oxidation (autoxidation) and a subsequent attack by microorganisms (i.e. biodegradation). Further ongoing studies on the biodegradation of pretreated LDPE-MB will be reported elsewhere. The induction time is accelerated by pretreatment. Irradiation or thermal treatment generate free radicals causing autoxidation which should facilitate a later biodegradation.

Influence of Buffer pH and Raw Corn Starch Addition on In Vitro Fiber Digestion Kinetics

The impact was studied of buffer pH (5.8, 6.2, and 6.8) on in vitro digestion kinetics of NDF from alfalfa hay, bromegrass hay, corn silage, and alfalfa and bromegrass hays with raw corn starch added to approximate a ration containing 30% NDF. Ash-free NDF was determined at 0, 6, 12, 18, 24, 30, 36, 48, 72, and 96h of fermentation. Kinetic parameters were estimated by nonlinear regression using an iteratively reweighted least squares technique. Addition of raw corn starch decreased fiber digestion rate for alfalfa hay and lag for bromegrass hay. Both rate and lag of NDF digestion of all substrates were affected negatively below pH 6.2. Predicted ruminal NDF digestibilities (as percentage of that at pH 6.8 treatment) declined below pH 6.2 for all forages; addition of starch decreased predicted ruminal NDF digestibility by 23% for both alfalfa and bromegrass hays, even at pH 6.8. Results suggest that low pH decreases fiber digestion rate and increases lag and that starch accentuates this effect for some substrates.

586 CORONARY DISEASE IN YOUNG CHILDREN: DIAGNOSIS AND SAO INTERVENTION IN 5 ASYMPTOMATIC PATIENTS (PTS) WITH HOMOZYGOUS FAMILIAL HYPERCHOLESTEROLEMIA (HFH)

Five pts with HFH (4m, If) were aged 22 months - 15 yrs at diagnosis. Two receptor negative (r.n.) pts had mean Chol of 24 mMol/1, LDL 22 mMol/1, HDL 0.64 mMol/1 and TG 2.22 mMol/l. Three receptor defective (r.d.) pts had mean Chol of 17.1 mMol/l, LDL 16 mMol/l, HDL 0.8 mMol/l and TG 1.14 mMol/1. One r.n. pt died at age 3 with coronary occlusion. All pts had normal ECG and chest x-ray. Abnormalities were seen on 2d Echo and exercise test in 1 of 5 pts and stress MUGA study in 2 of 3 pt studies. Coronary angiograms (c.a.) showed obstructive lesion of left main coronary artery of 60% in 1 r.n. pt (5 yrs) and 50% in 1 r.d. pt (7 yrs). It was normal in 1 r.d. pt (16 yrs). All pts had poor response to treatment with diet, Questran or Colestid and Niacin. In 2 pts (1 r.n. and 1 r.d.) continuous nocturnal intragastric feeding caused a moderate, but unsustained cholesterol lowering effect. In 2 r.d. pts addition of cornstarch to the diet led to a 25% reduction in Choi and LDL with stable HDL. In 1 r.n. pt aged 5 yrs repetitive plasma exchange every 2-3 weeks reduced Choi and LDL 56%, HDL 36% at maximum.Coronary disease in young asymptomatic HFH pts may be more severe in r.n. than r.d. pts. Non-invasive assessment can be helpful in diagnosis and follouwp. Regression of coronary lesions following plasma exchange in childhood HFH remains to be demonstrated.

Pulp dispersion in selective desliming of iron ores

In the upgrading of finely disseminated iron ores, selective desliming is a critical step prior to flotation. A prerequisite for selective desliming is a properly dispersed pulp; sodium silicate is commonly used as a dispersant. The mechanism by which pulp dispersion is attained by means of sodium silicate in the presence of calcium ions and magnesium hydroxide precipitates was examined by settling tests, abstraction tests, selective flocculation tests and electron microscope observations. Flocculation and disperson regions of quartz as functions of calcium, magnesium and sodium silicate levels were delineated. Pulps consisting of artificial mixtures of quartz and goethite dispersed nonselectively on addition of sodium silicate. At low silicate levels, addition of corn starch aided the flocculation of goethite over quartz; at higher silicate levels, addition of starch was ineffective. A model is presented to explain pulp dispersion in the presence of these species.