An Objective Illustration of the Inadequacy of the Official EC “<i>Ewers</i>” Method for the Determination of Starch

Kennedy, John F.; Stevenson, David; Junel, Kornelia

doi:10.1002/star.19900420104

Cited by 6 publications

(1 citation statement)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To determine the starch content (SC) and dry mater content (DMC), the analyses were carried out in the Laboratory of Quality Traits of Plant Cultivars in 2018-2022. SC was determined using the Ewers method based on starch hydrolysis with acid and recording the angle of rotation of the plane-polarised light of filtrates on a polarimeter (Kennedy et al, 1990;Methods…, 2021). To determine the DMC, at least two samples of each cultivar were homogenised and dried at 100°C for 6 h. Before the main drying stage, the samples were incubated at 120°C to inhibit the life processes and dried at 70°C to the air-dry condition (Methods…, 2021).…”

Section: Methodsmentioning

confidence: 99%

The environmental and genetic factors affect the productivity and quality of potato cultivars

Prysiazhniuk,

Sonets,

Shytikova

et al. 2023

Zemdirbyste-Agriculture

View full text Add to dashboard Cite

This study aimed to evaluate the impact of environmental and genetic factors on the yield, starch, and dry matter content in tubers of potato (Solanum tuberosum L.) cultivars belonging to different maturity groups considering cultivars diversity according to SSR markers. Twenty-four very early, early, medium, and late potato cultivars were evaluated. Field experiments were conducted in 2018-2020 in two locations: Forest Steppe and Forest zones of Ukraine. The SSRs analysis was carried out in 2021 using eight markers: STM0019, STM3009, STM2005, STM2028, STM3012, STM3023, STM5136, and STM5148. During this study, it was found that the growing zone and the year weather conditions had the greatest influence on the potato tuber yield -54% and 24%, while the effect of the cultivar genotype on the tuber yield was 8%. It was found that the cultivar genotype and the year weather conditions had the greatest influence on the potato tuber dry matter content -36% and 30%, respectively. The impact of cultivar genotype on the starch content was 31%, while the influence of the year weather conditions reached 21% and the growing zone 3%. Based on the distribution of alleles obtained by SSR markers, the majority of the very early ('Riviera', 'Prada', 'Duma', and 'Vzirets') and one of the early ('Zhytnytsia') tested potato cultivars were included in one cluster group. It was revealed that the 416 bp allele was identified by the STM5148 marker mainly in the very early potato cultivars, and the 424 bp allele was detected only in the very early and early ones. The study of SSRs and their associations with maturity can be considered as a reliable and rapid method for potato genotyping to find favourable combinations of alleles. Thus, to increase the nutritional value and productive potential of potatoes by developing and improving the main elements of cultivation technology, the biological characteristics of the potato cultivars in the agricultural and climatic conditions of Ukraine should be taken into account.

show abstract

Section: Methodsmentioning

confidence: 99%

The environmental and genetic factors affect the productivity and quality of potato cultivars

Prysiazhniuk,

Sonets,

Shytikova

et al. 2023

Zemdirbyste-Agriculture

View full text Add to dashboard Cite

show abstract

Evaluation of an Enzymic Method for Starch Purity Determination

Kennedy

Cabalda

1993

Starch Stärke

Self Cite

View full text Add to dashboard Cite

Independent evaluation of an enzyme method (AFNOR) on a wider than original array of starch types showed incomplete conversion of some starch components (up to 2.5%) to glucose, as assayed per gel permeation chromatography. The AFNOR method uses only a single enzyme regime consisting of amyloglucosidase from Aspergillus niger. Negligible amounts of starch were found in the precipitateslresidues obtained after starch hydrolysis of the starch hydrolysates (< 0.1 %).Standard deviation of the method was < 1% absolute for all starches studied. Bewertung einer enzymatischen Methode zur Bestimmung der Starkereinheit. Die unabhangige Bewertung einer Enzymmethode (AFNOR) in einem weiteren als ursprunglichen Bereich von Starkearten zeigte eine unvollstandige Konversion einiger Stlrkekomponenten (bis zu 2,5%) zu Glucose, wie durch Gel-Permeations-Chromographie bestimmt wurde. Die AFNOR-Methode verwendet nur ein einziges Enzymsystem, bestehend aus Am yloglucosidase aus Aspergillus niger. Vernachlassigbare Starkemengen (< 0.1 %) wurden in den nach der Starkehydrolyse der Starkehydrolysate in den Niederschlagen bzw. Resten gefunden. Die Standardabweichung der Methode betrug fur alle untersuchten Starken < 1% absolut. starchktarke 45 (1993) Nr. 2, S. 44-47 0 VCH Verlagsgesellschaft mbH, D-6940 Weinheim, 1993 starchistarke 45 (1993) Nr. 2, S. 45-47

show abstract

The Effects of Busan Preservative on Apparent Starch Purity Using the EC Ewers Method

1995

View full text Add to dashboard Cite

The effect of Busan preservative upon the starch purity values produced by the Ewers polarimetric assay was investigated. The results show that the use of a Busan blank results in a 1.2% underestimation of starch purity. If Busan effects are not compensated for, then a 0.657% underestimation of starch purity results. There is also a reduction in apparent starch purity values due to Busan reacting with some of the hydrochloric acid in the Ewers test. This portion of acid is therefore not available to react with starch in the Ewers test resulting in the loss of about 1% of acid before the test begins. This is important in an analysis where acid concentration is critical to results.

show abstract

An Objective Illustration of the Inadequacy of the Official EC “Ewers” Method for the Determination of Starch

Cited by 6 publications

References 9 publications

The environmental and genetic factors affect the productivity and quality of potato cultivars

The environmental and genetic factors affect the productivity and quality of potato cultivars

Evaluation of an Enzymic Method for Starch Purity Determination

The Effects of Busan Preservative on Apparent Starch Purity Using the EC Ewers Method

Contact Info

Product

Resources

About