Search

Fermented milks, with diverse manufacturing, fermentations and specific strains, have been consumed around the world, with a millennial knowledge of their production. These dairy products have a potential nutritional value, taking food industries to invest, nowadays, in dairy products with a functional and healthy appeal due to the changes in the habits and diet of the population. The addition of natural ingredients from vegetables and fruits into fermented milks is a tendency nowadays. The inclusion of natural additives may change the texture, composition, sensory attributes and increase of the shelf life since some compounds are related to have a high antioxidant activity, which decreases the development of deteriorating microorganisms. These called bioactive compounds are synthesized by plants and also may contribute to the fermented milk formulation, in special from fruits, which increase the sensory acceptance. Several classes of fruits bioactive compounds are associated to several health benefits and are a base of many studies about functional fermented milks, reported in this review. This theory background becomes essential for future studies and dairy products development. Made available in DSpace on 2022-07-27T12:21:49Z (GMT). No. of bitstreams: 1 FST-2022-HowImproveMilksAddedFruitsBioactive.pdf: 872152 bytes, checksum: eb1001d95a1b33bbeadf7fc10494850e (MD5) Previous issue date: 2022

Freeze concentration process was used to concentrate milk until the third stage of freeze concentration. Thus, two samples of ice creams were manufacture, one with milk and the other with concentrated milk from the first stage of block freeze concentration, and denominated ice cream 1 and ice cream 2, respectively. Both ice creams were characterized according to physicochemical characteristics, overrun, microscopy, melting rate, texture, color, and rheological properties. The use of concentrated milk influenced the physicochemical properties of ice cream 2, promoting an increase in the total solids, protein, carbohydrates, and ashes content. Moreover, it was noted that ice cream 2 had a higher overrun, lower firmness, smaller ice crystals, and tended to color greenish and yellowish, however had a higher melting rate and larger hysteresis area. The models of the Power Law and Casson satisfactorily described the rheological behavior of ice creams, which proved to be a Newtonian fluid.

This study’s main highlight to the effect of replacement of milk by different proportions of concentrated whey in the elaboration of ice creams and the characterization of their physicochemical and microstructural properties. Ice creams have high levels of total solids, acidity, and low pH values. All ice creams exhibited Newtonian fluid behaviors while the Power and Casson Law model adequately explained the flow properties. Viscosity and ​​hysteresis area increased as a higher ratio of concentrated whey was added. Ice cream formulations containing a higher proportion of milk showed greater brightness, the ice creams showed a greenish-yellow coloring tendency. The overrun values ​​ranged from 27 to 44%, and ice cream with partial replacement of milk by concentrated whey showed greater resistance to melting. The addition of concentrated whey did not influence the size of the ice crystals, fat globules, and air bubble diameters. However, the higher total solids content influenced the texture of the ice creams, promoting smoother and creamy ice creams. These results highlight the application of concentrated whey on the 50% substitution level, thus being an attractive alternative for the food industry, mainly about the cost-benefit and added value to the product, by enhancing the color, flavor, and texture.