RADIOCHEMICAL EVIDENCE FOR HETEROGENEITY IN WHEAT STARCH

1958 ◽  
Vol 36 (5) ◽  
pp. 810-813 ◽  
Author(s):  
A. S. Perlin
Keyword(s):  
Specific Activity ◽  
Wheat Starch ◽  
Carbon 14 ◽  
Minor Fraction ◽  
Wheat Starches ◽  
Leaching Procedure

Wheat starches labeled with carbon-14 have been fractionated by a novel leaching procedure to give amylose, amylopectin, and a highly-branched minor fraction designated "amylopectin C". Marked differences in the specific activity of the fractions are found. Subfractionation of amylopectin also gives products of varying specific activity. These findings provide radiochemical evidence for heterogeneity in wheat starch.

STUDIES ON WHEAT PLANTS USING C14 COMPOUNDS: VIII. FORMATION OF AMYLOSE AND AMYLOPECTIN IN THE WHEAT KERNEL

1958 ◽  
Vol 36 (9) ◽  
pp. 985-991 ◽  
Author(s):  
W. B. McConnell ◽  
A. K. Mitra ◽  
A. S. Perlin
Keyword(s):  
Specific Activity ◽  
Wheat Starch ◽  
Field Conditions ◽  
Conversion Process ◽  
Straight Chain ◽  
Active Growth ◽  
Carbon 14 ◽  
Wheat Kernel ◽  
Tracer Techniques ◽  
A Minor

Tracer techniques have been used to examine the pattern by which the straight-chain and branched components of wheat starch are laid down in the maturing kernel. The starches were isolated from kernels of wheat plants to which had been administered glucose-1-C14, acetate-1-C14, or acetate-2-C14 at different periods of active growth under field conditions. Fractionation of the starches gave amylose and amylopectin and, in addition, a minor fraction of amylopectin, all labelled with carbon-14. Notable differences were found in the specific activity of these starch fractions, and in the distribution of carbon-14 within the monomeric units of samples labelled via glucose-1-C14. These findings indicate that the process of starch deposition in the kernel is not extensively reversible. Amylopectin appears to be formed from amylose, in agreement with current views, and it is suggested that the minor amylopectin component is an intermediate in this conversion process.

STUDIES ON WHEAT PLANTS USING C14 COMPOUNDS: VIII. FORMATION OF AMYLOSE AND AMYLOPECTIN IN THE WHEAT KERNEL

1958 ◽  
Vol 36 (1) ◽  
pp. 985-991 ◽  
Author(s):  
W. B. McConnell ◽  
A. K. Mitra ◽  
A. S. Perlin
Keyword(s):  
Specific Activity ◽  
Wheat Starch ◽  
Field Conditions ◽  
Conversion Process ◽  
Straight Chain ◽  
Active Growth ◽  
Carbon 14 ◽  
Wheat Kernel ◽  
Tracer Techniques ◽  
A Minor

Tracer techniques have been used to examine the pattern by which the straight-chain and branched components of wheat starch are laid down in the maturing kernel. The starches were isolated from kernels of wheat plants to which had been administered glucose-1-C14, acetate-1-C14, or acetate-2-C14 at different periods of active growth under field conditions. Fractionation of the starches gave amylose and amylopectin and, in addition, a minor fraction of amylopectin, all labelled with carbon-14. Notable differences were found in the specific activity of these starch fractions, and in the distribution of carbon-14 within the monomeric units of samples labelled via glucose-1-C14. These findings indicate that the process of starch deposition in the kernel is not extensively reversible. Amylopectin appears to be formed from amylose, in agreement with current views, and it is suggested that the minor amylopectin component is an intermediate in this conversion process.

PREPARATION AND CHARACTERISATION OF ACETYLATED WHEAT STARCH SUPPORTING FOR DIABETES TREATMENT

2018 ◽  
Vol 8 (5) ◽  
pp. 78-84
Author(s):  
Uyen Tran Thi Ngoc ◽  
Nam Nguyen Khac ◽  
Dung Tran Huu
Keyword(s):  
Physicochemical Properties ◽  
Resistant Starch ◽  
Starch Content ◽  
Degree Of Substitution ◽  
Wheat Starch ◽  
Diabetes Treatment ◽  
Glucose Response ◽  
Swelling Capacity ◽  
Wheat Starches

Background: The purpose of the study was to prepare acetylated wheat starches which have amylase hydrolysis resistant capacity to use as functional food supporting for diabetes treatment. Method: Acetate wheat starches were prepared by acetylation reaction of native wheat starch with different mole ratios of acetic anhydride. These starches were determined for the physicochemical properties by 1H-NMR, SEM, X-ray, DSC, solubility and swelling capacity, the resistant capacity by amylase hydrolysis in-vitro. Results: Acetate wheat starches were prepared successfully with the increase in acetyl content and degree of substitution corresponding with the increase of anhydride acetic, which resulted in the change of physicochemical properties of the wheat starches, including constitution, solubility, swelling capacity and contributed to the increase in resistant starch content in the acetate wheat starches. The AC150-9 containing 2.42% acetyl with degree of substitution 0,094 and resistant starch 32,11% is acceptable by FDA guideline about food safety. Conclusion: Acetate wheat starches contain low rate of digestive starch, while containing a higher proportion of resistant starch than natural wheat starch, possessing a high resistance to amylase activities. Thus, it is hope that this kind of starch to control the rapid increase of postprandual blood glucose response for diabetes treatments effectively. Key words: Acetate wheat starch, substitution, DS, RS, amylase

THE METABOLISM OF VALERATE-2-C14 BY UREDOSPORES OF WHEAT STEM RUST

1963 ◽  
Vol 41 (1) ◽  
pp. 1-7 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
High Specific Activity ◽  
Water Soluble ◽  
Buffer Solution ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
Water Soluble Extract

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-2-C14, about 88% of the radioactivity was removed from the buffer solution in a period of 3 hours. About 40% of the carbon-14 taken from the buffer was found in a water-soluble extract of the spores and about 15% was respired as carbon dioxide. The result is compared with an earlier report that carbon 1 of valerate is more extensively released as carbon dioxide and less extensively incorporated into spore components. Glutamic acid, glutamine, γ-aminobutyric acid, and alanine of high specific activity were isolated. It was estimated from partial degradation that more than one-half of the carbon-14 of glutamic acid occurred in position 4 and that carbon 5 was very weakly labelled. Citric acid was also of high specific activity and was labelled predominantly in the internal carbons.It is concluded that respiring rust spores utilize externally supplied valerate by β-oxidation, which releases carbons 1 and 2 in a form which is metabolized as acetate by the tricarboxylic acid cycle.

STUDIES ON WHEAT PLANTS USING CARBON-14 LABELLED COMPOUNDS: X. THE INCORPORATION OF GLUTAMIC ACID-l-C14

1959 ◽  
Vol 37 (1) ◽  
pp. 933-936 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Wheat Plant ◽  
Protein Fractions ◽  
Appreciable Amount ◽  
Kernel Development ◽  
Carbon 14

Glutamic acid-1-C14 was injected into the top internode of wheat stems at a stage of growth when kernel development was rapid (71 days after seeding). The plants were harvested 31 days later when they had matured and the incorporation of carbon-14 studied. About one-third of the carbon-14 administered was found in the upper portions of the mature plants, much of the remaining radioactivity having apparently been respired. About 85% of the carbon-14 recovered was found in the kernel. The protein fractions of these were most radioactive, but an appreciable amount of carbon-14 also appeared in the starch. Glutamic acid had the highest specific activity of the amino acids isolated from the gluten, but proline and arginine were also strongly labelled. Since these three amino acids were labelled predominantly in carbon-1 their close metabolic relationship in the wheat plant seems probable.

scholarly journals The Effect of Germinated Sorghum Extract on the Pasting Properties and Swelling Power of Different Annealed Starches

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1602
Author(s):  
Hesham Alqah ◽  
M. S. Alamri ◽  
A. A. Mohamed ◽  
S. Hussain ◽  
A. A. Qasem ◽  
...  
Keyword(s):  
Sweet Potato ◽  
Amylose Content ◽  
Potato Starch ◽  
Amorphous Region ◽  
Enzymatic Digestion ◽  
Pasting Properties ◽  
Wheat Starch ◽  
Predictive Tool ◽  
Swelling Power ◽  
Wheat Starches

Starches were extracted from chickpea (C.P.), corn (C.S.), Turkish bean (T.B.), sweet potato (S.P.S.), and wheat starches (W.S.). These starches exhibited different amylose contents. The extracted starches were annealed in excess water and in germinated sorghum extract (GSE) (1.0 g starch/9 mL water). The α-amylase concentration in the GSE was 5.0 mg/10 mL. Annealing was done at 40, 50, and 60 °C for 30 or 60 min. The pasting properties of annealed starches were studied using Rapid Visco-Analyzer (RVA), in addition to the swelling power. These starches exhibited diverse pasting properties as evidenced by increased peak viscosity with annealing, where native starches exhibited peak viscosity as: 2828, 2438, 1943, 2250, and 4601 cP for the C.P., C.S., T.B., W.S., and S.P.S., respectively, which increased to 3580, 2482, 2504, 2514, and 4787 cP, respectively. High amylose content did not play a major role on the pasting properties of the tested starches because sweet potato starch (S.P.S.) (22.4% amylose) exhibited the highest viscosity, whereas wheat starch (W.S.) (25% amylose) had the least. Therefore, the dual effects of granule structure and packing density, especially in the amorphous region, are determinant factors of the enzymatic digestion rate and product. Swelling power was found to be a valuable predictive tool of amylose content and pasting characteristics of the tested starches. The studied starches varied in their digestibility and displayed structural differences in the course of α-amylase digestion. Based on these findings, W.S. was designated the most susceptible among the starches and S.P.S. was the least. The most starch gel setback was observed for the legume starches, chickpeas, and Turkish beans (C.P. 2553 cP and T.B. 1172 cP). These results were discussed with regard to the underlying principles of swelling tests and pasting behavior of the tested starches. Therefore, GSE is an effortless economic technique that can be used for starch digestion (modification) at industrial scale.

Carbon-14 Distribution in Peanut Fruit Parts During Maturation Following 14CO Treatment of Intact Plants1

1974 ◽  
Vol 1 (2) ◽  
pp. 63-67 ◽  
Author(s):  
Harold E. Pattee ◽  
Elizabeth B. Johns ◽  
John A. Singleton ◽  
Timothy H. Sanders
Keyword(s):  
Seed Coat ◽  
Developmental Stages ◽  
Specific Activity ◽  
Total Radioactivity ◽  
Maturity Stage ◽  
Early Maturity ◽  
Early Maturation ◽  
Carbon 14 ◽  
Fruit Part ◽  
Successive Feeding

Abstract Effects of sampling date and developmental stage on the distribution of radioactivity within the crude ethanol, lipid, and starch fractions from fruit, seed coat, and seed of peanut were investigated. Major differences were found between the first and fourth feeding dates in the amount of 14C-labeled photo-synthate translocated to individual peanut fruit parts. Maximum levels of radioactivity in the pericarp, seed coat, and seed were attained at progressively later developmental stages as the respective part became the dominant metabolic sink. Within the fruit, maximum radioactivity in starch was reached during early maturity (stage 3) and total radioactivity generally decreased with successive feeding dates. Thus the level of photosynthate being translocated to a given fruit decreases as more fruit develop on the plant. Observed relationships between level of radioactivity and specific activity of fruit-part components were interpreted as indicating that metabolic reserves are built up in the fruit and seed coat during early maturation and utilized later during seed development and maturation when the level of available translocated photosynthate has diminished.

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