ABSTRACT
El objetivo del presente trabajo fue evaluar los cambios en el perfil de ácidos grasos y microestructura en el puré de aguacate por efecto del tratamiento térmico con microondas. Los resultados obtenidos muestran que el componente mayoritario del perfil de ácidos grasos fue el ácido oleico, seguido del ácido palmítico, linoleico y palmitoleico. El perfil de ácidos grasos de los purés no presentó cambios al ser calentado con microondas (p < 0.05). Así mismo, no se detectaron ácidos grasos trans. Por otra parte, cambios significativos en la microestructura del puré de aguacate tratado con microondas fueron detectados. Se encontró que a tiempos menores de 40 s, se conserva en mayor grado la estructura de los idioblastos del aguacate, mientras que a tiempos mayores de 40 s, se observaron zonas de rompimiento de las paredes y membranas celulares, liberando el aceite y mostrando restos de idioblastos vacíos, lo cual se correlaciona con la evaluación sensorial en donde se encontró que a tiempos de calentamiento de 60 s, las muestras fueron calificadas como aceitosas o grasas.
Changes in the fatty acid profile and the microstructure of avocado puree after microwave treatment were evaluated. The main components of the fatty acid profile were oleic, palmitic, linoleic and palmitoleic acids. Fatty acids profile of microwaved avocado puree did not show significant changes (p < 0.05). Trans fatty acids were not detected. Microwaved avocado puree showed significant changes in its microstructure. Samples treated with microwaves for less than 40 s preserved the cells shape, causing only a minimal modification. On the other hand, microwave treated avocado puree using more than 40 s, showed a disruption of idioblast oil cells, releasing the oil contained on them. The results might be explained based on the sensory evaluation that was performed on the microwaved avocado puree, where samples at 60 s showed oily texture and grassy flavor.
Subject(s)
Fatty Acids/analysis , Microwaves , Persea , Heat-Shock Response/radiation effectsABSTRACT
Changes in the fatty acid profile and the microstructure of avocado puree after microwave treatment were evaluated. The main components of the fatty acid profile were oleic, palmitic, linoleic and palmitoleic acids. Fatty acids profile of microwaved avocado puree did not show significant changes (p < 0.05). Trans fatty acids were not detected. Microwaved avocado puree showed significant changes in its microstructure. Samples treated with microwaves for less than 40 s preserved the cells shape, causing only a minimal modification. On the other hand, microwave treated avocado puree using more than 40 s, showed a disruption of idioblast oil cells, releasing the oil contained on them. The results might be explained based on the sensory evaluation that was performed on the microwaved avocado puree, where samples at 60 s showed oily texture and grassy flavor.
Subject(s)
Fatty Acids/analysis , Food Handling/methods , Hot Temperature , Microwaves , Persea/chemistry , Plant Oils/chemistry , Nutritive Value , Persea/ultrastructure , Time FactorsABSTRACT
The inhibitory effect of the extract of Capsicum annuum bell pepper type was evaluated against Salmonella typhimurium and Pseudomonas aeruginosa, inoculated in minced beef meat mixed with different concentrations of the extract, and stored at 7 degrees C for 7 days. The combined effect of C. annuum extract and sodium chloride on the bacterial growth was evaluated. The minimum inhibitory concentration of the extract to prevent the growth of S. typhimurium in minced beef was 1.5 ml/100 g of meat; the addition of 1%, 2%, 3% and 4% w/w of sodium chloride did not have any additional inhibitory effect on Salmonella. In the case of P. aeruginosa, a concentration of 0.3 ml of the extract/100 g of meat showed a bacteriostatic effect, while a concentration of 3 ml/100 g of meat showed a bactericidal effect. When 1% w/w of sodium chloride was added to the meat together with the extract, the concentration needed to kill P. aeruginosa was reduced.
Subject(s)
Capsicum/chemistry , Meat Products/microbiology , Plant Extracts/pharmacology , Pseudomonas aeruginosa/drug effects , Salmonella typhimurium/drug effects , Dose-Response Relationship, Drug , Food Handling/methods , Food Microbiology , Microbial Sensitivity Tests , Pseudomonas aeruginosa/growth & development , Salmonella typhimurium/growth & development , Sodium Chloride/pharmacology , Time FactorsABSTRACT
Because Mexico is the number one producer of avocados in the world, this fruit has potential as a source for oil extraction. It is appropriate to further investigate the detailed changes that the oil undergoes when different extraction methods are applied. This research paper presents the study of the physical and chemical changes, the fatty acids profile, the trans fatty acid content, and the identification of volatile compounds of the oils from avocado pulp (Persea americana Mill.), obtained by four different extraction methods. The method with the greatest extraction yield was the combined microwave-hexane method. The amount of trans fatty acids produced in the microwave-squeezing treatment was <0.5 g/100 g. On the other hand, the amounts of trans fatty acids produced with the hexane and acetone treatments were 0.52 and 0.87 g/100 g, respectively. The method that caused the slightest modification to the oil quality was a novel combined extraction method of microwave-squeezing proposed by the authors.
