Composition of tomato fruit. V.—Comparison of the differently coloured areas of the walls of ‘blotchy’ tomatoes

Abstract

A comparative study has been made of some components of the green and red areas of the walls of ‘blotchy’ tomatoes. The juices expressed from the green areas showed a significantly lower titratable acidity than those from the red areas, and had a lower content of sugars and nitrogenous compounds. Juices from the green areas also contained less soluble solids, as determined by oven‐drying, and had lower refractive indices. The content of ethanol‐soluble total sugars and free and total acids was significantly lower in the green than in the red areas. The proportion of alcohol‐insoluble solids was higher in the green areas. The results are discussed in relation to the changes in composition previously found during ripening. Some aspects of the results suggest that ‘blotchy’ cannot merely be attributed to delayed ripening in the affected areas.

Composition of tomato fruit. IV.—Changes in some constituents of the fruit walls during ripening

“…Determinations of sugars, total solids, total nitrogen and titratable acidity were made by methods previously described. 4 Further samples were, on occasion, plunged into boiling absolute ethanol, sufficient to bring the final concentration of ethanol to a'bout 80%. The material was later extracted in a Soxhlet apparatus, and total sugars determined by the volumetric method of Scales as modified by Roy & Hughes5 The acidity of the alcoholic extracts was determined by titration with o.m-NaOH, and phenolphthalein indicator.…”

Ultrastructural Characterization of Yellow Shoulder Disorder in a Uniform Ripening Tomato Genotype

“…These results are compatible with the findings of Sadik and Minges (1966), who observed disorganization of parenchyma cells and the deposition of a lignin-like material in the intercellular spaces in immature-green fruit at the early stages of certain color disorders. Chemical analysis of fruit with blotchy ripening disorders also suggests that blotchy fruit are not merely delayed, but are altered in development (Davies, 1966;Winsor et al, 1962). It is more appropriate to consider YSD to involve modified development rather than delayed development.…”

“…Blotchy ripening disorders are often described as delayed ripening phenomena, with the cells of affected tissue retaining immature characteristics (Bewly and White, 1926). Considerable physiological evidence suggests that most blotchy ripening disorders involve aberrant ripening (Davies, 1966;Winsor et al, 1962). The expression and severity of blotchy ripening disorders is influenced by nutritional, meteorological, and pathological factors (Hanif-Khan et al, 1998;Hobson and Davies, 1976;Jones and Alexander, 1962;Picha and Hall, 1981).…”

Protein and enzyme changes in tomato fruit in relation to blotchy ripening and potassium nutrition

“…Blotchy tomato fruit are deficient in dry matter, total solids, nitrogenous compounds, sugars and organic acids,12,25 and a significant negative correlation between the incidence of the disorder and the potassium content of the fruit has resulted from a number of trials.3 It has been concluded from comparative studies of normal and blotchy tomato fruit that the latter are abnormal and not merely delayed in ripening. 25 Further support for this contention was provided by an examination of the organic acid composition of the differently coloured areas of blotchy fruit.12 Both red and green areas of blotchy fruit tissue displayed certain distinctive characteristics which are not encountered during normal tomato ripening. The primary objectives of the present study were to investigate whether the proteins of blotchy tomatoes were different from those of evenly ripening fruit and to what extent any changes could be explained in terms of the effect of potassium deficiency on the fruit.…”