Soluble Constituents and Buffer Properties of Orange Juice

Abstract

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.

Development of an original lab-scale filtration strategy for the prediction of microfiltration performance: Application to orange juice clarification

“…For both orange juices, the values of physico-chemical characteristics were in the same range of that reported in literature for fruit juices [23][24][25].…”

Rheological study of orange juices for a better knowledge of their suspended solids interactions at low and high concentration

“…All results were given as mean of three independent measurements. For the three juices, dry matter content was close to data reported in the literature (Bartholomew and Sinclair, 1943;Vieira et al, 2010). Suspended solids (SS) represented a small part of the total solids; their dry mass represented less than 0.6% of the total suspension mass.…”

Clarification, preservation, and shelf life evaluation of cashew apple juice

“…TTA was almost stable (0.321±0.3) in these samples up to 90 days indicating stable concentration of malic acid in the juice (21). Similarly, TSS content was stable (14.0±2.0%Bx) in T 1 , T 2 , and T 3 up to 90, 45, and 60 days, respectively, indicating the collection of fruits at mature stage (22). It was further observed that the stability in TSS was directly proportional to sugar content.…”