• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.37-44
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• 2007

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Although phosphates have never been classified as antimicrobial agents, a number of investigators have reported that phosphates have antimicrobial activities. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activities of sodium phytate(SPT), sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP) on Escherichia coli O157:H7 on tryptic soy broth and in beef, pork and chicken. In tryptic soy broth, SPT, SPP and STPP at the concentrations of 0.05, 0.1, and 0.5% effectively inhibited the growth of Escherichia coli O157:H7 in a concentration-dependent manner. The bactericidal activity of SPT was the stronger than that of SPP or STPP at the same concentrations. In addition, the antibacterial effects of SPT, SPP and STPP at the concentrations of 0.05, 0.1, 0.3, and 0.5% on Escherichia coli O157:H7 were also investigated in raw or cooked meats including beef, pork and chicken. SPT, SPP and STPP significantly inhibited the bacterial growth in a dose-dependant manner (p<0.05). The bactericidal effect of SPT was stronger than that of SPP or STPP. The addition of SPT, SPP and STPP in meats increased meat pHs. SPP and STPP also increased the levels of soluble orthophosphate in meats but STP did not. These results indicate that SPT is very effective for inhibition of bacterial growth and that can be used as a muscle food additive for increasing functions of meats.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.2
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• pp.237-246
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• 2014

Two experiments were conducted to evaluate the efficacy of feeding an Escherichia coli (E. coli) derived phytase to pigs fed P deficient, corn-soybean meal diets. In Exp. 1, one hundred and twenty crossbred piglets ($9.53{\pm}0.84$ kg) were allocated to one of five treatments which consisted of four low P diets (0.61% Ca, 0.46% total P and 0.24% non-phytate P) supplemented with 0, 500, 1,000, or 20,000 FTU/kg E. coli phytase as well as a positive control formulated to be adequate in all nutrients (0.77% Ca, 0.62% total P and 0.42% non-phytate P). The treatments were applied to six pens with four pigs per pen for 28 days. In Exp. 2, ten crossbred pigs ($19.66{\pm}1.16$ kg) fitted with ileal T-cannula were used in a nutrient balance study. The pigs were assigned to treatments similar to those used in Exp. 1 in a doubly replicated $5{\pm}4$ incomplete Latin square design (5 diets with 4 periods). Each period consisted of a 5-d adjustment period followed by a 3-d total collection of feces and urine and then a 2-d collection of ileal digesta. Supplementation with phytase linearly increased (p<0.05) weight gain, feed intake, feed efficiency, bone breaking strength and fat-free dry and ash bone weight. There were linear increases (p<0.01) in the apparent ileal digestibility (AID) of DM, GE, CP, Ca, total P, inositol hexaphosphate ($IP_6$) and some AA with increasing dose of E. coli phytase. Pigs fed 20,000 FTU/kg had a greater (p<0.05) AID of IP6 (80% vs 59% or 64%, respectively) than pigs fed diets with 500 or 1,000 FTU/kg phytase. There were linear increases (p<0.05) in the total tract digestibility of Ca, total P, Na, K, Mg, and Zn as well as in the retention of Mg and Zn with increased phytase dose. The retention and utilization of Cu, and the total tract digestibility of CP and Cu quadratic increased (p<0.05) with increased phytase dose. In conclusion, supplementation of 500 FTU of phytase/kg and above effectively hydrolyzed phytate in low-P corn-soybean diets for pigs. In addition, a super dose of phytase (20,000 FTU/kg) hydrolyzed most of the IP6 and consequently further improved mineral use, protein utilization and performance.

• BMB Reports
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• v.31 no.6
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• pp.595-599
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• 1998

To investigate conformational information of a low oxygen affinity recombinant hemoglobin (rHb) containing $96Val{\rightarrow}Trp$ mutation at the ${\alpha}96$ position, we ave produced rHb (${\alpha}96Val{\rightarrow}Phe$) and rHb (${\alpha}96Val{\rightarrow}Tyr$), using the Escherichia coli expression system and site-directed mutagenesis. The oxygen affinity of rHb (${\alpha}96Val{\rightarrow}Phe$) is similar to that of human normal adult hemoglobin (Hb A). However, the oxygen affinity of rHb (${\alpha}96Val{\rightarrow}Tyr$) showed much lower oxygen affinity than Hb A which is similar to that of rHb (${\alpha}96Val{\rightarrow}Tyr$), providing an opportunity as a potential candidate for a hemoglobin-based blood substitute. Both rHb (${\alpha}96Val{\rightarrow}Phe$) and rHb (${\alpha}96Val{\rightarrow}Tyr)$ showed high cooperativity in oxygen binding. IH-NMR spectroscopy shows that both rHb (${\alpha}96Val{\rightarrow}Phe$) and rHb (${\alpha}96Val{\rightarrow}Tyr$) have very similar tertiary structure around the heme pockets and uaternary structure in the ${\alpha}_1/{\beta}_2$ subunit interface ompared to Hb A. The low oxygen affinity of rHb (${\alpha}96Val{\rightarrow}Tyr$) has been suggested to be due to a hydrogen bond caused by an extra hydroxyl group not present in rHb (${\alpha}96Val{\rightarrow}Phe$). However, investigation of the carbonmonoxy form of rHb (${\alpha}96Val{\rightarrow}Phe$) and (${\alpha}96Val{\rightarrow}Try$) in the presence of inositol hexaphosphate at low temperature suggests that low oxygen affinity of (${\alpha}96Val{\rightarrow}Try$) may arise from a mechanism different to that of rHb (${\alpha}96Val{\rightarrow}Trp$).

• Korean Journal of Veterinary Research
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• v.47 no.4
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• pp.449-456
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• 2007

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Although phosphates have never been classified as antimicrobial agents, a number of investigators have reported that phosphates have antimicrobial activities. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activities of sodium phytate (SPT), sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP) on Salmonella typhimurium in tryptic soy broth and in row meat media including chicken, pork and beef. SPY, SPP and STPP at the concentrations of 0.5 and 1% dose-dependently inhibited the growth of S. typhimurium in tryptic soy broth at various pHs. The antibacterial activities of SPT and STPP were the stronger than that of SPP. In chicken, pork, and beef, SPT, SPP and STPP at the concentrations of 0.1, 0.5 and 1.0% significantly inhibited the bacterial growth in a dose-dependant manner (p < 0.05). The antibacterial activities of SPT, SPP, and STPP were more effective in chicken than beef. SPT and STPP at the concentration of 1% reduced the bacterial count by about 2 log units. The addition of SPT, SPP and STPP at the concentration of 0.5% in meats increased the meat pHs by 0.28-0.48 units in chicken, pork, and beef. These results suggest that SPT and STPP were equally effective for the inhibition of bacterial growth both in TSB and meat media and that SPT can be used as an animal food additive for increasing shelf-life and functions of meats.