A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and t...A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% mcthanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds ol'foods studied. The average concentrations ofchlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.展开更多
The effect of the addition of natural antioxidants from strawberry tree （Arbutus unedo L.; AU） and dog rose （Rosa canina L.; RC）, in frankfurters elaborated with or without the addition of antioxidant additives （...The effect of the addition of natural antioxidants from strawberry tree （Arbutus unedo L.; AU） and dog rose （Rosa canina L.; RC）, in frankfurters elaborated with or without the addition of antioxidant additives （sodium ascorbate and nitrite） was studied. Six different types of experimental frankfurters were prepared depending on the addition of phenolic-rich extracts from RC and AU and the presence （P） or absence （C） of antioxidant additives. Thiobarbituric acid reactive substances （TBARS）-numbers signiifcantly increased during chilled storage of C-frankfurters while additives and fruit phenolics inhibited lipid oxidation in P-frankfurters. The amount of protein carbonyls signiifcantly increased in all treatments except in P-AU frankfurters. The discoloration process that occurred during the chilled storage was reduced by the addition of substances with proven antioxidant activity （P-frankfurters）. Texture characteristics as hardness, springiness, cohesiveness and gumminess also suffered a signiifcant deterioration in C-frankfurters. The use of phenolic fruit extracts in combination with traditional antioxidant additives is a successful strategy to enhance the oxidative stability of frankfurters without modifying their color and texture properties.展开更多
文摘A simple isocratic HPLC technique has been developed for the quantitative analysis of phenolic acids (PAs) in fruits and vegetables. Nine benzoic and cinnamic acid derivatives were separated in less than 30 min, and the resolution was all more than 1.23. The ranges of linearity for PAs standards were 0.2-100 ng, even up to 600 ng (r = 0.983-1.000) and the detection limits were 0.02-0.24 mg/kg. Samples of fresh vegetables and fruits were extracted with 80% mcthanol and ethyl acetate, then purified with C18 Sep-Pak cartridge and determined by HPLC. This method was applied to the determination of PAs in 7 kinds of fruits and vegetables, i.e., apple, pear, Chinese cabbage, cauliflower, turnip, soybean sprout and white grape wine. The content of the 9 PAs varied widely in the 7 kinds ol'foods studied. The average concentrations ofchlorogenic acid in apple (100.2 mg/kg) and pear (30.8 mg/kg) were quite high, and sinapinic acid was remarkable (42.5 mg/kg) in Chinese cabbage, and protocatechuic acid had the highest concentration of all the PAs in white wine.
基金supported by the Spanish CDTI Program(IDI 20090264)the Spanish Ministry of Science and Innovation for the contract through the Ramón y Cajal(RYC-2009-03901) program+3 种基金the support through the project Protein Oxidation in Frozen Meat and Dry-Cured Products:MechanismsConsequences and Development of Antioxidant Strategies(AGL2010-15134)The European Community (Research Executive Agency) is also acknowledged for the Marie Curie Reintegration Fellowship(PERG05-GA-2009-248959 Pox-MEAT)
文摘The effect of the addition of natural antioxidants from strawberry tree （Arbutus unedo L.; AU） and dog rose （Rosa canina L.; RC）, in frankfurters elaborated with or without the addition of antioxidant additives （sodium ascorbate and nitrite） was studied. Six different types of experimental frankfurters were prepared depending on the addition of phenolic-rich extracts from RC and AU and the presence （P） or absence （C） of antioxidant additives. Thiobarbituric acid reactive substances （TBARS）-numbers signiifcantly increased during chilled storage of C-frankfurters while additives and fruit phenolics inhibited lipid oxidation in P-frankfurters. The amount of protein carbonyls signiifcantly increased in all treatments except in P-AU frankfurters. The discoloration process that occurred during the chilled storage was reduced by the addition of substances with proven antioxidant activity （P-frankfurters）. Texture characteristics as hardness, springiness, cohesiveness and gumminess also suffered a signiifcant deterioration in C-frankfurters. The use of phenolic fruit extracts in combination with traditional antioxidant additives is a successful strategy to enhance the oxidative stability of frankfurters without modifying their color and texture properties.
