Poojary Mahesha M, Zhang Wei, Olesen Sarah Bisgaard, Rauh Valentin, Lund Marianne N
Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark.
Department of Forensic Medicine, Aarhus University, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.
J Agric Food Chem. 2020 Nov 17. doi: 10.1021/acs.jafc.0c05995.
Epigallocatechin gallate (EGCG)-enriched green tea extract (GTE) was added to lactose-reduced UHT-treated milk to evaluate its role in perturbing the Maillard reaction and the formation of advanced glycation endproducts (AGEs) during 1-year storage. The UHT processing caused epimerization of EGCG into gallocatechin gallate (GCG). For milk samples with added 0.1% w/v GTE, a EGCG/GCG loss of 26% was found soon after the UHT treatment and the loss increased to 64% after the 1-year of storage. LC-MS/MS analysis revealed the presence of various EGCG/GCG-α-dicarbonyl adducts and EGCG/GCG-hydroxymethylfurfural adducts in milk samples, while EGCG/GCG-amino acid adducts were not detected. Although EGCG/GCG trapped α-dicarbonyl compounds including glyoxal, methylglyoxal, 3-deoxyglucosone/3-deoxygalactosone, and diacetyl, it did not lower their net steady-state concentrations, except of 3-deoxyglucosone. The addition of GTE reduced the formation of Arg-derived AGEs by 2- to 3-fold, but surprisingly enhanced the accumulation of furosine and lysine-derived AGEs [ε-(carboxymethyl)lysine and ε-(carboxyethyl)lysine)] by 2-4-fold depending on the concentration of the added GTE and storage time. The present study shows that trapping of α-dicarbonyl compounds by EGCG may not be the major pathway for inhibiting the formation of AGEs in milk.
将富含表没食子儿茶素没食子酸酯（EGCG）的绿茶提取物（GTE）添加到经超高温瞬时灭菌（UHT）处理的低乳糖牛奶中，以评估其在1年储存期内对美拉德反应及晚期糖基化终产物（AGEs）形成的影响。UHT处理导致EGCG差向异构化为没食子儿茶素没食子酸酯（GCG）。对于添加了0.1% w/v GTE的牛奶样品，UHT处理后很快就发现EGCG/GCG损失了26%，储存1年后损失增加到64%。液相色谱-串联质谱（LC-MS/MS）分析表明，牛奶样品中存在各种EGCG/GCG-α-二羰基加合物和EGCG/GCG-羟甲基糠醛加合物，而未检测到EGCG/GCG-氨基酸加合物。尽管EGCG/GCG捕获了包括乙二醛、甲基乙二醛、3-脱氧葡萄糖酮/3-脱氧半乳糖酮和二乙酰在内的α-二羰基化合物，但除了3-脱氧葡萄糖酮外，它并没有降低它们的净稳态浓度。添加GTE使精氨酸衍生的AGEs形成减少了2至3倍，但令人惊讶的是，根据添加GTE的浓度和储存时间，糠氨酸和赖氨酸衍生的AGEs [ε-（羧甲基）赖氨酸和ε-（羧乙基）赖氨酸] 的积累增加了2至4倍。本研究表明，EGCG捕获α-二羰基化合物可能不是抑制牛奶中AGEs形成的主要途径。
