Influencia del aceite esencial de orégano en la elaboración tradicional de quesos: efecto sobre el fermento láctico / Influence of oregano essential oil on traditional Argentinean cheese elaboration: Effect on lactic starter cultures

The aim of this work is to study the oregano essential oil (OEO) composition from Northwestern Argentinean regions and to evaluate its effect on the lactic starter cultures. The oregano used, Origanum vulgare var hirtum, was obtained from Andalgalá, Catamarca. The essential oil presented high amounts of α-terpinene (10%), γ-terpinene (15.1%), terpinen-4-ol (15.5%) and thymol (13.0%) as the main components. No negative effect on growth or metabolic activity of lactic acid bacteria Streptococcus thermophilus CRL 728 and CRL 813, Lactobacillus delbrueckii subsp. bulgaricus CRL 656 and CRL 468, and Lactococcus lactis subsp. lactis CRL 597 up to the maximum concentration (200 μg/g) assayed was observed. No differences in the organoleptic characteristics of semi-hard cheeses flavored with oregano essential oil (200 μg/g) and homemade cheeses flavored with oregano leaves were found. With respect to the microbiological quality of the products, neither enterobacteria nor mold and yeast were detected during ripening in essential-oil flavored cheese compared to control cheese (enterobacteria 2 × 10³ UFC/g) and cheese flavored with oregano leaves (mold/yeast 4 × 10(4) CFU/g). Our results showed that the use of oregano essential oil and lactic starter culture considerably improved cheese quality.

El objetivo de este trabajo fue estudiar la composición del aceite esencial de orégano recolectado en el noroeste argentino y evaluar su efecto sobre algunos fermentos lácticos. El orégano recolectado correspondió a la especie Origanum vulgare var. hirtum proveniente de Andalgalá, Catamarca. En su aceite esencial (obtenido por arrastre con vapor de agua) se detectó principalmente α-terpineno (10%), γ-terpineno (15,1%), terpinen-4-ol (15,5%) y timol (13,0%). El aceite esencial no tuvo efecto inhibitorio (máxima concentración ensayada 200 μg/g) sobre el crecimiento ni sobre la actividad metabólica de Streptococcus thermophilus CRL 728 y CRL 813, de Lactobacillus delbrueckii subsp. bulgaricus CRL 656 y CRL 468, y de Lactococcus lactis subsp. lactis CRL 597. No se observaron diferencias en las características organolépticas de quesos semiduros aromatizados con el aceite esencial (200 μg/g) comparados con quesos artesanales aromatizados con hojas de orégano. Respecto de la calidad microbiológica de los productos, no se detectaron enterobacterias ni hongos o levaduras durante la maduración en los quesos aromatizados con el aceite esencial de orégano comparados con los quesos control, que presentaron desarrollo de enterobacterias (2 × 10³ UFC/g), y con los quesos elaborados con hojas de orégano, en los que hubo desarrollo de hongos/levaduras (4 × 10(4) CFU/g). Los resultados obtenidos demostraron que el uso del aceite esencial de orégano y del fermento láctico incrementó la calidad general de los quesos artesanales.

Composición química, valoración nutricional, satisfacción y aceptabilidade de bayas de goji (lycium barbarum l) y productos elaborados / Chemical composition, nutritional value, satisfaction and acceptability of goji berries (lycium barbarum l) and finished products / Composição química, valorização nutricional, satisfação e aceitabilidade de bagas de goji (lycium barba rum l) E produtos elaborados

Las bayas de goji son frutas de un color rojo intenso, aproximadamente del tamaño de una pasa de uva y con un sabor que podría asemejarse a una mezcla de arándanos y cerezas. Las bayas frescas tienen un aspecto similar,tanto en la forma como en el tamaño, a la de los tomates cherry. China es el principal proveedor de bayas de gojiy se cultiva mayoritariamente en la provincia de Ni ngxia. Se comercializan principalmente desecadas, pero en elmercado también se encuentran jugos, aceites, extractos, compotas, mermeladas o jaleas, barras de cereal,muesli, y una gran variedad de productos cosméticos. Se les atribuyen numerosas propiedades nutricionales, pero debe destacarse que muy pocas han sido comprobadas científicamente. Objetivos del trabajo: Estudiar las características nutri cionales y organolépticas de las bayas de goji y de productos alimenticios elabo-rados con ellas, compararlos con los mismos productos sin bayas. Cuantificar los macronutrientes y antioxidan-tes, realizar la valoración nutricional, y determinar la aceptabilidad y satisfacción de los alimentos elaborados. Metodología: Este estudio es descriptivo y asimismo, corresponde a un diseño mixto, ya que p resenta una etapa no experi-mental-transeccional-descriptiva y en otra etapa, el diseño es cuasi-experimental. Resultados y conclusiones: Los alimentos que se elaboraron exitosamente con y sin bayas de goji fueron barritas de cereal y yogur helado, que resultaron con características organolépticas satisfactorias. Los productos elaborados con bayas fueron losque mayor contenido de carbohidratos y prote ínas contenían. En el caso de los lípidos, no se observaron grandes diferencias entre los productos elaborados con y sin bayas. Todos los alimentos presentaron fibra alimentaria en su composición. En cuanto al contenido de compuestos fenólicos, los resultados evidenciaron claramentesu aumento en los alimentos...

Goji berries are intense red-colored fruitsand approximately the size of a raisin. Its taste could be described as a combination of blueberries and cherries.Fresh goji berries are similar in form as well as in size tocherry tomatoes. China is the main supplier of goji berries, which are mostly harvested in the province of Ningxia. They are primarily marketed as dried fruits, but you can also find juices, oils, extracts, compotes, jams or jellies, cereal bars, muesli and a great variety of cosmetic products. Many nutritional properties are attributed to them, but it is worth noting that only a few of them have been proven scientifically. Objectives: To study the nutritional and sensory propertiesof goji berries and of food products made with them, and to compare these products with those that don't contain goji berries. To quantify the macronutrients and antioxidants, evaluate the nutritional value and determine theacceptability and satisfaction of the finished products. Methodology: This is a descriptive study with a mixed design, since it combines a non-experimental, descriptive and transactional phase with a quasi experimental phase. Results and conclusions: The foods that were successfullymade with and without goji berries were cereal bars and frozen yogurt, resulting in satisfactory sensory properties.The products made with goji berries had a higheramount of carbohydrates and proteins. As regards lipids, there were no significant differences between the products made with and without goji berries. All products had dietary fiber in their composition. Concerning the content ofphenolic compounds, the results clearly showed an increase of them in the foods made with goji berries. The results ofthe microbiological analysis of the frozen yogurt withand without goji berries were found to be within the microbiological criteria established by the Argentine Food Cod...

As bagas de goji são frutas de cor vermelha intensa, aproximadamente do tamanho de uma uva passa e com um sabor que poderia assemelhar-se ao de uma mistura de blue berry e cerejas. As bagas frescas têm um aspecto similar, tanto na forma como no tamanho, às do tomate cereja. A China é o principal fornecedor de bagas de goji e são cultivadas em sua maioria na p rovíncia de Ningxia. São comercializadas principalmente dessecadas, mas no mercado também se encontram sucos, óleos, extratos, compotas, marmeladas, geleias barra de cereal, musli e uma grande variedade de produtos cosméticos. São atribuídas a elas numerosas propriedades nutricionais, mas é preciso ressaltar que muito poucas foram comprovadas cientificamente. Objetivos do trabalho: Estudar as características nutricionais e organolépticas das bagas de goji e de produtos alimentícios elaborados com elas compará-los com os mesmos produtos sem bagas. Quantificar os macronutrientes e antioxidantes, realizar a valorização nutricional, e determinar a aceitabilidade e satisfação dos alimentos elaborados. Metodologia: Este estudo é descritivo e também, corresponde a um desenho misto, já que apresenta uma etapa não experimental-transversal-descritiva e em outra etapa, o desenho é quase experimental. Resultados e conclusões:Os alimentos que foramelaborados com sucesso com e sem bagas de gofi foramas barrinhas de cereais e iogurte gelado, que resultaram com característica organolépticas satisfatórias. Os produtos elaborados com bagas foram os que apresentaram maior conteúdo de carboidrato e proteínas. No caso dos lipídios, não foram observadas grandes diferenças entre os produtos elaborados com e sem bagas. Todos os alimentos apresentaram fibra alimentar em sua composição. Quanto ao conteúdo de compostos fenólicos, os resultados evidenciaram claramente o seu aumento nos alimentos com bagas de gojitanto o elaborado com bagas como sem elas, estavam...

beta-Glucuronidase method to determine mastitis levels in goat milk.

Mastitis is a general term that refers to the inflammation of the mammary gland. It is the most common illness in dairy farms and it has different causes, mainly a great number of germs that infect the gland. These infectious diseases induce gross variations in milk composition, reflected by physical, chemical, and bacteriological changes. They produce milk jellification, a decrease in important components such as lactose, casein, and fats and minerals such as calcium, phosphorus, and potassium and increases in other unimportant technological components, such as serum proteins and chlorides; all these affect the cheese efficiency and the starter culture action. Assuming that cheese making is the principal use of goat milk in industry, an evaluation of the quality of the milk used as the raw material is of fundamental importance. It is impossible to obtain quality products by using milk with an anomalous chemical composition. Somatic cell count (SCC) is the indicator most used for mastitis detection. These cells, which are contained in milk, can be grouped into three types: epithelial cells, blood cells, and cytoplasmatic particles. During an attack of mastitis, the immune defenses of the udder are activated, polynucleated leukocytes pass from the blood toward the mammary gland in large numbers, and the number of somatic cells in the milk increases. The level of somatic cells in goat milk is characterized by great variability between different countries and between regions of the same country. Different authors show averages between 750,000 and 5,400,000 cells/mL. These values differ greatly between cow and goat milk, mainly because normally nonleukocytic cell-like particles can be found as a result of the particular apocrine secretion process in the goat mammary gland. These particles are large fragments of cytoplasm originating from the distal portion of alveolar secretory cells and are of similar size (5-30 microm in diameter) to milk leukocytes. They contain abundant RNA-positive granular material (associated with dilated cisternae of the rough endoplasmic reticulum), large amounts of protein, and some lipids, but no DNA. Thus it is important to use techniques that disregard these other substances and allow only a count of somatic cells.