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Caprine whey protein concentrates (WPC) were incorporated as emulsifiers in a salad dressing. The concentrates were manufactured by ultrafiltration-diafiltration with or without previous clarification by thermocalcic precipitation. Aggregates obtained in the clarification treatment and a commercial bovine WPC were also used as emulsifiers. Good emulsifying properties of caprine products were observed. Dressings made with caprine products showed higher firmness and stability than dressings made with bovine WPC. Thermocalcic precipitation improved the properties of caprine WPC. Aggregates modified the colour of dressings contributing to a more yellowish aspect. Microstructure of emulsions was affected by the type of protein.

The objective of this work was the use of goat and sheep liquid whey concentrates (LWCs) produced by ultrafiltration (UF) for the manufacturing of frozen yoghurts. In a first step, natural yoghurts using only goat’s and sheep’s LWCs as raw material were obtained. One day after production, these yoghurts were used to produce frozen yoghurts with different concentrations of added inulin. The physicochemical characteristics of ewe’s and goat’s yoghurts were significantly different regarding dry matter, protein, fat and minerals. Ewe’s yoghurts were solid, while goat’s yoghurts behaved as a viscous liquid. Frozen yoghurts with different levels of inulin addition also presented significant differences concerning physicochemical and microbiological characteristics. Overrun was similar for all formulations except for that produced with ewe’s LWC containing 5.0% inulin, which presented a significantly higher value. Higher meltdown rates in goat’s frozen yoghurts were observed. The survival rates of lactic acid bacteria were lower than the data reported for similar products. Concerning sensory acceptance, both products showed encouraging results. It can be considered that the production of frozen yoghurts by using LWCs as the main ingredient can be an interesting option to broaden the product portfolio of small/medium scale dairy producers.

The search for new food products that promote consumers health has always been of great interest. The dairy industry is perhaps the best example regarding the emergence of new products with claimed health benefits. Cheese whey (CW), the by-product resulting from cheese production, and second cheese whey (SCW), which is the by-product of whey cheese manufacture, have proven to contain potential ingredients for the development of food products with improved nutritional characteristics and other functionalities. Nowadays, due to their nutritional quality, whey products have gained a prominent position among healthy food products. However, for a long time, CW and SCW were usually treated as waste or as animal feed. Due to their high organic content, these by-products can cause serious environmental problems if discarded without appropriate treatment. Small and medium size dairy companies do not have the equipment and structure to process whey and second cheese whey. In these cases, generally, they are used for animal feed or discarded without an appropriate treatment, being the cause of several constraints. There are several studies regarding CW valorization and there is a wide range of whey products in the market. However, in the case of SCW, there remains a lack of studies regarding its nutritional and functional properties, as well as ways to reuse this by-product in order to create economic value and reduce environmental impacts associated to its disposal.

The effects of the addition of whey protein concentrates and clarification by-products obtained from ovine cheese whey and deproteinized whey (Sorelho) on the yield and quality of the whey cheese (Requeijão) have been evaluated. Whey protein concentrates were obtained by ultrafiltration of skimmed whey and Sorelho. The clarification by-products were obtained after the treatment of the skimmed whey and Sorelho by thermocalcic precipitation and microfiltration with two membranes (0.20 and 0.65 μm pore size). Next, the liophilization of the corresponding retentates was carried out. Each powder was added in three different mass ratios: 0.5, 1.0 and 1.5 %. The addition of the powders caused higher yields of the whey cheese – mainly the one with the additional whey powder – but it did not affect the strength of the products. The retention of water and other components of whey and milk in the whey cheese was influenced by the protein composition of the powders. In relation to colour parameters, the whey cheese manufactured with ultrafiltration and microfiltration retentate powders showed lower values of ligthness than the control whey cheese – mainly the whey cheese with 1.5 % of added powders. The microstructure constituted of small aggregates in the whey cheese manufactured with ultrafiltration and 0.20-μm microfiltration retentate powders and also by large, smooth structures in the other whey cheeses, especially in batches with added Sorelho powders.

The presence of clays in copper minerals has a significant negative impact during their processing, leading to low recoveries during the flotation process. In saline environments, the presence of these clays promotes operational problems associated with salinity, leading to decreases in the copper concentrate grade, alterations in the rheology of the mineral pulp, reduction in the selectivity of copper during the flotation process, declines in the quality of clarified water, and excessive corrosion of metallic components. This study explores the electroflotation of kaolinite and montmorillonite clays in NaCl solutions using a modified Hallimond tube coupled with Ti Gr. 2 electrodes for bubble generation via water electrolysis and the corrosion analysis of these electrodes applying the superposition model. The electroflotation results show recovery of clays close to 72.68% for kaolinite, 88.44% for montmorillonite, and 67.36% for a mixture of both clays. The presence of clays helps reduce the corrosive effects of Ti Gr. 2 from 0.069 A/m2 in NaCl to 0.0073 A/m2 in NaCl with montmorillonite clay.