CHICKPEA AQUAFABA AS AN EMULSIFIER IN FOOD-OIL SYSTEMS

Abstract

Aquafaba (AQ) is a viscous liquid produced during boiling or pressure-cooking chickpea seed in water. This by-product solution has been gaining popularity since 2014, when a blogger used AQ as an egg replacement in a vegan meringue. Due to its foaming and emulsion properties, AQ is increasingly being used as an egg replacement to add functionality to food products, such as mayonnaise, ice cream, pudding, and baked goods. The objective of this study is to select a chickpea cultivar that produces superior AQ for production of food oil emulsions as well as standardize AQ production. Seed of five chickpea cultivars were selected for AQ production: CDC Leader, CDC Orion, CDC Consul, CDC Luna, and Amit. Emulsion capacity and stability of AQ derived from different chickpea cultivars were determined. Physicochemical properties of different chickpea cultivars, such as hundred seed weight, seed coat incidence, seed dimensions, hydration kinetics, and proximate composition (moisture, ash, protein, fat, carbohydrate, and crude fibre) were also measured to determine possible correlations of these parameters with AQ emulsion properties. The effects of soaking and boiling of chickpea seed on yield and properties of AQ were determined. After selection of optimum conditions for preparing AQ, five drying methods (freeze drying, spray drying, oven drying, rotary evaporation drying, and vacuum drying) were compared. Dried AQ was rehydrated with distilled water, and its emulsion capacity and stability were measured. AQ from CDC Leader had the greatest emulsion capacity (1.10 ± 0.04 m2 g-1) and stability (71.9 ± 0.8%) and produced the most stable food oil emulsions. There were no correlations observed between AQ emulsion properties and chickpea seed chemical properties. On the other hand, AQ emulsion properties were negatively correlated with AQ yield and moisture content, indicating that AQ with higher dry-matter content displayed better emulsion properties. Among the treatments tested, soaking chickpea seed in 4 °C water for 16 h followed by cooking for 30 min produced AQ with the greatest emulsification properties. Spray drying achieved a high drying rate and drying efficiency, so it was a superior method for AQ production. In conclusion, AQ can simulate the function of egg in food oil emulsions and can be prepared from all cultivars tested but cooking conditions and genotype must be controlled to produce a consistent product.