Physical properties of yogurt fortified with various commercial whey protein concentrates

Abstract

The effects of whey protein concentrates on physical and rheological properties of yogurt were studied. Five commercial whey protein concentrates (340 g kg −1 protein nominal) were used to fortify milk to 45 g protein kg −1 . Fermentation was performed with two different starters (ropy and non-ropy). Resulting yogurts were compared with a control yogurt enriched with skim milk powder. The waterholding capacity of the yogurt fortified with skim milk powder was 500 g kg −1 and ranged from 600 to 638 g kg −1 when fortified with whey protein concentrates. Significant rheological differences have been noticed between the yogurts fortified with different whey protein concentrates, independent of the starter used. Three whey protein concentrates generated yogurts with a behavior similar to the control. The two others produced yogurt with lower firmness (15 g compared with 17 g), lower Brookfield viscosity (6 Pa s compared with 9 Pa s), lower yield stress (2 Pa compared with 4 Pa), lower complex viscosity (13 Pa s compared with 26 Pa s), and lower apparent viscosity (0.4 Pa s compared with 1 Pa s) than the control, respectively. The yogurts with the lowest firmness and viscosity were produced with concentrates which contained the highest amount of non-protein nitrogen fraction (160 g kg −1 versus 126 g kg −1 of the total nitrogen), and the highest amount of denaturation of the whey protein (262 versus 200 g kg −1 of the total nitrogen).

Effect of Selected Milk Protein Preparations on Growth and Survival of Lactobacillus Acidophilus as Well as on Rheological Properties of Fermented Milk Beverages

“…Jednym z etapów przemysłowej produkcji jest zwiększenie suchej masy mleka przerobowego. W celu uzyskania odpowiedniej tekstury najczęściej stosowany jest dodatek hydrokoloidów polisacharydowych lub preparatów białkowych, przede wszystkim białek serwatkowych [10,28]. Wzrost zainteresowania białkami serwatkowymi wynika z ich właściwości funkcjonalnych, jak i żywieniowych [29].…”

Some functional characteristics of extruded blends of fiber from sugarcane bagasse, whey protein concentrate, and corn starch

“…Bagasse is also used in healthy foods formulated with dietary fiber (FERNANDEZ et al, 1996;ARRIGONI et al, 1986;GOURGUE et al, 1994;GAJULA et al, 2008). Several researchers have shown the potential use of fibers by using extrusion and other thermo-mechanical processes in order to improve the fibers' functional properties and to increase their incorporation into breadmaking products (FERNANDEZ et al, 1996;GAJULA et al, 2008;SANGNARK;NOOMHORM, 2004), meat products, dehydrated gravies, puddings, feed and extruded snacks (CAMIRE; KING, 1991;KESTERSON;BRADDOCK, 1973), enriched extruded wheat flour, cookies, and tortillas (GOULD et al, 1989;RANHOTRA et al, 1991;LARREA et al, 2005b;BERGLUND et al, 1994;SODINI et al, 2005;GIUNTINI et al, 2003). However, attempts to incorporate high levels of fiber into extruded products often give them a compact and resistant texture, neither crunchy nor desirable, as a result of reduced expansion (LARREA et al, 2005a;AGUILAR-PALAZUELOS et al, 2007;GOURGUE et al, 1994;GAJULA et al, 2008); although expanded extruded products can be milled and the resulting precooked flours can increase their incorporation into foods.…”

Desenvolvimento e caracterização físico-química, microbiológica e sensorial de bebida láctea fermentada elaborada com diferentes estabilizantes/espessantes

“…Estudos mostram que o soro de queijo, na forma de concentrado proteico, apresenta capacidade emulsificante, geleificante e de retenção de água, adequada viscosidade e adesividade, retêm e incorporam gordura, facilitam o batimento, a formação de espuma e aeração, realçam a cor, o sabor e a textura (REGESTER et al, 1996;SODINI;MONTELLA;TONG, 2005). A incorporação de biopolímeros, especialmente proteínas e hidrocolóides, representa uma das estratégias mais comuns utilizados para estabilizar emulsões alimentares (MCCLEMENTS, 2007;DICKINSON, 2009).…”