The influence of milk protein-based ingredients on the textural characteristics, sensory properties, and microstructure of probiotic yogurt during a refrigerated storage period of 28 d was studied. Milk was fortified with 2% (wt/vol) skim milk powder as control, 2% (wt/vol) sodium calcium caseinate (SCaCN), 2% (wt/vol) whey protein concentrate (WPC) or a blend of 1% (wt/vol) SCaCN and 1% (wt/vol) WPC. A commercial yogurt starter culture and Bifidobacterium lactis Bb12 as probiotic bacteria were used for the production. The fortification with SCaCN improved the firmness and adhesiveness. Higher values of viscosity were also obtained in probiotic yogurts with SCaCN during storage. However, WPC enhanced water-holding capacity more than the caseinate. Addition of SCaCN resulted in a coarse, smooth, and more compact protein network; however, WPC gave finer and bunched structures in the scanning electron microscopy micrographs. The use of SCaCN decreased texture scores in probiotic yogurt; probably due to the lower water-holding capacity and higher syneresis values in the caseinate-added yogurt sample. Therefore, the textural characteristics of probiotic yogurts improved depending on the ingredient variety.

This study evaluated the effect of 5 dietary fibers (apple, orange, oat, bamboo, and wheat) on the physicochemical, rheological, and textural characteristics; sensory properties; and culture viability of probiotic ice cream stored at -18°C for 180 d. The presence of orange and apple fibers increased the titratable acidity, decreased the lightness (color) value of the ice creams, and enhanced the red and yellow coloration. Compared with the control sample, the consistency indices and apparent viscosities of the experimental samples increased with the addition of all dietary fibers except oat fiber. The highest viscosity was obtained in the sample fortified with apple fiber, whereas the ice cream containing orange fiber showed the highest hardness after d 60 of storage. The addition of orange and apple fibers significantly increased melting resistance; however, panelists did not generally like these samples in terms of taste-flavor. All ice creams had viable counts of Lactobacillus acidophilus of ≥7 log cfu/g during storage except the samples with orange and bamboo fiber. Bifidobacterium lactis counts were also found to be >6 log cfu/g in those samples until d 150 of storage.

The possibility of using a commercial vegetable fat blend in Kashar cheese was investigated. Kashar cheeses were manufactured by replacing the milk fat (MF) with a vegetable fat (VF) blend. Kashar cheeses from whole milk were also manufactured to compare textural, microstructural, meltability, color and sensory characteristics during a ripening period of 90 days. The use of vegetable fat decreased the meltability, hardness, cohesiveness, gumminess and chewiness of the cheese; while increasing adhesiveness where springiness was not affected. Differences became less notable toward the end of ripening. Scanning electron micrographs displayed VF cheese with a compact network with small and uniform fat globules embedded in the protein matrix. The MF cheese exhibited an open protein matrix containing milk fat globules of various sizes and forms. The color analysis demonstrated significant differences between cheeses. Finally, all sensory characteristics of the cheese were affecte d by the vegetable fat blend.<br><br>La posibilidad de usar una mezcla de grasas vegetales comerciales en queso Kashar fue investigada. Los quesos Kashar fueron elaborados con una mezcla de grasas vegetales (VF) en lugar de grasa de leche (MF). Quesos Kashar con leche entera fueron también elaborados para comparar las características sensoriales, de color, de fusión, microestructurales y de textura durante el periodo de maduración de 90 días. El uso de grasas vegetales decreció la dureza y las propiedades de fusión, de cohesión, de gomosidad y de masticación e incremento la adhesividad mientras que la elasticidad no fue afectada. Las diferencias se hicieron menos notables hacia el final de la maduración. La micrografía electrónica de barrido de quesos VF mostro una red compacta con pequeños y uniformes glóbulos de grasa embebidos en la matriz de proteínas. Los quesos MF exhibieron una matriz de proteínas abierta conteniendo glóbulos de grasa de leche de varios tamaños y formas. El análisis del color demostró significativas diferencias entre los quesos. Finalmente, todas las características sensoriales del queso fueron afectadas por la mezcla de grasas vegetales

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