foods Article Interactions between Pea Protein Isolate and Carboxymethylcellulose in Neutral and Acid Aqueous Systems Ying Yue †, Shujie Pang †, Nana Li, Litao Tong , Lili Wang, Bei Fan, Chunhong Li, Fengzhong Wang * and Liya Liu * Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Beijing 100193, China;
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[email protected] (L.L.) † These two authors contributed equally to this work. Abstract: Pea protein isolate (PPI), as an emerging plant protein, has gradually aroused the attention of the public, but the PPI, especially high-concentration PPI’s low stability in the acidic aqueous sys- tem, was still a problem that limited its application. In this research, we investigated the interactions between relatively high concentrations of PPI (3.0%) and carboxymethylcellulose (CMC, 0–0.5%) in neutral and acid aqueous systems to explore the change of the phase behavior and stability of PPI as affected by CMC. It showed that the stability of PPI in the aqueous systems strongly depended on the CMC concentration, especially at the acidic aqueous systems. At neutral aqueous system, a certain amount addition of CMC into the PPI caused serious phase separation. While stable PPI solutions Citation: Yue, Y.; Pang, S.; Li, N.; Tong, can be obtained at a narrow region around pH 4.5 to 5.5 by adding different amounts of CMC.