Effects of endogenous small molecular compounds on the rheological properties, texture and microstructure of soymilk coagulum: Removal of phytate using ultrafiltration.
This study aims to clarify the roles played by endogenous small molecular components in soymilk coagulation process and the properties of gels. Soymilk samples with decreasing levels of small molecules were prepared by ultrafiltration, to reduce the amount of phytate and salts. CaSO4-induced coagulation process was analyzed using rheological methods. Results showed that removal of free small molecules decreased the activation energy of protein coagulation, resulting in accelerated reaction and increased gel strength. However, too fast a reaction led to the drop in storage modulus (G'). Microscopic observation suggested that accelerated coagulation generated a coarse and non-uniform gel network with large pores. This network could not hold much water, leading to serious syneresis. Endogenous small molecules in soymilk were vital in the fine gel structure. Coagulation rate could be controlled by adjusting the amount of small molecules to obtain tofu products with the optimal texture.
China Agricultural University, College of Food Science and Nutritional Engineering, Beijing 100083, China.
Ruican
R
Wang
China Agricultural University, College of Food Science and Nutritional Engineering, Beijing 100083, China. Electronic address: shuntang@cau.edu.cn.
Shuntang
S
Guo
D005511:Food Handling; D005782:Gels; D010833:Phytic Acid / Q000737:chemistry*; D012212:Rheology; D045730:Soy Foods; D041942:Soy Milk / Q000737:chemistry*; D014462:Ultrafiltration
D005782:Gels; D010833:Phytic Acid
Calcium chloride anhydrous (PubChem CID: 5284359); Calcium citric (PubChem CID: 13136); Calcium sulfate dehydrate (PubChem CID: 6694: 24497); Citric acid monohydrate (PubChem CID: 22230); Coomassie brilliant blue G-250 (PubChem CID: 61364); Disodium phosphate dodecahydrate (PubChem CID: 61456); Ethanol (PubChem CID: 702); Glutaraldehyde (PubChem CID: 3485); Microstructure; Phosphoric acid (PubChem CID: 1004); Phytate; Rheological properties; Rhodamine B (PubChem CID: 6694); Small molecules; Sodium dihydrogen phosphate dihydrate (PubChem CID: 23673460); Soymilk coagulation; Trichloroacetic acid (PubChem CID: 6421); t-Butanol (PubChem CID: 6386)