Iodine Affinity Research Articles

The effects of iodine on the biological activities of myxoviruses.

Lugol's solution destroys the biological activities of Newcastle disease virus (NDV) after 15 s incubation at 37 degrees C. The rates of inactivation are slower at lower temperatures and at acid pH. At 4 degrees C and pH 5.8, the functions associated with the virus membrane, (haemolysis (HL), cell fusion and infectivity) are inactivated within 32 min, while haemagglutination (HA) and neuraminidase (N) are resistant to inactivation for several hours. Adjustment of NDV, Sendai and influenza A virus allantoic harvests to pH 5.8 and subsequent treatment with undiluted Lugol's solution (pH 5.8) for 15 min has a minimal effect on HA but results in complete loss of infectivity. It is suggested that iodination could be a useful method for vaccine production with membrane-bound viruses. It is postulated that the separation and dissociation of the membrane-associated properties of paramyxoviruses from the glycoprotein functions is due to the higher affinity of iodine for the lipids. Iodine could react with the carbon-carbon double bond (C=C) of the unsaturated fatty acids. This could lead to a change in the physical properties of the lipids and membrane immobilization.

Effect of Embraced Lipid on the Gelatinization of Rice Starch

AbstractQuantitative evalution of starch‐lipid interaction was attempted by means of amylography, the degree of gelatinization, iodine affinity, iodine color intensity, solubility and swelling power using isolated non‐defatted, defatted, and re‐embraced or impregnated starch with fatty acids, whose starch was isolated from non‐glutinous rice. The data obtained support that characteristics of rice starch are greatly affected by a trace amount of embraced lipid. The saturated amount of lipid in the rice starch might be reasonably deduced to be about 1 % or less. This value estimated from set back and maximum viscosity in amylography is in good agreement with the data obtained already.

Oat Starch: Some Recent Developments

AbstractStarches from Canadian oat varieties have been examined. Iodine affinity, solubility and λmzx of the iodine complex are lower than those found for other cereal starches. Swelling power, limiting viscosity number and hot paste cooling curves are all higher than for other cereal starches. Gel chromatography reveals a fraction of molecular weight between amylose and amylopectin and which is present in greater amount than that found in wheat starch. The β‐amylase digestion limit is lower than that found for wheat and corn and may suggest a more branched structure for oat starches.

Composition, Starch Properties and Protein Quality of Lentils

The chemical composition, cooking quality, starch properties and protein quality of the newly licensed lentil (Lens culinaris Medik.) cultivar Laird were generally similar to Tekoa and Commercial; the former is the only licensed cultivar of lentils in North America. Starch isolated from the three cultivars had similar pasting characteristics and contained, on the average, 35% amylose determined by iodine affinity. Scanning electron microscopy showed the starch granule to be simple, oval in shape and about 10–15um in size. Methionine, cystine and tryptophan were the limiting amino acids and, partly because of these, the mean chemical and protein scores and essential amino acid index of lentils were 23, 33 and 63, respectively.

Studies on the Gelatinization of Starches. Part 2. Effect of Lower Alcohols on the Gelatinization of Cereal Starches

AbstractThe effect of lower alcohols (methyl to amyl alcohol) on the gelatinization of cereal starches was studied by means of amylography and the determination of degree of gelatinization by glucoamylase digestion and iodine affinity. The straight chain primary alcohols other than methyl alcohol considerably decreased the transition temperature of the amylograms of these starches with the increase of molecular weight. The characteristic modification of the amylograms by these alcohols was inferred to be due to the exchange of the alcohols for the lipids in the amylose‐lipids complex of starch.

Iodine reaction of vinyl acetate/vinyl propionate copolymers. III. Iodine affinities of the radically polymerized copolymers and the copolymers derived from partially saponified polyvinyl acetate

AbstractThe minimum sequence lengths (nc) of vinyl acetate (VAc) units necessary to form a colored iodine complex were determined to be 4 and 17 for radically polymerized VAc/vinyl propionate (VPr) and VAc/isopropenyl acetate (IPAc) copolymers, respectively.The iodine affinities (I/VAc) of VAc/VPr copolymers (SP‐series) obtained by propionylation of partially saponified polyvinyl acetate (PVAc) were remarkably affected by the saponification conditions. An increase of the water content in acetone/water mixture as saponification solvent brought about a decrease of the iodine affinities of the SP‐series. The dependence of the iodine affinity on the saponification of monomer units in the SP‐series was compared with that in the radically polymerized VAc/VPr copolymers by taking the sequence probability as the measure of monomer unit distribution. The results strongly supported an occurence of the slide fastener reaction at high degrees of saponification, which was well‐known in the saponification of PVAc. Furthermore, it was found that the saponification mode of PVAc at low degrees of saponification was influenced uniquely by the water content in saponification solvents and the saponification temperature.

New Starches. Preparation and Properties of Starch and Its Fractions of Two Varieties of Groundnuts

AbstractThe isolation and properties of starch and its fractions from two varieties of groundnuts have been investigated. Starch contents were 13.0 and 18.2% on dry basis of defatted flours. Gelatinization temperatures were 62.0°–66.5°–71.0°C and 63.4°–68.2°–73.2°C and iodine affinities were 5.95 and 6.3 for the two varieties, respectively. Starches from both varieties presented single‐staged swelling and solubility behaviour. The amylose content of starch was found to be 30.0% and 28.2%. The molecular weight determinations of amyloses were obtained by gel filtration. The molecular weights of amyloses were approximately 350,000 and 380,000 respectively. The amylopectin fractions from both varieties of groundnuts seem to have molecular weights higher than 20 × 106. Both starches were found to be non‐ionic.

Iodine reaction of vinyl acetate — vinyl propionate copolymers II. Dependence of iodine affinities of the copolymers on the sequence distribution of vinyl acetate‐units

AbstractThe reactions of iodine with vinyl acetate (VAc) — vinyl propionate (VPr) copolymers in aqueous solutions of potassium iodide were investigated photometrically. The iodine affinity (I/VAc) of VAc‐units was defined as the number of bound iodine atoms per VAc‐unit and determined from the absorbance of the formed colored complex. The dependence of the I/VAc values on the copolymer composition was discussed with respect to the sequence distribution of VAc‐units in the copolymer chains. The dependence of the I/VAc value on the copolymer composition of block copolymers provided a useful information concerning the saponification of PVAc because the here used block copolymers were prepared by propionylation of partially saponified PVAc.

Effects of Surfactants and Freezing and Thawing on Starch and Pectic Substances in the Production of Dehydrated Mashed Potatoes

The effects of surfactants on starch gel and on water soluble pectic substances formed during the production of potato granules were studied. In potato mash two kinds of surfactants — glycerol monostearate alone, and a mixture of glycerol- and propylene glycol-monosterates — were found to reduce the content of free “non-clathrated” starch. This decrease was followed spectrophotometrically by the blue color absorbance (Blue Value Index) due to the iodine affinity of free starch. The reduction of the Blue Value Index was linearly proportional to the amount of the surfactants added up to a certain level, beyond which further addition of the surfactants had no influence. When the mash was cooled to 5.5°C the presence of surfactant did not noticeably effect the Blue Value Index. However, freezing and thawing drastically reduced this Index regardless of the presence of any surfactant in the mash. The combination of a surfactant and freezing and thawing effected a greater reduction of the Index than either of the treatments alone. Similarly, potato granules processed by the freeze-thaw treatment without the addition of surfactant had a considerably higher Blue Value Index than those processed with the addition of the surfactant.In a model system using slow set pectin solutions and a surfactant, it was found that a mixture of glycerol- and propylene glycol-monostearates at 0.1%, and glycerol monostearate alone at 0.05%, reduced the viscosity of a 1% pectin solution to a minimum. Alternatively, excessive amounts of the surfactants in the solutions brought about an increase in the viscosity. This effect of surfactant on pectin, as well as that on free starch content, was used in the production of potato granules by the freeze-thaw technique and this resulted in granules superior to those processed by the conventional add-back procedure.

Changes in the carbohydrate constituents of yam tuber (dioscorea rotundata, poir) during growth

AbstractThe amounts of sugars, starch, hemicellulose and cellulose in yam tubers were estimated at different stages of maturity and in yam tuber (“EgbodO”) sections. Maltose, sucrose, glucose and fructose were the free sugars identified in the ethanolic extracts of the yam samples. Sucrose formed the bulk of the total sugars. The “bottom” portion of the “Egbodo” yam tuber was richer in total sugars (4.9%) than either the “middle” (1.8%) or the “head” (2.4%) regions. Starch accounted, respectively, for 60, 77 and 78% of total carbohydrates in the “bottom”, “middle” and “head” regions of the “egbodo” yam tuber. A peak value of 84% starch was obtained 6 months after planting the yam setts. Its decrease to 64% at 8 months has been partly attributed to reduced photosynthetic activity through yellowing and subsequent loss of leaves. The sum of cellulose and hemicellulose, regarded as non‐available carbohydrates was less than 7% of the total carbohydrates. The linear fraction, amylose, formed about 17.8% of the starch prepared from whole yam tubers of varying maturities, and from yam tuber sections, the remaining being amylopectin. The observed amylose and amylopectin values did not vary significantly over the period of observation. These amylose and amylopectin fractions had iodine affinities of 17 and 0.1%, respectively.

The Determination of the Iodine Affinity of Poly(vinyl acetate)

The Determination of the Iodine Affinity of Poly(vinyl acetate)

Changes in the carbohydrate constituents of cassava root-tuber (Manihot utilissima Pohl) during growth.

AbstractSucrose formed the bulk of the sugars in cassava root‐tubers, accounting for more than 69% of the total sugars. Other sugars included fructose, glucose and maltose. Maltose was consistently present as the lowest amount. The highest concentration of sugars (5.7%) was attained nine months after planting. Starch accounted for the highest proportion of the carbohydrates. A peak value of 81% was observed eight months after planting. The decrease to 78% at nine months was accompanied by an increase in sugar concentration from 3.5% to 5.7%. The sum of cellulose and hemicellulose constituted the non‐available carbohydrate fraction to non‐ruminants. This was less than 7% of total carbohydrates. Paper chromatography of the neutralised hydrolysate of the extracted hemicellulose revealed the presence of glucose and xylose only. The amylose content of cassava starch varied between 16.2% and 17.4% during growth. This variation was significant at 1% F level. The separated amylose had an iodine affinity of 17.0% while amylopectin had 0.1%.

Accurate Analytical Wave Functions forI−

Self-consistent-field calculations by the expansion method, and the calculation of dimagnetic susceptibility, were carried out for the negative ion ${\mathrm{I}}^{\ensuremath{-}}$, ($Z=53$), $5{s}^{2}5{p}^{6}$, $^{1}S$. The results are the most accurate available. Also, we calculated the electronic affinity of atomic iodine, which agrees with the value determined by experiments to two significant figures. In general, this work presents additional information to our previous publications on heavy-atom systems.

Physical properties of starch granules of tobacco leaves during maturity stage

Abstract Although there are many studies concerning starch accumulation pattern of tobacco leaves during maturity stage (1, 2, 3, 4, 5), much less attention has been paid to physical properties of starch granules of tobacco leaves. Matheson et al. (6) reported in their study of starch changes in developing and senescing tobacco leaves, that the viscosities and iodine affinities of isolated starch granules increased with increasing age of the leaf, the β-amylosis limits of the whole starch and chain length of the amylopectins Were constant through the growth of the leaf and that the average granule size increased as the leaf matured and decreased as the starch conent decreased. One of the cl1aracteristics of maturity is to accumulated a large amount of starch after topping, but they used non topped f1ants, therefore the starch content was rather low. In our previous work (7) it has been demonstrated by using starch granules isolated rom tobacco leaves of topped plants, that the granule size and the ratio of amylopectin to amylose increased with the leaf maturity, a large alllount of calcium oxalate was found in the granules, and that the activity of starch synthetase bound with starch granules decreased with time after topping.

Studies on the Starches of Dioscorea. D.alata, eatable and D.cinnamomifolia, non eatable

AbstractThe starches of the species of Dioscorea that have been studied are composed of granules of different sizes and shapes. The average iodine affinity is 4.6% so, the amylose content is not very high. The values of the free‐swelling power and solubility and the quick and progressive solubilization in DMSO suggest a heterogeneous structure, with weak linking forces and a low degree of association inside the granules. The Brabender viscosity curves are very similar to the ones of the bread‐fruit starch, exception made to the cold paste viscosity. The properties of the starches of those species of Dioscorea suggest useful applications.

Iodine Affinity of the Seven Starch of a Team Project

Iodine Affinity of the Seven Starch of a Team Project

Lablab Bean Starch. I. Properties of its Granules and Pastes

AbstractThe variety of lablab bean (Dolichos lablab) starch studied by the authors, presents smaller‐sized, rounded granules, and others, larger ones, which are generally oval‐shaped and measure up to 30 micra. These latter show 1, 2 or 3 polarization crosses under polarized light. The gelatinization temperature of the granules varies between 65–70–76 °C and iodine affinity shows a value of 6.05.Graphs were drawn for the swelling power, percentage of solubles, Brabender viscosity of the hot and cold pastes, and also for the observation of the effect of a‐amylase on these pastes.It was observed that the starch pastes present the cross‐linked type Brabender viscosity curves, which greatly resemble those of the chick pea, yellow pea and navy bean starches. Several theories relating to the composition and structure of the starch, and which might explain its behavior, were approached by the authors.

The Iodine Affinity of Polyvinyl Acetate and Its Derivatives

The Iodine Affinity of Polyvinyl Acetate and Its Derivatives

Absorption Cross Section and Photoionization Yield of I2 between 1050 and 2200 Å

The total absorption cross section and photoionization yield of molecular iodine were measured from 1050 to 2200 Å. Two thresholds were observed in the photoionization yield curve. The first was associated with the ion-pair production I+ + I− and the second to direct ionization of I2. From the appearance potential for ion-pair production and the accurate ionization potential of I2 it was possible to calculate the value of the electron affinity of iodine, namely, 3.073 ± 0.014 eV.

Estimation of the Iodine Affinity of Starch by Three Types of the Automatic Titration

Iodine affinity (I. A.) values of potato of starch (P. S.) and corn starch (C. S.) were estimated by three different types of the automatic titration and the results were compared with each other. (1) The apparatus reported previously of the automatic amperometric titration for I. A. estimation was partly improved. (2) The shape of the amperometric titration curve of P. S. was found to be different from that of C. S.. The difference might be due to a structural difference of amylopectin components of these starches. (3) The potentiometric titration for I. A. estimation was also carried out automatically. The same I. A. value (3.6) was obtained by the two titration methode for P. S., but for C. S. the value obtained by the potentiometric method (4.6) was slightly higher than the one by the amperometric method (4.3). (4) The sample of C. S. used contained an unidentified substance which affected considerably the potential value of the initial reaction mixture. (5) The I. A. value of starch was also calculated from the curves of the automatic photometric titration. The values obtained were widely varied with titration conditions; they were always higher than those estimated by the above two methods, and became higher as the concentration of starch decreased.