The effect of orientation on the properties of amylose and starch films was studied in order to determine if film strength, flexibility, and water resistance could be improved. Potato amylose and high (70%) amylose corn starch were peracetylated, cast into films, stretched in hot glycerol 1-6 times the original length, and deacetylated. Molecular orientation of potato amylose films was much hig...

High temperature significantly alters the amylose content of rice, resulting in mature grains with poor eating quality. However, only few genes and/or quantitative trait loci involved in this process have been isolated and the molecular mechanisms of this effect remain unclear. Here, we describe a floral organ identity gene, OsMADS7, involved in stabilizing rice amylose content at high temperat...

Cluster, correlation, and multivariate regression analyses were used to rationalize the effects of grain composition, starch fine structure, and leaching characteristics on cooked rice texture (hardness and stickiness). The head rice grain composition of 23 U.S. long-grain cultivars was evaluated in terms of apparent amylose content, crude protein, and surface lipids. Starch samples were prepar...

The occurrence of amylose-lipid complexes was determined in maize and teff starch biphasic pastes i.e. peak viscosity pastes at short and prolonged pasting times. Maize and teff starches were pasted for 11.5 and 130 min with or without added stearic acid followed by thermo-stable alpha-amylase hydrolysis in a rapid visco-analyzer. X-ray diffraction analysis of pastes before and residues after h...

Factors controlling the concentration of resistant starch (RS) in foods are of considerable interest on account of the potential for this type of fibre to deliver health benefits to consumers. The present study was aimed at establishing changes in starch granule morphology as a result of human small-intestinal digestion. Volunteers with ileostomy consumed six selected foods: breakfast cereal (m...

For this study seventy-eight rice samples from 2008 of mediumand long-grain rice cultivars were harvested and selected from Rohwer, Keiser, and Corning locations in Arkansas. Bulk milled rice samples of ~11.5 grams and 100 individual milled rice kernels fitted with single kernel adapter were scanned using a diode-array-analyzer of each cultivar/location. Partial least squares regression (PLS) w...

Cereal Chem. 78(4):442–446 In this study, 3% aqueous high-amylose maize starch (Hylon VII) dispersions were heated to temperatures of 140–165°C. The onset and rate of gel formation was observed using a small-strain oscillation rheometer as a function of temperature from 90 to 25°C. The gel formation clearly began earlier in high-amylose starch paste preheated at lower temperatures, but the rate...

in this study, variations of the pasting properties, swelling power and solubility of two rice starches, low amylose (8.7%) and high amylose (26%) at two citric acid concentrations (0 and 0.01 m) was investigated. the results showed that the peak viscosity and breakdown viscosity of rice starch decreased significantly (p 0.05).the swelling power and solubility of both starch pastes with and wit...

Foods high in resistant starch have the potential to improve human health and lower the risk of serious noninfectious diseases. RNA interference was used to down-regulate the two different isoforms of starch-branching enzyme (SBE) II (SBEIIa and SBEIIb) in wheat endosperm to raise its amylose content. Suppression of SBEIIb expression alone had no effect on amylose content; however, suppression ...

We compared the effects of a diet in which 25% of the carbohydrate was replaced by high-amylose starch with those of a similar diet high in oat bran or low-amylose starch in 23 hypertriglyceridemic subjects who were overweight mostly because of abdominal adiposity. Each diet was consumed for 4 wk in random order and in a crossover fashion. Overall, the diets were high in carbohydrate (> 55% of ...