Sheep’s and Goat’s Frozen Yoghurts Produced with Ultrafiltrated Whey Concentrates

Abstract

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.

Evaluation of the Characteristics of Sheep’s and Goat’s Ice Cream, Produced with UF Concentrated Second Cheese Whey and Different Starter Cultures

“…The overrun values ( Table 4 ) are higher in sheep’s ice creams when compared to goat’s ice creams; however, in all cases, overrun values can be considered low when compared to data referred by other authors [ 17 ]. Regarding the meltdown rate, S-Yoghurt and S-Probiotics presented lower values, with the latter presenting the higher resistance to melt.…”

“…A possible solution can be the utilization of liquid SCW concentrated by ultrafiltration (UF) or nanofiltration (NF) as the main ingredient to produce fermented drinks or other dairy products, as is the case of ice cream. We recently evaluated the performance of sheep’s and goat’s whey in the production of frozen yoghurts [ 17 ].…”

Application of Ultrafiltration to Produce Sheep’s and Goat’s Whey-Based Synbiotic Kefir Products

“…The lower levels of protein in goat kefir was the cause for their liquid nature. Marnotes et al [ 23 ] also observed that sheep yogurts before freezing were solid, and goat yogurts were viscous liquids due to differences in protein concentrations of the LWCs used as raw materials.…”

“…The results of cost–benefit and sensitivity analyses show that an integrated process of ultrafiltration/nanofiltration (UF/NF) is economically viable in small/medium cheese producers [ 20 ]. Sheep dairy products, other than cheese, are also being developed and are looked at as an opportunity to valorize peripheral rural areas through the transformation of dairy products into competitive value-added commodities [ 22 , 23 , 24 ].…”

Application of Ultrafiltration To Produce Sheep’s and Goat’s Whey Based Synbiotic Kefir Products

“…The results of cost-benefit analysis and sensitivity analysis show that an integrated process of ultrafiltration/nanofiltration (UF/NF) is economically viable in small/medium sized cheese dairies [16]. Sheep's dairy products other than cheese are also being developed and are looked at as an opportunity to valorize peripheral rural areas through the transformation of dairy products into competitive value-added commodities [17][18][19]. Concomitantly, increasing awareness on health has increased demand for healthy food which is confirmed by raising market sales of functional foods.…”