Abstract
In order to clarify the bacterial contamination and the characteristics of carboxylic acid of commercial soybean curds (Tofu), which were packed in plastic cases, total bacterial counts, coliform organisms, streptococci, pH and carboxylic acid were examined with 30 samples of soaking water in these cases.
The results obtained are summarized as follows:
1. Mean values of total bacterial counts, plate counts of coliform organisms on desoxycholate agar medium, counts of streptccocci on AC medium and pH were 3.1×104/ml,4.4×10/ml,2.9/ml and 5.98, respectively.
2. Bacterial type of coliform organisms isolated from soybean curds was found to be mostly K. aerogenes I type
3. Correlation coefficients between total bactesial counts and coliform organisms and betwen total bacterial counts and pH of soybean curds were 0.68 and -0.71, respectively (P<0.001).
4. Carboxylic acids contained in soybean curds were examined with samples immediately after purchase and glutamic, lactic, acetic, pyruvic, malic, citric and formic acids were identified.
5. By the storage of these for 72 hours at 10°C, the amounts of lactic and acetic acids increased.
