In this paper, dyeing processes of silk-like fabric of ultra-fine polyester fiber are studied through orthogonal experiment, dyeing properties (K/S value, L* value, and C* value) of the fabric are tested under differe...In this paper, dyeing processes of silk-like fabric of ultra-fine polyester fiber are studied through orthogonal experiment, dyeing properties (K/S value, L* value, and C* value) of the fabric are tested under different dyeing conditions (pH value, time, and bath ratlo), and optimum dyeing conditions are arrived at through analysis.展开更多
Bread is still the most important food in Polish households. Staropolski and Pytlowy are two typical Polish breads, prepared with wheat and rye flour. The aim of this study was to examine the occurrence of volatile co...Bread is still the most important food in Polish households. Staropolski and Pytlowy are two typical Polish breads, prepared with wheat and rye flour. The aim of this study was to examine the occurrence of volatile contaminants such as furan and its derivatives, and present a volatile profile of the most common furan derivatives in the described products. To measure concentration of chemical compounds such as furan and furan derivatives, fast and effective solid-phase micro-extraction/gas chromatography/mass spectrometry （SPME/GC/MS） methods were adapted. This study showed the differences in furan occurrence between Pytlowy and Staropolski, however, the greater differences were observed between different times and temperatures of baking rather than between the bread types. Clearly, the higher concentrations were found in products prepared during the longest baking time period of 50 min, and temperatures of 230 ℃ and 240 ℃. The highest furan level was detected in Staropolski 28.89 ± 1.16/μg/kg, baked for 50 min at 230 ℃ in bread crust. The volatile fraction of bread crust was composed of 5-9 furan derivatives while crumb layer contained only furan-2-pentyl. It was concluded that furan is present in almost each type of bread and percentage of furan derivatives in all volatile fractions ranged from 0.5 % to 60.6% in crust of examined bars.展开更多
文摘In this paper, dyeing processes of silk-like fabric of ultra-fine polyester fiber are studied through orthogonal experiment, dyeing properties (K/S value, L* value, and C* value) of the fabric are tested under different dyeing conditions (pH value, time, and bath ratlo), and optimum dyeing conditions are arrived at through analysis.
文摘Bread is still the most important food in Polish households. Staropolski and Pytlowy are two typical Polish breads, prepared with wheat and rye flour. The aim of this study was to examine the occurrence of volatile contaminants such as furan and its derivatives, and present a volatile profile of the most common furan derivatives in the described products. To measure concentration of chemical compounds such as furan and furan derivatives, fast and effective solid-phase micro-extraction/gas chromatography/mass spectrometry （SPME/GC/MS） methods were adapted. This study showed the differences in furan occurrence between Pytlowy and Staropolski, however, the greater differences were observed between different times and temperatures of baking rather than between the bread types. Clearly, the higher concentrations were found in products prepared during the longest baking time period of 50 min, and temperatures of 230 ℃ and 240 ℃. The highest furan level was detected in Staropolski 28.89 ± 1.16/μg/kg, baked for 50 min at 230 ℃ in bread crust. The volatile fraction of bread crust was composed of 5-9 furan derivatives while crumb layer contained only furan-2-pentyl. It was concluded that furan is present in almost each type of bread and percentage of furan derivatives in all volatile fractions ranged from 0.5 % to 60.6% in crust of examined bars.
