Comparison of composition, sensory, and volatile components of thirty-four percent whey protein and milk serum protein concentrates

Abstract

The objectives of this study were to identify and compare the composition, flavor, and volatile components of serum protein concentrate (SPC) and whey protein concentrate (WPC) containing about 34% protein made from the same milk to each other and to commercial 34% WPC from 6 different factories. The SPC and WPC were manufactured in triplicate with each pair of serum and traditional whey protein manufactured from the same lot of milk. At each replication, SPC and WPC were spray dried (SD) and freeze dried (FD) to determine the effect of the heat used in spray drying on sensory properties. A trained sensory panel documented the sensory profiles of rehydrated SD or FD powders. Volatile components were extracted by solid-phase microextraction (SPME) and solvent extraction followed by solvent-assisted flavor evaporation (SAFE) with gas chromatography-mass spectrometry and gas chromatography-olfactometry. Whey protein concentrates had higher fat content, calcium, and glycomacropeptide content than SPC. Color differences (Hunter L, a, b) were not evident between SPC and WPC powders, but when rehydrated, SPC solutions were clear, whereas WPC solutions were cloudy. No consistent differences were documented in sensory profiles of SD and FD SPC and WPC. The SD WPC had low but distinct buttery (diacetyl) and cardboard flavors, whereas the SD SPC did not. Sensory profiles of both rehydrated SD products were bland and lower in overall aroma and cardboard flavor compared with the commercial WPC. Twenty-nine aroma impact compounds were identified in the SPC and WPC. Lipid and protein oxidation products were present in both products. The SPC and WPC manufactured in this study had lower total volatiles and lower concentrations of many lipid oxidation compounds when compared with commercial WPC. Our results suggest that when SPC and WPC are manufactured under controlled conditions in a similar manner from the same milk using the same ultrafiltration equipment, there are few sensory differences but distinct compositional and physical property differences that may influence functionality. Furthermore, flavor (sensory and instrumental) properties of both pilot-scale manufactured protein powders were different from commercial powders suggesting the role of other influencing factors (e.g., milk supply, processing equipment, sanitation).

Comparison of the Flavor Chemistry and Flavor Stability of Mozzarella and Cheddar Wheys

“…Of these compounds, 29 were tentatively identified by comparing RI, odor, and MS with authentic standards, 8 were tentatively identified by comparing RI and odor with authentic standards, 3 were tentatively identified by RI and previously published standards, and 10 remained unknown. The majority of these compounds were reported previously in liquid or dried whey protein products (Karagul‐Yuceer and others 2003; Mahajan and others 2004; Carunchia‐Whetstine and others 2005; Evans and others 2009). …”

Foaming Properties of Reduced-Fat Whey Protein Concentrates

“…Wyprodukowane w warunkach przemysłowych koncentraty WPC 35 powinny zawierać 33 ÷ 37 % białka, 43 ÷ 51 % laktozy, 1 ÷ 3,5 % tłuszczu, 7,9 ÷ 9,5 % związków mineralnych w postaci popiołu i maksymalnie 4 % wody [5]. Typowy skład WPC 80 to: 80 ÷ 82 % białka, 4 ÷ 8 % laktozy, 4 ÷ 8 % tłuszczu, 3 ÷ 4 % popiołu i 3,5 ÷ 4,5 % wody [10].…”

Sensory Properties of Dairy Proteins

“…Recent published work has highlighted the impact of these specific processing steps (cheesemaking procedure, liquid storage, dry storage, bleaching, solids) on final whey protein flavor (Whitson et al, 2011;Wright et al, 2009;Croissant et al, 2009;Evans et al, 2009;Jervis et al, 2012;Campbell et al, 2013). Liquid whey is subjected to a host of processing techniques to concentrate and separate the whey protein.…”

“…Recent work has suggested that native whey proteins might provide a product with the functional and nutritional benefits of whey proteins with superior flavor properties (Evans et al, 2009;Campbell et al, 2013). Native whey proteins are simply whey proteins that are removed from fluid milk prior to the initiation of cheesemaking.…”

“…However, research also indicates that consumers can discern differences in whey protein flavors and that these flavors carry through into ingredient applications (Drake, 2006). Wright et al (2009) andEvans et al (2009; conducted consumer acceptance testing with whey proteins that were documented as distinct when profiled in 10% solution by trained panelists. The nature of the off-flavor and the ingredient application will also influence flavor carry-through (Drake, 2006).…”