Soybean vegetable protein (Tofu) preserved with high pressure

Tofu is a soybean vegetable protein that Asians have long consumed; its intake is increasing in other countries. Tofu was purchased at a local shop. The tofu samples were already preserved in plastic bags subjected to vacuum and storage (5 degrees C). Tofu samples were subjected to high pressure (HP) of 400 MPa at 5 degrees C for 5, 30, and 45 min. Microbial analysis, sensorial evaluation, and structure were determined. HP treatment in tofu reduces the microbial population. Most of the microorganisms found in the initial population belonged to the Enterobacteriaceae family, bacteria Gram-negative (no Enterobacteriaceae), and bacteria Gram-positive. After HP treatment, Hafnia alvei and Bacillus cereus were found. After HP treatment, tofu is a pasteurized product, which is safer in terms of secondary pathogenic microbial contamination. Sensorial test results revealed that treated tofu was acceptable to consumers. The micrographs on the cryofracture observed with a cryoscanning electron microscope revealed a more compact structure after pressure compared with that of untreated samples, but the aggregates in the treated samples were more disperse.