Investigating the suitability of sunflower press-cake proteins in formulated sports beverages†

Abstract

In a context where whey proteins currently dominate the protein sports beverage sector and pea proteins are usually commercialized as protein sources, this study proposes using sunflower press-cake, which contains approximately 44% protein, as an alternative and sustainable protein source. After the extraction from the press-cake, sunflower proteins were dispersed in an aqueous medium with varying xanthan gum concentrations (0.2%, 0.4% and 0.6% w/v) to simulate protein-rich sports beverages. Their performance was compared to that of whey and pea proteins, each at a 10% concentration. To enhance protein dispersibility and align with the trends of alkaline beverages, a K–P buffer at pH 9 was used as the dispersion medium, and 0.2% caffeine was included for cognitive benefits. Pasteurized dispersions were tested for rheological behavior and physical stability at 4 °C. Sunflower proteins, with a total polyphenolic content (TPC) of 35.2 mg_GAE g_DB⁻¹, outperformed whey (0.8 mg_GAE g_DB⁻¹) and pea (2.8 mg_GAE g_DB⁻¹) proteins. Sunflower dispersions exhibited a significantly lower volatile profile than those enriched with pea or whey proteins, reducing the need for odor-masking agents. Additionally, sunflower dispersions had a lower flow index than whey or pea dispersions, indicating easier processing. Despite the promising flow behaviour and optimal physical stability (stability index < 1.0), in vitro bioaccessibility analysis revealed a similar percentage of protein bioaccessibility between pea and whey dispersions, while sunflower ones had the lowest percentage. TPC bioaccessibility followed a similar trend. These findings highlight the feasibility of incorporating sunflower proteins into sports beverages, broadening options for formulators and promoting sustainability by repurposing agricultural by-products and adopting plant-based proteins.