Value addition of red beet (Beta vulgaris L.) by-products: Emulsion formation and stability

Replacement of synthetically derived food additives and increase of sustainability are two major trends within the food industry, and usage of by-products may represent a potential solution. We characterised an extract obtained from red beet that could also be obtained from red beet peels, that are typical industrial by-products, and examined its interfacial and emulsion forming properties. Results showed that red beet extract contained considerable amounts of surface-active saponins. The smallest negatively charged droplets (~1.36 μm, −40 mV) were obtained at low emulsifier-to-oil ratio and were fairly stable over a wide range of environmental stresses such as a wide pH range and temperature (<50 °C) despite some oiling-off. Emulsions showed flocculation at low pH, as well as coalescence at high temperature (≥50 °C) and phase separation after a freeze–thaw cycle. Overall, our results indicate red beet extract may be employed as new naturally derived emulsifier for food and beverage products.