Grapefruit, pulp

Seymour, T.A. Preston, J.F. Wicker, L. Lindsay, J.A. Marshall, M.R. 1991a. Purification and properties of pectinesterases of Marsh white grapefruit pulp. J. Agric. Food Chem. 39 1080-1085. 

Whioie Grapefruit Some studies have found that grapefruit pulp, segments, or extract may increase the AUCs of nifedipine, nisoldipine and feiodipine by 1.3-fold, 1.3-fold and threefold respectively. ... 

Ohtani H Kawabata S, Kariya S, Uchino K, Itou K, Kotaki H, Kasuyama K, Morikawa A, Seo I, Nishida N. Effect of grapefruit pulp on the pharmacokinetics of the dihydrcpyridine calcium antagonists nifedipine and nisoldipine, Yakigaku Zasshi (2002) 122,323-9. 

Citrus (oranges, lemons, grapefruit) is processed into juice and oil for human uses and into molasses and dried pulp for use as animal feed. The fruit is first washed with a detergent and rinsed with water. The oil is localized in oil sacs on the surface of the fruit. The surface is scarified under a water spray to form an emulsion of oil and water. The oil is recovered by centrifugation. Altered to remove high melting point fats, and dried with sodium sulfate, which is removed by filtration. 

For lemon juice, the flavonoid composition was characterized by HPLC with photodiode detection at 287 nm (108), the HPLC condition based on a procedure proposed by Kirksey et al. (103) for the detection of fruit juice adulteration. Hesperidin and eriocitrin were the characteristic flavonoids of lemon juice. Flavonoid content by HPLC was used to study the effects of processing and pulp removal on flavonoid composition in lemon juice. Eriocitrin is also used in distinguishing lemon juice from grapefruit and orange juices, which do not contain this flavonoid. 

In a study of yield and recovery of various citrus byproducts, it was reported that juice finisher pulp recovery was about 4.4 kg/100 kg of oranges and 2.7 kg/100 kg of grapefruit. Commercial recovery of soluble solids (ss) as pulp-wash should yield approximately 0.6 kg ss (oranges) and 0.2 kg ss (grapefruit) from 100 kg fruit (38). 

Introduction. This test is commonly called centrifuge pulp or fine pulp. The amount of centrifuge pulp contained in frozen concentrated orange juice is regulated in Florida. It is a factor in the U. S. Standards for Grade of grapefruit juice. 

Most of the bitter glucosides are in the albedo and segment membranes so that commercial production of grapefruit juice without removal of naringin is possible. Production of juice from natsudaidai oranges 180) and restoration of the pink color to pink grapefruit juice by addition of pulp 181) require debittering. 

The monoterpene o-limonene is a naturally occurring chemical which is the major component in oil of orange and other natural oils including lemon, grapefruit, berry, leaf, caraway, dill, bergamot, peppermint, and spearmint oils. o-Limonene may be obtained by steam distillation of citrus peels, from pulp resulting... 

Nearly 5 million metric tons of citrus peel and pulp waste materials are produced annually In the manufacturing of concentrated citrus juices In Florida. Although these materials are currently processed Into cattle feed, they are rich In polysaccharides and can be considered as a source of dietary fiber. Alcohol-Insoluble solids (AIS) of 3 different fractions of the processing residues discharged from commercial juice manufacturing equipment were analyzed for pectin, easily hydrolyzable polysaccharides, and cellulose. Two varieties of orange and one of grapefruit that are the predominant citrus fruit used in Juice production were included In this study. 

The dilute alkali removed 46 to 53% of the AIS of the peel, 50 to 60% of that of the rag and 62 and 64% of that of the pulp of Pineapple orange and Marsh grapefruit. In the pulp of Valencia oranges, which has much higher AIS content, only 46% was removed (Table III). 

The uronlc add content of the total monomers amounted to 70% in the pulp of Valencia orange to 92% in that of grapefruit peel. Grapefruit peel is known to produce better pectin than orange peel (13) and the ratio of its uronlc acid to the sugar monomers is much higher. The sum of all monomers of all components only accounted for 55 to 70% of the total amount extracted. These values did not vary much from those reported earlier ( ). Some of these differences probably were due to protein and minerals. The Incomplete hydrolysis could be another explanation of the low recovery. 

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