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S Trakhtenberg - One of the best experts on this subject based on the ideXlab platform.
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characteristics of blond and red star ruby jaffa Grapefruits citrus paradise results of the studies in vitro in vivo and on patients suffering from atherosclerosis
II International Symposium on Human Health Effects of Fruits and Vegetables: FAVHEALTH 2007 Houston Texas USA 9-13 October 2007., 2009Co-Authors: Park Yongseo, Abraham Caspi, Imanuel Libman, Henry Tzvi Lerner, S Trakhtenberg, H Leontowicz, M Leontowicz, Z Tashma, Elena Katrich, S GorinsteinAbstract:The purpose of this study was to investigate blond and red Star Ruby Jaffa Grapefruits (in vitro and in vivo) as a supplement to atherosclerosis preventing diets. It was found that the contents of the bioactive compounds, especially phenolics and the antioxidant capacity of the red Grapefruits, are higher than in blond cultivar. Diets supplemented with red Grapefruits significantly hindered the rise in the plasma lipid levels in cholesterol fed rats. Diets supplemented with red Grapefruits significantly decreased the plasma lipid levels, especially triglycerides in patients suffering from coronary atherosclerosis and related hyperlipidemia: a) total cholesterol (TC) by 15.5% and 7.6% b) low density lipid cholesterol (LDL-C): by 20.3% and 10.7% c) total triglycerides (TG) by 27.2%, and 5.6%, for experimental group (EG1, red grapefruit) and EG2, blond grapefruit, respectively. Only the EG1 patients registered a significant decrease in hypertriglyceridemia. In conclusion, the combined results of the in vitro, in vivo and on humans investigations are a solid basis for recommendation to include red grapefruit in atherosclerosis preventive diet.
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characterization of blond and star ruby red jaffa Grapefruits using antioxidant and electrophoretic methods
International Journal of Food Science and Technology, 2006Co-Authors: S Gorinstein, Elena Katrich, Jerzy Drzewiecki, Yongseo Park, Soonteck Jung, Seonggook Kang, Ratiporn Haruenkit, Fernando Toledo, S TrakhtenbergAbstract:Summary Antioxidant and electrophoretic methods were used to characterize the quality differences between blond and Star Ruby (red) Grapefruits. Dietary fibre, minerals and trace elements, total polyphenols, anthocyanins, flavonoids, phenolic and ascorbic acids were also determined. The antioxidant potential of red grapefruit was significantly higher than that of the blond fruit (P < 0.05) and correlated well with the total polyphenols (R2 from 0.8456 to 0.9711). In both the cultivars studied, thirty-two electrophoretic bands were detected [sodium dodecyl-polyacrylamide gel eletrophoresis (SDS-PAGE)]. The main electrophoretic bands occurred between 20 and 43 kDa in both Grapefruits with few minor differences between the varieties. Our findings indicate the following (i) red grapefruit is preferable: it has a higher concentration of bioactive compounds and antioxidant potential than the blond; (ii) 1, 1-diphenyl-2-picrylhydrazyl (DPPH) test is a more sensitive method for the determination of antioxidant potential; (iii) there are some minor differences in electrophoretic patterns; (iv) antioxidant and electrophoretic methods are a good combination for characterization of differences of the same citrus fruits.
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original article characterization of blond and star ruby red jaffa Grapefruits using antioxidant and electrophoretic methods
2006Co-Authors: S Gorinstein, Elena Katrich, Jerzy Drzewiecki, Yongseo Park, Soonteck Jung, Seonggook Kang, Ratiporn Haruenkit, Fernando Toledo, S TrakhtenbergAbstract:Summary Antioxidant and electrophoretic methods were used to characterize the quality differences between blond and Star Ruby (red) Grapefruits. Dietary fibre, minerals and trace elements, total polyphenols, anthocyanins, flavonoids, phenolic and ascorbic acids were also determined. The antioxidant potential of red grapefruit was significantly higher than that of the blond fruit (P < 0.05) and correlated well with the total polyphenols (R 2 from 0.8456 to 0.9711). In both the cultivars studied, thirty-two electrophoretic bands were detected [sodium dodecyl-polyacrylamide gel eletrophoresis (SDS-PAGE)]. The main electrophoretic bands occurred between 20 and 43 kDa in both Grapefruits with few minor differences between the varieties. Our findings indicate the following (i) red grapefruit is preferable: it has a higher concentration of bioactive compounds and antioxidant potential than the blond; (ii) 1, 1-diphenyl-2-picrylhydrazyl (DPPH) test is a more sensitive method for the determination of antioxidant potential; (iii) there are some minor differences in electrophoretic patterns; (iv) antioxidant and electrophoretic methods are a good combination for characterization of differences of the same citrus fruits.
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red star ruby sunrise and blond qualities of jaffa Grapefruits and their influence on plasma lipid levels and plasma antioxidant activity in rats fed with cholesterol containing and cholesterol free diets
Life Sciences, 2005Co-Authors: S Gorinstein, H Leontowicz, M Leontowicz, Elena Katrich, Jerzy Drzewiecki, Zenon Jastrzebski, Maria Soledad Tapia, S TrakhtenbergAbstract:Bioactive compounds of peels and peeled red Star Ruby (Sunrise) and blond qualities of Jaffa Grapefruits were analyzed and their antioxidant potential was assessed. The dietary fibers were determined according to Prosky et al., the total polyphenol content by Folin‐Ciocalteu method and measured at 765 nm, minerals and trace elements by atomic absorption spectrometer, phenolic and ascorbic acids by HPLC and the antioxidant potential by two different antioxidant assays (DPPH and h-carotene linoleate model system). It was found that the contents of most studied bioactive compounds in both qualities are comparable. Only the contents of total polyphenols and flavonoids were higher in red Grapefruits, but not significant. The antioxidant potentials of red peeled Grapefruits and their peels were significantlyhigher thanofblondpeeled Grapefruitsand theirpeels (Pb0.05inbothcases). Diets supplementedwith peeled red and blond qualities of Jaffa Grapefruits and their peels have increased the plasma antioxidant capacity and
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effect of antioxidants and proteins on the quality of israeli jaffa red and blond Grapefruits
European Food Research and Technology, 2005Co-Authors: S Gorinstein, S Trakhtenberg, Elena Katrich, Jerzy Drzewiecki, Ami Sivan, Joaquin Giner, Robert Solivafortuny, Pedro Elezmartiinez, Olga MartinbellosoAbstract:Some biochemical characteristics of Israeli Jaffa Star Ruby (red) and blond Grapefruits were defined using atomic absorption spectrometry, antioxidant tests and the protein electrophoretic technique. It was found that the contents of dietary fibers, major and minor minerals, phenolic and ascorbic acids in both Grapefruits were without significant differences. The contents of total polyphenols, anthocyanins and flavonoids were higher in red Grapefruits, but also these differences were not significant. The antioxidant capacity was determined by two modified antioxidant methods, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS⋅+) and scavenging activity against nitric oxide, and was compared with the Folin–Ciocalteu assay. The two antioxidant assays used have shown that the antioxidant potential of the Star Ruby (red) grapefruit is higher than of the blond (P<0.05) grapefruit. Proteins were extracted and separated. Some small differences were found in the sodium dodecyl sulfate–protein bands in the region of 36 kDa. Antioxidants and proteins can be used for characterization of the quality of Grapefruits as a fruit diet.
Kil Sun Yoo - One of the best experts on this subject based on the ideXlab platform.
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influence of electron beam irradiation on bioactive compounds in Grapefruits citrus paradisi macf
Journal of Agricultural and Food Chemistry, 2008Co-Authors: Basavaraj Girennavar, Sara E Mclin, Joe Maxim, Kil Sun YooAbstract: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.
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Development of a method for the quantification of D-glucaric acid in different varieties of Grapefruits by high-performance liquid chromatography and mass spectra.
Journal of chromatography. A, 2008Co-Authors: Jose L Perez, Kil Sun YooAbstract:Grapefruits were found to contain D-glucaric acid, which has anticancer properties. In the present investigation, a method has been developed for the quantification of D-glucaric acid in grapefruit by high-performance liquid chromatography (HPLC) using a simple isocratic mobile phase with detection at 210 nm. Grapefruit samples were homogenized, centrifuged and filtered through a 0.45 microm membrane and injected into a HPLC system. The developed method was used for the quantification of D-glucaric acid in nine widely used grapefruit varieties. Furthermore, the identity of D-glucaric acid was confirmed by mass spectra. Seasonal variation of D-glucaric acid within the individual varieties were also measured in fruits harvested during November, February and May. The overall trend of D-glucaric acid level was increased from early to late season fruits. The developed method has a sensitivity of D-glucaric acid as low as 0.05 microg with an accuracy and precision >95%. This method was found to be simple, fast, accurate and reproducible. Moreover, the identity of D-glucaric acid was confirmed by mass spectra. Additionally, the labor intensity and cost of sample preparation were greatly reduced as compared to reported methods. This is the first report on quantification of D-glucaric acid in different varieties of Grapefruits from three harvesting sessions.
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ionizing radiation and marketing simulation on bioactive compounds and quality of grapefruit citrus paradisi c v rio red
Food Chemistry, 2007Co-Authors: Jairam K P Vanamala, Kil Sun Yoo, Greg Cobb, Julio Loaiza, Leonard M PikeAbstract:Abstract Bioactive compounds in citrus fruits have been shown to be protective against chronic diseases such as cancer and heart disease, but their levels may be affected by postharvest treatments such as storage and irradiation. In this study, Grapefruits were exposed to gamma irradiation at 0, 150 and 300 Gy and then stored at 10 °C for 36 d, followed by an additional 20 d at 20 °C. Flavonoid content, terpenoid content, quality (acidity and total soluble solids) and phenylalanine ammonia-lyase (PAL) activity were evaluated at regular intervals during storage. Irradiation and storage affected ( P ⩽ 0.05) the levels of bioactive compounds in grapefruit; however, the effect of storage was prominent. Irradiation differentially affected the flavonoid content of pulp and peel. Fruits exposed to 300 Gy had higher ( P ⩽ 0.01) narirutin content in peel compared to control fruits at 12 and 56 d after storage. While storage increased the d -limonene and myrcene content in all treatments, control fruit had higher terpenoid content at the end of the storage. PAL activity was found to be in traces in the peel. In general, irradiation or storage had no considerable effect on total soluble solids; however, acidity decreased ( P ⩽ 0.05) with storage.
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bioactive compounds of grapefruit citrus paradisi cv rio red respond differently to postharvest irradiation storage and freeze drying
Journal of Agricultural and Food Chemistry, 2005Co-Authors: Jairam K P Vanamala, Kil Sun Yoo, Greg Cobb, Nancy D Turner, Joanne R Lupton, Leonard M PikeAbstract:In the present study, the effect of irradiation, storage, and freeze drying on grapefruit bioactive compounds was investigated. Grapefruits were exposed to one of two irradiation doses: 0 (control) or 300 Gy (137Cs, a proposed treatment against fruit flies) and then stored for up to 6 days. At the last storage time point (6 days after harvest), grapefruit pulp from control and irradiated fruits was freeze-dried. Bioactive compounds were extracted from Rio Red grapefruit pulp and analyzed with reverse phase liquid chromatography while volatile compounds were analyzed using gas chromatography. Freeze-dried pulp from irradiated fruits had a higher (P < or = 0.05) flavonoid content (naringin and narirutin) as compared to the freeze-dried pulp from the control fruits. Freeze-drying treatment reduced (P < or = 0.05) the lycopene content, but the reduction (P < or = 0.05) in beta-carotene content occurred only in the control fruit. Reduction in d-limonene and myrcene was observed in the irradiated fruits at 6 days after harvest and in the freeze-dried samples. These results warrant testing of the effect of postharvest treatments and processing on bioactive compounds in functional systems as they have varied effects on different bioactive compounds of grapefruit.
Maria Jesus Rodrigo - One of the best experts on this subject based on the ideXlab platform.
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resistance to chilling injury in red lycopene accumulating tissue of cold stored Grapefruits
Acta Horticulturae, 2015Co-Authors: Joanna Lado, Maria Jesus Rodrigo, Paul J R Cronje, Lorenzo ZacariasAbstract:Grapefruits are widely recognized by their extreme sensitivity to develop chilling injury (CI) during postharvest storage at low temperature. Moreover, many cultivars and mutants of Grapefruits exhibit important differences in both external and internal coloration, from yellow to deep red, due to a distinctive accumulation of the red carotene lycopene. Thus, in this study the genetic variability in external peel coloration of Grapefruits has been used to examine the potential relationship between carotenoid content and composition, and susceptibility to CI. CI increased progressively after 2 weeks storage at 2°C in fruit of the yellow grapefruit âMarshâ (M) but in the fruits of red cultivar âStar Rubyâ (SR) CI symptoms were exclusively restricted to the yellow areas of the peel. Thus, CI was absent in red peel tissue, even after prolonged cold storage, in which lycopene content was about 14-times higher than in yellow tissue. In addition, SR Grapefruits growing under shaded conditions developed an intense external red coloration and accumulated large amount of lycopene, and were also highly resistant to CI upon subsequent postharvest cold storage. To further explore the mechanisms involved in the resistance to CI induced by lycopene, total antioxidant activity was determined in yellow and red peel tissue of grapefruit, and the potential relationship between carotenoids and the development of CI is discussed.
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molecular and functional characterization of a novel chromoplast specific lycopene β cyclase from citrus and its relation to lycopene accumulation
Journal of Experimental Botany, 2009Co-Authors: Berta Alquezar, Lorenzo Zacarias, Maria Jesus RodrigoAbstract:Carotenoids are the main pigments responsible of the colouration of Citrus fruits. The β-cyclization of lycopene, catalysed by the lycopene β-cyclases (β-LCY), seems to be a key regulatory step of the carotenoid pathway. In the present study, two β-LCYs from orange fruits (Citrus sinensis), named Csβ-LCY1 and Csβ-LCY2 have been isolated and the activity of the encoded proteins was demonstrated by functional analysis. Csβ-LCY1 was expressed at low levels and remained relatively constant during fruit ripening while Csβ-LCY2 showed a chromoplast-specific expression and a marked induction in both peel and pulp of orange fruits in parallel with the accumulation of β,β-xanthophylls. The potential involvement of Csβ-LCY2 in the accumulation of lycopene, characteristic of some Citrus species such as red Grapefruits, was investigated. Expression of Csβ-LCY2 and another seven carotenoid biosynthetic genes were studied in the peel and pulp of the high lycopene-accumulating grapefruit, Star Ruby, and compared with those of ordinary Navel orange. In Star Ruby, the accumulation of lycopene during fruit maturation was associated with a substantial reduction in the expression of both β-LCY2 and β-CHX genes with respect to Navel orange. Moreover, two different alleles of β-LCY2: β-LCY2a and β-LCY2b were isolated from both genotypes, and functional assays demonstrated that the lycopene β-cyclase activity of the allele b was almost null. Interestingly, Star Ruby grapefruit predominantly expressed the unfunctional β-LCY2b allele during fruit ripening whereas Navel oranges preferably expressed the functional allele. It is suggested that the presence of diverse alleles of the β-LCY2 gene, encoding enzymes with altered activity, with different transcript accumulation may be an additional regulatory mechanism of carotenoid synthesis involved in the accumulation of lycopene in red Grapefruits.
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molecular and functional characterization of a novel chromoplast specific lycopene β cyclase from citrus and its relation to lycopene accumulation
Journal of Experimental Botany, 2009Co-Authors: Berta Alquezar, Lorenzo Zacarias, Maria Jesus RodrigoAbstract:Carotenoids are the main pigments responsible of the colouration of Citrus fruits. The beta-cyclization of lycopene, catalysed by the lycopene beta-cyclases (beta-LCY), seems to be a key regulatory step of the carotenoid pathway. In the present study, two beta-LCYs from orange fruits (Citrus sinensis), named Csbeta-LCY1 and Csbeta-LCY2 have been isolated and the activity of the encoded proteins was demonstrated by functional analysis. Csbeta-LCY1 was expressed at low levels and remained relatively constant during fruit ripening while Csbeta-LCY2 showed a chromoplast-specific expression and a marked induction in both peel and pulp of orange fruits in parallel with the accumulation of beta,beta-xanthophylls. The potential involvement of Csbeta-LCY2 in the accumulation of lycopene, characteristic of some Citrus species such as red Grapefruits, was investigated. Expression of Csbeta-LCY2 and another seven carotenoid biosynthetic genes were studied in the peel and pulp of the high lycopene-accumulating grapefruit, Star Ruby, and compared with those of ordinary Navel orange. In Star Ruby, the accumulation of lycopene during fruit maturation was associated with a substantial reduction in the expression of both beta-LCY2 and beta-CHX genes with respect to Navel orange. Moreover, two different alleles of beta-LCY2: beta-LCY2a and beta-LCY2b were isolated from both genotypes, and functional assays demonstrated that the lycopene beta-cyclase activity of the allele b was almost null. Interestingly, Star Ruby grapefruit predominantly expressed the unfunctional beta-LCY2b allele during fruit ripening whereas Navel oranges preferably expressed the functional allele. It is suggested that the presence of diverse alleles of the beta-LCY2 gene, encoding enzymes with altered activity, with different transcript accumulation may be an additional regulatory mechanism of carotenoid synthesis involved in the accumulation of lycopene in red Grapefruits.
S Gorinstein - One of the best experts on this subject based on the ideXlab platform.
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characteristics of blond and red star ruby jaffa Grapefruits citrus paradise results of the studies in vitro in vivo and on patients suffering from atherosclerosis
II International Symposium on Human Health Effects of Fruits and Vegetables: FAVHEALTH 2007 Houston Texas USA 9-13 October 2007., 2009Co-Authors: Park Yongseo, Abraham Caspi, Imanuel Libman, Henry Tzvi Lerner, S Trakhtenberg, H Leontowicz, M Leontowicz, Z Tashma, Elena Katrich, S GorinsteinAbstract:The purpose of this study was to investigate blond and red Star Ruby Jaffa Grapefruits (in vitro and in vivo) as a supplement to atherosclerosis preventing diets. It was found that the contents of the bioactive compounds, especially phenolics and the antioxidant capacity of the red Grapefruits, are higher than in blond cultivar. Diets supplemented with red Grapefruits significantly hindered the rise in the plasma lipid levels in cholesterol fed rats. Diets supplemented with red Grapefruits significantly decreased the plasma lipid levels, especially triglycerides in patients suffering from coronary atherosclerosis and related hyperlipidemia: a) total cholesterol (TC) by 15.5% and 7.6% b) low density lipid cholesterol (LDL-C): by 20.3% and 10.7% c) total triglycerides (TG) by 27.2%, and 5.6%, for experimental group (EG1, red grapefruit) and EG2, blond grapefruit, respectively. Only the EG1 patients registered a significant decrease in hypertriglyceridemia. In conclusion, the combined results of the in vitro, in vivo and on humans investigations are a solid basis for recommendation to include red grapefruit in atherosclerosis preventive diet.
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characterization of blond and star ruby red jaffa Grapefruits using antioxidant and electrophoretic methods
International Journal of Food Science and Technology, 2006Co-Authors: S Gorinstein, Elena Katrich, Jerzy Drzewiecki, Yongseo Park, Soonteck Jung, Seonggook Kang, Ratiporn Haruenkit, Fernando Toledo, S TrakhtenbergAbstract:Summary Antioxidant and electrophoretic methods were used to characterize the quality differences between blond and Star Ruby (red) Grapefruits. Dietary fibre, minerals and trace elements, total polyphenols, anthocyanins, flavonoids, phenolic and ascorbic acids were also determined. The antioxidant potential of red grapefruit was significantly higher than that of the blond fruit (P < 0.05) and correlated well with the total polyphenols (R2 from 0.8456 to 0.9711). In both the cultivars studied, thirty-two electrophoretic bands were detected [sodium dodecyl-polyacrylamide gel eletrophoresis (SDS-PAGE)]. The main electrophoretic bands occurred between 20 and 43 kDa in both Grapefruits with few minor differences between the varieties. Our findings indicate the following (i) red grapefruit is preferable: it has a higher concentration of bioactive compounds and antioxidant potential than the blond; (ii) 1, 1-diphenyl-2-picrylhydrazyl (DPPH) test is a more sensitive method for the determination of antioxidant potential; (iii) there are some minor differences in electrophoretic patterns; (iv) antioxidant and electrophoretic methods are a good combination for characterization of differences of the same citrus fruits.
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original article characterization of blond and star ruby red jaffa Grapefruits using antioxidant and electrophoretic methods
2006Co-Authors: S Gorinstein, Elena Katrich, Jerzy Drzewiecki, Yongseo Park, Soonteck Jung, Seonggook Kang, Ratiporn Haruenkit, Fernando Toledo, S TrakhtenbergAbstract:Summary Antioxidant and electrophoretic methods were used to characterize the quality differences between blond and Star Ruby (red) Grapefruits. Dietary fibre, minerals and trace elements, total polyphenols, anthocyanins, flavonoids, phenolic and ascorbic acids were also determined. The antioxidant potential of red grapefruit was significantly higher than that of the blond fruit (P < 0.05) and correlated well with the total polyphenols (R 2 from 0.8456 to 0.9711). In both the cultivars studied, thirty-two electrophoretic bands were detected [sodium dodecyl-polyacrylamide gel eletrophoresis (SDS-PAGE)]. The main electrophoretic bands occurred between 20 and 43 kDa in both Grapefruits with few minor differences between the varieties. Our findings indicate the following (i) red grapefruit is preferable: it has a higher concentration of bioactive compounds and antioxidant potential than the blond; (ii) 1, 1-diphenyl-2-picrylhydrazyl (DPPH) test is a more sensitive method for the determination of antioxidant potential; (iii) there are some minor differences in electrophoretic patterns; (iv) antioxidant and electrophoretic methods are a good combination for characterization of differences of the same citrus fruits.
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red star ruby sunrise and blond qualities of jaffa Grapefruits and their influence on plasma lipid levels and plasma antioxidant activity in rats fed with cholesterol containing and cholesterol free diets
Life Sciences, 2005Co-Authors: S Gorinstein, H Leontowicz, M Leontowicz, Elena Katrich, Jerzy Drzewiecki, Zenon Jastrzebski, Maria Soledad Tapia, S TrakhtenbergAbstract:Bioactive compounds of peels and peeled red Star Ruby (Sunrise) and blond qualities of Jaffa Grapefruits were analyzed and their antioxidant potential was assessed. The dietary fibers were determined according to Prosky et al., the total polyphenol content by Folin‐Ciocalteu method and measured at 765 nm, minerals and trace elements by atomic absorption spectrometer, phenolic and ascorbic acids by HPLC and the antioxidant potential by two different antioxidant assays (DPPH and h-carotene linoleate model system). It was found that the contents of most studied bioactive compounds in both qualities are comparable. Only the contents of total polyphenols and flavonoids were higher in red Grapefruits, but not significant. The antioxidant potentials of red peeled Grapefruits and their peels were significantlyhigher thanofblondpeeled Grapefruitsand theirpeels (Pb0.05inbothcases). Diets supplementedwith peeled red and blond qualities of Jaffa Grapefruits and their peels have increased the plasma antioxidant capacity and
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effect of antioxidants and proteins on the quality of israeli jaffa red and blond Grapefruits
European Food Research and Technology, 2005Co-Authors: S Gorinstein, S Trakhtenberg, Elena Katrich, Jerzy Drzewiecki, Ami Sivan, Joaquin Giner, Robert Solivafortuny, Pedro Elezmartiinez, Olga MartinbellosoAbstract:Some biochemical characteristics of Israeli Jaffa Star Ruby (red) and blond Grapefruits were defined using atomic absorption spectrometry, antioxidant tests and the protein electrophoretic technique. It was found that the contents of dietary fibers, major and minor minerals, phenolic and ascorbic acids in both Grapefruits were without significant differences. The contents of total polyphenols, anthocyanins and flavonoids were higher in red Grapefruits, but also these differences were not significant. The antioxidant capacity was determined by two modified antioxidant methods, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS⋅+) and scavenging activity against nitric oxide, and was compared with the Folin–Ciocalteu assay. The two antioxidant assays used have shown that the antioxidant potential of the Star Ruby (red) grapefruit is higher than of the blond (P<0.05) grapefruit. Proteins were extracted and separated. Some small differences were found in the sodium dodecyl sulfate–protein bands in the region of 36 kDa. Antioxidants and proteins can be used for characterization of the quality of Grapefruits as a fruit diet.
Leonard M Pike - One of the best experts on this subject based on the ideXlab platform.
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ionizing radiation and marketing simulation on bioactive compounds and quality of grapefruit citrus paradisi c v rio red
Food Chemistry, 2007Co-Authors: Jairam K P Vanamala, Kil Sun Yoo, Greg Cobb, Julio Loaiza, Leonard M PikeAbstract:Abstract Bioactive compounds in citrus fruits have been shown to be protective against chronic diseases such as cancer and heart disease, but their levels may be affected by postharvest treatments such as storage and irradiation. In this study, Grapefruits were exposed to gamma irradiation at 0, 150 and 300 Gy and then stored at 10 °C for 36 d, followed by an additional 20 d at 20 °C. Flavonoid content, terpenoid content, quality (acidity and total soluble solids) and phenylalanine ammonia-lyase (PAL) activity were evaluated at regular intervals during storage. Irradiation and storage affected ( P ⩽ 0.05) the levels of bioactive compounds in grapefruit; however, the effect of storage was prominent. Irradiation differentially affected the flavonoid content of pulp and peel. Fruits exposed to 300 Gy had higher ( P ⩽ 0.01) narirutin content in peel compared to control fruits at 12 and 56 d after storage. While storage increased the d -limonene and myrcene content in all treatments, control fruit had higher terpenoid content at the end of the storage. PAL activity was found to be in traces in the peel. In general, irradiation or storage had no considerable effect on total soluble solids; however, acidity decreased ( P ⩽ 0.05) with storage.
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bioactive compounds of grapefruit citrus paradisi cv rio red respond differently to postharvest irradiation storage and freeze drying
Journal of Agricultural and Food Chemistry, 2005Co-Authors: Jairam K P Vanamala, Kil Sun Yoo, Greg Cobb, Nancy D Turner, Joanne R Lupton, Leonard M PikeAbstract:In the present study, the effect of irradiation, storage, and freeze drying on grapefruit bioactive compounds was investigated. Grapefruits were exposed to one of two irradiation doses: 0 (control) or 300 Gy (137Cs, a proposed treatment against fruit flies) and then stored for up to 6 days. At the last storage time point (6 days after harvest), grapefruit pulp from control and irradiated fruits was freeze-dried. Bioactive compounds were extracted from Rio Red grapefruit pulp and analyzed with reverse phase liquid chromatography while volatile compounds were analyzed using gas chromatography. Freeze-dried pulp from irradiated fruits had a higher (P < or = 0.05) flavonoid content (naringin and narirutin) as compared to the freeze-dried pulp from the control fruits. Freeze-drying treatment reduced (P < or = 0.05) the lycopene content, but the reduction (P < or = 0.05) in beta-carotene content occurred only in the control fruit. Reduction in d-limonene and myrcene was observed in the irradiated fruits at 6 days after harvest and in the freeze-dried samples. These results warrant testing of the effect of postharvest treatments and processing on bioactive compounds in functional systems as they have varied effects on different bioactive compounds of grapefruit.
