Unequal Distribution of Soluble Solids in the Pulp of Citrus Fruits

Self Cite

Orange fruits undergo certain definite and progressive changes in chemical composition during growth and maturation. The rates at which these changes occur depend chieflv upon climatic and soil conditions, but they are also somewhat affected by the rootstock, as shown by HODGSON and EGGERS (15), SINCLAIR and BARTHOLOMEW (17), and others. While studying the influence of rootstocks on the composition of citrus fruits, it seemed important to the authors to investigate the changes that occur in the soluble constituents of the juice during growth and maturity of the fruit, and, especially, to correlate the concentration of one soluble constituent with that of another for the purpose of determining their physiological and biochemical characteristics. The present studies were therefore undertaken.It is well known that differences in the composition of citrus fruits are due not only to variety and similar factors, but also to the influence of the geographical location in which the fruits are grown, and to seasonal changes affecting the rate of the ripening processes. A study of the effects of these environmental factors on the composition and quality of the fruit has clearly demonstrated that, without actual investigation, it is not safe to conclude that the characteristics of the citrus fruits in one locality are the same as those of the fruits in another locality. For this reason it is of extreme importance to know the changes in soluble solids, total and reducing sugars, acids, and pH that occur during the growth and maturity of citrus fruits in the different citrus-growing areas of southern California. A knowledge of the interrelation of these particular constituents has served as a foundation upon which a more extended and specialized program of research on citrus fruits has been initiated.The results reported in the first part of the present paper, which concerns the interrelation of juice constituents, are especially significant because they show the combined effects of different rootstocks, soils, and regional and annual climatic factors on the constituents of orange juice, over a period of several years. Data presented later in the paper show the effect of external factors and of some of the juice constituents on the buffer properties of the juice.

Section: Materials and Methods Fruit And Juice Samplessupporting

confidence: 66%

Section: Materials and Methods Fruit And Juice Samplesmentioning

confidence: 99%

Soluble Constituents and Buffer Properties of Orange Juice

Bartholomew

Sinclair

1943

Self Cite

“…BARTHOLOMEw and SINCLAIR (4) reported that mature oranges and grapefruits had a considerably higlher concentration of total soluble solids in the stylar than in the stem-l-ends. LALL (6) and ARCHBOLD and BARTER (1) found that the concentration of soluble solids was hiigher in the bluslhed than in the unblushed side of an apple, and that these constituents increased froimi the stalk-end to blossom-end and from-l the inside to outside.…”

mentioning

confidence: 99%

Distribution of Total Soluble Solids, Ascorbic Acid, Total Acid, and Bromelin Activity in The Fruit of the Natal Pineapple (Ananas Comosus L. MERR.)

Miller¹,

Hall²

1953

“…There were several exceptions to this gradient (e.g., Fig. 2), however, which may be caused by sampling from fruit segments around the axis having no longitudinal gradient (4). Materials entering the vesicles from the pericarp apparently move against an osmotic potential gradient (Fig.…”

Section: Methodsmentioning

confidence: 99%

Water Potential Components in Growing Citrus Fruits

Kaufmann

1970

Anatomical evidence suggests that water moving through a citrus fruit follows the vascular bundles in the mesocarp, diffuses through the exocarp, and evaporates on the surface. Carbohydrates also move through the vascular network in the mesocarp. Those carbohydrates ultimately reaching the vesicles first cross the endocarp underlying the mesocarp and then pass through the vesicle stalk into the vesicle. The vesicles, located within the fruit, are not involved in the water transport pathway in fruit transpiration and are located at the end of the carbohydrate translocation pathway. In addition, no vascular connections exist between the vesicles and the phloem or xylem in the pericarp. Based upon these anatomical considerations, it can be hypothesized that factors affecting transpiration or translocation will have little effect on the water relations of the vesicles. This hypothesis is supported by the work of Rokach (11), which suggests that diurnal changes in water content of the fruit result from changes of water content of the pericarp rather than of the pulp. This paper examines the effects of changes in transpiration and disruption of translocation in an attempt to learn more about water and carbohydrate flux in specific parts of a growing citrus fruit. Osmotic potential was measured at many locations to determine local differences among tissues, and several experiments were designed to learn if osmotic potential changes equally in all tissues under certain experimental conditions.