Yellow passion fruit seed oil (Passiflora edulis f. flavicarpa): physical and chemical characteristics

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fruit quality of 'Tahiti' lime (Citrus latifolia Tanak) grafted on twelve different rootstocks

No presente trabalho, avaliou-se a influência de doze porta-enxertos sobre a qualidade dos frutos da lima-ácida 'Tahiti' (Citrus latifolia Tanaka), clone 'IAC-5', amostrados em duas posições nas plantas, em experimento conduzido na Estação de Citricultura de Bebedouro, em um pomar de três anos. O espaçamento utilizado foi de 8.0 x 5.0m. Os porta-enxertos utilizados foram: citrangeiro 'Carrizo' (C. sinensis (L.) Osbeck x Poncirus trifoliata (L.) Raf.); os híbridos 'Cravo' x 'Swingle' (C. limonia Osbeck x P. trifoliata (L.) Raf. x C. paradisi Macf.) e 'Changsha' x 'English Small' (C. sunki Hort. ex Tan. x P. trifoliata Raf.); as tangerineiras 'Sun Chu Sha Kat' (C. reticulata Blanco) e 'Sunki' (C. sunki Hort. ex Tanaka); os limoeiros 'Cravo Limeira' e 'Cravo FCAV' (C. limonia Osbeck); o citrumeleiro 'Swingle' (P. trifoliata Raf. x C. paradisi Macf.), o tangeleiro 'Orlando' (C. reticulata Blanco x C. paradisi Macf.) e os trifoliateiros 'Rubidoux', 'FCAV' e 'Flying Dragon' (Poncirus trifoliata Raf.). Foi utilizado um delineamento em blocos casualizados, com doze tratamentos e seis repetições. Os distintos porta-enxertos induziram diferenças na qualidade dos frutos, entretanto todas as características de qualidade foram consideradas aceitáveis para a variedade, sendo bons substitutos para o limão 'Cravo'.

Effect of drying method on the adsorption isotherms and isosteric heat of passion fruit pulp powder

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reguladores vegetais e o desbaste químico de frutos de tangor murcote

O tangor 'Murcote' apresenta necessidade de desbaste de frutos devido a alternância de produção, caracterizado por anos de excessiva produção intercalado com anos de baixa produção, evitando assim, a diminuição da qualidade dos frutos. O presente trabalho teve por objetivo avaliar a eficiência de reguladores vegetais, a auxina ANA (ácido naftalenacético) e ethephon (etileno) no desbaste químico de frutos de tangor 'Murcote' aplicado 40 dias após o pleno florescimento. O experimento foi conduzido em Pratânia, SP, onde plantas de 5 anos de idade, enxertadas sobre o limoeiro 'Cravo', foram pulverizadas com ANA a 0, 100, 200, 300 e 400 mg L-1 e com ethephon a 200, 300 e 400 mg L-1, ambos em solução aquosa juntamente com adjuvante não iônico a 0,05%. A contagem dos frutos foi realizada previamente aos tratamentos em 2 ramos marcados por planta. O ANA não interferiu significativamente no desbaste de frutos, com porcentagens de queda variando entre 7 a 14%, enquanto que as pulverizações com ethephon mostraram maior eficiência no desbaste de frutos, principalmente na dose de 400 mg L-1, promovendo 66,6% de queda de frutos, sem contudo induzir a abscisão foliar. As doses inferiores de ethephon também promoveram desbaste de frutos da ordem de 40%. As porcentagens de queda de frutos foram pequenas, para plantas pulverizadas com ANA, enquanto que a aplicação de ethephon promoveu maior eficiência no desbaste de frutos.

Cultivar affects browning susceptibility of freshly cut star fruit slices

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Water adsorption isotherms and isosteric sorption heat of spray-dried and freeze-dried dehydrated passion fruit pulp with additives and skimmed milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fluorometric fiber optic drop sensor for atmospheric hydrogen sulfide

A fluorometric technique based on a liquid drop excited from its interior by an optical fiber is described for the measurement of low concentrations of atmospheric hydrogen sulfide (H2S). A drop of alkaline fluorescein mercuric acetate (FMA) solution is suspended in a flowing air sample stream and serves as a renewable sensor. An optical fiber contained within the conduit that forms the drop, brings in the excitation beam; the fluorescence emission is measured by an inexpensive photodiode positioned close to the drop. As H2S in the sample is collected by the alkaline drop, it reacts rapidly with FMA resulting in a significant decrease in fluorescence intensity, proportional to the concentration of H2S sampled. The chemistry of this uniquely selective reaction has been well established for many years, the present technique permits a simple fast inexpensive near real-time measurement with very little reagent consumption. Even without prolonged sampling/preconcentration steps, limits of detection (LODs) in the double digit ppbv range is readily attainable. (C) 1997 Elsevier B.V. B.V.

Cathodic stripping voltammetric determination of ceftazidime in urine at a hanging mercury drop electrode

A method was developed for the differential-pulse cathodic stripping voltammetric determination of ceftazidime with a hanging mercury drop electrode using its reduction peak at -0.43 V in Britton-Robinson buffer pH 4.0. The optimum accumulation potential and time were -0.15 V and up to 60 s, respectively. Linear calibration graphs were obtained from 1 x 10(-8) M and 1.5 x 10(-7) M. The limit of determination was calculated to be 5 x 10(-9) M. The coefficient of variation was 4% (n = 7) at 1 x 10(-7) M ceftazidime. The effect of various components of urine on the voltammetric response was studied, and creatinine, uric acid, urea, and glucose were shown to interfere in the method. Ceftazidime bound to human albumin gives a unique stripping peak at -0.48 V. Recoveries of 87% +/- 2% of the ceftazidime (n = 5) were obtained from urine spiked with 1.27 mu g ml(-1) using C-18 solid phase extraction cartridges. (C) 1997 Academic Press.

Colorimetric determination of formaldehyde in air using a hanging drop of chromotropic acid

A simple and sensitive method to determine parts per billion (ppb) of atmospheric formaldehyde in situ, using chromotropic acid, is described. A colorimetric sensor, coupled to a droplet of 15.5 muL chromotropic acid, was constructed and used to sample and quantify formaldehyde. The sensor was set up with two optical fibers, a right emitting diode (LED) and two photodiodes. The reference and transmitted light were measured by a photodetection arrangement that converts the signals into units of absorbance. Air was sampled around the chromotropic acid droplet. A purple product was formed and measured after the sampling terminated (typically 7 min). The response is proportional to the sampling period, analyte concentration and sample flow rate. The detection limit is similar to2 ppb and can be improved by using longer sampling times and/or a sampling flow rate higher than that used in this work, 200 mL min(-1). The present technique affords a simple, inexpensive near real-time measurement with very little reagent consumption. The method is selective and highly sensitive. This sensor could be used either for outdoor or indoor atmospheres.

Activity of pectinmethylesterase, pectin content and vitamin C in acerola fruit at various stages of fruit development

In order to know which stage of fruit development is better for acerola industrialization, we studied the PME specific activity, pectin content and vitamin C at various stages of development. The acerola fruits were classified according to colour and weight in five stages: immature green (2.62-3.21 g), green (4.04-4.83 g), mature green/yellow (5.03-5.88 g), pale-red (6.16-6.77 g) and ripe mature (6.92-8.37 g). The results showed that the highest content of pectin and vitamin C occurred at the immature green stage, 4.51 +/- 0.1% yield, 2424 mg/100 g of pulp and decreased as fruit ripened, 2.99 +/- 0.03% yield, 957 +/- 0.0 mg/100 g of pulp, respectively. However, at the same stages, the values of PME specific activity were lowest, 0.61 +/- 0.01 and 0.55 +/- 0.0 units g(-1)/g of pulp, respectively. The highest value of PME activity was 2.08 +/- 0.01 units g(-1)/g of pulp in the green stage. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Cathodic stripping voltammetric detection and determination at a hanging mercury-drop electrode of dye contaminants in purified biomaterials: study of the human serum albumin and reactive dye 120 system

Procion red HE-3B (RR120) is an example of dye currently used in affinity purification. A method is described for determining trace amounts of RR120 dye contaminant in human serum albumin by cathodic stripping voltammetry. The method is based on a measure of a well-defined peak at -0.58 V, obtained when samples of HSA protein (0.01-2% w/v) containing dye concentrations are submitted to a heating time of 330 min at 80degreesC in NaOH, pH 12.0 and the samples are removed to a solution containing Britton-Robinson buffer, pH 4.0. Using an optimum accumulation potential and tune of 0 V and 240 s, respectively, linear calibration curves were obtained from 1.0 X 10(-9) to 1.0 X 10(-8) mol 1(-1) for RR120 dye. Leakage/hydrolysis of reactive red 120 from an agarose support (e.g. at pH 2 or 12) can also be conveniently determined at very low levels (sub-mug ml(-1)) by means of cathodic stripping voltammetry, which involves adsorptive accumulation of the dye onto the hanging mercury-drop electrode. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Cathodic stripping voltammetric determination of ceftazidime with reactive accumulation at a poly-L-lysine modified hanging mercury drop electrode

Ceftazidime is hydrolysed only slowly at pH 10 at room temperature. This is indicated by a small cathodic stripping voltammetric peak obtained at pH 10 at a hanging mercury drop electrode at about -0.6 V which corresponds to the reduction of the hydrolysis product. This peak is enhanced more than tenfold by the addition of poly-L-lysine (PLL) to the electrolyte solution. The optimum accumulation potential is between 0 and -0.1 V: the size of the peak decreases steadily, however, as the accumulation potential is moved to more negative potentials and is about one-sixth the size for accumulation at -0.4 V. Existing knowledge of the organic chemistry of cephalosporins indicates that the accumulation must involve an aminolysis reaction of the unprotonated PLL with the beta-lactam ring of the ceftazidime. The limit of detection (3 sigma) in standard solutions was calculated to be 1 x 10(-10) mol l(-1). The detection limit in buffer solution containing 1% of urine was calculated to be 5 x 10(-9) mol l(-1), i.e. 5 x 10(-6) mol l(-1) in the urine. (C) 1999 Elsevier B.V. B.V. AU rights reserved.

Influence of two methods of CaCl2 application and concentrations used to maintain passion fruit firmness

This is a report on the influence of the methods of postharvest application of CaCl2 in several concentrations, on the maintenance of the firmness of the sweet passion fruit (Passiflora alata Dryander). The fruits, picked in the pre-climateric stage, were selected desinfection with thiabendazol and submitted to CaCl2 in concentrations of 0% (control), 1%, 2%, 3% or 4% with two methods: immersion (for 2 h) and infiltration under vacuum and pressure (- 25 vacuum kPa, for 1 minute and, + 25 pressure kPa, for 1 min). All fruits were stored under refrigeration (9 degreesC, 85-90% RH), for 30 d. The fruits were evaluated for texture every 3 d. From the results, it is concluded that application of CaCl2 by infiltration favored the maintenance of fruit consistency during the first 18 days of storage. Fruits treated with 1% and 2% of CaCl2 were firmer than the others.

Persistence of some pesticides in peach fruit

The persistence of five pesticides (acephate, azinphos methyl, carbendazim, diazinon and dimethoate) in peach fruit was studied in real operating conditions. Pesticides showed different degradation rates. Diazinon was degraded with a half-life (t(1/2)) of 5.2 days, acephate, azinphos methyl and dimethoate with t(1/2) of ca 12 days and carbendazim with t(1/2) of 15.5 days. After the pre-harvest interval (PHI) all pesticide residues were within the limits established by Italian law.