Showing papers on "Grapefruit juice published in 2015"

Thermosonication: a potential technique that influences the quality of grapefruit juice

Abstract: Summary Thermosonication (TS) is an emerging nonthermal processing technique used for the liquid food preservation and is employed to improve the quality and acceptability of grapefruit juice In this study, fresh grapefruit juice samples were subjected to TS treatment in an ultrasonic cleaner with different processing variables, including temperature (20, 30, 40, 50 and 60 °C), frequency (28 kHz), power (70%, 420 W) and processing time (30 and 60 min) for bioactive compounds, inactivation of enzymes pectin methylesterase (PME), peroxidase (POD) and polyphenolase (PPO) and micro-organisms (total plate count, yeasts and moulds) The micro-organism activity was completely inactivated in the treatment (60 °C for 60 min) The TS treatment at 60 °C for 60 min exposure reduced PME, PPO and POD activity by 91%, 90% and 89%, respectively Results indicate that the advantages of TS for grapefruit juice processing at low temperature could enhance the inactivation of enzymes and micro-organisms and it can be used as a potential technique to obtain better results as compared to alone

A potential of ultrasound on minerals, micro-organisms, phenolic compounds and colouring pigments of grapefruit juice

Abstract: Summary The grapefruit juice was sonicated in an ultrasonic bath at 28 kHz frequency (amplitude 70%), for 0, 30, 60 and 90 min at 20 °C. This research was focused on the effects of ultrasound treatment on phenolic compounds, minerals, viscosity, lycopene, total anthocyanins, total carotenoids, micro-organism analysis and sugars. A statistically significant increase was observed in total carotenoids, lycopene, sugar contents (sucrose, glucose and fructose) and phenolic compounds, whereas a decrease in viscosity and micro-organisms were found in all the grapefruit juice samples sonicated for 30, 60 and 90 min as compared to control. However, maximum improvement was observed in the sonication treatment for 90 min. The results of this study suggest that ultrasound treatment may improve the quality of grapefruit juice.

Combined effects of sonication and pulsed electric field on selected quality parameters of grapefruit juice

Abstract: The aim of this study was to evaluate the combined effects of sonication and pulsed electric field on some quality parameters of grapefruit juice. The juice was treated by pulsed electric field and sonication treatment. No significant change was observed in pH, acidity, °Brix and electrical conductivity. However, a significant decrease in viscosity and increase in cloud value was observed after the combined treatment. Findings of present study suggested that combined treatment could improve the quality of grapefruit juice and may successfully be employed for the processing of grapefruit juice.

Influence of different pulsed electric field strengths on the quality of the grapefruit juice

Abstract: Summary Grapefruit juice was investigated using pulsed electric fields (PEF) with (electric field strengths: 0, 5, 10, 15, 20 and 25 kV cm−1; flow rate: 80 mL min−1; pulse frequency: 1 kHz at 40 °C for 600 μs). Total phenolics, DPPH, total antioxidant capacity (TAC), total anthocyanins, total carotenoids, sugars and physicochemical properties of grapefruit juice were studied. In addition, the effect of PEF treatment on micro-organisms was also observed. Results indicated that no significant change was observed in pH, Brix, titratable acidity, sugars, total anthocyanins and colour attributes with the increase in pulsed electric strength as compared to control treatment. However, significant decrease in nonenzymatic browning (NEB) and viscosity while an increase in cloud value, DPPH, TAC, total phenolics and total carotenoids, while reduction in the activity of micro-organisms, was also observed with the increase in pulsed electric strength as compared to control treatment. This study suggested that PEF at 25 kV cm−1 could improve the quality of grapefruit juice.

Quinine Bitterness and Grapefruit Liking Associate with Allelic Variants in TAS2R31.

Abstract: Multiple psychophysical gene-association studies suggest a single nucleotide polymorphism (SNP) within the bitter receptor gene TAS2R19 on chromosome 12 may be functional. Previously, the Arg299Cys SNP (rs10772420) has been associated with differential bitterness of quinine and differential liking for grapefruit juice. However, quinine does not activate TAS2R19 in vitro; likewise, limonin and naringin, bitter compounds in grapefruit, do not activate TAS2R19 in vitro. Here, we examined quinine bitterness (whole-mouth swish-and-spit stimuli and regionally delivered quinine across 4 loci) and remembered liking for grapefruit juice to test whether they associate with SNPs in another nearby gene, TASR2R31. We observed SNP-phenotype associations between whole-mouth quinine bitterness and self-reported liking for grapefruit juice with SNPs in TAS2R31, and regional quinine bitterness followed a similar trend, but did not reach significance. Present data provide independent replication of prior associations reported for TAS2R19. However, we also observed strong linkage disequilibrium (LD) between TAS2R19 and TAS2R31 SNPs. When present data are considered in light of existing functional expression data, this suggests phenotypic associations reported previously for rs10772420 may potentially be due to LD between this SNP and polymorphism(s) in, or closer to, TAS2R31. If confirmed, this would reduce the number of TAS2Rs with putatively functional polymorphisms to 5.

Original article A potential of ultrasound on minerals, micro-organisms, phenolic compounds and colouring pigments of grapefruit juice

Abstract: Summary The grapefruit juice was sonicated in an ultrasonic bath at 28 kHz frequency (amplitude 70%), for 0, 30, 60 and 90 min at 20 °C. This research was focused on the effects of ultrasound treatment on phenolic compounds, minerals, viscosity, lycopene, total anthocyanins, total carotenoids, micro-organism analysis and sugars. A statistically significant increase was observed in total carotenoids, lycopene, sugar contents (sucrose, glucose and fructose) and phenolic compounds, whereas a decrease in viscosity and micro-organisms were found in all the grapefruit juice samples sonicated for 30, 60 and 90 min as compared to control. However, maximum improvement was observed in the sonication treatment for 90 min. The results of this study suggest that ultrasound treatment may improve the quality of grapefruit juice.

Evolution during refrigerated storage of bioactive compounds and quality characteristics of grapefruit [Citrus paradisi (Macf.)] juice treated with UV-C light

Abstract: The effect of the UV-C light (doses: 0.0–3.94 J/cm2) on the main bioactive compounds of grapefruit juice and their stability were evaluated throughout 30 and 16 days of storage at 4 and 10 °C respectively. Organic acids (citric, malic, ascorbic and tartaric) and flavonoids (naringin, hesperidin and neohesperidin) were quantified by HPLC, whereas total phenols and the antioxidant capacity were determined by spectrophotometric methods. The UV-C treatments caused a significant decrease (15%–30%) in ascorbic acid and antioxidant capacity (10%–27%), which was related to the applied dose. However, no changes (p > 0.05) in others organics acids, individual flavonoids, total phenols, pH, °Brix, color and titratable acidity were observed after UV-C treatment. During the storage at both temperatures, a decrease in the neohesperidin levels (43%–53%) was detected whereas the others parameters analyzed did not show changes (p > 0.05). The microbiological quality of grapefruit juices treated with 3.94 J/cm2 was maintained for 15 and 10 days at 4 and 10 °C respectively.

Enzyme- and transporter-mediated beverage–drug interactions: An update on fruit juices and green tea

Abstract: Beverage-drug interactions have remained an active area of research and have been the subject of extensive investigations in the past 2 decades. The known mechanisms of clinically relevant beverage-drug interactions include modulation of the activity of cytochrome P450 (CYP) 3A and organic anion-transporting polypeptide (OATP). For CYP3A-mediated beverage-drug interaction, the in vivo CYP3A inhibitory effect is limited to grapefruit juice (GFJ), which increases the bioavailability of several orally administered drugs that undergo extensive first-pass metabolism via enteric CYP3A. In contrast, clinically significant OATP-mediated beverage-drug interactions have been observed with not only GFJ but also orange juice, apple juice, and, most recently, green tea. Fruit juices and green tea are all a mixture of a large number of constituents. The investigation of specific constituent(s) responsible for the enzyme and/or transporter inhibition remains an active area of research, and many new findings have been obtained on this subject in the past several years. This review highlights the multiple mechanisms through which beverages can alter drug disposition and provides an update on the new findings of beverage-drug interactions, with a focus on fruit juices and green tea.

Effects of the flavanone combination hesperetin-naringenin, and orange and grapefruit juices, on airway inflammation and remodeling in a murine asthma model.

Abstract: We investigated whether flavanones, hesperetin–naringenin, orange, and grapefruit juices reduce airway inflammation and remodeling in murine chronic asthma model. To establish chronic asthma, mice received house dust mite (HDM) for 3 days in 2 weeks, followed by twice per week for 4 weeks. Concurrently, during the last 4 weeks, mice received hesperetin plus naringenin (HN), orange plus grapefruit juice (OGJ), orange juice (OJ), or grapefruit juice (GJ); whereas the asthmatic control (AC) group and non-asthmatic control (NC) group consumed water ad libitum. In histopathological examination, no goblet cells metaplasia was observed in the HN, OJ, and GJ groups; also, intra-alveolar macrophages decreased compared with those of the AC group. Hesperetin plus naringenin significantly decreased subepithelial fibrosis, smooth muscle hypertrophy in airways, and lung atelectasis compared with the AC group. Also, there was a reduction of subepithelial fibrosis in airways in OJ and GJ groups compared with AC group, but it was not noticed in OGJ group. In bronchoalveolar lavage fluid, macrophages numbers decreased in OJ and OGJ groups, whereas eosinophil numbers were increased in OJ group compared with NC group. Our finding revealed that hesperetin plus naringenin ameliorate airway structural remodeling more than orange juice and grapefruit juice in murine model of HDM-induced asthma. Copyright © 2015 John Wiley & Sons, Ltd.

Microorganisms and Some Quality of Red Grapefruit Juice Affected by High Pressure Processing and High Temperature Short Time

Abstract: The aim of this study was to evaluate the effects of high pressure processing (HPP; 550 MPa/10 min) and high temperature short time (HTST; 110 °C/86 s) on microorganism, ascorbic acid, total phenols, antioxidant capacity, color, enzyme activity, and rheological behavior in red grapefruit juice during 30 days of storage at 4 °C After HPP, the total plate count (TPC) and yeast and molds (Y & M) in red grapefruit juice were significantly decreased by 483 and 415 log cycles and showed to be microbiologically safe during storage The activity of pectin methylesterase (PME) and peroxidase (POD) was only inactivated by 225 % and increased by 104 % by HPP, but completely inactivated by HTST For all the other quality properties (such as total phenols, ascorbic acid, antioxidant capacity, color) except cloud stability studied in this article, their retention was significantly better in the HPP-treated samples than in the HTST-treated samples during storage, which were closer to natural grapefruit juice A longer shelf life was observed in HPP-treated grapefruit juice compared to HTST-treated ones

Effect of lyophilized grapefruit juice on P-glycoprotein-mediated drug transport in-vitro and in-vivo

Abstract: The administration of grapefruit juice (GFJ) has been postulated to inhibit the activity of P-glycoprotein (P-gp) transport system and thus can enhance the uptake of substrate drugs. However, for various reasons, the results obtained have been always swaying between confirmation and refutation. This study aims at re-evaluating the effect of lyophilized freshly-prepared grapefruit juice (LGFJ) prepared from the whole peeled fruit on P-gp activity using the model drug doxorubicin (DOX) in-vitro and timolol maleate (TM) in-vivo. Human uterine sarcoma MES-SA/DX5v cells, grown under nanomolar concentration of DOX and highly expressing P-gp, were used as model cells for in-vitro studies whereas white New Zealand male rabbits were used for in-vivo studies. Results showed that the accumulation of DOX in MES-SA/DX5v cells was increased by 18.3 ± 2.0% in presence of LGFJ compared to control experiments. Results from in-vivo absorption studies showed that the relative oral bioavailability of TM ingested with...

Original article Thermosonication: a potential technique that influences the quality of grapefruit juice

Abstract: Summary Thermosonication (TS) is an emerging nonthermal processing technique used for the liquid food preservation and is employed to improve the quality and acceptability of grapefruit juice. In this study, fresh grapefruit juice samples were subjected to TS treatment in an ultrasonic cleaner with different processing variables, including temperature (20, 30, 40, 50 and 60 °C), frequency (28 kHz), power (70%, 420 W) and processing time (30 and 60 min) for bioactive compounds, inactivation of enzymes pectin methylesterase (PME), peroxidase (POD) and polyphenolase (PPO) and micro-organisms (total plate count, yeasts and moulds). The micro-organism activity was completely inactivated in the treatment (60 °C for 60 min). The TS treatment at 60 °C for 60 min exposure reduced PME, PPO and POD activity by 91%, 90% and 89%, respectively. Results indicate that the advantages of TS for grapefruit juice processing at low temperature could enhance the inactivation of enzymes and micro-organisms and it can be used as a potential technique to obtain better results as compared to alone.

Effect of grapefruit juice on the bioactivation of prasugrel.

Abstract: Aims The P2Y12 inhibitor prasugrel is a prodrug, which is activated after its initial hydrolysis partly by cytochrome P450 (CYP) 3A4. Grapefruit juice, a strong inactivator of intestinal CYP3A4, greatly reduces the activation and antiplatelet effects of clopidogrel. The aim of this study was to investigate the effects of grapefruit juice on prasugrel.

Carotene reactivity in pink grapefruit juice elucidated from model systems and multiresponse modeling

Abstract: This study was carried out to assess the impact of pink grapefruit juice composition and structure on the degradation kinetics of lycopene and β-carotene using model systems and multiresponse modeling Carotenes were heated at four temperatures in their native matrix (juice) or were extracted and incorporated in water/ethanol emulsion systems formulated with or without ascorbic acid or naringin Kinetic analysis showed that the rate constants and activation energy were lower for lycopene than for β-carotene in the juice, while this trend was inversed in the model system Multiresponse modeling was used to analyze the role of ascorbic acid and naringin in carotene degradation Ascorbic acid had a very low impact, while naringin significantly increased the carotene degradation and isomerization rates We concluded that lycopene was more sensitive to thermal degradation and phytochemical interactions than β-carotene, but this behavior was masked in the fruit juice matrix by better structural protection

A Comprehensive Review of Potential Warfarin-Fruit Interactions

Abstract: Purpose The aim of this review is to discuss possible interactions that may occur between warfarin and fruit products. Methods A literature search was conducted using the search terms: “warfarin (Coumadin®) and fruit interactions, warfarin and fruit, warfarin and fruit juice, case reports and clinical trials”. Results A total of 23 citations (15 case reports and 7 controlled clinical trials) were reviewed. The majority of cases involved cranberry products, while pomegranate juice, avocado, grapefruit juice, mango, and papain were also implicated in reports of suspected warfarin-fruit interactions. Cranberry juice was also the most frequently studied fruit product. Other fruit products evaluated with warfarin in controlled clinical trials were cranberry concentrate and grapefruit juice. Conclusion Although a number of case reports have been published that suggest warfarin has the potential to interact with several fruit products, it is difficult to determine their relevance, as scientific evidence is scarce. Until further information is available, clinicians may want to encourage patients to consume cranberry products and grapefruit juice in small to moderate quantities and to inquire about the recent consumption of mangos, pomegranate juice, and avocados when taking a dietary history or when assessing possible causes for international normalized ratio (INR) instability.

Study on obtaining vegetables juices with high antioxidant potential, preserved by ohmic pasteurization

Abstract: In recent years is growing the interest in healthy eating to help prevent diseases. Numerous scientific studies have demonstrated the importance to human health of consumption of raw vegetables and fruits. The natural juices of vegetables and fruits are a concentrated form of vitamins, minerals and antioxidants. Our team proposes a healthy drink with a balanced nutrient content and low caloric value, which also constitutes an important source of vitamins, antioxidant compounds and dietary fiber needed for digestion. In the present study were used juices obtained from vegetables grown on Romania, namely pumpkin, carrot and celery, mixed with citrus fruits, oranges and grapefruits. It was analyzed the chemical composition and the content of antioxidant compounds of some variants of cocktails, only with vegetal juices. To ensure preservation of these cocktails it was used ohmic pasteurization, which can provide better nutritional properties and keeping sensory characteristics for a period of 14 days. From experimental data resulted that thermic effect of ohmic method is less harmful on flavonoids than conventional method. After this period of 14 days of storage, the highest amount of polyphenols was fined for sample P 3 of cocktails, with grapefruit juice. The lowest content of flavonoids was found for sample P 1, with the smallest amount of pumpkin juice. Finally, checking of acceptability of consumers by sensory analysis revealed that ohmic pasteurisation of juices have obtained a higher score than conventionally pasteurisation and had no negative influence on flavor of juices.

Comparison of Ascorbic Acid, Total Phenolic Content and Antioxidant Activities of Fresh Juices of Six Fruits Grown in Oman

Abstract: Background: Regular consumption of fruits and their juices play a beneficial role in the prevention of many diseases owing to the presence of dietary antioxidants such as ascorbic acid, flavonoids and polyphenols. Aim: The aim of the study was to analyze and estimate total phenolics, ascorbic acid content and to investigate free radical scavenging activity of six locally grown and commonly eaten fruits in Oman. Methods: The fruits were thoroughly washed and mechanically squeezed to obtain the juices. The fruit juices after filtration were analyzed for total acidity, ascorbic acid, total phenolic content and in- vitro antioxidant activity by alkalimetery, iodimetric (volumetric), Folin Ciocalteu reagent (colorimetric) and 1,1, diphenyl picrylhyrazyl (DPPH) assay methods respectively. Key findings: Lime juice was found to be the most acidic while grapefruit juice had the maximum ascorbic acid content. Total phenolic content of the juices were observed in the following order of decreasing levels; pomegranate>grapefruit>lemon>lime>s weet melon>watermelon. The result of in- vitro antioxidant activity of all juices, barring watermelon and sweet melon, were quite significant, but the highest scavenging activity of DPPH radicals was exhibited by pomegranate juice closely followed by grapefruit and lemon juices respectively. Conclusion: The Results of this study indicated that these fruits are important to the consumer’s health and a potential source of dietary antioxidants due to their high phenolic and ascorbic acid contents.

Method for producing grapefruit juice by employing ultra-high pressure technology

Abstract: The invention relates to a method for producing a grapefruit juice by employing an ultra-high pressure technology. The method comprises the following steps: (1) preparation of grapefruit juice: sequentially squeezing, filtering and centrifuging grapefruit pulp to obtain the grapefruit juice; and 2) ultra-high pressure treatment: carrying out ultra-high pressure treatment on the grapefruit juice obtained in the step (1) at 400-600MPa for 5-10 minutes, so as to obtain the grapefruit juice which is subjected to ultra-high pressure treatment. The low-temperature and high-quality grapefruit juice which is not easy to brown, high in acidity, rich in Vc and phenolic substances and high in antioxidant ability is produced in a low-temperature storage condition of 4 DEG C; the nutrients, the quality and the functions of the grapefruit juice are well protected; the progress of research on marketization and commercialization of related HHP (high-hydrostatic pressure) techniques is improved; a certain theoretical basis is provided for development and industrial application of the low-temperature and high-quality grapefruit juice; and meanwhile, the method provided by the invention is also applicable to production of other ultra-high pressure fruit juice products.

Effect of Citrus paradisi and Citrus sinensis on glycemic control in rats

Abstract: This study was conducted to explore the effects of Citrus sinensis (orange juice) and Citrus paradisi (grapefruit juice) at three different doses alone and their two combinations on plasma insulin and blood glucose levels in healthy and diabetic rats. Diabetes was induced by alloxan after which rats were treated with C. sinensis and C. paradisi juices for six weeks, blood glucose and plasma insulin concentration was estimated. C. sinensis showed significant reduction in blood glucose and a significant rise in plasma insulin at all three doses. However C. paradisi revealed highly significant fall in blood glucose and highly significant rise in plasma insulin levels only at 0.5 ml/kg. Whereas combination dose group CSP-2 (5 + 0.3 ml/kg) showed highly significant reduction in blood glucose and highly significant rise in plasma insulin levels as compared to diabetic control. These results suggest that flavonoids and other essential nutrients present in citrus fruits juices might be responsible for these effects. Hence, it may be concluded that these juices may be used in combination to produce a synergistic effect in decreasing blood glucose and elevating plasma insulin levels. Key words: Grape fruit, orange, glucose level, insulin.

A MEKC method for naringenin from natural and biological samples

Abstract: The work reported describes the development of a micellar electrokinetic chromatographic (MEKC) method for the determination of naringenin in real samples including grapefruit juice and human blood serum using a PDA detector. The effects of different CE parameters such as concentration and pH of the running buffer, voltage, injection time and concentration of sodium dodecyl sulfate (SDS) were optimized. Under the optimized conditions, naringenin could be well determined within 6 min using 40 mM borate buffer, 40 mM SDS at pH 9.0, at an applied voltage of 25 kV. For the quantitative determination of naringenin (flavonoid aglycone) in grapefruit juice, the naringin (flavonoid glycoside) was hydrolysed and the resulting aglycone was identified and quantified. The calibration curve was linear in the studied concentration range of 0.1 to 50 μg mL−1 (R2 = 0.995). The detection limit and the limit of quantification were found to be 0.05 and 0.19 μg mL−1, respectively.

Predictive performance of three practical approaches for grapefruit juice‐induced 2‐fold or greater increases in AUC of concomitantly administered drugs

Abstract: Summary What is known and objective Clinical pharmacists have a challenging task when answering patients’ question about whether they can take specific drugs with grapefruit juice (GFJ) without risk of drug interaction. To identify the most practicable method for predicting clinically relevant changes in plasma concentrations of orally administered drugs caused by the ingestion of GFJ, we compared the predictive performance of three methods using data obtained from the literature. Methods We undertook a systematic search of drug interactions associated with GFJ using MEDLINE and the Metabolism & Transport Drug Interaction Database (DIDB version 4.0). We considered an elevation of the area under the plasma concentration‒time curve (AUC) of 2 or greater relative to the control value [AUC ratio (AUCR) ≥ 2·0] as a clinically significant interaction. Results and discussion The data from 74 drugs (194 data sets) were analysed. When the reported information of CYP3A involvement in the metabolism of a drug of interest was adopted as a predictive criterion for GFJ‒drug interaction, the performance assessed by positive predictive value (PPV) was low (0·26), but that assessed by negative predictive value (NPV) and sensitivity was high (1·00 for both). When the reported oral bioavailability of ≤0·1 was used as a criterion, the PPV improved to 0·50 with an acceptable NPV of 0·81, but sensitivity was reduced to 0·21. When the reported AUCR was ≥10 after co-administration of a typical CYP3A inhibitor, the corresponding values were 0·64, 0·79 and 0·19, respectively. What is new and conclusion We consider that an oral bioavailability of ≤0·1 or an AUCR of ≥10 caused by a CYP3A inhibitor of a drug of interest may be a practical prediction criterion for avoiding significant interactions with GFJ. Information about the involvement of CYP3A in their metabolism should also be taken into account for drugs with narrow therapeutic ranges.

Consumer response to media information: the case of grapefruit-medicine interaction

Abstract: This study measured the effect of media exposure on grapefruit/grapefruit juice consumption changes, in particular grapefruit-medicine interaction. Respondents’ attitudes about health news on television and the internet were measured to account for consumers exposed versus not exposed to such information. Results of a sample selection model show that consumer attitudes toward health news were significantly related to exposure to media information. Also, news exposure about grapefruit-medicine interaction has a tendency to result in reduced grapefruit consumption. Consumers who are directly affected by the medication interaction significantly react to the news, and the effect varies by age. Even though consumer’s age was positively related to the probability of increased grapefruit consumption, when consumers took the medication, consumer’s age was negatively related to the probability of increased grapefruit consumption.

Grapefruit and honey mask

Abstract: The invention relates to the field of daily cosmetics, and specifically relates to a grapefruit and honey mask. The grapefruit and honey mask is mainly prepared from the following components and raw materials: 5 to 10 parts of grapefruit juice, 2 to 4 parts of aloe extracting liquid, 5 to 7 parts of honey, 2 to 4 parts of rose extracting liquid, 1 to 3 parts of glycerinum, 1 to 3 parts of hyaluronic acid, and the balance of deionized water. The grapefruit and honey mask has the advantages that rich vitamin C provides rare trace elements to the skin, so that the resistance of the skin can be improved, and the skin can be white and energetic; the honey is adopted and can condition and moisture the skin, the moisture level and smoothness of the skin can be improved, the melanin can be reduced, melanin can be eliminated, the quality of the skin can be improved, and the balance of skin moisture and nutrition can be rebuilt.