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Problems in Measuring Leucoanthocyanin Content of Pears
Author(s) -
SMATHERS RENATA URY,
CHARLEY HELEN
Publication year - 1967
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1967.tb01319.x
Subject(s) - acetone , chemistry , methanol , anthocyanidin , yield (engineering) , pear , butanol , ethanol , slurry , organic chemistry , botany , materials science , pigment , composite material , metallurgy , biology
SUMMARY— Four solvents, 95% ethanol, methanol, and both ethanolic and aqueous acetone, were used to extract leucoanthocyanin from Bartlett pears. Ethanol extracted approximately one‐fourth, methanol one‐third, and acetone somewhat less than two‐thirds, based on the amount in the corresponding slurry. Conversion of leucoanthocyanin to anthocyanidin was influenced by the dispersing medium, the normality of the butanol in which the conversion was effected, and the source of the leucoanthocyanin (pear mart, slurry, or synthetic leucocyanidin). When ethanolic acetone was the dispersing medium, yields of anthocyanidin were greatest. Developer acidified to a normality of 0.025 compared to 0.6 reduced phlobaphene formation and gave higher yields of anthocyanidin except in the case of pear mart previously extracted with 70% ethanol and then dispersed in acetone. When conversion was effected at a normality of 0.025, yield of anthocyanidin from the mart of pear in acetone was somewhat less than half that obtained when ethanol was the dispersing' medium, that from the slurry was 25% greater, and the yield from synthetic leucocyanidin was almost twice as great.