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

The aim of this work was to evaluate antioxidant activity of lemon seeds added to soybean oil, submitted to accelerated incubator-storage test and to determine its synergistic effect with the synthetic antioxidant TBHQ. The treatments Control, TBHQ (50 mg/kg), LSE (2,400 mg/kg Lemon Seed Extract), Mixture 1 (LSE + 50 mg/kg TBHQ) and Mixture 2 (LSE + 25 mg/kg TBHQ) were prepared and subjected to the accelerated incubator-storage test at 60 ºC for 12 days; samples were taken every 3 days and analyzed regarding peroxide value and conjugated dienes. The results showed that antioxidant activity of the tested treatments were: TBHQ = Mixture 1 = Mixture 2 > LSE > Control.

Composição química e atividade anticolinesterásica de uma fração ativa do extrato de folhas de Citrus limon (L.) Burm

This paper describes the chemical composition and acetylcholinesterase inhibition of an active chromatographic fraction of the EtOAc extract of Citrus limon leaves. The composition of the active fraction presented a mixture of two coumarins, 5,8-dimethoxy-psoralen and 5,7- dimethoxycoumarin, identified by ¹H and ¹³C NMR data analysis, including DEPT, COSY, HMBC and HSQC experiments. It was also demonstrated that this mixture presents qualitative and quantitative AChE inhibition. In vitro studies indicated a CE50 value of 340 µg/mL with 95% of confidence. In vivo studies (10 and 25 mg/kg) revealed inhibition of 30.09 and 30.06% of AChE activity in relation to neostigmine, respectively.

Caracterização dos óleos das sementes de limão rosa (Citrus limonia Osbeck) e limão siciliano (Citrus limon), um resíduo agroindustrial

A finalidade deste estudo foi caracterizar os óleos extraídos das sementes de limão rosa e limão siciliano, como aproveitamento de resíduos industriais. Foram determinados os índices de iodo, ácidos graxos livres (AGL,% em ácido oléico) e teor de peróxidos. Foram realizadas análises termoanalíticas (termogravimetria, TG; termogravimetria diferencial, DTG e calorimetria diferencial exploratória, DSC); espectroscópicas (infravermelho e ultravioleta) e cromatográficas (cromatografia gasosa). Foram identificados no óleo das sementes de limão rosa os seguintes ácidos graxos na forma de ésteres metílicos: caprílico (0,90%), palmítico (21,40%), esteárico (2,60%), oléico (21,20%), linoléico (43,00%), linolênico (7,60%) e araquídico (0,20%) e no óleo das sementes de limão siciliano: caprílico (1,00%), mirístico (0,10%), palmítico (19,60%), esteárico (3,00%), oléico (28,60%), linoléico (34,40%), linolênico (10,00%) e araquídico (0,20%). Os resultados indicaram que ambos os óleos apresentam estabilidade térmica até 250ºC, composição química semelhante e alto teor de ácidos graxos insaturados (71,80 e 73,00%). Pela composição de ácidos graxos também foi possível determinar a provável composição em triacilgliceróis dos óleos. Os resultados mostraram que os óleos apresentam características semelhantes a óleos comestíveis de boa qualidade.

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

O presente trabalho teve como principais objetivos avaliar o comportamento do óleo de soja acrescido de extratos de sementes de limão (Citrus limon), em diferentes concentrações, por meio da estabilidade oxidativa e medir a atividade antioxidante através do método do radical livre DPPH e compostos fenólicos totais. A concentração de 2.400 mg.kg-1 para o extrato de sementes de limão, variedade galego, foi a que conferiu melhor estabilidade oxidativa ao óleo de soja. As atividades antioxidantes máximas e os valores da concentração de extrato natural suficientes para obter 50% do efeito máximo, estimado em 100% (EC50), determinados pelo DPPH para o extrato e ácido gálico foram 70,58%, 69,94 μg.mL-1 e 75,07%, 64,73 μg.mL-1, respectivamente. A concentração de compostos fenólicos totais, determinada pelo método de Folin-Ciocalteu foi de 76 mg.g-1. Foi possível concluir que o extrato de sementes de limão galego possui ação antioxidante natural, podendo ser aplicado em alimentos.

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)

Efficacy of a Nasal Spray from Citrus limon and Cydonia oblonga for the Treatment of Hay Fever Symptoms - A Randomized, Placebo Controlled Cross-Over Study

Nasal spray from lemon and quince (LQNS) is used to treat hay fever symptoms and has been shown to inhibit histamine release from mast cells in vitro. Forty-three patients with grass pollen allergy (GPA) were randomized to be treated either with placebo or LQNS for one week, respectively, in a cross-over study. At baseline and after the respective treatments patients were provoked with grass pollen allergen. Outcome parameters were nasal flow measured with rhinomanometry (primary), a nasal symptom score, histamine in the nasal mucus and tolerability. In the per protocol population absolute inspiratory nasal flow 10 and 20 min after provocation was higher with LQNS compared to placebo (-37 ± 87 mL/s; p = 0.027 and -44 ± 85 mL/s; p = 0.022). The nasal symptom score showed a trend (3.3 ± 1.8 in the placebo and 2.8 ± 1.5 in the LQNS group; p = 0.070) in favor of LQNS; the histamine concentration was not significantly different between the groups. Tolerability of both, LQNS and placebo, was rated as very good. LQNS seems to have an anti-allergic effect in patients with GPA. Copyright © 2016 John Wiley & Sons, Ltd.

Impact of different solvents on the recovery of bioactive compounds and antioxidant properties from lemon (Citrus limon L.) pomace waste

The effects of different solvents on the recovery of (i) extractable solids (ES), (ii) total phenolic compounds (TPC), (iii) total flavonoid content (TFC), (iv) vitamin C, and (v) antioxidant activity from lemon pomace waste were investigated. The results revealed that solvents significantly affected the recovery of ES, TPC, TFC, and antioxidant properties. Absolute methanol and 50% acetone resulted in the highest extraction yields of TPC, whereas absolute methanol resulted in the highest extraction of TFC, and water had the highest recovery of vitamin C. 50% ethanol, and 50% acetone had higher extraction yields for TPC, and TFC, as well as higher antioxidant activity compared with their absolute solvents and water. TPC and TFC were shown to be the major components contributing to the antioxidant activity of lemon pomace.

Enhancement of the total phenolic compounds and antioxidant activity of aqueous Citrus limon L. pomace extracts using microwave pre-treatment on the dry powder

The effect of microwave pre-treatment on the levels of total phenolic compounds, flavonoids, proanthocyanidins and individual major compounds as well as the total antioxidant activity of the dried lemon pomace was investigated. The results showed that microwave pre-treatment significantly affected all the examined parameters. The total phenolic content, total flavonoids, proanthocyanidins, as well as the total antioxidant activity significantly increased as the microwave radiation time and power increased (e.g., 2.5 folds for phenolics, 1.4 folds for flavonoids and 5.5 folds for proanthocyanidins), however irradiation more than 480 W for 5 min resulted in the decrease of these parameters. These findings indicate that microwave irradiation time and power may enhance higher levels of the phenolic compounds as well as the antioxidant capacity of the dried lemon pomace powder. However, higher and longer irradiation may lead to a degradation of phenolic compounds and lower the antioxidant capacity of the dried lemon pomace.

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)