Seasonal variation of bitterness components, pulp, and vitamin C in Texas commercial citrus juices

Abstract

The bitter components, naringin (in grapefruit) and limonin (in oranges and grapefruit), were quantitated along with pulp, pH, acid, °Brix, oil, vitamin C (ascorbic acid), and color in single-strength and reconstituted concentrated juices packed by the major Texas commercial processors over three seasons. By December, for orange, and by March, for grapefruit, no juice contained more than 6 ppm of limonin. The 3-year mean for oranges was 3 ppm of limonin and for grapefruit 7 ppm of limonin and 585 ppm of naringin (by the Davis test). In both juices, limonin concentration decreased rapidly as the season progressed; naringin concentration remained steady until spring when it began to increase. There was found to be no linear correlation between pulp content of either juice and the concentration of the bitter components. Pulp content of orange juice varied considerably and consistently between plants. The three-year means of vitamin C in grapefruit and orange juices were 31.3 and 43.8 mg/100 mL, respectively.

Bioavailability of β‐cryptoxanthin is greater from pasteurized orange juice than from fresh oranges – a randomized cross‐over study

“…The amount of centrifugable pulp (12.3%) indicates a rather pulp‐rich juice, since pulp contents in orange juices usually vary between ca. 8 and 12% .…”

A naturally occurring naringenin derivative exerts potent bone anabolic effects by mimicking oestrogen action on osteoblasts

“…Citrus and other fruits are rich sources of naringenin, isosakuranetin, poncirin and phloretin (Albach et al ., 1981; Dunlap et al ., 1962; Manach et al ., 2004). NCG, however, is not present in fruits and has been isolated from the bark of an Indian medicinal plant, U. wallichiana , which is known for ethno‐traditional use in fracture healing (Jain, 1991; Gaur, 1999).…”

Vitamin C and the Role of Citrus Juices as Functional Food

“…Valencia Late oranges contain the lowest concentration (29.0 mg/100 mL of juice) [16]. This is related to the lowest vitamin C levels at the end of the season, when Valencia Late ripen and are processed [85].…”

“…In commercial orange juice [85] the highest vitamin C concentration is found in juices that also have the highest concentration of pulp. These data agree with that of Abeysinghe et al [39], that orange pulp has higher vitamin C content than simple juice.…”