Effects of concentration methods on the characteristics of spray‐dried black soybean cooking water

Abstract

Summary Legume cooking water (CW) is a food by‐product with the potential of becoming a plant‐based egg white replacement; however, limited research has been performed on processes to propel its industrialisation. Consequently, this study assessed the impact of concentration methods (thin‐film evaporation; cryoconcentration [CC]; and stove‐top boiling [BL]) on the composition and characteristics of spray‐dried CW powders. CW was concentrated from 6.8 to 22 °Brix. Subsequent analyses showed that the powder characteristics were an outcome of their particle size and composition. CC powders with 18.56 ± 0.85% protein and D50 = 0.14 ± 0.01 μm presented the lowest‐performing functionality. Conversely, BL powders (25.13 ± 0.50% protein and D50 = 3.70 ± 0.47 μm) displayed enhanced emulsification and foaming. Hence, the properties of CW improved with thermal concentration. These results lay the ground for selecting and optimising a concentration procedure aiming to industrialise the production of CW.

Black soybean cooking water (aquasoya) powder as a novel clean‐label ingredient in plant‐based vegan patties

“…This parameter decreased linearly for both samples; however, the heated solution showed a higher viscosity across the whole range, further corroborating that the heat treatment enhanced its rigidity. Previous research carried out by our group also established that the foaming and emulsifying properties of BSCW powder were improved by a heating step during its production (Echeverria‐Jaramillo & Shin, 2022).…”

“…Soy proteins are majorly composed of the storage proteins glycinin and conglycinin (Kasapis & Tay, 2009) which are expected to gel when heated and cooled at a concentration of minimum 10% (Hua et al ., 2005; Khatkar et al ., 2020). Therefore, since the protein content of BSCW powder was reported to be 22.79 ± 0.85% on a dry basis (Echeverria‐Jaramillo & Shin, 2022), a 40% aqueous solution, which is the highest concentration of BSCW powder solution that flowed, would have a protein concentration of less than 9% and thus not reach the minimum amount of protein to gel satisfactorily. Furthermore, most of the carbohydrates present in BSCW powder have been reported to be insoluble fibre and low molecular weight oligosaccharides (He et al ., 2021b); therefore, they are not expected to contribute to gelling either.…”

“…BSCW powder and methylcellulose were used as enhancers. The preparation of the BSCW powder is detailed in our previous work (Echeverria‐Jaramillo et al ., 2021; Echeverria‐Jaramillo & Shin, 2022). Briefly, black soybean ( Glycine max (L.) Merr.)…”

“…The concentrate was then spray‐dried in a pilot‐scale spray dryer (HSK‐100‐DJ; Niro, Gyeonggi‐do, Korea) working at a 180–200 °C inlet and 80 °C outlet air temperatures. BSCW powder is composed of 62.23 ± 0.52% total carbohydrates, 22.79 ± 0.85% protein, 9.76 ± 0.43% ash and negligible fat expressed on a dry basis (Echeverria‐Jaramillo & Shin, 2022).…”

“…Consequently, BSCW constitutes the preferred source of material for this study. This by‐product has the potential of becoming a valuable upcycled ingredient in the food industry due to its high availability in Asian countries since it is the main waste material in the production of local staple products such as fermented soybean pastes (Echeverria‐Jaramillo & Shin, 2022).…”