Oxidative Stability and alpha-Tocopherol Retention in Soybean Oil with Lemon Seed Extract (Citrus Limon) under Thermoxidation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Potencial antioxidante de extratos de sementes de limão (Citrus limon)

The present study aimed at evaluating the behavior of the soybean oil with the addition of lemon seed extracts (Citrus limon), in different concentrations, through oxidative stability and also at measuring the antioxidant activity using the DPPH free radical method and total phenolic compounds. The concentration of 2,400 mg.kg(-1) for the lemon seed extract, galego variety, was the one that provided the soybean oil with the best oxidative stability. The maximum antioxidant activities and the concentration values of the natural extract sufficient to obtain 50% of maximum effect, estimated at 100% (EC(50)), determined by DPPH for the extract and gallic acid were 70.58%, 69.94 mu g.mL(-1) and 75.07%, 64.73 mu g.mL(-1), respectively. The concentration of total phenolic compounds, determined by the Folin-Ciocalteu method, was of 76 mg.g(-1). Thus, it can be said that the lemon seed extract, galego, presents natural antioxidant action demonstrating potential to be used in foods.

Atividade antioxidante do extrato de sementes de limão (Citrus limon) adicionado ao óleo de soja em teste de estocagem acelerada

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biologia de Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) em limão siciliano (Citrus limon Burm)

No estudo da biologia de Polyphagotarsonemus latus em limão Siciliano, foram utilizados potes plásticos circulares com capacidade de 250 ml, contendo areia esterilizada como suporte para dois frutos novos com aproximadamente 2,0 cm de diâmetro. O ensaio foi conduzido a 27,1 ± 0,5°C, umidade relativa de 67,6 ± 1,3% e fotofase contínua. O período de ovo a adulto durou 3,7 ± 0,1 dias para fêmeas e 3,6 ± 0,1 dias para machos, com sobrevivência de 100%. Após um período de pré-oviposição de 1,0 ± 0,2 dias, as fêmeas depositaram 5,6 ± 0,5 ovos por dia durante 10,5 ± 0,9 dias, totalizando 58,9 ± 6,7 ovos por fêmea. A longevidade foi de 13,4 ± 1,0 dias para fêmeas e 12,0 ± 2,4 dias para machos. A razão intrínseca de aumento (rm) foi de 0,359, a razão finita de aumento (l) de 1,43 indivíduos por fêmea por dia, o tempo médio de uma geração (T) de 10,34 dias e a taxa líquida de reprodução (Ro) de 41,0.

Oxidative stability and α-tocopherol retention in soybean oil with lemon seed extract (Citrus limon) under thermoxidation

The synergistic effect of lemon seed extract with tert-butylhydroquinone (TBHQ) in soybean oil subjected to thermoxidation by Rancimat was investigated, and the influence of these antioxidants on α-tocopherol degradation in thermoxidized soybean oil. Control, LSE (2,400 mg/kg Lemon Seed Extract), TBHQ (50 mg/kg), Mixture 1 (LSE + 50 mg/kg TBHQ) and Mixture 2 (LSE + 25 mg/kg TBHQ) were subjected to 180°C for 20 h. Samples were taken at time 0, 5, 10, 15 and 20 h intervals and analysed for oxidative stability and α-tocopherol content. LSE and Mixtures 1 and 2 showed the capacity of retarding lipid oxidation when added to soya oil and also contributed to α-tocopherol retention in oil heated at high temperatures. However, Mixtures 1 and 2 added to the oil presented a greater antioxidant power, consequently proving the antioxidants synergistic effect.

Fatty acids profile and alteration of lemon seeds extract (Citrus limon) added to soybean oil under thermoxidation

This paper aimed at evaluating fatty acids profile and the total alteration of lemon seeds extract added to soybean oil under thermoxidation, verifying the isolated and synergistic effect of these antioxidants. Therefore, Control treatments, LSE (2,400 mg/kg Lemon Seeds Extract), TBHQ (mg/kg), Mixture 1 (LSE + 50 mg/kg TBHQ) and Mixture 2 (LSE + 25 mg/kg TBHQ) were subjected to 180 C for 20 h. Samples were taken at 0, 5, 10, 15 and 20 h intervals and analyzed as for fatty acid profile and total polar compounds. Results were subjected to variance analyses and Tukey tests at a 5% significance level. An increase in the percentage of saturated fatty acids and mono-unsaturated, and decrease in polyunsaturated fatty acids was observed, regardless of the treatments studied. For total polar compounds, it was verified that Mixtures 1 and 2 presented values lower than 25% with 20 h of heating, not surpassing the limits established in many countries for disposal of oils and fats under high temperatures, thus proving the synergistic effect of antioxidants. © 2011 Association of Food Scientists & Technologists (India).

Estabilidade oxidaditiva do óleo de soja adicionado de extrato de sementes de limão (Citrus limon)

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

Acceleration of the decomposition of Sicilian lemon leaves as an auxiliary measure in the control of citrus black spot

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

Phytochemicals and Antioxidant Activity of Citrus Seed Oils

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

Avaliação de métodos de inoculação de Phytophthora parasitica e mapeamento de QTLs de resistência em híbridos de Citrus sunki vs. Poncirus trifoliata a gomose

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Caracterização de Diaporthe citri em diferentes meios de cultura, condições de temperatura e luminosidade

Estudou-se o crescimento micelial de dez isolados de Diaporthe citri, utilizando-se seis meios de cultura (aveia-ágar, maltose-peptona-ágar, batata-dextrose-ágar, folha de laranja-dextrose-ágar, folha de limão-dextrose-ágar, milho-ágar) à temperatura de 22 ± 2 °C e fotoperíodo de 12 h claro/12 h escuro. O cultivo em meio de batata-dextrose-ágar (BDA) foi conduzido em cinco temperaturas diferentes (10, 15, 20, 25 e 30 °C). Três diferentes regimes de luminosidade (12 h claro/12 h escuro, claro contínuo, escuro contínuo) foram utilizados para verificar o crescimento do fungo. Foram observadas variações na produção de picnídios e de massa micelial nos diferentes meios de cultura, temperaturas e regimes de luminosidade testados, sendo que, para a maioria dos isolados, o meio de cultura de aveia-ágar, a faixa de 20 a 25 °C e o regime de claro contínuo induziram maior crescimento micelial. A produção de picnídios foi maior para o regime de luz contínua. O teste de patogenicidade foi feito por inoculação de discos de micélio de 5 mm de diâmetro em ferimentos em ramos e caule de limão 'Feminelo' (Citrus limon) enxertado em citrumelo 'Swingle'(Poncirus trifoliolata x Citrus paradisi) e plantas de limão 'Cravo' (C. limonia) enxertados com laranja 'Valência' (C. sinensis). Após sete dias, houve o aparecimento de exsudação de goma nas plantas inoculadas com os isolados, mas não na testemunha. Todos os isolados mostraram-se patogênicos, sendo os isolados PC2 e PC5, os que causaram comprimento de lesão maior nas plantas.

Preparo de amostras e métodos para a determinação do teor de óleo essencial de frutos de limoeiro

Objetivou-se avaliar alternativas de preparo da amostra e os métodos quantitativos para a determinação do teor de óleo em frutos de limão. Os tratamentos foram avaliados por meio do delineamento estatístico inteiramente casualizado, em esquema fatorial 2x2x6, com quatro repetições, sendo duas variedades-copa de limoeiro verdadeiro ('Siciliano' e 'Eureka'), dois métodos analíticos para a determinação do teor de óleo (Scott e Clevenger) e seis formas de preparo dos frutos para análise (análise do fruto inteiro; frutos cortados na longitudinal e análise de ¼; frutos cortados na longitudinal e análise de ¹/2; frutos cortados ao meio e análise da parte superior; frutos cortados ao meio e análise da parte inferior; e análise de ²/8 do fruto). O método denominado de Clevenger foi o mais eficiente na determinação do teor de óleo essencial, e as formas de preparo de amostras ½ inferior, ½ superior, ¼ longitudinal e ½ longitudinal dos frutos proporcionaram valores superiores de óleo essencial.

Effect of heated solutions on decay control and residues of imazalil in lemons

Freshly harvested lemons [(Citrus limon (L.) Burm)] were dipped 3 min in water with and without imazalil (IMZ) at 50, 100, and 200 ppm at 50 degrees C and at 1000 ppm IMZ at 20 degrees C. Following treatments fruit were kept at 9 degrees C and 90%-95% relative humidity (RH) for 13 weeks and an additional week at 21 degrees C and ca. 75% RH, to simulate a marketing period (SMP). No decay control was observed with fruit dipped in water at 50 degrees C. In contrast, IMZ treatments provided 90%-96% control of Penicillium rots during cold storage and SMP. Fungi other than Penicillium spp. were also found in all samples as differences among treatments were negligible. IMZ treatment caused some external damage to the fruit (peel browning), and the percentage of damaged fruit was related to the amount of active ingredient (AI) present in it. Dipping in 200 or 1000 ppm IMZ promoted off-flavor development after 10 weeks of storage, and fruit were judged to be unacceptable for consumption after 13 weeks of cold storage. After 1000 ppm IMZ dipping at 20 degrees C, residue concentration in fruit was 8.20 ppm; this value doubled that found in a previous investigation on lemons treated with comparable IMZ levels. Residue concentrations in fruit after treatment at 50 degrees C was strictly related to the amount of fungicide employed. After 13 weeks Al residues in fruit decreased to average ca. 35% of the initial values. During the 1 week SMP, residue levels decreased by a further ca. 25%. It was concluded that it is possible to achieve significant control of decay in lemons during longterm storage by dipping fruit in 50 ppm IMZ mixtures at 50 degrees C. Such treatment should be advised to remarkably reduce potential pollution in the environment due to packinghouse wastewater disposal.

Eficiência de extratos de plantas medicinais e aromáticas em atrair a abelha africanizada (Apis mellifera L.) em cultura de abacateiro (Persea americana Mili.)

The objective of the experiment was to test attractive substances for Africanized honey bees, Apis mellifera L., in avocado, Persea americana Mill. Were pulverized extracts of lemon grass (Cympobogon citratus), ocimum (Ocimum sellowii), Lippia alba, orange leaves (Citrus sinensis), eucaliptus leaves (Eucalyptus sp), eugenol and linalol and the frequency of bees on flowers were evaluated. The frequency of honey bees did increase with the application of the extracts falsa melissa, eucaliptus leaves and orange leaves, used as attractants in Quintal variety. The products tested in Eppendorf tubes did not increased the frequency the bees in Quintal and Fortuna varieties.

Metabolite profiles of essential oils in citrus peels and their taxonomic implications

China is an important center of origin for the genus Citrus L. of the family Rutaceae and is rich in wild Citrus species. The taxonomy of Citrus has been a subject of controversy for more than a half century. We propose that the metabolite profiles of Chinese native Citrus species can be used for classification and understanding of the taxonomic relationships within the Citrus germplasm. In this study, triplicate gas chromatography-mass spectrometry (GC-MS) metabolite profiles of 20 Citrus species/varieties were acquired, including 10 native varieties originating in China. R-(+)-limonene, alpha-pinene, sabinene and alpha-terpinene were found to be major characteristic components of the essential oils analyzed in this study, and these compounds contributed greatly to the metabolic classification. The three basic species of the subgenus Eucitrus (Swingle's system), i.e., C. reticulata Blanco, C. medica L. and C. grandis Osb., were clearly differentiated based upon their metabolite profiles using hierarchical cluster analysis (HCA) and partial least square-discriminant analysis (PLS-DA). All the presumed hybrid genotypes, including sweet orange (C. sinensis Osb.), sour orange (C. aurantium L.), lemon (C. limon Burm.f.), rough lemon (C. jambhiri Lush.), rangpur lime (C. limonia Osb.) and grapefruit (C. paradisi Macf.), were grouped closely together with one of their suggested parent species in the HCA-dendrogram and the PLS-DA score plot. These results clearly demonstrated that the metabolite profiles of Citrus species could be utilized for the taxonomic classification of the genus and are complementary to the existing taxonomic evidence, especially for the identification and differentiation of hybrid species.