Marsh White Research Articles

Fifteen SPS Chapters Receive Marsh White Outreach Awards

Fifteen SPS Chapters Receive Marsh White Outreach Awards

Fourteen SPS Chapters Receive Marsh White Outreach Awards

Fourteen SPS Chapters Receive Marsh White Outreach Awards

Influence of Electron-Beam Irradiation on Bioactive Compounds in Grapefruits (Citrus paradisi Macf.)

Phytochemical levels in fruits and vegetables can be affected by several postharvest factors. In the present study, the effect of electron-beam (E-beam) irradiation was studied on grapefruit bioactive compounds. 'Rio Red' and 'Marsh White' grapefruits were irradiated with E-beam at 0, 1.0, 2.5, 5.0, and 10.0 kGy. Changes of various bioactive compounds, such as vitamin C, flavonoids, carotenoids, furocoumarins, and limonoids, were measured. The acidity decreased slightly with an increasing E-beam dose, whereas the total soluble solids were increased. Irradiation did not affect the vitamin C content at 1 kGy; however, doses beyond 1 kGy significantly reduced the vitamin C content. Lycopene and beta-carotene did not change significantly from the irradiation. Lycopene levels decreased as the E-beam dose increased, while the beta-carotene content slightly increased. Dihydroxybergamottin levels exhibited a decreasing trend, while the bergamottin content did not change. Naringin, a major flavonoid of grapefruit, showed a significant increase over the control at 10 kGy in both 'Rio Red' and 'Marsh White'. Nomilin continued to decrease with an increasing dose of E-beam irradiation, while limonin levels remained the same at all of the doses. Low-dose E-beam irradiation has very little effect on the bioactive compounds and offers a safe alternative to existing postharvest treatments for the disinfection and decontamination of grapefruits.

Influence of pre- and post-harvest factors and processing on the levels of furocoumarins in grapefruits (Citrus paradisi Macfed.)

The changes in the levels of three furocoumarins such as dihydroxybergamottin (DHB), paradisin A and bergamottin in Rio Red and Marsh White cultivars of grapefruits were monitored from November to May. The levels of DHB and bergamottin in both varieties of grapefruits decreased as the season progressed except for the bergamottin in Marsh White grapefruit. Influence of growing location, processing and storage on the levels of these compounds were also evaluated. Among the varieties the highest levels of DHB (2.266μg/ml) and bergamottin (2.411μg/ml) were found in Flame grapefruit grown in Florida. The highest level of paradisin A was found in Rio Red grapefruit grown in California and the lowest levels were observed in Rio Red grapefruit grown organically in Texas. Hand squeezed juice contained 1.98, 1.06 and 3.03-fold more DHB, paradisin A and bergamottin, respectively as compared to processed juice. The levels of furocoumarins showed a decreasing trend in all the juices with progress of storage. Levels of furocoumarins were more in cartons container than the cans and cardboard container juices.

(178) Ultraviolet Radiation Influences Grapefruit Juice Bioactive Furocoumarins

Irradiation of fruit and vegetables can potentially be used by industry as a quarantine method to contain insect pests, microorganisms, and to extend shelf life. Gamma, electron beam, and ultraviolet radiation are the most frequently used radiation techniques. These radiation treatments have an effect on bioactive compounds. Grapefruit juice contains bioactive compounds such as limonoids, flavonoids, and furocoumarins. Bioactive furocoumarins in grapefruit juice have been found to increase the bioavailability of many drugs. Bergamottin, dihydroxybergamottin, and paradisin A are major furocoumarins that are shown to inhibit the activity of CYP P450 3A4 and P-gylcoprotein, which are involved in the first pass metabolism of drugs in the gut. This results in a dose-dependent increase of the drug beyond what is intended. Furocoumarins are photoreactive compounds and will readily react to ultraviolet radiation. The effect of various doses of ultraviolet radiation was investigated on `Rio Red' and `Marsh White' grapefruit. Grapefruit juice (50 mL) was irradiated with Ultraviolet A, B, and C radiation for either 5 or 10 min. Treated and control juice was extracted with 100, 50, and 50 mL of ethyl acetate. The extract was then dried and reconstituted with methanol and filtered through a 0.4-μm PTFE membrane filter. The methanol extracts were analyzed by HPLC and the concentrations of bergamottin, dihydroxybergamottin, and paradisin A were compared for UVA, UVB, UVC, and control. This project is based upon work supported by the USDA-CSREES under Agreement USDA IFAFS # 2001 52102 02294 and USDA # 2005-34402-14401 “Designing Foods for Health” through the Vegetable & Fruit Improvement Center.

(197) E-beam Irradiation Influences Grapefruit–Drug Interaction-related Furocoumarins

Food and drug interaction has been under discussionm and specifically grapefruit and drug interaction has been under investigation, in recent years. Irradiation of food has multiple benefits in food preservation through several processes, such as sprout inhibition, disinfection, decontamination, delayed maturation, and sterilization. When ionizing radiation is passed through food, it may affect the functional components, including organoleptic characteristics. In addition to naringin, dihydroxybergamottin, paradisin A, and bergamottin, as well as their isomers, are considered putative bioactive furocoumarins present in the grapefruit juice, which interfere with the first pass metabolism of the drugs. These compounds inhibit the activity of CYP P450 3A4 and P-glycoprotein, which, in turn, will increase bioavailability of certain medications. In order to investigate the effect of pre-and postharvest practices on furocoumarins, `Rio Red' and `Marsh White' grapefruits were irradiated with 1, 5, and 10 kGys of e-beam. The irradiated fruit juice was analyzed for qualitative and quantitative changes in furocoumarins. Fifty milliliters of grapefruit juice was extracted with ethyl acetate three times and ethyl acetate extract was dried under vacuum and analyzed by HPLC. Irradiation at 1 kGys showed a decrease in the total content of dihydroxybergamottin, paradisin A, and bergamottin compared to 5 kGys, 10 kGys, and control. This project is based upon work supported by the USDA-CSREES under Agreement USDA IFAFS # 2001 52102 02294 and USDA # 2005-34402-14401 “Designing Foods for Health” through the Vegetable & Fruit Improvement Center.

Antioxidant Activity of `Rio Red', `Marsh White', and Commercial Juice In Vitro Model Systems

Antioxidant activity is widely used as a parameter to characterize different plant materials for potential health benefits. This activity is related with compounds capable of protecting a biological system against the harmful effect of reactions that can cause excessive oxidation, involving reactive oxygen and nitrogen species (RONS). There has been growing interest in the beneficial health effects of consuming fruits and vegetables. Mainly, the presence of lycopene, ascorbic acid, and phenolic antioxidants is believed to have the protective mechanism. The free radical-scavenging activities of grapefruit extract of `Rio Red', `Marsh White', and commercial juice were extracted with different solvents, such as hexane, ethyl acetate, and chloroform. The dried extracts were screened for their radical scavenging activity using the α,α -diphenyl-β-picrylhydrazyl (DPPH) method. The ethyl acetate extracts of commercial juice and `Marsh White' were found to possess more radical scavenging activity compared with the other two extracts. However, chloroform extracts of `Rio Red' grapefruit were the most active, which may be ascribed to the presence of more lycopene. Furthermore, the antioxidant capacity of `Rio Red' and `Marsh White' extracts was assayed through the phosphomolybdenum method and expressed as equivalent to ascorbic acid (μmol·g-1 of the extract). The order of antioxidant capacity for `Rio Red' extracts was found to be hexane > chloroform > ethyl acetate, while the order for `Marsh White' was chloroform > hexane > ethyl acetate. The results indicate that the extent of antioxidant activity of the extract is in accordance with the amount of lycopene/phenolics present in that extract; commercial juice and `Rio Red' may provide a good source of antioxidants.

Grapefruit-Drug Interaction: Levels of Furocoumarin in Different Varieties

Grapefruit juice contain furanocoumarin derivatives which are known to interact with various drugs such as felodipine, leading to the increased bioavailability. Due to very low concentrations of furocoumarin in grapefruit juice, isolation of these compounds has been a challenge to researchers. Five grapefruit (Citrus paradisi Macf.) varieties such as `Marsh White', `Duncan', `Rio Red', `Orange Flesh', and `Mexican Red' were harvested and analyzed. Samples were extracted successively three times with ethyl acetate until all furocoumarins were extracted. The dried extract was reconstituted in methanol and used for quantification using high-performance liquid chromatography. Furanocoumarins were quantified by gradient elution with methanol and water as mobile phase with a flow rate of 1.1 mL/min at 240 nm. The concentrations of bergamottin, dihydroxybergamotin (DHB) and dimer of DHB were shown to distinctly differ among varieties. Red colored grapefruit showed lower concentrations of the furocoumarins compared to white colored grapefruit. Among the five varieties, `Rio Red' grapefruit contain lower concentrations of bergamottin and DHB. Further studies are continued to quantify other dimers and commercial varieties. Knowledge of furocoumarin levels in grapefruit may eventually help the consumer to make decision about eating grapefruit and/or drinking juice while taking certain medications.

370 GRAPEFRUIT QUALITY IMPORTED INTO THE NETHERLANDS

Size 56 grapefruit (Citrus paradisi Macf.) were sampled biweekly from importers Rotterdam, the Netherlands from October 1992 through September 1993. For each sample, fruit size, weight, diameter, peel thickness, internal color, juice volume, total soluble solids (TSS), and total acid (TA) were measured for three cultivars `Marsh White', `Ruby Red' and `Star Ruby' from 12 countries of origin. Florida fruit followed by Cuban fruit weighed more, had the thinnest peel, the most juice, the lowest TA, and the highest TSS/TA ratio for all three cultivars compared to most other origins. Spanish `Ruby Red' and `Star Ruby' fruit weighed the least and had the least amount of juice compared to other origins. Turkish fruit had the highest TA and the lowest TSS/TA ratio for all three cultivars. Israelian `Marsh White' and `Star Ruby' had the highest TSS.

Susceptibility of Citrus Fruit to Bacterial Spot and Citrus Canker

A pressurized spray (1 g/mm 2 ) that water-soaked the rind of citrus fruit was used to obtain infection by Xanthomonas campestris pv. citri, X. c. citrumelo, and other X. campestris pathovars capable of infecting leaves of the citrus hybrid Swingle citrumelo (Poncirus trifoliata × Citrus paradisi). An aggressive strain of X. c. citrumelo readily infected fruit 20-40 mm in diameter, but fruit of smaller and larger diameters were not as susceptible. Marsh White and Marsh Red grapefruit cultivars developed larger lesions over a wider range of fruit sizes compared with Hamlin and Valencia sweet orange and Orlando tangelo (...)

SPS Announces 1987 Allied and Marsh White Awards

SPS Announces 1987 Allied and Marsh White Awards

Five colleges win Marsh White Awards

Five colleges win Marsh White Awards

Marsh White awards: SPS calls for proposals

Marsh White awards: SPS calls for proposals

Book Notes

Book review in this article Local Government Reorganization Stockport Position Statement Local Government in Britain Town and Country Planning in Britain. Local Government Manual and Directory Town and County Planning in Britain J.B.Cullingworth Public Administration Bulletin Public Administration Committee Local Administration in West Africa Ronald Wraith State‐Municipal Relations: A Functional Analysis Mohit Bhattacharya Municipal Administration in India A.Avasthi Anti‐Politics, Consensus, Reform and Protest in Britain Trevor Smith assisted by Alison Thomson. Charles Knight, 1972. Pp. 200. £1·50. Westminster Workshop: A Student's Guide to the British Constitution R.K.Mosley Treasury Officials 1660–1870 J.C.Sainty Adaptation of Public Personnel Administration to Changes in Society, Aryeh Attir Cost Benefit Analysis: Theory and Practice Ajit K.Dasgupta and D.W.Pearce Handbook for Managers Chief Editor: Bote Folkertsma The Evaluation of Management Training ‐ A Review Matt Whitelaw Trends in British Society since 1900: A Guide to the Changing Social Structure of Britain A.H.Halsey Social Indicators and Social Policy Andrew Shonfield and Stella Shaw The Year Book of Social Policy in Britain 1971 Kathleen Jones Information and Advice Centres Rosalind Brooke. Occasional Papers on Social Administration. Introduction to Administrative Law David Foulkes The Role and Accountability of Nationalized Industries Richard Marsh White Collar Unions: A Review Institute of Personnel Management