Transforming acid whey retentate into effective fat replacer in fat-free cream cheese
Can we turn acid whey (a dairy waste product) into a useful fat substitute for low-fat cream cheese that makes it taste and feel more like the full-fat version?
College of Health researcher(s)
Highlights
Highlights
- Acid whey retentate gelled at 3 % protein content under heating at 85 °C for 15 min
- Majority of calcium interacted with proteins and contributed to gelation
- Higher pH decreased the gel strength, and protein and calcium bioavailability
- Acid whey retentate gels softened the fat-free cream cheese
- The gels loosened the casein network and reduced its wall thickness
Abstract
The production of whey protein-based fat replacers often requires significant energy (75–90 °C) and/or extended duration (25–50 min), limiting their production efficiency and application in food systems. This study developed a whey protein aggregates-based fat replacer using acid whey (AW), with reduced heat input and processing time. AW was concentrated under alkaline conditions (pH 8) by ultrafiltration to recover proteins and calcium as retentate (AWR), followed by heating (85 °C for 15 min) at pH 6, 7, and 8 to induce aggregation. Although aggregation occurred across all pH levels, the samples at pH 8 demonstrated the lowest storage modulus (G′). Surface charge and hydrophobicity were the highest for AWR aggregates formed at pH 8 compared to pH6 and pH7, probably due to a more complete denaturation of whey proteins under alkaline condition. Compositional and energy-dispersive X-ray analysis revealed that calcium and whey proteins in AWR participated in aggregation. These AWR aggregates were incorporated into skim milk to develop cream cheese, which exhibited significantly lower G′, fully relaxable stress amplitude, and characteristic relaxation times comparable to those of low-fat cream cheese. Cryo-SEM showed that AWR aggregates reduced the compactness and continuity of casein network in cream cheese. This laboratory-scale study presents a promising strategy for valorizing acid whey as an effective fat replacer in dairy products and contributes toward more sustainable dairy processing.