Abstract
S ummary Evidence is presented which shows that when plant tissues are extracted with metaphosphoric acid at room temperature, some oxidation of ascorbic acid to dehydroascorbic acid occurs. This oxidation was diminished, though no conclusive proof was obtained that it was eliminated, by extracting the tissue with either metaphosphoric acid at —3°C or with methanol‐metaphosphoric acid at —70°C, in the absence of oxygen. An effect attributed to disorganization occurred if the tissue was held in the frozen state and as a result ascorbic acid Avas oxidized during disintegration in an acid extractant. The effect of disorganization was greater when the period in the frozen state was extended. The lowest values for dehydroascorbic acid in plant tissues have been obtained, either by extraction in metaphosphoric acid at —3°C or by rapid freezing and immediate extraction with methanol‐metaphosphoric acid solution at —70°C, both extractions being carried out in the absence of oxygen. These procedures gave similar results within the limits of experimental error.
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Claims 8
Claim · model-written summary
Room-temperature metaphosphoric acid extraction oxidized some ascorbic acid.
Verbatim
e0“when plant tissues are extracted with metaphosphoric acid at room temperature, some oxidation of ascorbic acid to dehydroascorbic acid occurs”
Claim · model-written summary
Metaphosphoric acid at —3°C diminished oxidation.
- Taxon
- plant tissuest0
- Treatment
- metaphosphoric acid at —3°Ce0
- Outcome
- oxidatione0
- Direction
- diminishede0
- Qualifier
- no conclusive proof was obtained that it was eliminatede0
Not reportedComparator
Verbatim
e0“This oxidation was diminished, though no conclusive proof was obtained that it was eliminated, by extracting the tissue with either metaphosphoric acid at —3°C or with methanol‐metaphosphoric acid at —70°C, in the absence of oxygen”
t0“PLANT TISSUES”
Claim · model-written summary
Methanol-metaphosphoric acid at —70°C diminished oxidation.
- Taxon
- PLANT TISSUESt0
- Treatment
- methanol‐metaphosphoric acid at —70°Ce0
- Outcome
- oxidatione0
- Direction
- diminishede0
Not reportedComparator
Verbatim
e0“This oxidation was diminished, though no conclusive proof was obtained that it was eliminated, by extracting the tissue with either metaphosphoric acid at —3°C or with methanol‐metaphosphoric acid at —70°C, in the absence of oxygen”
t0“PLANT TISSUES”
Claim · model-written summary
Holding tissue frozen caused ascorbic acid oxidation during disintegration.
Verbatim
e0“An effect attributed to disorganization occurred if the tissue was held in the frozen state and as a result ascorbic acid Avas oxidized during disintegration in an acid extractant”
t0“PLANT TISSUES”
Claim · model-written summary
Longer frozen storage increased the disorganization effect.
Verbatim
e0“The effect of disorganization was greater when the period in the frozen state was extended”
t0“PLANT TISSUES”
Claim · model-written summary
Metaphosphoric acid at —3°C gave the lowest dehydroascorbic acid values.
Verbatim
e0“The lowest values for dehydroascorbic acid in plant tissues have been obtained, either by extraction in metaphosphoric acid at —3°C”
Claim · model-written summary
Immediate extraction with methanol-metaphosphoric acid at —70°C also gave the lowest values.
Verbatim
e0“or by rapid freezing and immediate extraction with methanol‐metaphosphoric acid solution at —70°C”
t0“PLANT TISSUES”
Claim · model-written summary
The two low-temperature procedures gave similar results within experimental error.
Verbatim
e0“These procedures gave similar results within the limits of experimental error”
t0“PLANT TISSUES”