Chickpea-Based Milk Analogue Stabilized by Transglutaminase

Abstract

Plant-based milk substitutes are becoming increasingly popular in the food industry. Among different plant proteins, chickpea proteins (CP) offer unique qualities as good functional and nutritional properties, followed by pleasant taste. This study examines the ability of the production of o/w emulsions resembling milk analogue (3% w/w chickpea protein, 3% w/w canola oil) by using chickpea protein isolate with/without the enzyme transglutaminase (TG) (50 U/g of protein). As a reference material, commercial soymilk was used. The emulsions were characterized by particle size distribution, zeta potential, viscosity, and microstructure. The TG-crosslinked chickpea protein milk analogue demonstrated improved stability, characterized by enhanced zeta potential (-24.7 mV) and extended shelf life compared to chickpea protein milk analogue without TG and soymilk. Stable particle size distribution (D[3,2] 0.11-0.17 µm) and shear-thinning behaviour (viscosity values of 2.16 mPas at 300 1/s) additionally contributed to their stability and desirable viscosity. Overall, chickpea protein milk analogue crosslinked by TG presents a promising alternative to traditional and plant-based milk products, offering clean-label, functional, and shelf-stable formulations. The additional optimization of protein concentration and processing conditions could enhance the overall functionality even further.

Keywords: chickpea protein; plant-based milk analogues; shelf-life; stability; transglutaminase.

Figure 1

The visual appearance of chickpea-based milk analogues with TG (1), without TG addition (2), and commercial soymilk (3) over 28 days of storage time at 4 °C and room temperature (RT).

Figure 2

Particle size distribution of chickpea-based milk analogues with TG addition (A), without TG addition (B), and in commercial soymilk (C) over 28 days of storage time at 4 °C.

Figure 3

Zeta potential of chickpea-based milk analogues without TG (3% CP control), with TG addition (3% CP + 50 U/g TG), and commercial soymilk sample over the storage time of 28 days at 4 °C. a, b, c different letters denote significant differences (p < 0.05) between plant-based milk analogues over one month of storage time at 4 °C.

Figure 4

Dynamic viscosity of chickpea-based milk analogues without TG (3% CP control), with TG addition (3% CP + TG), and commercial soymilk sample at 1st and 28th day of storage at 4 °C, as determined at shear rate range of 0.5 to 300 1/s.

Figure 5

Observation in light microscope (magnitude ×40) of chickpea-based milk analogues without TG addition (-TG), with TG addition (+TG), and commercial soymilk sample at 3rd and 28th day of storage at 4 °C. The red arrows indicate areas of coalescence and aggregation, highlighted within the red squares.