RESUMEN
This study evaluated effects of vacuum-infused fresh chicken breast meats with grape seed extracts, green tea extracts, or tertiary butyl hydroquinone on pH, texture, color, and thiobarbituric reactive substances after cooking using a microwave or conventional electric oven for 12 d storage at 5 degrees C. Thiobarbituric reactive substances values of uncooked (raw) chicken breast meats for 0 to 12 d of storage ranged from 1.12 to 3.5 mg of malonaldehyde/100 g of chicken. During 0 to 12 d of storage, thiobarbituric reactive substances values ranged from 2.50 to 7.80 and from 2.4 to 7.35 mg of malonaldehyde/100 g of chicken breast meat cooked by microwave and conventional electric oven, respectively. Meats cooked by microwave had higher redness and lower lightness values than those cooked by conventional electric oven. Also, meats cooked by microwave had higher maximum shear force, working of shear, hardness, springiness, cohesiveness, and chewiness values than meats cooked by conventional electric oven. Tertiary butyl hydroquinone was the most effective in raw and cooked meats in reducing lipid oxidation, followed by grape seed and green tea extracts. Plant extracts are effective in preventing undesirable changes in chemical properties in chicken breast meat caused by microwave and conventional electric oven cooking.
Asunto(s)
Pollos , Culinaria , Carne , Microondas , Extractos Vegetales/farmacología , Animales , Calor , Hidroquinonas , Peroxidación de LípidoRESUMEN
The levels of cadmium, nickel, manganese, lead, zinc, iron, tin, copper and arsenic in fresh sheep's milk, white brined cheese preserved in glass jars and in tin containers and their corresponding brines, salt and tin plates were determined by atomic absorption spectrophotometry. The results have been compared with those reported in recent years. Although metal levels were comparable with other investigators' data, our data shows that white brined cheese picked-up metals from tin containers and from the naturally contaminated salt, on the contrary brined cheese in preserved glass jars showed lower levels of metals. We recommend a purified salt for brine preparation and glass jars for white cheese preservation in order to minimize cheese contamination with metals from tin cans and salt.
Asunto(s)
Queso , Contaminación de Alimentos , Conservación de Alimentos , Metales/análisis , Animales , Jordania , OvinosRESUMEN
The constituent polypeptide chains I, II, III and IV of the giant extracellular haemoglobin of the oligochaete Lumbricus terrestris were isolated by mono Q ion-exchange chromatography and C8 reverse-phase chromatography. The N-terminal amino acid sequences of Lumbricus chains I, III and IV were determined and aligned with those of Lumbricus chain II and the four chains of the extracellular haemoglobin of the polychaete Tylorrhynchus heterochaetus. Three invariant amino acid residues, Cys-7, Val-15 and Trp-19, were found to occur in the N-terminal segments (17-22 residues) of the eight chains of Lumbricus and Tylorrhynchus haemoglobins. In addition, it was found that the eight sequences could be separated into two groups: 'A', consisting of Lumbricus chains I and II and Tylorrhynchus chains I and IIA, having invariant Lys-14 and Lys-16, and 'B', consisting of Lumbricus chains III and IV and Tylorrhynchus IIB and IIC, having invariant Cys-6, Ser-8 and Asp-11. This result suggests that there are two strains of globin chain in the annelid extracellular haemoglobins.