Fermented Quinoa Starch Conjugates Effectively Replace Fat in Low-Fat Yogurt

Food scientists have developed composite fat replacers using fermented quinoa starch and whey protein, demonstrating their potential to replicate the mouthfeel and structure of full-fat yogurt. Starch-protein composites have long been recognized as promising candidates for fat substitution, but achieving structural stability and desirable interfacial functionality in reduced-fat foods has presented substantial processing hurdles. By utilizing an anti-solvent precipitation method across starch-to-protein mass ratios ranging from 1:0 to 1:0.5, researchers evaluated whether microbial fermentation could modify starch surface properties to overcome these longstanding functional barriers.

Comparative structural assessments revealed that fermentation significantly enhanced the binding performance between quinoa starch and whey protein. At a mass ratio of 1:0.2, the fermented complexes achieved a complexation efficiency of 84.99 percent, markedly outperforming the 74.48 percent efficiency observed in their native counterparts. Spectroscopic and physical dissociations confirmed that this elevated affinity stemmed from stronger hydrogen bonding, enhanced hydrophobic effects, and robust electrostatic interactions, which were accompanied by pronounced changes in zeta potential across the formulated particles.

The physical characteristics of the composites varied according to the precise formulation ratio, with optimal properties emerging at a 1:0.3 starch-to-protein ratio. Under these parameters, fermented complexes attained a nanoscale particle size of 134.01 nanometers, compared to 250.40 nanometers in native starch complexes. Furthermore, the fermented particles exhibited a larger contact angle of 82.17 degrees compared to 74.25 degrees for native versions, alongside superior emulsifying capacity, denser microstructural networks, and enhanced stability in rheological testing.

To assess practical dairy performance, investigators incorporated the optimized conjugates into reduced-fat milk at concentrations spanning from 0.5 to 8 percent by weight during yogurt production. Formulations containing a 4 percent addition of the fermented composites delivered the highest performance, yielding yogurt with a peak water-holding capacity of 85.18 percent and minimized whey separation. The resulting gel network exhibited textural and rheological profiles that closely mirrored conventional full-fat yogurt, providing an effective clean-label strategy for improving low-fat fermented dairy systems.

Subject of Research: Evaluation of fermented quinoa starch and whey protein conjugates as fat replacers in low-fat yogurt

Article Title: Fermented quinoa starch-whey protein conjugate as an effective fat substitute in low-fat yogurt

Article References: Chen, W., Gu, W., Zhang, J., Wang, T., Zhang, W., Wang, Y., & Qiao, H. (2026). Fermented quinoa starch-whey protein conjugate as an effective fat substitute in low-fat yogurt. npj Science of Food. https://doi.org/10.1038/s41538-026-01222-7

Image Credits: AI Generated

DOI: 10.1038/s41538-026-01222-7

Keywords: quinoa starch, whey protein, fat replacer, low-fat yogurt, fermentation, starch-protein conjugate, anti-solvent precipitation, water-holding capacity, emulsifying capacity, dairy rheology, food microstructure, zeta potential, contact angle, clean-label ingredients, dairy science, food biopolymers