The aim of this study was to describe the compositional, functional and sensory properties of six traditional Mexican cheeses: Panela, Oaxaca, Manchego, Manchego Botanero, Tenate, and Morral. A total of 50 cheeses were analysed. Relevant compositional parameters including pH, a w , proximate composition, NaCl, sugars, lactic and acetic acids, mineral contents, free-amino acid nitrogen, fat acid degree value and total fatty acids were determined. In addition, colour and texture profile analyses of unmelted cheeses and their meltability were investigated. Furthermore, other 30 cheeses were used for a descriptive sensory analysis. Properties of cheeses were described, compared between each cheese, and related to their respective making processes.

No abstract

The effect of adding either skim milk or a commercial dry milk protein concentrate (MPC) to whole milk on the composition, yield, and functional properties of Mexican Oaxaca cheese were investigated. Five batches of Oaxaca cheeses were produced. One batch (the control) was produced from whole milk containing 3.5% fat and 9% nonfat solids (SNF). Two batches were produced from milk standardized with skim milk to 2.7 and 1.8% fat, maintaining the SNF content at 9%. In the other 2 batches, an MPC (40% protein content) was used to standardize the milk to a SNF content of 10 and 11%, maintaining the milk fat content at 3.5%. The use of either skim milk or MPC caused a significant decrease in the fat percentage in cheese. The use of skim milk or MPC showed a nonsignificant tendency to lower total solids and fat recoveries in cheese. Actual, dry matter, and moisture-adjusted cheese yields significantly decreased with skim milk addition, but increased with MPC addition. However, normalized yields adjusted to milk fat and protein reference levels did not show significant differences between treatments. Considering skim milk-added and control cheeses, actual yield increased with cheese milk fat content at a rate of 1.34 kg/kg of fat (R=0.88). In addition, cheese milk fat and SNF:fat ratio proved to be strong individual predictors of cheese moisture-adjusted yield (r(2) ≈ 0.90). Taking into account the results obtained from control and MPC-added cheeses, a 2.0-kg cheese yield increase rate per kg of milk MPC protein was observed (R=0.89), with TS and SNF being the strongest predictors for moisture adjusted yield (r(2) ≈ 0.77). Reduced-fat Oaxaca cheese functionality differed from that of controls. In unmelted reduced-fat cheeses, hardness and springiness increased. In melted reduced-fat cheeses, meltability and free oil increased, but stretchability decreased. These changes were related to differences in cheese composition, mainly fat in dry matter and calcium in SNF.

The aim of this work was to identify and characterize lactobacilli strains from Mexican Oaxaca cheese. Twenty-seven lactobacilli isolated from Oaxaca cheese were identified at species level by 16S rRNA sequencing. Selected isolates were further characterized by ribotyping. Isolates were screened, among others, by acidifying capacity, antibiotic resistance, and activity against pathogens. Lactobacillus plantarum was predominant in Oaxaca cheese. The intraspecies variability of Lb. plantarum isolates was great. Multiple antibiotic resistances were observed. Eight isolates showed antimicrobial activity against the pathogenic species tested. Four Lb. plantarum strains showing low antibiotic resistance index, antimicrobial activity against enterotoxigenic Staphylococcus aureus and Listeria innocua stains, amine-negative decarboxylase activity, and resistance to NaCl and bile salt solutions, could be preselected to complete studies focused on designing a culture for use in pasteurized-milk Oaxaca cheese manufacturing.

No abstract

No abstract

La fortificación de los alimentos ha sido una práctica común en las sociedades actuales, buscando ofrecer alimentos más nutritivos sobre todo a sectores de la población con problemas de desnutrición Güemes et al. (2008). Los productos de panificación, debido a sus características de vida de anaquel (baja a w , por lo que es menos susceptible a crecimiento microbiano), su bajo costo y formulación, son productos que pueden ser enriquecidos al adicionar otras proteínas, como concentrados o aislados proteicos de diversas leguminosas. existen varios reportes referentes a modificar el contenido proteico de masas y panes sin alterar las características del producto final. Taha, Attia y Saeta (1982) utilizaron cinco fuentes diferentes de proteínas en el enriquecimiento de pan blanco, añadiendo concentrados de proteína de semillas de girasol, soya, harina de lupino, arroz y pescado a niveles del 5 y 10%, encontrando que el contenido de proteína se elevó de 16 a 60%, dependiendo del concentrado utilizado, pero utilizar un nivel del 5% de adición de los concentrados favorece el enriquecimiento del pan blanco sin afectar características de color, aroma, sabor o textura. Por otra parte, el uso de concentrados y aislados de harina de lupino sin grasa mezclados con harina de trigo demostraron que la proteína de esta semilla mejoró la estructura proteica de las masas Güemes, Arciniega y Davila (2004). Del mismo modo, aislados de ajonjolí pueden ser añadidos a panes de harina de trigo incrementando el nivel de proteína en ResumoA fortificação de alimentos é importante devido a uma população crescente em estado de má nutrição. A adição de proteínas pode causar problemas tecnológicos. Por essa razão, o objetivo deste trabalho foi determinar o efeito da adição de soro de leite a formulações de pães tipo concha nas propriedades químicas e na textura das massas. Foram utilizadas diferentes concentrações de um soro comercial e de outro soro obtido por processo de precipitação por calor. Foi avaliado o perfil de textura da massa e dos pães. Os resultados indicaram que o controle apresentou maior adesividade enquanto o soro precipitado produziu amostras com valores intermediários. A dureza foi maior (p < 0,05) em amostras com soro comercial, porém com menor coesividade que as fortificadas com soro precipitado pelo calor. Não houve variação significativa (p > 0,05) na firmeza, quando utilizadas diferentes porcentagens dos dois soros testados. Há correlação entre a concentração de soro e a adesividade das massas. Palavras-chave: pão; fortificacion; fortificação de alimentos; textura; adesividade. ResumenLa fortificación de alimentos es importante debido a una creciente población en estado de malnutrición, por las sequías provocadas a nivel mundial y por personas de bajos recursos económicos. La adición de proteínas puede causar problemas tecnológicos. Por ello, el objetivo de este trabajo fue determinar el efecto de la adición de proteínas de lactosuero a pan dulce tipo "concha" sobre las propiedades químicas y de texturas de las masas y ...

Non-ruminantsFull-length research article Carcass and meat quality of rabbits fed Tithonia tubaeformis weed ABSTRACT -The objective of this study was to use different parts of the Tithonia tubaeformis plant in feed for fattening rabbits and then observe the effects on carcass and meat quality. Forty-eight weaned rabbits (35 days of age) were randomly assigned to four groups (n = 12 by treatment). Animals were fed ad libitum a control diet as well as three experimental diets, with addition of Tithonia tubaeformis leaves, whole plant, and stems. Rabbits were slaughtered after 63 days of age without fasting. Results indicate that live weight (0.917), skin (0.79), feet (6.679), and lumbar circumference of the carcass (0.707) have higher positive correlations with hot carcass. There were no significant differences between treatments for all variables measured, except for kidneys and kidney fat. pH and color values were different among treatments. The results indicate that Tithonia tubaeformis leaves or the whole plant could be added to feed for growing rabbits.