Antioxidative characteristics of oils in ground pork-fat patties cooked with soy sauce

Ground pork-fat patties were cooked alone (control), with NaCl solution, wi th NaCl solution containing sucrose, with fermented soybean broth, with fer mented blade soybean broth, and with commercial soy sauce products at 125 d egreesC for 2 h. The top-layer oils were then stored at 60 degreesC for per iodical determinations of conjugated diene hydroperoxide (CDHP) contents. T he fermented broth-cooked and soy sauce-cooked oils were stable against CDH P formation during storage. This supports the customary impression that soy sauce-cooked pork is stable against oxidative rancidity. Analysis of the f atty acid compositions showed tho presence of linoleic,linolenic, and arach idonic acids, which are susceptible to oxidation. When the fermented broth- cooked oils were extracted with methanol, concentrated, and introduced to t he control oils for storage, an estimated antioxidative potency close to th at of 2 ppm butylated hydroxyanisole was observed. in comparing free amino acid compositions of the fermented soybean and blade soybean broths before and after cooking the ground pork-fat patties, threonine, serine, glutamic acid, alanine, isoleucine, leucine, tryptophan, and tyrosine contents decre ased while proline, valine, histidine, and arginine contents increased.