| Bogenic amines are essential for human beings, but which could induce detrimental effects on humans at large dose, such as migraine, hypertension, hypotension, rash and digestive prob-lems, and their presence may lead to death in very severe cases. Sufu (including white sufu, red sufu and grey sufu) and stinky tofu are Chinese traditional fermented soybean products, and they are produced in an open-type natural condition, which provides a perfect environment for the production of biogenic amines owing to the plentiful supply of amino acids derived from tofu decomposition. Changes in biogenic amines in sufu and tinky tofu during production and stor-age have not yet been reported. Thus, the objective of our work was to investigate the changes in biogenic amines in sufu and stinky tofu during production and storage. Results of our research are as follows:1. We established a HPLC-UV method to determine ten biogenic amines (putrescine, ca-daverine, spermidine, spermine, tryptamine,2-phenethylamine, histamine, serotonin, tyramine and agmatine) simultaneously in sufu and stinky tofu. Biogenic amines in sufu (28 white sufu,7 red sufu and 3 grey sufu) and stinky tofu (5) samples were studied, results show that in the three types of sufu, putrescine and tyramine were those in the largest proportions, and putrescine and cadaverine were the most commonly found biogenic amines. In addition, the mean total bio-genic amine content in grey sufu was higher than that in white sufu, red sufu and stinky tofu. moreover, white sufu posed the highest risk to histamine toxication.2. During the produciton of sufu. biogenic amines increased quickly from tofu to pehtze and from pehtze to the salted pehtze periods and at the beginning of the ripening stage, we ad-vised that the total number of bacterial in sufu plant workshop should be controled; the yellow wine and red rice could inhibite biogenic amines formation, and safe herb extracts and additives could be used in the seasoning of sufu to minimize content of biogenic amines. Putrescine, ca-daverine, tryptamine,2-phenethylamine, histamine and tyramine were formed during the ripen-ing stage of sufu, while spermine. spermidine and agmatine reduced significantly (p<0.05). Effect of temperature (5.20 and 35℃,8% NaCl) and salt concentration (5,8 and 11% NaCl,20℃) on biogenic amines in white sufu during producion, results show that biogenic amines could be inhibited by higher temperature (35℃) and higher salt (11%,w/w) concentration of sufu during ripening. The physiochemical properties of sufu during the ripening period were also in- vestigated, there was no direct relationship between the physiochemical properties and biogenic amines content of sufu.3. Changes in biogenic amines in sufu during storage (20℃) were studied, results show that putrescine, cadaverine, histamine, tyramine and the total content of biogenic amines in-creased significantly (p< 0.05) in white sufu in 12 months; cadaverine, histamine and tryp-tamine decreased signicantly (p< 0.05) and tyramine increased sinificantly (p< 0.05) in red sufu; and putrescine, cadaverine, tyramine and the total biogenic amine contents increased sig-nificantly (p< 0.05) in grey sufu; and white sufu posed the highest risk to histamine toxication after storaged for 12 months. Influence of temperature (5.20 and 35℃,8% NaCl) and y-irraditon (0,5 and 10 KGy,20℃) on biogenic amine during storage was investigated, results show that contents of tryptamine,2-phenethylamine, tyramine and the total content of biogenic amine in white sufu after storaged 12 months at 5℃were lower (p< 0.05) than that storaged at 20℃and 35℃. In addition, contents of putrescine, cadaverine, tryptamine,2-phenethylamine, histamine, tyramine and the total content of bogenic amine in the irradiated white sufu which storaged for 12 months at 20℃were lower (p< 0.05) than that of un-irradiated white sufu. Therefore, lower temperature (5℃) and y-irraditon could inhibite biogenic amines in sufu sam-ples during storage.4. Changes in biogenic amines in stinky tofu during the traditional production were studied, putresince, cadaverine. spermine, spermidine and agmatine were detected; putrescine and ca-daverine formed, with spermidine, spermine and agmatine reduced during the fermentation of stinky tofu. The effect of temperature (15.25 and 35℃.2% NaCl) and salt concentration of stinky brine (1.2 and 3%.25℃) on biogenic amines during stinky tofu production was studied, results show that the fermentation temperature (15.25 and 25℃) higher and the stinky brine concentration (1,2 and 3%) lower.the time of producing stinky tofu shorter and the changes rate of biogenic amines in stinky tofu higher. In order to reduce content of biogenic amines in stinky tofu, the fermentation time of stinky tofu should be controlled. We also found that the stinky brine permeated tofu and the content of NH3 in stinky tofu increased during the production of stinky tofu, thus we could regard the content of NH3 as a fermentation degree of stinky tofu.5. Changes in biogenic amines in stinky tofu during storage were studied, putrescine. ca-daverine, spermidine. spermine. tryptamine,2-phenethylamine and tyramine were detected. Pu- trescine, cadaverine,2-phenethylamine and tyramine contents increased significantly (p<0.05) in stinky tofu storaged for 10 days at 20℃. Effect of temperature (5,20 and 35℃) and y-irraditon (0,5 and 10 KGy,20℃) on biogenic amines in stinky tofu during storage were re-searched, we found that putrescine, cadaverine, spermine and spermidine in stinky tofu were detected after storaged for 10 days at 5℃, and only putrescine, cadaverine, spermidine and tyramine could be detected in y-irradiated stinky tofu after storaged for 10 days at 20℃. In ad-dition, the content of biogenic amine was decreased significantly (p< 0.05) in stinky tofu which was storaged at lower temperature (5℃) or pre-irradiated. Thus the lower temperature (5℃) and pre- irradiation could inhibite accumulation of biognenic amines in stinky tofu during stor-age.
|
PDF Full Text Request