Developing a chickpea protein–flaxseed oil emulsion gel meat analogue using the freeze-alignment technique

Abstract

The rising demand for sustainable protein alternatives has driven the development of plant-based meat analogues to address environmental, ethical, and health concerns associated with animal-derived meat. This study aimed to develop a chickpea protein–flaxseed oil emulsion gel meat analogue using the freeze-alignment technique and to optimize its formulation for desirable physicochemical and nutritional properties. A Box–Behnken design was employed to evaluate the effects of freezing temperature (−5 °C to −15 °C), solid-to-liquid (S/L) ratio (5–15% w/w), and chickpea protein isolate-to-flour (CP/CF) ratio (25–75% w/w) on six critical responses: moisture content, water holding capacity (WHC), cutting force, cooking loss, frying loss, and water activity. The optimal processing conditions were identified as a freezing temperature of −10.00 °C, an S/L ratio of 7.00%, and a CP/CF ratio of 75.00%, resulting in a desirability score of 0.8393. Under these conditions, the final product exhibited a moisture content of 65.63%, WHC of 70.38%, cutting force of 18.27 N, cooking loss of 15.02%, frying loss of 24.94%, and water activity of 0.91. The corresponding protein content reached 26.48% on a dry basis, and the fat content was 4.21% (wet basis), reflecting a balanced nutritional profile. Rheological analysis of the emulsion slurry confirmed shear-thinning behavior with low temperature sensitivity (E_a = 10.046 kJ mol⁻¹), indicating stable flow properties. Scanning electron microscopy revealed a porous, fibrous microstructure with uniform ice crystal templating, confirming the effectiveness of the freeze-alignment process. These findings demonstrate the feasibility of producing a nutritionally valuable and structurally stable chickpea-based meat analogue. However, high moisture levels could limit shelf-life, necessitating further investigation into non-freezing preservation methods and sensory evaluation to enhance consumer acceptance and industrial applicability.