Commercial Corn Starch Research Articles

Soluble Amylose Cornstarch Is More Digestible than Soluble Amylopectin Potato Starch in Rats ,

In liquid enteral formulations, high molecular weight soluble starches may be able to replace glucose and low molecular weight glucose polymers that have high glycemic indices. Male rats were fed either commercial cornstarch, dextrose, modified soluble potato (70–75% amylopectin) starch, or modified soluble amylomaize-7 (70% amylose) starch for 4 wk. Body weights did not differ among the groups. Food consumption was significantly higher in the two modified starch–fed groups than in the two control groups. Commercial cornstarch, dextrose, modified potato starch and modified amylomaize-7 starch were 100 ± 0, 100 ± 0, 69.0 ± 1.0 and 91.5 ± 0.8% digestible, respectively (n = 9, mean ± SEM). The modified potato starch–fed group deposited the least fat, protein and energy. In both modified starch–fed groups, liver weights were significantly greater than in the two control groups. In food-deprived rats, serum free fatty acid concentrations in the modified potato starch–fed group were significantly higher than in the two control groups, and serum glucose concentrations were significantly higher in the two modified starch–fed groups than in the controls. The insulin to glucagon ratios were significantly lower in the modified potato starch–fed and amylomaize-7 starch–fed groups than in the dextrose-fed control group. Serum protein concentrations, measured after food deprivation, were significantly lower in the modified potato starch–fed group than in the other three groups. Gluconeogenesis from fermentation products might account for the high serum glucose concentrations in the two experimental groups. These data indicate that only the modified amylomaize-7 starch may be useful in the development of food products for liquid nutritional supplements because of the high digestibility and the low resultant insulin levels.

Isolation and Cationization of Barley Starches at Laboratory and Pilot Scale

ABSTRACTPrime barley starches were isolated in the laboratory by a conventional extraction procedure from regular (Condor), waxy (SB89528), and high amylose (Glacier) barleys; cationized; and evaluated as wet‐end additives in papermaking. The cationized barley starches showed functionality (contribution to paper strength) comparable that of to a commercial grade cationic corn starch. The laboratory evaluation was followed by a pilot plant study in which an air‐classified starch‐rich fraction from Condor barley was purified by a short wet‐extraction procedure. The starch obtained was then cationized, using a slightly different procedure than that used in the laboratory. Mass balances for starch extraction and cationization were obtained for the pilot plant study. The cationized barley starch needs evaluation in a Canadian paper mill.

Glucose syrup production from Indonesian palm and cassava starch

Six palm starch samples and one cassava starch sample from Indonesia were converted into glucose syrup with comparison to a commercial corn starch, sample. The conversion was carried out by both liquefaction using α-amylase from B. stearothermophilius and saccharification using glucoamylase from A. niger. The liquefaction time for Metroxylon starch samples was longer than that observed for the other starch samples. Viscosity during liquefaction for palm and cassava starch samples showed the same variation. Based on dextrose equivalent (DE) and high performance liquid chromatography (HPLC) results, starch conversion to glucose for five of the palm and the cassava starch sample was equivalent to that observed for the corn starch sample. Starch conversion to isomaltose and maltose for the palm and cassava starch samples was equivalent to that for the corn starch sample. In general, starch conversion to higher oligosaccharides (DP-3 to DP-7) for the palm and cassava starch samples was higher than that observed for the corn starch sample. Therefore, based on the liquefaction time, percent conversion to glucose and total oligosaccharides, all palm and cassava starch samples, except for one A. pinnata starch sample, could be used for glucose syrup production.

Preparation and Application of Starch Graft Poly(vinyl) Copolymers as Paper Coating Adhesives

AbstractA series of starch graft copolymers were prepared from commercial cornstarch products and vinyl monomers and were evaluated as adhesives in pigmented paper coatings. Hypochlorite oxidized (HO), acid modified (AM), and hydroxyethlated acid modified (HEAM) starches were reacted separately with acrylamide (AAm), acrylic acid (AAc), and acrilonitrile (AN) using ceric ammonium nitrate as the polymerization initiator to yield copolymers containing 2–45% synthetic polymer. Pigmented coating mixtures with 6–14 parts co‐polymer/100 parts clay and 40–50% total solids were prepared and applied on one side of the paper stock using a hand‐drawn doctor blade. Viscosities, adhesive strength, and wet‐rub resistance of the coating adhesives and mixtures were determined. Adhesive strength of starch graft polyacrylamide (S‐g‐PAAm) copolymers containing as little as 12% PAAm was considerably superior to the commercial starches as paper coating adhesives. Adhesive strength of S‐g‐PAAc copolymers was similar to that of the HO and HEAM commercial starches, whereas adhesive strength of the S‐g‐PAN copolymers was poor. Copolymers that were prepared from the HO starch were slightly superior to those prepared from the AM and HEAM starches. Wet‐rub resistance of the pigmented copolymer coatings was not improved over that of the coatings containing the commercial starches.

Starch‐derived glycol and glycerol glucosides prepared by reactive extrusion processing

AbstractPreviously, starch‐derived glycol and glycerol glucosides were prepared by batch‐reaction processes and had excellent potential as chemical intermediates for a wide range of products. However, more efficient processes for preparation of these derivatives are needed. In this present work, a modern corotating, intermeshing, twin‐screw extruder with a barrel length/screw diameter (L/D) ratio of 43: 1 was used to study the reaction of starch with ethylene glycol and glycerol in the presence of sulfuric acid catalyst at elevated temperatures. A fully continuous process was used. Variables that were investigated included temperature (140–180°C), glycol or glycerol/starch AGU mol ratio (1.5–4.0), starch feed rate (5–30 lb/h), screw speed (100–475 rpm), residence time, specific energy, and several types of commercial cornstarch and corn flour products. Rates and extents of reaction that occurred in the barrel were determined by analyzing samples that were quenched just prior to extrusion. The major glucosides were quentitated by high‐performance liquid chromatography. Results of this study show that starch can be continuously, rapidly, and efficiently converted to glucosides in 90% yield at high production rates. Such processing is expected to be technically feasible for the reaction of a wide range of polyhydroxy alcohols with various starch substrates.

A Differential Scanning Calorimetry Study on the Effect of Annealing on Gelatinization Behavior of Corn Starch

ABSTRACTGelatinization characteristics of laboratory‐isolated and commercial corn starch were compared by differential scanning calorimetry (DSC) before and after being annealed at subgelatinization temperatures in excess water. Prior to annealing, commercial corn starch has a relatively narrow gelatinization range, with a peak temperature at 71°C. Starches isolated in the laboratory have wide gelatinization ranges and lower peak temperatures. After annealing, commercial starch showed little change in gelatinization characteristics, whereas laboratory starches all had narrowed gelatinization ranges, higher peak temperatures, and increased gelatinization enthalpy, indicating changes in the internal structure of the starch granules. This demonstrates that the wet‐milling process anneals corn starch during the isolation procedure.

Cationic Aminoethyl Cereal Flours. Semicommercial Production

AbstractBoth soft white wheat and yellow corn flours were reacted with ethylenimine by a continuous, dry process capable of making up to 300 pounds of cationic aminoethyl cereal flour per hour. When either cationic flour was evaluated as a wet‐end paper additive, each was equivalent to a high‐quality commercial cationic corn starch in improving dry‐strength properties of paper and increasing pigment retention. Laboratory storage of the flour products for 1/2 year did not change their effectiveness. Estimates based on a plant producing 15 million pounds of cationic flour a year indicate that the cost‐to‐make is about 10 cents per pound.

A study of the effect of various factors on the swelling of certain cereal starches

Three methods of determining the swelling power of cooked starch were studied. The swelling power results by the three methods were very highly correlated. However, the method employing loss in weight of gelatinized starch by heating in an electric oven appeared to be slightly more convenient than alternative methods of finding the weight of a given quantity of starch after gelatinization or the volume of the swollen starch. As was expected, an analysis of variance of the data showed significant differences in starch swelling among gelatinization temperatures, among wheat, barley and corn starches and among 1%, 2% and 3% (dry basis) starch concentrations. On the basis of the results it was decided to employ 1% starch concentration with a heating period of 5 minutes. Significant differences in swelling power were found among starches prepared from wheat, barley, rye, millet and commercial corn starch. The use of 0.5% NaOH in the cold (5°C.) was found to increase markedly the swelling power of cereal starches. A solution of 0.001 N Al 2(SO 4) 3 when employed in cooking the starch, decreased the swelling power of starch treated with NaOH, but was without effect on starch prepared with water. The evidence presented shows the great effect on swelling power capacity of mode of starch preparation, variations in cooking technique, etc. Inherent differences in individual starches may be entirely overshadowed by variations in the mode of strach preparation.