ABSTRACT
Minimally processed strawberries have high acceptability but a short shelf life. The application of edible coatings with essential oils may be an alternative to preserve these fruits. Our objective was to develop, apply and characterize the effect of bioactive edible coatings based on agar or sodium alginate with thyme and/or sweet orange essential oils with antimicrobial properties, mainly against Listeria monocytogenes, for strawberries. The effect of the coatings on the physicochemical, microbiological, and sensory properties that determine the shelf life of strawberries was verified at 1, 8, and 15 days. The effect against Listeria monocytogenes bacteria in strawberries artificially contaminated with this microorganism was also evaluated. Thyme and sweet orange essential oils had thymol and D-limonene, respectively, as main components. Alginate coating with sweet orange and thyme essential oil showed the best results. For Listeria monocytogenes, the coating applied after fruit contamination had an antimicrobial effect.
Las fresas mínimamente procesadas tienen una alta aceptación, pero una vida útil corta. La aplicación de recubrimientos comestibles con aceites esenciales puede ser una alternativa para conservar estos frutos. El objetivo fue desarrollar, aplicar y caracterizar el efecto del uso de recubrimientos comestibles bioactivos, a base de agar agar o alginato de sodio, adicionados con aceites esenciales de tomillo y/o naranja dulce, con propiedades antimicrobianas, principalmente anti-Listeria monocytogenes sobre la fresa. Se verificó el efecto de los recubrimientos sobre las características fisicoquímicas, microbiológicas y sensoriales que determinan la vida útil de las fresas a 1, 8 y 15 días. También se evaluó el efecto contra la bacteria Listeria monocytogenes en fresas contaminadas artificialmente con este microorganismo. Los aceites esenciales de tomillo y naranja dulce presentaron timol y D-limoneno como compuestos mayoritarios, respectivamente. El recubrimiento de alginato con aceite esencial de naranja dulce y tomillo mostró los mejores resultados. Para Listeria monocytogenes, el recubrimiento aplicado después de la contaminación de la fruta tuvo un efecto antimicrobiano.
ABSTRACT
ABSTRACT This study aimed to evaluate the microbiological, physicochemical and fatty acid profile of the of "Tambica" (Oligosarcus robustus) raw fish meat and develop and characterize a fish burger. The fish burger was subjected to a sensory analysis. The raw fish meat showed a high content of moisture (82.3%) and minerals (3.1%), a low content of fat (1.5%) and a considerable protein content (13.1%). The raw fish showed a high count of positive coagulase Staphylococcus. Tambica lipid fraction was composed of 41.9% unsaturated and 58.2% saturated fatty acids. Palmitic acid and oleic acid were the major fatty acids in the raw meat fish. The fish burger was well accepted by sensory analysis.
RESUMEN Este estudio tuvo como objetivo evaluar el perfil microbiológico, fisicoquímico y de ácidos grasos de la carne de pescado cruda "Tambica" (Oligosarcus robustus); y desarrollar y caracterizar una hamburguesa de pescado. La hamburguesa de pescado fue sometida a análisis sensorial. La carne de pescado cruda mostró un alto contenido de humedad (82,3%) y minerales (3,1%), bajo contenido de grasa (1,5%) y un contenido de proteína considerable (13,1%). El pescado crudo mostró un recuento alto de Staphylococcus coagulasa positivo. La fracción lipídica de Tambica estaba compuesta por un 41,9% de ácidos grasos insaturados y 58,2% de ácidos grasos saturados. El ácido palmítico y el ácido oleico fueron los principales ácidos grasos en el pescado de carne cruda. La hamburguesa de pescado fue bien aceptada por el análisis sensorial.
Subject(s)
Animals , Fatty Acids , Meat Proteins , Meat , Staphylococcus , Microbiological Techniques , Fish ProductsABSTRACT
Synthetic preservatives are widely present in processed foods, but most of them have carcinogenic potential, requiring the development of new natural alternatives such as fruit extracts, for microbial control. The objective of the study was to evaluate the chemical characterization, antioxidant, and antimicrobial activity of the sugar apple pulp (Annona squamosa L.). Physicochemical characteristics were evaluated, an extract was prepared, and its antioxidant activity by DPPH method and antimicrobial by disk diffusion. Minimal inhibitory concentration and minimum bactericidal concentration against strains of Salmonella typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus were evaluated. The physicochemical analysis revealed that sugar apple pulp had 75.0% moisture, 3.0% ash, 4.0% protein, 0.2% lipids, 3.3% fibers, and 14.5% carbohydrates. The antioxidant activity of the extract by the DPPH method was 20.6%. The pulp extract from the sugar apple had inhibition zone for Staphylococcus aureus, satisfactory inhibitory effect against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium, but did not present a bactericidal effect. Sugar apple pulp presents adequate levels of nutrients and potential for food application due to its microbiological activity and antioxidant properties.
Los conservantes sintéticos están ampliamente presentes en los alimentos procesados, pero la mayoría tienen potencial carcinogénico, lo que requiere el desarrollo de nuevas alternativas naturales para el control microbiano, como los extractos de frutas. El objetivo del estudio fue evaluar la caracterización química, la actividad antioxidante y antimicrobiana de la pulpa de manzana de azúcar (Annona squamosa L.). Se evaluaron las características fisicoquímicas, y se evaluó su actividad antioxidante mediante el método DPPH y antimicrobiano por difusión en disco, concentración inhibitoria mínima y concentración bactericida mínima contra cepas de Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes y Staphylococcus aureus. El análisis fisicoquímico reveló que la pulpa de manzana de azúcar tiene 75.0% de humedad, 3.0% de cenizas, 4.0% de proteínas, 0.2% de lípidos, 3.3% de fibras y 14.5% de carbohidratos. La actividad antioxidante del extracto por el método DPPH fue del 20.6%. El extracto de pulpa de la manzana de azúcar tenía zona de inhibición para Staphylococcus aureus, efecto inhibidor satisfactorio contra Staphylococcus aureus, Escherichia coli, Listeria monocytogenes y Salmonella Typhimurium, pero no presenta efecto bactericida. La pulpa de manzana de azúcar presenta niveles adecuados de nutrientes y potencial para la aplicación de alimentos debido a su actividad microbiológica y propiedades antioxidantes.
Subject(s)
Plant Extracts/pharmacology , Annona/chemistry , Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Salmonella typhimurium/drug effects , Staphylococcus aureus/drug effects , Carbohydrates/analysis , Plant Extracts/chemistry , Proteins/analysis , Microbial Sensitivity Tests , Escherichia coli/drug effects , Lipids/analysis , Listeria monocytogenes/drug effects , Anti-Bacterial Agents/chemistry , Antioxidants/chemistryABSTRACT
The objective of this work was to characterize the blueberry (Vaccinium spp.) cultivar Climax, Rabbiteye group (Vaccinium ashei Reade). In order to achieve that, a survey with blueberry plants (cultivar Climax), in full production, was conducted during the 2012/13 and 2013/14 seasons in the mesoregion of Pelotas, Rio Grande do Sul State, Brazil. Data regarding the distribution of flower and vegetative buds on branches of two lengths (long and short) was collected. Another evaluation, considering three positions of flower buds in the branch (apical, medial and basal), the number of flower primordia, open flowers and fruits formed was performed. Data were subject to ANOVA and, when significant, the averages were compared using either the F or Tukeys HSD test (p ≤ 0.05). The results demonstrate the presence of flower buds intercalated with vegetative ones. The total number of flower and vegetative buds, flower primordia, flowers and fruits was influenced by the length of the branch. Likewise, the position of the bud on the branch affected the results, with a greater number of flower primordia on the basal, a greater number of flowers on the medial and a greater number of fruits on the apical portions of the branches.
Objetivou-se realizar a caracterização do mirtileiro (Vaccinium spp.), cultivar Clímax, grupo Rabbiteye (Vaccinium ashei Reade). Para tanto, foi conduzida a pesquisa com plantas da cultivar Clímax, em plena produção, durante as safras de 2012/13 e 2013/14. Foram coletados dados referentes à distribuição das gemas floríferas e vegetativas nos ramos de dois comprimentos (longos e curtos). Bem como, sob estes, foi avaliado, considerando-se três posições de gemas floríferas no ramo (apical, mediana e basal), o número de primórdios florais, flores abertas e frutos formados. Os dados foram submetidos à análise de variância e quando houve efeito significativo suas médias foram comparadas pelo teste de F e/ou Tukey (p ≤ 0,05). Os resultados demonstraram a presença de gemas floríferas intercaladas às vegetativas. O número total de gemas floríferas e vegetativas, de primórdios florais, flores e frutos foi influenciado pelo comprimento do ramo. Da mesma forma, a posição da gema no ramo, influenciou os resultados, sendo observado maior número de primórdios florais na gema basal, maior número de flores na porção mediana e maior número de frutos na apical.