Quantitative Study of Free Sugars and Myo-Inositol in Citrus Juices by HPLC and a Literature Compilation

Abstract

Three hundred and six (306) commercial samples from 19 processing plants in Florida, composed of frozen concentrated orange juice, orange juice from concentrate, and pasteurized orange juice, were analyzed for their sugars content by HPLC. In addition, the sugar profile of fresh-squeezed juice from 9 different cultivars of sweet oranges, 2 tangors, and 4 tangelos grown in Florida are included. Sucrose, fructose, glucose, total sugars, glucose/fructose ratio, and myo-inositol contents are presented.Mean ± standard deviation sugar levels for 100 mL of frozen concentrated orange juice were 4.1 ± 0.5 g of sucrose, 2.1 ± 0.2 g of fructose, 1.9 ± 0.2 g of glucose, and 0.1 ± 0.1 g of myo-inositol, from juices processed in Florida. A review of the methodology for the detection of sugars by HPLC in citrus products is presented; most results having been acquired by HPLC analysis utilizing NH 2 column and acetonitrile/water. A compilation of literature furnishing information on free sugar contents in orange and grapefruit juices by cultivar, and in commercial samples, is also presented. 2123

Inositols and methylinositols in sea buckthorn (Hippophaë rhamnoides) berries

“…Also scyllo-, muco-, neo-, (+)-chiro-, and (−)-chiroinositols have been found in plants [44]. Myo-inositol is the most common cyclitol in fruits with high content found in citrus fruits, kiwifruit, and cantaloupe [45][46][47][48][49][50][51]. In addition to myo-inositol, citrus fruits contain scyllo-and chiro-inositol [51].…”

Fruit juice drink production containing hydrolyzed collagen

“…Glucose and fructose are the main sugars of the grapes whereas fructose is the dominant one in apples. Sucrose, glucose, and fructose represent about 80% of the total soluble solids of orange juice, and the ratios of sucrose:glucose:fructose are generally about 2:1:1 (Chaudhary, Yadav, & Grewal, 2014;Fuleki, Pelayo, & Palabay, 1994;Lee & Coates, 2000;Roberts & Gaddum, 1937).…”

Comparing equivalent thermal, high pressure and pulsed electric field processes for mild pasteurization of orange juice

“…They are inherently responsible for the sweetness of the juice, making its content an important quality attribute. In the present study, the initial total sugar concentration of the fresh orange juice was 86.9 g/L, which can be considered as an average value for orange juice (Lee & Coates, 2000). Sucrose, glucose and fructose were determined as the three sugar compounds of the orange juice, with a respective concentration of 45.7 g/L, 18.7 g/L and 22.5 g/L (Fig.…”

“…Sucrose, glucose and fructose were determined as the three sugar compounds of the orange juice, with a respective concentration of 45.7 g/L, 18.7 g/L and 22.5 g/L (Fig. 3), confirming the 2:1:1 ratio usually mentioned in literature (Lee & Coates, 2000;Ting, 1980).…”