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Changes in nitrogen content and amino acid composition of navel oranges during ripening
Author(s) -
Tadeo José L,
Ortiz JesúS M,
Martín Bernardo,
Estellés Antonio
Publication year - 1988
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740430302
Subject(s) - chemistry , composition (language) , ripening , proline , amino acid , food science , nitrogen , horticulture , zoology , maturity (psychological) , botany , biochemistry , biology , psychology , developmental psychology , philosophy , linguistics , organic chemistry
Nitrogen content and composition of amino acids in juice and rind of navel oranges were studied. The compared varieties were ‘Navelina’ ‘Washington Navel’ and ‘Navelate’, early, mid‐season and late types, respectively. Total N content in juice increased during the season with values from about 60 to near 100 mg 100 ml −1 in Navelina and ‘Washington Navel’ and from 60 to about 80 mg 100 ml −l in ‘Navelate’; amino N increased from 30 to 60 mg 100 ml −l approximately in the three varieties. The total N content in rind was quite similar in all cases, with values that decreased with time from 1 to around 0·6 g 100 g −l dry weight (DW), 50–60% corresponding to the protein N. The main free amino acids in juice and rind at different maturity stages are tabulated. Proline represents at maturity around 50% of the total free amino acids in rind, with values near to 1·5 mmol 100 ml −l in juice and over 5·0 mmol 100 g −1 DW in rind. Total protein amino acids in rind decreased during maturation, reaching final values of about 20 mmol 100 g −1 DW. Differences in composition among the three studied varieties are discussed.