Rogério Luis Cansian

EVALUATION OF ORIGANUM VULGARE ESSENTIAL OIL AS ANTIMICROBIAL AGENT IN SAUSAGE

This work reports antimicrobial activity of oregano (Origanum vulgare) essential oil against several bacteria in sausage. The in vitro minimum inhibitory concentration (MIC) was determined for 9 selected aerobic heterotrofic bacteria. The antimicrobial activity of distinct concentrations of the essential oil on the basis of the highest MIC found was tested in a food system comprised of fresh sausage. Batch food samples were also inoculated with Escherichia coli with a fixed concentration and the time course of the product was evaluated with respect to the action of the different concentrations of essential oil. Sensory analysis were conducted, and results showed that the addition of oregano essential oil to sausage may be a promising route as bacteriostatic effect was verified for oil concentrations lower than the MIC.

Insecticidal and repellency activity of essential oil of Eucalyptus sp. against Sitophilus zeamais Motschulsky (Coleoptera, Curculionidae).

BACKGROUND The objective of this work was to evaluate the insecticidal and repellent effect of essential oils of Eucalyptus dunnii, E. saligna, E. benthamii, E. globulus and E. viminalis in the control of Sitophilus zeamais in maize grains. RESULTS The essential oils chemical composition showed that the E. benthamii presents the cis-ocimene (56.88%) as major compound. Results permitted us to verify that the evaluated species presented different insecticidal action under Sitophilus zeamais. About 100% of mortality was achieved with doses of 65, 100 and 400 microL for E. dunnii, E. saligna and E. benthamii, respectively. After regression analysis the LD(50) values were calculated and E. dunnii was shown to be the most efficient (25.03 microL), followed by E. saligna (37.93 microL) and E. benthamii (121.09 microL). Using the previously calculated LD(50) values, the repellency activity was calculated, allowing us to conclude that all species presented significant values in terms of this important parameter. CONCLUSION The essential oil of Eucalyptus sp. presented insecticidal and repellency against Sitophilus zeamais Motschulsky (Coleoptera, Curculionidae). Although from an economic point of view synthetic chemicals are still more frequently used as repellents, natural products (essential oils) have the potential to provide efficient and safer repellents for humans and the environment.

Antifungal Activity of Basil Essential Oil (Ocimum basilicum L.): Evaluation In Vitro and on an Italian-type Sausage Surface

This study aimed to evaluate the antifungal activity of basil essential oil in vitro and on the surface of an Italian-type sausage. This is justified by the relevance of obtaining safety and functional products, with emphasis on the use of natural additives and on the lack found in the literature related to the control of the fungi on the surface of food products. The results can be considered important since no significant differences were observed in the products taste using different oil concentrations, viabilizing the technical application of this natural compound on the maturation chambers at the industrial scale. Similar behaviors were observed in the in vitro and on the product surface evaluation, validating the methodology used in plate. A previous evaluation of the results reveals that the basil essential oil seems to be a promising option as an antifungal compound, making possible its use as substitute for chemical additives.

Chemical characterization and antimicrobial activity of essential oils of salvia L. species

In this work, the essential oils of S. officinalis, S. sclarea, S. lavandulifolia and S. triloba were chemically analyzed by gas chromatography coupled to a mass spectrometry detector (GC/MSD), and their antimicrobial activity was tested against 10 microorganisms using the disk diffusion method and the Minimum Inhibitory Concentration (MIC) technique. The following major compounds were identified in the essential oils: α - and β-thujone, camphor and 1,8-cineole, except in S. sclarea, where linalool, linalyl acetate and α-terpineol were the major constituents. The antimicrobial activity showed significant differences (p < 0.05) only when obtained by the MIC method. Gram-positive microorganisms presented larger sensitivity for the essential oils. The lowest MIC was observed when Staphylococcus aureus was exposed to 2.31 mg.mL-1 of S. lavandulifolia essential oil, while the highest MIC value was obtained when Shigella flexneri was exposed to 9.25 mg.mL-1 of the same essential oil, thus demonstrating that this essential oil may be effective as a bacteriostatic agent against Gram-positive microorganisms.

Optimization of Extraction of Lipase from Wheat Seeds (Triticum aestivum) by Response Surface Methodology

This work aimed to evaluate the effects of particle size, solid/solvent ratio (w/v), and reaction time on hydrolytic and esterification activities of a lipase extract from wheat seeds. The higher hydrolytic activity was 5.9 U/g with a particle size of 425 microm, solid/solvent ratio of 30:60 (w/v), and reaction time of 15 h, with maximum hydrolytic activity of 14.47 U/g after 24 h of precipitation. For esterification activity the best result was 57.88 U/g with a particle size of 425 microm and solid/solvent ratio of 30:120 (w/v) for 5 h, with a maximum value after 10 h of precipitation reaching 208.20 U/g. The partial characterization showed that the optimal pH and temperature were found to be 5.5 and 32-37 degrees C, respectively. The extract stability at low temperatures was kept after 48 h of storage in terms of esterification activity. The hydrolytic activity was kept constant at -10 degrees C during 72 h and diminished considerably after 24 h at 4 degrees C.

Caracterização química de extratos de Ocimum basilicum L. obtidos através de extração com CO2 a altas pressões

This work reports extraction yield and chemical characterization of the extracts obtained by high-pressure CO2 extraction of a cultivar of Ocimum basilicum L. The experiments were performed in the temperature range of 20 to 50 °C, from 100 to 250 atm of pressure. Chemical analyses were carried out by gas chromatography coupled to mass spectrometry, permitting to identify 23 compounds that were grouped into five chemical classes. Results showed that temperature and solvent density influenced positively the extraction yield. At 20 °C and 0.41 g cm-3 occurred a rise in the concentration of monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes.

Lipid and protein oxidation in the internal part of italian type salami containing basil essential oil (Ocimum basilicum L.)

Different concentrations of basil essential oil (Ocimum basilicum L.) (0.19; 0.38; 0.75; 1.87; 3.75 and 6.00 mg.g-1) were evaluated in relation to their antioxidant activity using the DPPH● radical methodology. From the IC50 obtained data, the concentrations of 0.19; 0.38; 0.75; 1.87; 3.75; 6.00 and 12.00 mg.mL-1 were applied directly to the product and these were sensorially evaluated by the test of control difference. The concentrations related to the highest acceptability (0.19; 0.38 and 0.75 mg.g-1) were tested for antioxidant activity in the internal part of Italian type salami - during the processing and after 30 days of storage, in terms of lipid and protein oxidation. The oxidation of lipids was determined using the method of TBARS. The method of carbonyl compounds was employed for proteins oxidation. Five different formulations of salami were elaborated: blank (without the use of antioxidant); control (using sodium eritorbate as antioxidant); and adding 0.19; 0.38 and 0.75 mg.g-1 of basil essential oil. The product was kept between 25 oC and 18 oC and UR between 95% and 70%, for 28 days. Analyses were carried out on the processing day and after 2, 7, 14, 21 and 28 days, and also following 30 days of storage. The basil essential oil in vitro presented an antioxidant activity of IC50 12 mg.mL-1. In the internal part of the Italian type salami the commercial antioxidant (control) and the formulation containing 0.75 mg.g-1 of basil essential oil presented antioxidant activity in relation to the lipids, but not to the proteins - during processing and storage.

Perfil da composição química e atividades antibacteriana e antioxidante do óleo essencial do cravo-da-índia (Eugenia caryophyllata Thunb.)

A busca por substâncias antibacterianas e antioxidantes naturais tem sido alvo de diversos estudos cientificos. Foi objetivo determinar as atividades antibacteriana e antioxidante e a concentracao inibitoria minima do oleo essencial do cravo-da-india, obtido por hidrodestilacao. O estudo por CG-EM identificou o eugenol como o constituinte majoritario do oleo essencial e os testes de atividade antibacteriana mostraram bons resultados para quase todos os microorganismos avaliados. Os valores de concentracao inibitoria minima variaram de 0,2 mg.mL-1 a 0,6 mg.mL-1. Aatividade antioxidante demonstrou uma correlacao linear com a concentracao de oleo essencial. Os resultados demonstraram potencial antibacteriano e antioxidante do oleo essencial de Eugenia caryophyllata, constituindo-se uma opcao para a formulacao de novos produtos alimenticios.

Solvent-Free Production of Bioflavors by Enzymatic Esterification of Citronella (Cymbopogon winterianus) Essential Oil

Enzymatic esterification of citronella essential oil towards the production of geranyl and citronellyl esters may present great scientific and technological interest due to the well-known drawbacks of the chemical-catalyzed route. In this context, this work reports the maximization of geranyl and citronellyl esters production by esterification of oleic and propionic acids in a solvent-free system using a commercial immobilized lipase as catalyst. Results of the reactions showed that the strategy adopted for the experimental design proved to be useful in evaluating the effects of the studied variables on the reaction conversion using Novozym 435 as catalyst. The operating conditions that maximized the production of each ester were determined, leading, in a general way, to conversions of about 90% for all systems. New experimental data on enzymatic esterification of crude citronella essential oil for geranyl and citronellyl esters production in solvent-free system are reported in this work.

Screening of microorganisms for production of carotenoids Selección de microorganismos para la producción de carotenoides

This work aimed at screening microorganisms capable of producing carotenoids. Microorganisms were isolated from soil, leaves, fruits, flowers, agro-industrial wastes, and processed product in decomposition and then grown in an orbital shaker, using 10% (w/v) of inoculum (25 °C, 180 rpm for 48 h) and incubated for 120 h in a dark room. A total of 116 microorganisms were isolated and screened: 16 yeasts, 65 bacteria, and 35 fungi. Three yeasts demonstrated great potential to produce red carotenoids, with a total carotenoid content of 707–818 μg L−1 (99–263 μg g−1). One filamentous fungus and two bacteria produced mostly yellow pigments in a final concentration ranging from 1063 to 2563 μg L−1 (239–2310 μg g−1). From 116 isolated microorganisms, several of them showed potential for production of carotenoid-synthesizing activity. RAPD analysis was used to check the genetic differences between the screened strains, showing that all microorganisms were from different species. El objetivo de este trabajo fue examinar los microorganismos capaces de producir carotenoides. Microorganismos de tierra, hojas, frutos, flores, residuos agro-industriales y producto procesado en descomposición se aislaron y se cultivaron en un agitador orbital, usando 10% (w/v) de inóculo (25 °C, 180 rpm durante 48 horas) e incubados durante 120 h en una habitación oscura. Se aislaron y examinaron un total de 116 microorganismos, 16 levaduras, 65 bacterias y 35 hongos. Tres levaduras demostraron un gran potencial para producir carotenoides rojos, con un contenido total de carotenoides de entre 707 a 818 μg L−1 (de 99 a 263 μg g−1). Un hongo filamentoso y dos bacterias produjeron en su mayoría pigmentos amarillos en una concentración final de entre 1063 a 2563 μg L−1 (239 a 2310 μg g−1). De 116 microorganismos aislados, varios de ellos mostraron potencial para la producción de actividad sintetizadora de carotenoides. Se usó el análisis RAPD para revisar las diferencias genéticas entre las cepas examinadas, mostrando que todos los microorganismos eran de diferentes especies.