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Antioxidative properties of roselle (Hibiscus sabdariffa L.) in linoleic acid model system
Abstract
A study was conducted to determine the antioxidative properties of roselle (Hibiscus sabdariffa L.) methanol extract by monitoring the formation of diene-conjugated compounds and thiobarbituric acid reactive substances (TBARS) in linoleic acid model system. The properties were compared to those of butylated hydroxy-anisole (BHA) and a-tocopherol. Results indicated that the roselle extract showed stronger antioxidant properties than BHA or a-tocopherol. A total of 200 parts per million (ppm) of the extract inhibited more than 85 per cent of diene-conjugated compounds after seven days of incubation at 40?C. The total phenolic compound was found to be 2.96mg/g calyx as gallic acid equivalent. This indicates that roselle is a good source of natural antioxidants which may protect the body from damage by free radicals and lipid peroxidation. The protective effect is probably through the action of highly bioavailable ascorbic acid, ß-carotene and phenolic compounds, especially the anthocyanins.
... According to Pau, Salmah and Suhaila (2002) Roselle (Hibiscus sabdariffa) is a species of Hibiscus native to West Africa, used for the production of bastfibre and as an infusion, in which it may also be known as carcade. It is an annual or perennial herb or woody-based subshrub, growing to 2-2.5 m (7-8 ft) tall. ...
... The crop is extensively cultivated in tropical Africa, Asia, Australia and Central America. It is a rare plant in Kenya hence it has not been exploited despite its existing potential for a wider application in food and textile Industry (Pau, Salmah, Suhaila, 2002). ...
This study sought to analyze market integration as determinant of household decision-making in the production of Roselle plant in Mwea Sub-County. This study employed a descriptive survey since this method is designed to obtain pertinent and precise information concerning the status of phenomena and whenever possible to draw valid general conclusions from the facts discovered. The target population was 200 farmers drawn from four areas i.e. Karie, Kangai, Ngariama and Mutithi. The sampling technique used in this study was the stratified type since the population is divided into four strata. Data collected was analyzed qualitatively and quantitatively using SPSS tool and presented in form of frequencies, pie-charts, tables, and graphs. The results indicated that market integration was influencing farmers’ decisions to take up growing Roselle through respondents selling their produce as groups and also the agreement the farmers had with the processing company which enabled them to sell their produce to the company. Some of the recommendations made were the need to carry out further research on how the other parts of the Roselle plant like the roots, leaves, stem and seeds can be used to avoid disposing them yet they could be having potentials just like the calyces.
... Moreover, a methanolic extract of Roselle calyx has been reported to have higher anthocyanin content and antioxidant activities compared to an aquoues extract. The effectiveness of Roselle as antioxidant in food system such as beef frankfrukter and beef patties has also been proven previously (Chew, 2003;Tee et al. 2002). Roselle extract (RE) has been found to successfully inhibited lipid oxidation in beef pattis stored at 4°C for 14 days (Mohd-Esa et al. 2010). ...
... Roselle extract (RE) has been found to successfully inhibited lipid oxidation in beef pattis stored at 4°C for 14 days (Mohd-Esa et al. 2010). Besides, Tee et al. (2002) showed that RE incoporated into cooked refrigerated beef frankfurter have stronger antioxidant property than α-tocopherol. Based on these studies, the application shall be extended to a more complex food system such as oil-in-water emulsions. ...
This research was undertaken to investigate the effect of Roselle (Hibiscus sabdariffa. L) extract on the physical properties and stability of extra virgin olive oil emulsions. Four different emulsions were prepared with methanolic Roselle extract (0.01 and 0.02%) and 0.02% BHT (commercial antioxidant) as well as without the extract/ antioxidant (control). The physical properties were studied in terms of pH, droplet size distribution, microstructure, viscosity and stability towards phase separation and lipid oxidation (under accelerated oxidation at 60°C for 10 days). The emulsions with Roselle extract was found to exhibit lower polydispersity and more uniform droplet size as compared to control and BHT emulsions. The highest viscosity was observed for the emulsion with 0.02%. The BHT emulsion was the most unstable towards phase separation after 15 days of storage at 5°C. A protective effect of Roselle extract against lipid oxidation in the emulsions was clearly observed at 0, 2, 8 and 10 days of accelerated storage (at 60°C) with considerably low total oxidation values (5.4 to 13). All emulsions showed insignificant deterioration with peroxide value < 20 meq/kg after oxidation period. This study provided important preliminary data on possibility of applying Roselle extract (which is known to content a significant amount of bioactive compounds) in producing functional food emulsions with acceptable properties and stability.
Keywords: antioxidants, emulsion, roselle extract, stability, properties
... The antioxidant activity of the extract was determined based on the inhibition of linoleic acid peroxidation, using the TBARS method [36][37][38]. ...
Acer pseudoplatanus (maple) is a widely grown ornamental plant. In addition to its ornamental and ecological value, it also has potentially high economic value. It is a rich source of polyphenols and exhibits antioxidant activity. However, the relationship between polyphenol content and antioxidant activity in maple leaves of different colors (green, yellow, and red) has not yet been investigated. In this study, the total polyphenol (TP), total flavonoid (TFlav), tannin (TET), chlorophyll a and b (Chl a and b), total anthocyanin (TAN), and total carotene (TAC) contents in maple leaves of different colors were evaluated. Their antioxidant activities were determined based on the inhibition of lipid oxidation, DPPH scavenging, ferric ion-reducing antioxidant power, and iron-chelating abilities. The concentrations of TP, TET, TFlav, TAN, and TAC in red maple leaves were higher than those in green and yellow maple leaves. In addition, red maple leaves showed a higher antioxidant effect than the leaves of the other two colors. We observed that antioxidant activity was positively correlated with TP, TFlav, and TAN and negatively correlated with Chl a and b. Finally, we analyzed the metabolites of the different colored (i.e., green, yellow, and red) maple leaves using gas chromatography/mass spectrometry (GC/MS) and found that the metabolite profile significantly varied between the different colors. These results suggest that red leaves are a good source of polyphenols and antioxidants and have potential use in the development of functional foods and medicinal applications.
... It is best preserved by refrigeration which will control the microorganism reaction on the drink [12] . Due to the ubiquitous nature of micro-organisms, the level of contamination can be reduced if proceeded under standard hygienic conditions and at low temperatures to prevent the multiplication of pathogenic micro organisms that can cause infection to the consumers [13] . Delicate hibiscus flower requires special handling during and after preservation. ...
The phytochemical analyses, nutrient value and economic importance of Hibiscus sabdariffa commonly known as Zobo plant was carried out. In Nigeria the plant is used to make a popular beverage known as Zobo drink. Investigations revealed that the plant is highly rich in vital minerals and nutrients such as Iron, copper, calcium, magnesium, manganese required for healthy growth in humans. The phytochemicals were extracted from the dried calyces of Hibiscus sabdariffa using solvent extraction method. The preliminary phytochemical analysis showed that there are some plant chemicals present in the extract such as alkaloids, tannins, saponnins, glycosides, phenols and flavonoids and quantitative result revealed their presence as follows; Tannins (17.0%), saponnins (0.96%), phenols (1.1%), glycosides (0.13%), alkaloids (2.14%) and flavonoids 20.08%). Hibiscus sabdariffa has medicinal benefits as it causes reduction in hypertension and cholesterol. The plant is economically important for proper metabolic process to be adequately maintained. It was discovered that the dietary constituents contributing to the protective effects of these plant materials are plant secondary metabolites in the form of phytochemicals, vitamins and minerals. Medicinal and aromatic plants contain biologically active chemical substances such as saponins, tannins, glycosides and other chemical compounds which have curative properties. This study suggests that plant derived medicines are relatively safer than synthetic alternative offering profound therapeutic benefits and more affordable treatment, hence, Hibiscus sabdariffa is readily available to provide such benefits.
... Major organic acids present in flower extracts were citric acid, malic acid and ascorbic acid (Buogo andPicchinenna, 1937 andReaubourg andMonceaux, 1940). Hida et al. (2005) (Osman et al., 1975 andTee et al., 2002). The chemical analysis of roselle seeds has been carried out by some workers (Samy, 1980, Hainida et al., 2008and Nzikou et al., 2011. ...
Medicinal plants have been the keystone of health care since ancient time. Their
innumerable uses have been documented and transformed through the generation for
over more than 4000 years. In the early 19th century, as soon as the scientific
investigations began, numerous plant based drugs have been made available to cure
large number of global diseases. The 21st century started with exploration of these
traditional remedies to meet patient needs. Now we are in the era where science and
technologies have evolved to elucidate the safety and efficacy of traditional
medicines. Even though much more information on uses of plant/plant parts in various
health practices is still unrecorded. This book will present an overall illustration of
some selected medicinal plants and their medico biological application. It will also
throw light on critical areas of ongoing research, transforming the information on
medicinal plants and their recent applications.
... It is believed that the antioxidant content of Roselle extract has mediated its protection against INH-RIFinduced organ damage. Several investigations have revealed that the antioxidant capacity of Roselle extract was more potent compared to the typical antioxidants, such as butylated hydroxy-anisole and α-tocopherol (32). Supporting this, the administration of Roselle extracts in this study has appeared to improve the liver and renal injury biomarkers in the rats. ...
Introduction: Roselle (Hibiscus sabdariffa L.) calyces possess natural antioxidants that may provide therapeutic benefits. This study aimed to investigate the protective effects of Roselle calyx water extract against isoniazid (INH) and rifampicin (RIF) induced liver and renal toxicities.Methods: Male Wistar rats (150-250 g) were designated into five groups: control group, INH-RIF group that was treated with INH-RIF at the toxic doses (50-100 mg/kg for 4 weeks, followed by 100-200 mg/kg for 2 weeks), and Roselle groups that were treated daily with Roselle extract at the doses 62.5, 125, and 250 mg/kg, respectively prior to INH-RIF administration. Blood samples were withdrawn weekly for 6 weeks before removing rats’ livers and kidneys for tissue malondialdehyde (MDA) and histopathological analysis.Results: The results showed all rats in the INH-RIF group experienced marked elevations of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine, and tissue MDA levels compared to the controls (P<0.05). In contrast, these biomarkers were maintained at near-normal levels in Roselle extract groups. Significant inflammation and cellular degeneration were found in the liver and renal tissues of the INH-RIF group, which were noticeably reduced with Roselle extract pre-treatment at the dose of 250 mg/kg.Conclusion: It is concluded that Roselle calyx extract can provide protection against liver and renal toxicities induced by INH-RIF administration in rats.
... The strong antioxidant activity of roselle extract could be due to the presence of polyphenol compounds Abou-Arab et al., (2011) Investigated antioxidant activity of roselle plant extracted by different solvents and indicated that the ethanol acidified with 1% citric acid extracts exhibited higher value in total antioxidant activity and recorded (EC50) of 42.77 (µ/ml). Tee et al., (2002) reported that roselle extract had stronger antioxidant activity than BHA or tocopherol in a linoleic acid model system. ...
... As a fact, the health benefits of plant foods is not only due to their macro or micronutrient content only but also linked with the presence of the phytochemicals. 3 In vitro studies showed that H. sabdariffa has anti-oxidant properties 4-7 whereas in vitro/animal models study presented the extracts of this flower to hold hypocholesterolemic 8,9 as well as anti-hypertensive properties. [10][11][12][13] Concentrated H. sabdariffa drink was found to lower blood pressure (BP)in hypertensive patients 14 and type 2 diabetes 15 compared with black tea (C. ...
Background
Hypertension is a leading cause of mortality and morbidity worldwide. Hibiscus is a cheap readily available preparation.
Aims
We aimed to assess the effect of Hibiscus sabdariffa on blood pressure, lipid profile, plasma sugar, and h-sensitive C-reactive protein.
Methods
This is a prospective cohort study conducted among 19 College staff members at the University of Tabuk, Saudi Arabia during January 2020. The participants signed written informed consent, then responded to a questionnaire to report their demographic data. At baseline, the blood pressure was measured, anthropometric measures collected, and, and a blood sample was taken to measure fasting plasma sugar, serum cholesterol, triglycerides, high-density lipoproteins, and high-sensitive C-reactive protein. Participants thereafter took Hibiscus sabdariffa for four weeks, then the above measurements were repeated. The compliance of the participants was also assessed.
Results
No significant effects of Hibiscus sabdariffa consumption were observed on systolic and diastolic blood pressure, fasting plasma glucose, lipid profile, and high-sensitive C-reactive protein, P-value< 0.05.
Conclusion
No significant effects were observed among Hibiscus sabdariffa users on blood pressure, plasma sugar, lipid profile, and C-reactive protein. Further larger multicenter studies are recommended.
... As a fact, the health benefits of plant foods is not only due to their macro or micronutrient content only but also linked with the presence of the phytochemicals. 3 In vitro studies showed that H. sabdariffa has anti-oxidant properties 4-7 whereas in vitro/animal models study presented the extracts of this flower to hold hypocholesterolemic 8,9 as well as anti-hypertensive properties. [10][11][12][13] Concentrated H. sabdariffa drink was found to lower blood pressure (BP)in hypertensive patients 14 and type 2 diabetes 15 compared with black tea (C. ...
Background Hypertension is a leading cause of mortality and morbidity worldwide. Hibiscus is a cheap readily available preparation.
... Several studies, both in vitro [3,4] and in vivo [5,6] have shown that the extract of H. sabdariffa L. has a potent antioxidant effect. The antioxidant activity of the extract is due to its strong scavenging effect on reactive oxygen and free radicals [6,7]. ...
Aim of the Study: This study was undertaken to ascertain if Hibiscus sabdariffa extract can affect the lipid profile (Total cholesterol (TC), triglycerides (TG), high density lipoprotein (HDL), very low density lipoprotein (VLDL), and low density lipoprotein (LDL)) levels in a paracetamol-induced hepatotoxicity using albino Wistar rat as a model. Materials and Methods: Thirty (30) rats used for this study were divided into three groups. Group A (n=10) served as control. Group B (n=10) was administered paracetamol only at a dose of 750 mg/kg body weight. Group C (n=10) was administered paracetamol (dose 750 mg/kg body weight) and aqueous extract of H. sabdariffa (dose 10 ml/kg body weight) of the animal for 3 weeks. All animals were allowed free access to clean drinking water and normal rat chow. Results: Results of the study revealed that TC was significantly lower (p<0.05) in the paracetamol + H. sabdariffa-treated group as compared to paracetamol-treated group and control respectively. Original Research Article Umoren et al.; EJMP, 31(7): 54-60, 2020; Article no.EJMP.55530 55 Similar trend was observed with TG, VLDL-c, LDL-c and HDL-c. However, the decrease in HDL-c was not statistically significant when compared to control. Conclusion: The presence of bioactive constituents vis; anthocyanins, flavonoids, polyvenols and free radical scavenging properties in H. sabdariffa enabled a hypolipidemic effect on the animals by lowering the levels of serum TG, VLDL-c, LDL-c despite challenge on the liver. However, it was unable to produce significant effect on HDL concentration-very important cholesterol required in high level to maintain homeostasis inside the body. This may be due to the challenge on the liver as a result of the paracetamol abuse.
... In several countries, particularly in Africa, the extract from the calyces is utilized for preparing hot tea or cold drink (McKay et al., 2009) because of its elevated content of anthocyanins and organic acids (Hong andWrolstad, 1990 andGomez-Leyva et al., 2008) as well as flavour and colour additives in the production of jam, liquor, and jellies (Akindahunsi and Olaleye, 2003). Anthocyanins in addition to their colorful characteristics have antioxidant properties (Francis, 2000) which keep the body from damage by free radicals and lipid peroxidation (Tee et al., 2002 andLiu et al., 2002). Furthermore, roselle calyces have been utilized in folk medicines for several years and have been demonstrated to reduce blood pressure patients with hypertension and type II diabetes (Faraji and Tarkhani, 1999). ...
Glycinebetaine is an amino component that accumulates in many plant species under drought stress. In order to evaluate the response of vegetative growth, yield components, quality and anthocyanin content of roselle plants to glycinebetaine foliar application under water stress, a field experiment was performed during the two successive seasons of 2017 and 2018 at the Experimental Farm of Sakha Agricultural Research Station, Kafr El-Sheikh Governorate, Egypt as split plot. The irrigation treatments were 50±5, 65 ± 5 and 80±5% of available soil moisture depletion were allocated in the main plot while glycinebetaine foliar spray (25 and 50 mM) and distilled water as control were distributed in the sub-plots. Results showed that 80% reduced vegetative growth characters, fruit number, fruit fresh weight, calyces fresh and dry weight, calyces yield per plant and per fed as well as seed yield. Glycinebetaine at 25 and 50 mM enhanced vegetative growth and yield characters, TSS, acidity and total anthocyanin. Irrigation at 65 % combined with 25 mM glycinebetaine recorded the highest branch number, fruit number, fruit fresh weight, calyces fresh and dry weights/plant (g), seed yield per plant and calyces yield /fed, photosynthetic pigments, TSS, acidity % and total anthocyanin content while reduced pH value. Foliar spray of 25mM GB with 65 % of available soil moisture depletion was found to be more beneficial for avoiding the effects of water stress on above-mentioned attributes, which could be a feasible technique for roselle production that increases the yield and quality as compared to the other studied treatments.
... The roselle (Hibiscus sabdariffa Linn.) calyces has the several function, as the antioxidant [1], antimicrobial activity [2], immunoprotective [3] and natural colorant [4]. The antioxidant compound in roselle stronger than commercial antioxidants such as Butylated Hydroxyanisole (BHA) and α-tocopherol (TOCO) [5]. Anthocyanins and phenols are the main bioactive compounds in Roselle calyces. ...
Roselle (Hibiscus sabdarifa L) contains anthocyanins as the natural colorant and antioxidant. Drying the roselle extract was aims to produce the dry product that easy consumption as antioxidant. The carrier agent was added in roselle extract to improve the drying rate and maintain the nutritional value. This research studied the effect of carrier agent in drying rate and antioxidant activity. The method consists of two step involving roselle extraction using ultrasonic and the drying process. The roselle extraction by ultrasonic use the water as the solvent. The carrier agent (0%,5%,10% of maltodextrin) was added in roselle extract. The mixture was then dried in tray dryer dehumidification using zeolite in drying temperature 50,60, and 70⁰C. As the response, the moisture content was observed by gravimetry every 15 minutes for 150 minutes. The result showed that Page model was fitted to determine the constant of drying rate. Higher concentration of carrier agent enhanced the moisture evaporation process. Based on the DPPH analysis, the degradation of antioxidant activity in temperature 70⁰C was 2.14 times higher than in temperature 50⁰C. As the conclusion, addition of maltodextrin can speed up the drying process and retain the antioxidant activity of.
... Actually, Sorrel crop has attracted great interest because of the high antioxidant properties that is contained in the calyxes, which has been thoroughly evaluated (Tee et al., 2002;Tsai et al., 2002;Tsai and Huang, 2004;Tseng et al., 1997;Prenesti et al., 2007). The large-scale production of calyx is expected to lead to large quantity of seeds as by-product. ...
This work evaluated the quality of sorrel seeds as function of irradiation doses (0, 2.5, 5, 10, and 20kGy, respectively) so as
to determine dose level causing minimal undesirable changes to sorrel seed. Physicochemical properties (proximate, color,
peroxide value, free fatty acid value, saponification value and fatty acids), and functional properties (Water and oil holding
capacity, foaming capacity, emulsification and protein solubility) of the oil were determined using standard analytical
methods. The results showed that irradiation decreased crude protein and crude lipids significantly, while the ash content
and the crude fiber remained unaffected. Significant changes in peroxide values, saponification and free fatty acids were
observed after irradiation. Gas chromatography (GC) results revealed a clear trend toward an increase in the amount of
saturated fatty acids with increasing irradiation dose and a decrease in the amount of polyunsaturated fatty acids in the
triacylglycerol composition of the irradiated samples compared to the unirradiated sample. An inducement of trans-fatty
acids at 20kGy was also observed. The functional properties showed fluctuation with increasing dose of irradiation.
... The leaves are used in preparing spices and as a flavoring agent. [10][11][12] Other health benefit of Roselle plant includes diuretic and choloractic properties, intestinal antiseptic and mild laxative actions. It is also used in treating high blood pressure and calcified arteries. ...
... It is used extensively for making ropes and bags, and as a source of pulp for the paper industry, and is considered a cheap and sustainable alternative to forest wood (Anonymous 1959). The colored calyces are used for making a health drink (Pau et al. 2002), and its antioxidant potential has been explored (Mahadevan et al. 2009). The seed oil is reported to be a rich source of tocopherols (Mohamed et al. 2007). ...
An efficient protocol was developed for the micropropagation of Hibiscus sabdariffa through nodal explants (auxillary bud cultures) of in vitro seedlings. Nodal explants were able to induce multiple shoots on Murashige and Skoog (MS) basal medium supplemented with 2.0 mg L⁻¹ 6-benzylaminopurine, 0.5 mg L⁻¹ indole-3-acetic acid, and 10 μM silver nitrate (AgNO3; 7–8 shoots/explant) or 20 μg L⁻¹ triacontanol (TRIA; 4–5 shoots/explant). Medium devoid of AgNO3 that was supplemented with 0.1–0.5 mg L⁻¹ gibberellic acid (GA3) induced the proliferation of up to two shoots/explant, but supplementation with 1–5 mg L⁻¹ GA3 induced a single shoot. The highest frequency of shoot elongation and rooting was obtained on 0.5-strength MS medium supplemented with 0.1 or 0.5 mg L⁻¹ GA3, and on this medium, further proliferation of shoots was also evident. Micropropagated plants were hardened in the greenhouse and successfully established in soil. Ascorbic acid level in leaves of micropropagated plants from AgNO3- and TRIA-supplemented media was highest (2.24 ± 0.14 and 2.18 ± 0.13 mg g⁻¹ fresh weight, respectively), which was 2.8-fold more than normal ex vitro leaves of the same age (0.79 ± 0.03 mg g⁻¹ fresh weight).
... It is best preserved by refrigeration which will control the microorganism reaction on the drink [12] . Due to the ubiquitous nature of micro-organisms, the level of contamination can be reduced if proceeded under standard hygienic conditions and at low temperatures to prevent the multiplication of pathogenic micro organisms that can cause infection to the consumers [13] . Delicate hibiscus flower requires special handling during and after preservation. ...
Abstract The phytochemical analyses, nutrient value and economic importance of Hibiscus sabdariffa commonly known as Zobo plant was carried out. In Nigeria the plant is used to make a popular beverage known as Zobo drink. Investigations revealed that the plant is highly rich in vital minerals and nutrients such as Iron, copper, calcium, magnesium, manganese required for healthy growth in humans. The phytochemicals were extracted from the dried calyces of Hibiscus sabdariffa using solvent extraction method. The preliminary phytochemical analysis showed that there are some plant chemicals present in the extract such as alkaloids, tannins, saponnins, glycosides, phenols and flavonoids and quantitative result revealed their presence as follows; Tannins (17.0%), saponnins (0.96%), phenols (1.1%), glycosides (0.13%), alkaloids (2.14%) and flavonoids 20.08%). Hibiscus sabdariffa has medicinal benefits as it causes reduction in hypertension and cholesterol. The plant is economically important for proper metabolic process to be adequately maintained. It was discovered that the dietary constituents contributing to the protective effects of these plant materials are plant secondary metabolites in the form of phytochemicals, vitamins and minerals. Medicinal and aromatic plants contain biologically active chemical substances such as saponins, tannins, glycosides and other chemical compounds which have curative properties. This study suggests that plant derived medicines are relatively safer than synthetic alternative offering profound therapeutic benefits and more affordable treatment, hence, Hibiscus sabdariffa is readily available to provide such benefits.
Keywords: Hibiscus sabdariffa, Phytochemicals, Infusion, Zobo drink.
... The inhibitory effects on lipid peroxidation by rice grass and wheatgrass juices were evaluated by measuring TBARS according to a method described by Tee et al 18 ...
Juice squeezed from cereal grasses harvested at the jointing stage, i.e., wheatgrass (Triticum aestivum), exhibits high antioxidant activity. Rice (Oryza sativa) may also exhibit antioxidant activity. We therefore examined the antioxidant activity of juices squeezed from grasses harvested at the jointing stage for seven coloured and seven white Thai rice cultivars. The antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl, ferric reducing antioxidant power, β-carotene bleaching, and thiobarbituric acid reactive substances assays. The total phenolic content (TPC) and total monomeric anthocyanin content (TMAC) were also determined. Coloured (purple) rice grass juices exhibited greater antioxidant potential than the grass juices from white rice and wheat. The coloured rice cultivar Kum Doisaket exhibited the highest antioxidant activity in all assays. Correlation analysis indicated that the TPC and TMAC could be responsible for the antioxidant activity. The DNA protective properties of the coloured rice cultivars Kum Doisaket and Kum Noi and wheat were also examined. Only the Kum Doisaket cultivar exhibited a dose-dependent DNA protective effect. The notable antioxidant efficacy for the Kum Doisaket cultivar may be influenced by the high level of anthocyanins present in its grass juice. This finding suggests the possibility of developing functional foods from coloured rice grass.
... Nigeria produces 138,000 metric tonnes of Hibiscus calyces per annum. Hibiscus flower extract (HFE) have been reported to contain higher antioxidant property when extracted with water compared to methanol (Prenesti, Berto, Daniele, & Toso, 2007) and it is comparable with butylated hydroxyl anisole (BHA) and α-tocopherol which can prevent heart related diseases and some forms of cancer (Tee, Yusof, & Mohamed, 2002). ...
Beverages with bioactive compounds are consumed for their food value, thirst quenching ability and the health benefit they confer on consumers. Hot and cold cocoa:Hibiscus-flower-extract:ginger beverages were prepared in the laboratory. These ready-to-drink beverages were evaluated nutritionally for their antioxidant properties. The cold and hot water extracts of the beverages contained total phenolic content ranging from 11.61 to 22.01 mg GAE/g; the ferric reducing property ranged from 10.84 to 26.88 mg/g, while the vitamin C content ranged from 1.77 to 4.82 mg/g. The DPPH inhibition by the cold and hot water extracts of the beverages ranged from 38.60 to 87.53%. The ABTS scavenging ability was the lowest in the ginger extract with no significant differences among the other blends. Both 100% cocoa and 100% Hibiscus-flower-extract have high antioxidant properties and their combined effect increased the free radical scavenging potentials of the beverages. The cocoa–zobo–ginger beverage mixtures all have complimentary effect thus possessing high antioxidant activities.
... ngredients in Roselle powder might not dissociate well in the intestine of pigs. Wang et al. (2000) stated that the Roselle extract at the concentrations of 0.1 and 0.2 mg/ml in hepatotoxicity rat induced by tert-butyl hydroperoxide (t-BHP) significantly decreased the formation of MDA and it showed similar result as the report of Tseng et al. (1997). Tee et al. (2002 also confirmed that the Hibiscus extract had stronger antioxidant activity than BHA and β-carotene. On the other hand, the reason that the Roselle group did not clearly shown superiority over the other might be because of a too high level of physiological stress which increased lipid peroxidation, so the level of phenolic compound in ...
The study was conducted to investigate an antioxidant and acidifier properties of Roselle in fattening pigs.
Twenty crossbred pigs were randomly allocated to 4 treatments with 5 replicates. Four diets were calculated to be isocaloric and isonitrogenous: control diet, control diet supplemented with antibiotic (Chlortetracycline) 50 mg/kg or acidifier (Fra® Acid Dry) 4 g/kg and diet containing Roselle calyx powder at the level of 40 g/kg. Pigs were raised in individual concrete pen and received diet ad libitum for 8 weeks. Body weight, feed intake, blood constituent and thiobarbituric acid-reactive substances (TBARS) were measured in two consecutive periods at 4th and 8th week. Fecal content was collected at the end of the experiment to determine the coefficient of apparent total tract digestibility (CATTD). The blood constituent data was not significant difference (p>0.05) but the neutrophils to lymphocytes ratio was more likely high in both periods. TBARS value was not differed (p>0.05) among treatments. Roselle had the highest CATTD value of ether extract and significant difference from the others (p<0.05). Roselle also gave the highest CATTD value of phosphorous when compared to control and acidifier (p<0.05) but was not significantly different with antibiotic (p>0.05). Feed conversion ratio (FCR) was significant differences among treatment groups in the second period (p<0.05) and the best FCR was Roselle group but not significant difference when compared to control and antibiotic. The result implied that Roselle at the level of 40 g/kg could not clearly show neither antioxidant nor acidifier properties in fattening pigs.
... Phenolic compound has been regarded as a good antioxidant substance as vitamin E which was widely accepted on its effectiveness on inhibition of lipid peroxidation in biological systems (Kang, et al., 1998;Lanari et al., 2004). In addition, Kruawan and Kangsadalampai (2006) reported that Roselle calyx contained high level of phenolic compounds (210.72 mg of gallic acid equivalents/g) and exhibited high antioxidant activity which was 2220 μmol/g by ferric reducing antioxidant power (FRAP) value and 93.12 % scavenging effect by a stable radical 2,2-diphenyl-1picrylhydrazyl (DPPH), which was supported by Tseng et al. (2000), Wang et al. (2000), Tee et al. (2002), andUsoh et al. (2005). The use of Roselle calyx in the present study failed to show the effect on reducing TBARS value in plasma and yolk (Table 5). ...
An experiment was conducted to investigate the effect of Roselle calyx in two preparation forms in layer
diets on egg production performance, egg quality and TBARS value in plasma and yolk. Two hundred and seventy, 33-week-old, CP Brown laying hens were randomly allocated into 6 treatments with 5 replications of 9 hens each. The dietary treatments were control diet, control diet supplemented with 250 mg/kg α-tocopheryl acetate, diet containing 1 and 2% of Roselle calyx crude extracts, and diet containing 2% and 4% Roselle calyx powder. Egg production performance was recorded, egg quality was measured and TBARS value in plasma and yolk were analyzed after fed experimental diets for 4 and 8 weeks. Yolk TBARS after storage for 10 and 20 days in refrigerator and room temperature were also determined. The results demonstrated that there was no significant difference in egg production performance and egg quality and TBARS value in plasma and yolk at the 4th and 8th week among treatment groups (p>0.05). Roselle calyx tended to decrease TBARS value in yolk (p>0.05) while TBARS value in yolk significantly increased when storage times increased (p<0.01) in both storage methods. In conclusion, both forms and levels of Roselle had no adverse effect on egg production and egg quality. As an antioxidant, Roselle could not clearly show antioxidant activity. This may be due to the concentration of phenolic compound level in supplemented
Roselle. Storage time was an important factor to decrease egg quality and increase TBARS value in yolk in both storage methods.
... There is great interest exists in the crop of Sorrel due to the high antioxidant properties of the calyxes, which have been extensively evaluated (Tee et al., 2002;Tsai et al., 2002;Tsai and Huang, 2004;Tseng et al., 1997;Prenesti et al., 2007). Therefore, concomitant with the large-scale cultivation and commercial exploitation of the calyx is the expected production of a large quantity of seeds as by-product. ...
The effect of irradiation (dose levels of 0, 2.5, 5, 10 and 20 kGy) on nutritive (amino acids, and protein digestibility) and anti-nutritional characteristics [total phenols (PH), tannins (TA), phytic acids (PA) and oxalate (OX)], level of anti-nutrients in vitro digestibility (IVPD) and protein digestibilty corrected amino acid score (PDCAAS) of sorrel seeds (Hibiscus sabdariffa), were examined. The results showed that amino acids content were significantly (p < 0.05) enhanced by the irradiation up to the dose of 10 kGy in comparison with the control sample. Radiation processing significantly (p < 0.05) reduced the levels of total phenols, tannins, phytic acids and oxalate. IVPD and PDCAAS were significantly enhanced in a dose- dependent manner, relative to unirradiated control sample. The data sets for each dose level exhibited high correlation coefficient between dose and PH, TN, PA, OX and IVPD. We conclude that the overall dose of 10 kGy is very effective for hygienation and quarantine purposes and does not adversely affect the nutritional quality of sorrel seeds.
... The plant parts including seeds, leaves, fruits and roots are used in various foods such as wine, juice, jam, jelly, syrup, gelatin, pudding, cake, ice cream, tea, spice and other desserts. Roselle is a good source of natural antioxidants (protocatechuic acid and anthocyanins) that protect the body from damage by free radicals and lipid peroxidation (Tee et al., 2002; Liu et al., 2002; Ali et al., 2003, 2005). It is used for the treatment of several ailments, including high blood pressure, liver diseases, fever, urinary tract infection, pain of the muscles of the uterus and intestine *Corresponding author. ...
Today, there is emerging focus on the importance of medicinal plants that have occupied a significant position in solving the health care problems in human life. Karkade is an important medicinal plant and is used for curing various illnesses. The aim of this study was to improve growth performance by enhancing the photosynthetic pigments and enzyme carbonic anhydrase (CA) activity of Hibiscus sabdariffa L. (cv. Sabahia 17) under NaCl stress. Under non-saline condition, application of GA 3 enhanced growth parameters (shoot length, shoot fresh weight (FW), shoot dry weight (DW), root FW, root DW, leaf area), relative water content (RWC), CA activity, anthocyanin and photosynthetic pigments (chlorophyll (Chl) a, Chl b, and total Chl). However, the application of GA 3 reduced the inhibitory effect of NaCl on growth attributes and photosynthetic pigments by inducing the enzymes CA activity and enhancing RWC. Therefore, it is concluded that GA 3 might help in the tolerance of plants to salt stress.
... There has been increasing interest in hibiscus anthocyanins due to their beneficial health effects and high antioxidant properties which have been extensively evaluated (Prenesti, Berto, Daniele, & Toso, 2007;Tee, Yusof, & Mohamed, 2002;Tsai, McIntosh, Pearce, Camden, & Jordan, 2002). Studies with human patients have shown that the regular consumption of hibiscus extract has an antihypertensive effect (Haji Faraji & Haji Tarkhani, 1999;Herrera-Arellano, Flores-Romero, Chavez-Soto, & Tortoriello, 2004) and reduces serum cholesterol in men and women (Lin et al., 2007). ...
The effect of dense phase carbon dioxide (DPCD) processing (34.5 MPa, 8% CO2, 6.5 min, and 40 °C) on phytochemical, sensory and aroma compounds of hibiscus beverage was compared to a conventional thermal process (HTST) (75 °C for 15 s) and a control (untreated beverage) during refrigerated storage (4 °C). The overall likeability of the hibiscus beverage for all treatments was not affected by storage up to week 5. DPCD process retained more aroma volatiles as compared to HTST. Aroma profiles in the beverages were mainly composed of alcohols and aldehydes with 1-octen-3-ol, decanal, octanal, 1-hexanol, and nonanal as the compounds with the highest relative percentage peak areas. A loss of only 9% anthocyanins was observed for the DPCD processed hibiscus beverage. Phytochemical profiles in the hibiscus beverage included caffeoylquinic acids, anthocyanins, and flavonols. No major changes in total phenolics and antioxidant capacity occurred during the 14 weeks of storage.
... According to previous information, the investigation published around Roselle's calyx is focused on its watery infusion characteristics (Christian & Jackson, 2009;Chumsri, Sirichote, & Itharat, 2008;Domínguez-López et al., 2008;Du & Francis, 1973;Herrera-Arellano, Flores-Romero, Chávez-Soto, & Tortoriello, 2004;Mourtzinos et al., 2008;Nnam & Onyeke, 2003;Tsai, McIntosh, Pearce, Camden, & Jordan, 2002;Wróbel, Wróbel, & Colunga-Urbina, 2000), ethanolic infusions (Ali, Wabe, & Blunden, 2005;Alobo & Offonry, 2009;Mounigan & Badrie, 2007) and hydrophobic models as well (Tee, Yusof, & Mohamed, 2002). The intestinal absorption and the therapeutic effect of its functional isolated and purified molecules have been widely documented (Amos et al., 2003;Essa & Subramanian, 2009;Fouda, Daba, & Dahab, 2007;Frank et al., 2005;Hou, Tong, Terahara, Luo, & Fuji, 2005;Miyazawa Nakagawa, Kudo, Muraishi, & Someya, 1999). ...
... Primarily, roselle plant is cultivated for the production for fiber from its stem, which may be used as a substitute for jute in making burlap [337]. Roselle is considered to have antihypertensive and Antioxidative properties [338]. Roselle has been used in folk medicine as a diuretic, mild laxative, and treatment for cardiac and nerve diseases and cancer [339]. ...
... The plant parts including seeds, leaves, fruits and roots are used in various foods such as wine, juice, jam, jelly, syrup, gelatin, pudding, cake, ice cream, tea, spice and other desserts. Roselle is a good source of natural antioxidants (protocatechuic acid and anthocyanins) that protect the body from damage by free radicals and lipid peroxidation (Tee et al., 2002; Liu et al., 2002; Ali et al., 2003, 2005). It is used for the treatment of several ailments, including high blood pressure, liver diseases, fever, urinary tract infection, pain of the muscles of the uterus and intestine *Corresponding author. ...
Today, there is emerging focus on the importance of medicinal plants that have occupied a significant position in solving the health care problems in human life. Karkade is an important medicinal plant and is used for curing various illnesses. The aim of this study was to improve growth performance by enhancing the photosynthetic pigments and enzyme carbonic anhydrase (CA) activity of Hibiscus sabdariffa L. (cv. Sabahia 17) under NaCl stress. Under non-saline condition, application of GA 3 enhanced growth parameters (shoot length, shoot fresh weight (FW), shoot dry weight (DW), root FW, root DW, leaf area), relative water content (RWC), CA activity, anthocyanin and photosynthetic pigments (chlorophyll (Chl) a, Chl b, and total Chl). However, the application of GA 3 reduced the inhibitory effect of NaCl on growth attributes and photosynthetic pigments by inducing the enzymes CA activity and enhancing RWC. Therefore, it is concluded that GA 3 might help in the tolerance of plants to salt stress.
... Robards et al. (1999) reported the effect of the phenolic compounds including anthocyanins on the antioxidant properties of diverse fruits. These properties have been evaluated in roselle infusions by several groups of researchers (Duh & Yen, 1997;Tee et al., 2002;Tsai et al., 2002;Chen et al., 2004;Pale et al., 2004;Prenesti et al., 2007). ...
The degradation kinetics of anthocyanins in a Roselle infusion (Hibiscus sabdariffa L.), as assessed by visible absorption spectroscopy (absorbance at 520 nm), was verified (60–100 °C). The rate constants for absorbance retention were obtained from first-order reaction kinetic plots. Based on an Arrhenius-type model, the experimental data showed an energy of activation of 15.83 kcal mol−1 (66.22 kJ mol−1) and a Q10 value of 1.01. The obtained pattern allows to predict the retention of these antioxidant compounds as a function of temperature and time of thermal treatment.
... The presence of atocopherol in the coating slowed the oxidation rate to a lower saturation level compared to the rate for the control and the paperboard containing only nisin, which attained maximum level of TBARS in two days followed by steady decrease. The increase of TBARS to a certain maximum level and subsequent decrease was also observed by Tee et al. (2002) and may be attributed to the limited amount and oxidative characteristics of linoleic acid in the model emulsion solution. Incorporation of nisin in the coating did not provide any positive effect in the retardation of the oxidation rate. ...
A 3-mm thick nisin and/or α-tocopherol coating at a concentration of 3% was applied on a paper using a binder medium of vinyl acetate-ethylene copolymer to confer an antimicrobial and antioxidative property for use in the food packaging industry. The migration of nisin and α-tocopherol from the coating to a model emulsion composed of 66% water and 32% paraffin oil with 2% emulsifier was measured, and this was linked to the suppression of microbial growth and oxidative deterioration in the emulsion and in milk cream at 10 °C. The nisin migrated more slowly than α-tocopherol, and reached 9.3% of the total concentration incorporated in the coating, with α-tocopherol reaching an equilibrium level of 5.7%. The migration of each of the additives was not affected by the presence of the other. Incorporation of nisin in the coating was effective in inhibiting Micrococcus flavus, and α-tocopherol incorporation retarded lipid oxidation in the model emulsion and in the milk cream. Thus, the combination of nisin and α-tocopherol in the coating conferred both antimicrobial and antioxidative properties. However, it did not provide any further synergistic antimicrobial and antioxidative effect when compared to a single additive alone.
This book is depicting sufficient information on most popular indigenous vegetables account of the principles and its utility approach. The detailed index of the book gives a hope that it would be comprehensive, very rich in subject and well-organized. The book has been carefully compiled by the author and this would be helpful for the students, researchers, Home Scientists and people of the country. Each chapter is carefully laid out in a readable and easy to understand manner. The author has analyzed and drawn on a broad range of existing indigenous vegetables and on the basis of suitable material delivered in the compact form at one place in the form this book. The book based on appropriate information of crops which are not commonly known and in cultivation practices. The book is having systematic information regarding indigenous vegetables like their nutritional aspect, propagation, diversity and recipe of crop Content in tabular form and photographs of indigenous vegetables with recipes makes book more informative and it will help to identify the plants or vegetables easily.
The evolution of mankind has seen the use of medicinal plants for their beneficial and health purpose. This project work is to test the medicinal properties of those daily used plants like the usually used ornamental plant Hibiscus rosa-sinensis and a narrowly used Plectranthus ambionicus. The leaves and flower of test plant, H.rosa-sinensis, and leaves of P.ambionicus are powdered by shade drying and then tested with reference of the standard, Ocimum sanctum leaves and flowers. The ethanolic, methanolic and aqueous plant extracts were obtained and then compared by biochemical assays and biological test parameters. The objective of this project is to test the effectiveness of a daily used ornamental plant verses highly and commonly used Ocimum sanctum. This project also tests the test plants for the properties in the form of a substitute for the long- term use of Ocimum sanctum.
Background: Use of molecules with antioxidant properties have evolved as effective strategy for preventing oxidative damage caused by reactive oxygen species. Moringa oleifera and Hibiscus sabdariffa are ancient plants with antioxidant properties, and have served numerous therapeutic purposes, in addition to their nutritional benefits. Aim: This in vitro study compared the free radical scavenging efficacy of ethylacetate leaves extract of Moringa oleifera and ethylacetate petal extract of Hibiscus sabdariffa. Method: Determinations were carried out following standard procedures for analytical experiments. The leaves of Moringa oleifera and petals of Hibiscus sabdariffa were extracted by cool maceration with distilled water and ethylacetate, independently for 48 hours using soxhlet extractor. The free radical scavenging activities of the extracts were determined spectrophotometrically. DPPH free radical was used to determine the free radical scavenging activities of the extracts. The reducing power efficacy of the extracts was determined by their ability to reduce Fe3+ to Fe2+ ions using FERAP. Results:
Ethylacetate extract of Hibiscus sabdariffa petals had higher free radical scavenging efficacy and more reducing power with an inhibitory concentration (IC50) of 1.57 mg/ml compared to the ethylacetate extract of Moringa oleifera leaves which had an IC50 of 2.60 mg/ml. Phytochemical profile revealed that the predominant compounds in both extracts were flavonoids, phenols, and amino acids. Conclusion: This study has established that ethylacetate extract of the Petals of Hibiscus sabdariffa has more reducing power and free radical scavenging efficacy compared to ethylacetate extract of Moringa oleifera leaves. These plant parts could serve as novel sources for clinically efficient antioxidants.
Volume 8 is part of a multicompendium Edible Medicinal and Non-Medicinal Plants, on plants with edible flowers from Geraniaceae to Zingiberaceae (tabular) and 82 species in Geraniaceae, Iridaceae, Lamiaceae, Liliaceae, Limnocharitaceae, Magnoliaceae, Malvaceae, Meliaceae, Myrtaceae, Nyctaginaceae, Nymphaeaceae, Oleaceae, Onagraceae, Orchidaceae, Paeoniaceae, Papaveraceae, Plantaginaceae, Poaceae, Polygonaceae, Primulaceae, Proteaceae, Ranunculaceae, Rosaceae, Rubiaceae, Rutaceae, Solanaceae, Theaceae, Tropaeolaceae, Tyhpaceae, Violaceae, Xanthorrhoeaceae and Zingiberaceae in detail. This work is of significant interest to medical practitioners, pharmacologists, ethnobotanists, horticulturists, food nutritionists, botanists, agriculturists, conservationists and general public. Topics covered include: taxonomy; common/vernacular names; origin/distribution; agroecology; edible plant parts/uses; botany; nutritive/medicinal properties, nonedible uses and selected references.
The bacteriological quality of locally-produced sorrel beverage (Zobo) vended in Awka Campus of Nnamdi Azikiwe University, Nigeria was studied. Nutrient agar was used as the growth medium while the spread plate technique was employed in the isolation of the bacteria. A sample aseptically produced at the microbiology laboratory of the University was used as the control. The pH of the vended and control samples were also determined. The bacteria counts ranged between 10 and 30 cfu/ml while the control sample had no bacterial in it. Sample 4 had the highest count of 30 cfulml while samples 2 and 3 had the lowest counts of 10 cfu/ml. The pH of the vended samples ranged between 2.2 and 2.4 while that of the control sample was 2.1. The bacteria isolated from the samples were characterized and identified on the basis of their morphology and biochemical characteristics as Pseudomonas spp, Escherichia spp, Proteus spp and Klebsiella spp. Pseudomonas spp, Escherichia spp and Proteus spp were most frequently isolated in the samples examined. The bacteria may have entered the samples through the air, soil, water, packaging containers and handlers and have been reported to cause diseases of man and animals through the production of toxins. Good manufacturing practices must therefore be observed during the production, packaging and handling of Zobo beverage. The incorporation of effective food preservatives into the drink is also recommended.
The purpose of this study was to determine the optimal amounts and mixing condition of skim milk powder (A), and roselle (B) for the production of yogurt prepared with roselle. The experiment was designed according to the central composite design for estimating the response surface method, which yielded ten experimental points, including two replicates for the skim milk powder and roselle. The physicochemical and mechanical analysis of each sample, including pH (P
A smpile, rapid and accurate method for the determination of main mono and divalent inorganic anions in Roselle {Hibiscus sabdariffa L.) has been developed. The quantitative determination of anions F, Cl, NO 2, Br.N O, HPO 24SO 24, and I- was accomplished by suppressed conductimetric ion chromatography (IC). The separation is achieved on shim-pack IC-SA 2 250 mmL × 4.0 mm ID Peak, column operated at 30°C within 12.21 minutes by isocratic elution with 1.8 mM potassium carbonate, 12 mM Potassium bicarbonate and 0.0125mM of N- {[(ethylamino) thioxomethyl] hydrazine carbonlmethyl} trimethyl ammonium chloride (ETHTC) and pH 9.25 as eluent at flow rate of 1ml/ min. The method does not need a special sample treatment.
This study was carried out to investigate the antioxidant properties of synbiotic product, Lactobacillus acidophilus supplemented with 2.5% royal jelly in skim milk and Bifidobacterium bifidum supplemented with 7.5% royal jelly in skim milk, using DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical scavenging assay, reducing power, total antioxidant in linoleic acid system and formation of diene-conjugation assay. Results showed that the synbiotic effect of royal jelly and probiotic bacteria provided substantial antioxidant activities. Milk samples fermented by B. bifi dum supplemented with 7.5% royal jelly and L. acidophilus supplemented with 2.5% royal jelly exhibited high scavenging activity with 96.8 and 93.3%, respectively, at a concentration of 500 μg/mL. IC50 values were estimated at 226.7 μg/mL for B. bifidum supplemented with 7.5% royal jelly and at 210.2 μg/ml for L. acidophilus supplemented with 2.5% royal jelly. On the other hand, L. acidophilus supplemented with 2.5% royal jelly and B. bifidum supplemented with 7.5% royal jelly exhibited significantly high reducing power at a concentration of 1000 μg/mL. The percentages of peroxide inhibition of L. acidophilus supplemented with 2.5% royal jelly and B. bifidum with 7.5% royal jelly were 52% and 42%, respectively. Significant inhibitions were found in the formation of conjugated diene at 66.9% and 65.8% for L. acidophilus with 2.5% royal jelly and B. bifidum with 7.5% royal jelly, respectively. These results were compared with standards BHT, ascorbic acid and Trolox.
To investigate the effects of oral administration of aqueous extract of Hibiscus sabdariffa on renal Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in rats.
The 25 and 50 mg/(kg·d) of aqueous extracts of H. sabdariffa were respectively given to rats in the experimental groups for 28 d, and rats in the control group received an appropriate volume of distilled water as vehicle. Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in the kidney were assayed by spectrophotometric method.
Administrations of 25 and 50 mg/(kg·d) of aqueous extract of H. sabdariffa significantly decreased the Ca(2+)-Mg(2+)-ATPase activity in the kidney of rats (P<0.05). However, the renal Na(+)-K(+)-ATPase activity of the experimental rats was not affected by either dose of the extract. And the plasma Na(+), K(+) and Ca(2+) levels of the experimental rats had no significant changes. Administration of either dose of the extract did not result in any significant changes in body and kidney weights, the concentrations of plasma albumin and total protein, and alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase activities. However, concentrations of creatinine and urea were significantly reduced by 50 mg/kg of the extract (P<0.05).
The present study indicates that oral administration of aqueous extract of H. sabdariffa may preserve the renal function despite a decreased renal Ca(2+)-Mg(2+)-ATPase activity.
Three cultivars of Roselle seeds (“Mexico”, “China”, and “Sudan”) were collected from Guerrero State, Mexico and reconditioned to moisture contents ranging from ca. 13% to 25% w.b. The reconditioned seeds were then evaluated for dimensions, sphericity, bulk density, true density, porosity, thousand seed mass, and static coefficient of friction on several material surfaces. In the range of analyzed moistures, physical properties of Roselle seed are related to the moisture content by quadratic equations. Cultivars Mexico, China and Sudan increased their width in 10.9%, 7.8%, and 8.1%, in that order; similarly, their length was increased in 13.1%, 9.8%, and 7.2%, and their thickness was increased in 8.3%, 4.0%, and 13.7%. Seeds from the cultivar Mexico were the smallest. The sphericity changes with the increase in moisture content. Each cultivar had a single behaviour, thus cultivar Sudan comes closer to a spherical form, contrary to the cultivars Mexico or China. The bulk density and the true density for different moisture levels decrease with the increase in moisture content. The estimated porosity was found to increase with the increase in moisture content. The porosity started at 52.9%, 53.3%, and 54.7% and increased to 57.7%, 55.1%, and 56.9% for cultivars Mexico, China, and Sudan, respectively. The thousand seed mass increased with increase in seed moisture content from 21.85 to 81.00 g, 35.22 to 40.62 g and 36.37 to 41.78 g for the three cultivars mentioned above, respectively. The cultivars evaluated showed a comparable behaviour in relation with the static coefficient of friction, this variable increased with moisture content on four structural surfaces, namely concrete (0.32–0.34), galvanised iron (0.27–0.30), glass (0.25–0.30) and wood (0.23–0.30).
Roselle, or Jamaica sorrel (Hibiscus sabdariffa) is a popular vegetable in many tropical regions, cultivated for its leaves, seeds, stems and calyces which, the dried calyces are used to prepare tea, syrup, jams and jellies and as beverages. The main objectives of this study were to identify and characterise fungal pathogens associated with Roselle diseases based on their morphological and cultural characteristics and to determine the pathogenicity of four fungi infecting Roselle seedlings, namely Phoma exigua, Fusarium nygamai, Fusarium tgcq and Rhizoctonia solani in Penang. A total of 200 fungal isolates were obtained from 90 samples of symptomatic Roselle tissues. The isolates were identified based on cultural and morphological characteristics, as well as their pathogenicity. The fungal pathogen most frequently isolated was P. exigua (present in 45% of the samples), followed by F. nygamai (25%), Rhizoctonia solani (19%) and F. camptoceras (11%). Pathogenicity tests showed that P. exigua, F. nygamai, F. camptoceras and R. solani were able to infect both wounded and unwounded seedlings with different degrees of severity as indicated by the Disease severity (DS). R. solani was the most pathogenic fungus affecting both wounded and unwounded Roselle seedlings, followed by P. exigua that was highly pathogenic on wounded seedlings. F. nygamai was less pathogenic while the least pathogenic fungus was F. camptoceras, infecting only the unwounded seedlings but, surprisingly, not the wounded plants.
Unlabelled:
Calyxes from the Roselle plant (Hibiscus sabdariffa L.) were used to prepare cold (22 °C for 4 h) and hot (98 °C for 16 min) infusions/teas from both fresh and dried forms. Aroma volatiles were extracted using static headspace SPME and analyzed using GC-MS and GC-O with 2 different columns (DB-5 and DB-Wax). Totals of 28, 25, 17, and 16 volatiles were identified using GC-MS in the dried hot extract (DHE), dried cold extract (DCE), fresh hot extract (FHE), and fresh cold extract (FCE) samples, respectively. In terms of total GC-MS peak areas DHE ≫ DCE > FHE ≫ FCE. Nonanal, decanal, octanal, and 1-octen-3-ol were among the major volatiles in all 4 beverage types. Thirteen volatiles were common to all 4 teas. Furfural and 5-methyl furfural were detected only in dried hibiscus beverages whereas linalool and 2-ethyl-1-hexanol were detected only in beverages from fresh hibiscus. In terms of aroma active volatiles, 17, 16, 13, and 10 aroma active volatiles were detected for DHE, DCE, FHE, and FCE samples, respectively. The most intense aroma volatiles were 1-octen-3-one and nonanal with a group of 4 aldehydes and 3 ketones common to all samples. Dried samples contained dramatically higher levels of lipid oxidation products such as hexanal, nonanal, and decanal. In fresh hibiscus extracts, linalool (floral, citrus) and octanal (lemon, citrus) were among the highest intensity aroma compounds but linalool was not detected in any of the dried hibiscus extracts.
Practical application:
Hibiscus teas/infusions are one of the highest volume specialty botanical products in international commerce. The beverage is consumed for both sensory pleasure and health attributes and is prepared a number of ways throughout the world. Although color and taste attributes have been examined, little information is known about its aroma volatiles and no other study has compared extractions from both fresh and dried as well as extraction temperature differences. This is also, apparently, the first study to identify the aroma active volatiles in hibiscus beverages using GC-olfactometry. Manufacturers and consumers will now have a better understanding of why hibiscus teas prepared in different ways from either fresh or dried forms have a different flavor quality and intensity.
In vitro studies show Hibiscus sabdariffa L., an ingredient found in many herbal tea blends and other beverages, has antioxidant properties, and, in animal models, extracts of its calyces have demonstrated hypocholesterolemic and antihypertensive properties. Our objective in this study was to examine the antihypertensive effects of H. sabdariffa tisane (hibiscus tea) consumption in humans. A randomized, double-blind, placebo-controlled clinical trial was conducted in 65 pre- and mildly hypertensive adults, age 30-70 y, not taking blood pressure (BP)-lowering medications, with either 3 240-mL servings/d of brewed hibiscus tea or placebo beverage for 6 wk. A standardized method was used to measure BP at baseline and weekly intervals. At 6 wk, hibiscus tea lowered systolic BP (SBP) compared with placebo (-7.2 +/- 11.4 vs. -1.3 +/- 10.0 mm Hg; P = 0.030). Diastolic BP was also lower, although this change did not differ from placebo (-3.1 +/- 7.0 vs. -0.5 +/- 7.5 mm Hg; P = 0.160). The change in mean arterial pressure was of borderline significance compared with placebo (-4.5 +/- 7.7 vs. -0.8 +/- 7.4 mm Hg; P = 0.054). Participants with higher SBP at baseline showed a greater response to hibiscus treatment (r = -0.421 for SBP change; P = 0.010). No effects were observed with regard to age, gender, or dietary supplement use. These results suggest daily consumption of hibiscus tea, in an amount readily incorporated into the diet, lowers BP in pre- and mildly hypertensive adults and may prove an effective component of the dietary changes recommended for people with these conditions.
The antioxidant and prooxidant activities of gallic acid and its propyl, methyl, and (where solubility allowed) lauryl esters were investigated. Gallic acid (GA), propyl gallate (PG), and gallic acid methyl ester (GM) were able to scavenge hypochlorous acid at a rate sufficient to protect alpha-1-antiproteinase against inactivation by this molecule. When dissolved in ethanol, gallic acid lauryl ester (GL), PG, and GM decreased the peroxidation of ox brain phospholipids. GA had only a weak inhibitory effect. GM, GL, and PG reacted with CCl3O2. (trichloromethyl peroxyl radical) with rate constants of 1.23 X 10(7), 2.33 x 10(7), and 1.67 x 10(7) M-1 s-1, respectively. Gallic acid was much less reactive with a rate constant of 4.47 x 10(5) M-1 s-1. By contrast to these antioxidant properties, GA, GM, and PG accelerated damage to the sugar deoxyribose in the presence of ferric-EDTA and H2O2. GA also accelerated DNA damage by a ferric-bleomycin system. GM was less effective but GL had no effect. Reaction of NBT and cytochrome c by O2.- was only slightly inhibited by PG, GM, and GA, indicating that their rates of reaction with O2.- are low. Our data confirm the antioxidant actions of gallic acid lauryl, propyl, and methyl esters. However, they also show that both the prooxidant and antioxidant actions of ''proposed antioxidants'' should be fully characterized.
Publisher Summary This chapter discusses the analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Analyses of the Folin-Ciocalteu (FC) type are convenient, simple, and require only common equipment and have produced a large body of comparable data. Under proper conditions, the assay is inclusive of monophenols and gives predictable reactions with the types of phenols found in nature. Because different phenols react to different degrees, expression of the results as a single number—such as milligrams per liter gallic acid equivalence—is necessarily arbitrary. Because the reaction is independent, quantitative, and predictable, analysis of a mixture of phenols can be recalculated in terms of any other standard. The assay measures all compounds readily oxidizable under the reaction conditions and its very inclusiveness allows certain substances to also react that are either not phenols or seldom thought of as phenols (e.g., proteins). Judicious use of the assay—with consideration of potential interferences in particular samples and prior study if necessary—can lead to very informative results. Aggregate analysis of this type is an important supplement to and often more informative than reems of data difficult to summarize from various techniques, such as high-performance liquid chromatography (HPLC) that separate a large number of individual compounds .The predictable reaction of components in a mixture makes it possible to determine a single reactant by other means and to calculate its contribution to the total FC phenol content. Relative insensitivity of the FC analysis to many adsorbents and precipitants makes differential assay—before and after several different treatments—informative.
Three different methods to evaluate antioxidative effect using assay systems consisting of emulsified linoleic acid are described. Oxygen consumption was measured by a polarographic technique using hemin to accelerate the lipid oxidation. The formation of conjugated diene compounds during oxidation at 37° C was determined by spectrophotometric measurement of absorption at 234 nm. A sensitive gas chromatographic procedure was used for direct recording of the development of different volatile compounds by analyzing the headspace gas over the reaction medium. In the latter case denatured horseradish peroxidase was used as the catalyst. The advantages and limitations of the different methods are discussed.
Extracts of 14 different grapes were tested for their antioxidant activities in a copper-catalyzed lecithin liposome oxidation
assay and analyzed for their phenolic components by high-performance liquid chromatography (HPLC). The total phenolic contents
of the grape extracts varied from 176 to 1236 mg gallic acid equivalents (GAE)/L. Extracts of red wine grape varieties contained
higher concentrations of phenolics than other varieties. When compared at the same 20 µM GAE basis, the grape extracts inhibited
formation of conjugated diene hydroperoxides by 25.1 to 67.9%, and hexanal formation by 49.3 to 97.8%. Extracts of red table
grape varieties Red Globe and Emperor and white wine grape varieties Chardonnay and Sauvignon Blanc gave the highest antioxidant
activities. The relative percentage inhibition of conjugated dienes and hexanal correlated with total phenols (r=0.86 and 0.89). HPLC analyses showed that anthocyanins were the most abundant phenolic compounds in extracts of red grapes,
and flavonols were most abundant in extracts of white grapes.
The antioxidative activity of water extracts of three herbs, including the flower of Chrysanthemum morifolium Ramat (FCMR), the calyx of Hibiscus sabdariffa L. (CHSL) and roasted seed of Hordeum vulgare L. (RSHVL), which are commonly called Hang Chu, Lo Shen and Chao Mai in Taiwan, respectively, were investigated. FCMR, CHSL and RSHVL showed marked antioxidative activity, not only in linoleic acid but also in liposome model systems, indicating that the three herbal water extracts may protect the cell from damage by lipid peroxidation. FCMR, CHSL and RSHVL possessed high contents of phenolic compounds and exhibited reducing power, revealing that these herbal extracts may containreductones. The water extracts of the three herbs also showed good hydrogen-donating abilities, indicating that they had effective activities as radical scavengers. No mutagenicity in the water extracts of the three herbs was found in Salmonella typhimurium TA98 and TA100, either with or without S9 mix.
Publisher Summary This chapter discusses microsomal lipid peroxidation. Lipid peroxidation is a complex process known to occur in both plants and animals. It involves the formation and propagation of lipid radicals, the uptake of oxygen, a rearrangement of the double bonds in unsaturated lipids, and the eventual destruction of membrane lipids, producing a variety of breakdown products, including alcohols, ketones, aldehydes, and ethers. Biological membranes are often rich in unsaturated fatty acids and bathed in an oxygen-rich, metal-containing fluid. Lipid peroxidation begins with the abstraction of a hydrogen atom from an unsaturated fatty acid, resulting in the formation of a lipid radical. The formation of lipid endoperoxides in unsaturated fatty acids containing at least 3 methylene interrupted double bonds can lead to the formation of malondialdehyde as a breakdown product. Nonenzymic peroxidation of microsomal membranes also occurs and is probably mediated in part by endogenous hemoproteins and transition metals. The direct measurement of lipid hydroperoxides has an advantage over the thiobarbituric acid assay in that it permits a more accurate comparison of lipid peroxide levels in dissimilar lipid membranes.
Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) were evaluated for possible promoting activity for urinary bladder carcinogenesis in male F344 rats initiated by N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). The rats were treated with 0.01 or 0.05% BBN in the drinking water for 4 weeks and then administered 2% BHA or 1% BHT in the diet for 32 weeks. Surviving rats were killed at the end of week 36 of the experiment. The incidences of cancer and papilloma and the average number of cancers, papillomas and papillary or nodular hyperplasias (PN hyperplasias) per 10 cm of basement membrane were significantly increased in the group receiving BHA following initiation by 0.05% BBN compared with the group given BBN only. BHT also significantly increased these lesions of the bladder, but not the average number of cancers, in rats treated with 0.05% BBN. The ability of four antioxidants, BHA, BHT, sodium L-ascorbate (ascorbate) and ethoxyquin, to promote the induction of gamma-glutamyltranspeptidase (gamma-GT)-positive foci initiated by diethylnitrosamine (DENA) in the liver of F344 rats was tested. Rats were given a single i.p. injection of 200 mg/kg body weight of DENA, and 2 weeks later the animals were exposed to 2% BHA, 1% BHT, 5% ascorbate or 1% ethoxyquin, respectively, in the diet for 6 weeks. All animals were subjected to partial hepatectomy at the end of week 3. The number of gamma-GT-positive foci in the groups fed either BHA, BHT or ethoxyquin after DENA were significantly decreased compared with the control group. These findings show that BHA and BHT are promoters for the urinary bladder carcinogenesis initiated by BBN, but that these and other antioxidants significantly inhibit the induction of gamma-GT-positive foci in the liver.
Flavonoids are polyphenolic antioxidants naturally present in vegetables, fruits, and beverages such as tea and wine. In vitro, flavonoids inhibit oxidation of low-density lipoprotein and reduce thrombotic tendency, but their effects on atherosclerotic complications in human beings are unknown. We measured the content in various foods of the flavonoids quercetin, kaempferol, myricetin, apigenin, and luteolin. We then assessed the flavonoid intake of 805 men aged 65-84 years in 1985 by a cross-check dietary history; the men were then followed up for 5 years. Mean baseline flavonoid intake was 25.9 mg daily. The major sources of intake were tea (61%), onions (13%), and apples (10%). Between 1985 and 1990, 43 men died of coronary heart disease. Fatal or non-fatal myocardial infarction occurred in 38 of 693 men with no history of myocardial infarction at baseline. Flavonoid intake (analysed in tertiles) was significantly inversely associated with mortality from coronary heart disease (p for trend = 0.015) and showed an inverse relation with incidence of myocardial infarction, which was of borderline significance (p for trend = 0.08). The relative risk of coronary heart disease mortality in the highest versus the lowest tertile of flavonoid intake was 0.42 (95% CI 0.20-0.88). After adjustment for age, body-mass index, smoking, serum total and high-density-lipoprotein cholesterol, blood pressure, physical activity, coffee consumption, and intake of energy, vitamin C, vitamin E, beta-carotene, and dietary fibre, the risk was still significant (0.32 [0.15-0.71]). Intakes of tea, onions, and apples were also inversely related to coronary heart disease mortality, but these associations were weaker. Flavonoids in regularly consumed foods may reduce the risk of death from coronary heart disease in elderly men.
Jus hibiscus: bukan sekadar minuman biasa”, Dewan Ekonomi
- T B Muhammad
- A B Shakib
A Ray of Hope for Sufferers of Intractable Disease: The Amazing Effects of Out Developed Natural Antioxidants
- Y Niwa
The importance of roselle (Hibiscus sabdariffa L.) as a health food product
- S Yusof
- P L Tee
- P K Wong
- H M Ghazali