Studies on the extraction and characterization of pectin and bitter principles from New Zealand grapefruit and Philippine calamansi : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Food Technology at Massey University

A study was conducted to determine the presence of bitter components in NZ grapefruit and Philippine calamansi; describe the effect of maturity on the bitter components and other chemical constituents of grapefruit; reduce the bitterness of grapefruit juice by adsorption on polyvinylpyrrolidone; and to extract and characterize pectin from grapefruit peel. Naringin (995 PPm), narirutin (187 ppm), and limonoids (7.9 ppm) were detected in NZ grapefruit juice concentrate (27° Brix). Naringin was not detected in the calamansi juice, and limonin was detected at the level of 10.5 ppm in juice containing 5% crushed seeds. Maturation of the grapefruit caused an increase in pH from 3.00 to 3.50, an increase in total soluble solids from 10.8 to 14.4 with a decline to 13.5° Brix later in the season, a steady fall in acidity from 2.50 to 1.31 g citric acid/100 mL, and a continuous rise in the Brix/acid ratio from 4.2 to 10.3. Juice yield fluctuated throughout the season. Ascorbic acid remained fairly steady in the early and mid-season fruit but decreased in the late-season fruit. Naringin content was highest at the beginning of the season and fluctuated throughout the season. Naringin content in the grapefruit peel remained constant as the fruit matured. Narirutin was detected in the early-season fruit but disappeared later in the season. Limonoid content in both unpasteurized and pasteurized juices decreased with ripening. The use of polyvinylpyrrolidone significantly reduced naringin in grapefruit juice by up to 78.1% and limonin by up to 17.5% depending on the amount and reaction time of the adsorbent. A loss of 23.1% in ascorbic acid occurred with 5% PVP with a reaction time of 1 h. Pectin extraction at 85°C and the use of acidified isopropyl alcohol yielded a product with the following characteristics: 8.9% yield; 1.3% moisture content; 1.9% ash; 759 equivalent weight; 9.2% methoxyl content; 82.2% anhydrogalacturonic acid; 63.2% degree of esterification; 4.2 intrinsic viscosity; 89,362 molecular weight and setting time of 0.55 minute

Effects of Polyphenols on Oxidative Stress-Mediated Injury in Cardiomyocytes

Cardiovascular diseases are the main cause of mortality and morbidity in the world. Hypertension, ischemia/reperfusion, diabetes and anti-cancer drugs contribute to heart failure through oxidative and nitrosative stresses which cause cardiomyocytes nuclear and mitochondrial DNA damage, denaturation of intracellular proteins, lipid peroxidation and inflammation. Oxidative or nitrosative stress-mediated injury lead to cardiomyocytes apoptosis or necrosis. The reactive oxygen (ROS) and nitrogen species (RNS) concentration is dependent on their production and on the expression and activity of anti-oxidant enzymes. Polyphenols are a large group of natural compounds ubiquitously expressed in plants, and epidemiological studies have shown associations between a diet rich in polyphenols and the prevention of various ROS-mediated human diseases. Polyphenols reduce cardiomyocytes damage, necrosis, apoptosis, infarct size and improve cardiac function by decreasing oxidative stress-induced production of ROS or RNS. These effects are achieved by the ability of polyphenols to modulate the expression and activity of anti-oxidant enzymes and several signaling pathways involved in cells survival. This report reviews current knowledge on the potential anti-oxidative effects of polyphenols to control the cardiotoxicity induced by ROS and RNS stress

Supercritical fluid coating of API on excipient enhances drug release

A process to coat particles of active pharmaceutical ingredient (API) onto microcrystalline cellulose (MCC) excipient shows promise as a new way to dosage forms showing enhanced drug release. The process consists of a fluidized bed operated at elevated pressure in which API particles are precipitated from a Supercritical Anti-Solvent process (SAS). MCC particles were used as an excipient in the fluidized bed and collect the SAS-generated API particles. Naringin was selected as the model API to coat onto MCC. A number of operational parameters of the process were investigated: fluidization velocity, coating pressure, temperature, concentration of drug solution, drug solution flow rate, drug mass, organic solvent, MCC mass and size and CO2-to-organic solution ratio. SEM and SPM analyses showed that the MCC particle surfaces were covered with near-spherical nanoparticles with a diameter of approximately 100–200 nm, substantially smaller than the as-received API material. XRD showed that naringin changed from crystalline to amorphous during processing. The coated particles resulting from the SAS fluidized bed process have a higher loading of API, gave faster release rates and higher release ratios in comparison with those produced using a conventional fluidized bed coating process. The approach could be transferred to other industries where release is important such as agrochemical, cosmetic and food

Inactivation of Escherichia coli ATCC 25922 and Saccharomyces cerevisiae IMR-R-L 962 in grapefruit [Citrus paradisi (Macf.)] juice by UV-C light: changes in bioactive compounds and quality characteristics

The viability of UV-C treatment (0.0-2.36 J/cm²) at 254 nm as a non-thermal preservation process for grapefruit juice on microbial inactivation, the organic acids and individual flavonoids, as well as the quality characteristics (pH, ºBrix, titratable acidity, colour, total phenolics and antioxidant capacity) was evaluated. Additionally, pectin methylesterase (PME) activity was also measured. The effects of UV-C on microbial inactivation were assessed by kinetic studies on the inactivation of inoculated grapefruit juice with one strain of Escherichia coli ATCC 25922 and one strain of Saccharomyces cerevisiae IMR-R-L 962. The suitability of Weibull distribution and modified Gompertz models was analysed to characterise the UV-C inactivation kinetics for E. coli and S. cerevisiae in freshly squeezed grapefruit juice. Likewise, the changes after UV-C treatment in citric (CA), malic (MA), ascorbic (AA) and tartaric (TA) acids, as well as naringin (NAR), hesperidin (HES) and neohesperidin (NEO), were quantified by HPLC, whereas the total phenolics and antioxidant capacity (DPPH? and ABTS?+) were quantified by spectrophotometric methods. Nonlinear inactivation curves were successfully fitted with Weibull-type and modified Gompertz models. However, the Gompertz model allowed a better fit and more accurate estimation of the parameters. UV-C treatment at 1.83 J/cm² achieved a 5.18 ± 0.01 and 2.7 ± 0.15 log CFU/mL reduction in E. coli and S. cerevisiae, respectively, whereas no significant changes occurred in CA, MA, TA, NAR, HES, NEO, total phenolics, ABTS?+, pH, ºBrix, titratable acidity and colour of the grapefruit juices (p>0.05). However, PME was partially inhibited and the AA level and DPPH? decreased significantly after treatment, with losses up to 15.9 and 8% (at 1.83 J/cm²), respectively, which were associated with the UV-C dose intensity.Fil: la Cava, Enzo Luciano Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Sgroppo, Sonia Cecilia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentin

New fungal sources for α-L-Rhamnosidase: an important enzyme used in the synthesis of drugs and drug precursors

Two fungal strains were isolated and tentatively identified as Penicillium VY and Aspergillus VY. All the isolated species show the maximum production on third day in a liquid culture media. The pH optimum was found to be 10.0 for Penicillium VY and 11.0 for Aspergillus VY. The temperature optima were 50ºC in both the cases. The enzyme produced by Penicillium VY was found to be stable in the pH range 3.0-7.0 and 3.0–6.0 in case of Aspergillus VY. The enzyme does not loose activity up to 40º C in case of Penicillium VY and 40ºC in case of Aspergillus VY if exposed for 1 h.
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The influence of naringin or hesperidin dietary supplementation on broiler meat quality and oxidative stability

An experiment was conducted to examine the effects of supplementing broiler feed with hesperidin or naringin, on growth performance, carcass characteristics, breast meat quality and the oxidative stability of breast and thigh meat. Two hundred and forty 1-day-old Ross 308 broiler chickens were randomly assigned to 6 groups. One of the groups served as a control (C) and was given commercial basal diets, whereas the other five groups were given the same diets further supplemented with naringin at 0.75 g/kg (N1), naringin at 1.5 g/kg (N2), hesperidin at 0.75 g/kg (E1), hesperidin at 1.5 g/kg (E2) and a-tocopheryl acetate at 0.2 g/kg (E). At 42 days of age, 10 chickens per treatment group were slaughtered for meat quality and oxidative stability assessment. No significant differences were observed among groups in final body weight, carcass weight and internal organs weights (P>0.05) apart from liver that decreased linearly with increased levels of naringin (P-linear0.05). Measurement of lipid oxidation values showed that after hesperidin and naringin dietary supplementation, malondialdehyde values decreased in tissue samples in a dose depended manner (P-linear<0.05). In conclusion, hesperidin and naringin, positively influence meat antioxidative properties without negative implications on growth performance and meat quality characteristics in poultry, thus appearing as important additives for both the consumer and the industry

Pretreatment of citrus by-products affects polyphenol recovery:a review

A large amount of citrus waste is generated annually. This waste is of great economic worth, since it contains high levels of polyphenols, which have attracted scientific interest due to their potent antimicrobial and antiradical activities. Pretreatment is a crucial step that precedes the extraction process and influences the yields and quality of polyphenols. This review emphasizes the effect of different drying processes, such as freeze drying, hot-air drying, vacuum drying, microwave drying, infrared drying, and high-speed drying, on the polyphenol retention in citrus by-products. Further treatments of the dried citrus by-products for assisting the liberation of bound polyphenols are also provided and comprehensively discussed

Escobajos de la vid como fuente de compuestos fenólicos con propiedades antioxidantes

Winemaking industry generates considerable amounts of bunch stems that are usually wasted despite their potential value as source of bioactive compounds. Phenolic profiles and antioxidant capacity (AC) of bunch stem extracts from eight grape varieties of Vitis vinifera L. were determined. Sixteen phenolic compounds (PC) were quantified by high performance-liquid chromatography-diode array detection (HPLC-DAD). The maximum concentrations corresponded to the flavanols (+)-catechin (6462 μg g-1 DW) and procyanidin B1 (1987 μg g-1 DW), followed by the hydroxycinnamic acid caftaric acid (2967 μg g-1 DW). Naringin, myricetin and OH-tyrosol were identified for the first time in grape bunch stems. Total phenolic content (TPC) of extracts, assessed as gallic acid equivalents (GAE), ranged between 47 and 125 mg GAE g-1 DW. The AC of extracts was appraised by ORAC, ABTS and DPPH assays, with a good correlation between TPC and AC when measured by ABTS and DPPH (r ≥ 0.92), while for ORAC the correlation was lower (r ≤ 0.41). Samples of cv. Malbec, the most representative variety of Argentina, presented the highest contents in PC, particularly flavanols. The results showed that grape bunch stems may be an inexpensive, sustainable and high value source of bioactive compounds as functional ingredients.La industria vitivinícola genera cantidades considerables de escobajo que generalmente se desperdician a pesar de su valor potencial como fuente de compuestos bioactivos. En este trabajo se determinaron los perfiles fenólicos y capacidad antioxidantes (CA) de extractos de escobajo de ocho variedades diferentes de Vitis vinífera L. Se cuantificaron 16 compuestos fenólicos (PC) utilizando cromatografía líquida de alta resolución acoplada a detector de arreglo de diodos (HPLC-DAD). Las concentraciones más elevadas obtenidas correspondieron a los flavanoles (+)-catequina (6462 μg g-1 peso seco) y procianidina B1 (1987 μg g-1 peso seco), seguido del ácido caftárico (2967 μg g-1 peso seco). La naringenina, miricetina y OH-tirosol fueron identificados por primera vez en escobajos. El contenido total de compuestos fenólicos (TPC) de los extractos determinado con equivalentes de ácido gálico (GAE) presentó valores entre 47 y 125 mg GAE g-1 peso seco. La CA de los extractos fue determinada mediante las técnicas ORAC, ABTS y DPPH, evidenciando una buena correlación entre TPC y la CA medida mediante ABTS y DPPH (r ≥ 0,92), mientras que para ORAC la correlación fue más baja (r ≤ 0,41). La muestra de variedad más representativa de Argentina, cv. Malbec, presentó los mayores niveles de PC, particularmente flavanoles. Los resultados evidencian que los escobajos pueden ser una fuente económica, sostenible y de alto valor de compuestos bioactivos para su utilización como ingredientes funcionales.Fil: Ferreyra, Susana Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Bottini, Ambrosio Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina. Universidad "Juan Agustín Maza"; ArgentinaFil: Fontana, Ariel Ramón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentin