Chlorogenic Acid Moderately Decreases the Quality of Whey Proteins in Rats
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- 作者：Klaus J. Petzke ; Stefanie Schuppe ; Sascha Rohn ; Harshadrai M. Rawel ; and Jü ; rgen Kroll
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2005
- 出版时间：May 4, 2005
- 年：2005
- 卷：53
- 期：9
- 页码：3714 - 3720
- 全文大小：57K
- 年卷期：v.53,no.9(May 4, 2005)
- ISSN：1520-5118
文摘
During processing and storage, phenolic compounds (PCs) may react with food protein bound aminoacids (AAs). Such reactions have been reported to change physicochemical and to decrease in vitrodigestion properties of proteins. A rat growth and nitrogen (N) balance study was conducted to provewhether derivatization with chlorogenic acid (CA) affects the nutritional quality of 
-lactoglobulin (-LG). Test diets (10% protein level) contained nonderivatized -LG (LG, treated under omission ofCA), low derivatization level -LG (LGL), high derivatization level -LG (LGH), or casein supplementedwith L-methionine (0.3% of diet; C+met) as an internal standard. An additional group received untreated-LG supplemented with pure CA (1.03% of diet; LG+CA). The AA composition of test proteins,plasma AAs, and liver glutathione (GSH) concentrations were determined. Protein digestibility-corrected amino acid score (PDCAAS) was calculated using human or rat AA requirement patternsand rat fecal digestibility values. N excretion was significantly higher in feces and lower in urine ofrats fed with LGH as compared to LG and LGL. Consequently, true N digestibility (TND) wassignificantly lower with LGH as compared to LG and LGL. The lower content of methionine, cysteine,lysine, and tryptophan in LGH corresponded to a reduced TND. Net protein utilization (NPU) was notdifferent between treated -LG fed diet groups but was lower than in LG+CA and C+met fed groups.Only at a relatively high level of derivatization with CA, the otherwise good nutritional quality of -LGis affected so that TND is reduced, while NPU still remains unaffected. Derivatization of -LG withCA does not seem to lead to an additional deficiency in a specific indispensable AA in growing ratsfed with 10% protein.Keywords: Chlorogenic acid; lactoglobulin isolate derivatization; protein quality; nitrogen balance;rats
-lactoglobulin (-LG). Test diets (10% protein level) contained nonderivatized -LG (LG, treated under omission ofCA), low derivatization level -LG (LGL), high derivatization level -LG (LGH), or casein supplementedwith L-methionine (0.3% of diet; C+met) as an internal standard. An additional group received untreated-LG supplemented with pure CA (1.03% of diet; LG+CA). The AA composition of test proteins,plasma AAs, and liver glutathione (GSH) concentrations were determined. Protein digestibility-corrected amino acid score (PDCAAS) was calculated using human or rat AA requirement patternsand rat fecal digestibility values. N excretion was significantly higher in feces and lower in urine ofrats fed with LGH as compared to LG and LGL. Consequently, true N digestibility (TND) wassignificantly lower with LGH as compared to LG and LGL. The lower content of methionine, cysteine,lysine, and tryptophan in LGH corresponded to a reduced TND. Net protein utilization (NPU) was notdifferent between treated -LG fed diet groups but was lower than in LG+CA and C+met fed groups.Only at a relatively high level of derivatization with CA, the otherwise good nutritional quality of -LGis affected so that TND is reduced, while NPU still remains unaffected. Derivatization of -LG withCA does not seem to lead to an additional deficiency in a specific indispensable AA in growing ratsfed with 10% protein.Keywords: Chlorogenic acid; lactoglobulin isolate derivatization; protein quality; nitrogen balance;rats