MODIFIED PROCEDURE FOR THE DETERMINATION OF DIASTATIC ACTIVITY AND Α-Amylase ACTIVITY

Bendelow, V. M.

doi:10.1002/j.2050-0416.1963.tb01954.x

Cited by 37 publications

(11 citation statements)

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“…No amylase activity could be detected in the three selected peak fraetions with a 3,5-dinitrosalicylic acid method (Bendelow 1963). This result confirms that P-amylase is not present as an impurity.…”

Section: Physieal Parameter Valuesupporting

confidence: 63%

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Purification and properties of protein Z – a major albumin of barley endosperm

Hejgaard

1982

Physiologia Plantarum

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A major albumin of barley grain, called protein Z, has been purified from endosperm flour. Extraction with 0.05 Mβ‐mercaptoethanol and successive use of (NH 4)2SO4‐precipitation, anion exchange at pH 7.5, cation exchange at pH 4.5, and anion exchange at pH 8.0 resulted in a highly pure protein as judged from various electrophoretic and immunoelectrophoretic tests. As protein Z is a major protein component of beer, antibodies towards a protein‐rich beer fraction could be used to detect the protein during purification. Protein Z consists of at least four antigenically identical molecular forms with isoelectric points in the range 5.55–5.8, but same molecular mass near 40000. Dimer and, probably, tetramer forms were detected by gel filtration in the absence of reducing agents. Monospecific antibodies towards protein Z were prepared. Immunoelectrophoretic properties of the protein were not affected by treatment at pH 1–13 (30 min at 30°C) or up to 100°C (30 min at pH 7). Commonly grown barley varieties contained about 1.5–2.5 mg protein Z/g grain, but a much lower content (∼ 0.2 mg/g grain) was found in a few varieties. Like barley β‐amylase, protein Z was present in both salt‐extractable “free” (20–30%) and thiol‐extractable “latent” (70–80%) forms in the grain. Protein Z contains 2 cysteine and 20 lysine residues per monomer molecule and is relatively rich in leucine and other hydrophobic residues. Protein Z may contribute up to 5% of the total grain lysine in normal varieties and more than 7% in some high‐lysine barleys.

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Section: Physieal Parameter Valuesupporting

confidence: 63%

“…Enzymatic liberation of reducing sugars from starch was determined with a 3,5-dinitrosalicylic acid method (Bendelow 1963).…”

Section: Methodsmentioning

confidence: 99%

Purification and properties of protein Z – a major albumin of barley endosperm

Hejgaard

1982

Physiologia Plantarum

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“…The released reducing sugars were then determined by the DNS method using glucose as standard. The total amylase activity of ten grains was expressed as total glucose produced per 5 mg native starch, according to the definition of Bendelow (1963).…”

Section: Seed Vigour and Total Amylase Activitymentioning

confidence: 99%

Characterisation of starch during germination and seedling development of a rice mutant with a high content of resistant starch

Sun

et al. 2015

Journal of Cereal Science

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“…83,1977] method has been reported which measures the rate of diffusion of the activity through a gel containing starch1" and in still another method the maltose produced from starch is measured by the colour formed with 3,5 dinitrosalicylic acid. 34 The diastatic power does not forecast the fermcntability of a wort. Indeed, even under the assay conditions, whilst the amount of reducing sugar formed is proportional to the diastatic power the amount of fermentable sugar formed is not.263 OL-Amylase.-The activity of a-amylasc is usually determined by measuring the rate of conversion of a /3-limit dextrin, previously prepared from soluble starch, to dextrins which give a standard colour with iodine.173 Alternatively the rate of decrease in iodine-colouring capacity is measured with malt extracts heated under defined conditions to inactivate /?-amylase.…”

Section: Malt Analysismentioning

confidence: 99%