Use of Calcium Salts for Soybean Curd Preparation

Abstract

One of the delicate steps in the preparation of soybean curd is the addition of a salt to precipitate soy protein. The commonly employed salt is calcium sulfate. In this study, the use of other calcium salts (calcium chloride, calcium lactate, calcium acetate, calcium carbonate, calcium phosphate, calcium hydroxide, calcium gluconate) and two noncalcium compounds (gluconod-lactone and acetic acid) was'investigated. The result showed that soy protein was pfecipitated by calcium chloride, calcium lactate, calcium acetate, calcium gluconate, gluconod-lactone, and acetic acid. The amount of chemical added to precipitate soy protein varied depending upon the type of compound used, but in all cases, soy protein was pmcipitated when the pH of soy milk was at or near 6.0. Calcium acetate and calcium chloride appeared to be good precipitants for soybean curd preparation. The quality and sensory score of the soybean curd prepared from these salts requires less skill than calcium sulfate because of solubility; besides, the amount of the salt needed to precipitate soy protein was less than one-half that of calcium sulfate.

A statistical approach to define some tofu processing conditions

“…Assays 1, 9, and 13 resulted in tofu protein contents above commercial tofu range, which is an advantage from the nutritional point of view. These results agree with those in the literature, which varied from 4.5 (ROSSET, 2007) to 12.2 g protein.100 g -1 tofu (LIM et al, 1990), while Lu et al (1980), Cai et al (1997), Cai and Chang (1998), and Min, Yu and Sant Martin (2005) found intermediate values.…”

Magnesium Chloride Concentration-Dependent Formation of Tofu-Like Precipitates with Different Physicochemical Properties

“…11) It has been proposed that the first step in making tofu is the formation of a network of protein particles at a low calcium concentration, with subsequent binding of soluble proteins into the network due to the further addition of calcium and decreasing pH value. 8) Although the correlation between the yield and textural properties of tofu and the coagulant concentration has been widely reported, 10,[12][13][14][15][16][17][18][19][20][21][22] the difference in intermolecular interaction between silken tofu and regular tofu has not been elucidated. It has been found difficult to compare the difference of initiating protein concentration between silken tofu and regular tofu in the industrial process.…”

Influence of calcium chloride concentration on the physicochemical and sensory characteristics of tofu

“…Wang and Cavins (1989) found similar values of moisture (87.3%), total solids (12.7%) and fat (4.1%). Tofu is considered a precipitated soy protein and its clotting begins at a pH of approximately 6.0 (Lu et al, 1980;Knorr, 1984). In the present investigation, the pH varied between 6.13 and 6.20.…”