Suppression of catechin astringency by milk components
2010
Miura, T., Nippon Veterinary and Life Science Univ., Musashino, Tokyo (Japan). Faculty of Applied Life Science | Akuzawa, R.
The tea catechin astringency suppression effect in milk component was examined. Simple sensory comparison, scoring test and paired reference test were used to evaluate the intensity of the astringency catechin. The solutions of catechin-milk component preparations were produced by combining catechin solution (6.26mg/mL) with milk, 9% skim milk (w/v), 4.5% lactose (w/v), and 3.8% cream solution (v/v), and were allowed to equilibrate for 20 min at 4degC. The astringency suppression effect was about 58-65% in the three samples that exclude lactose, especially skim milk was clearly significant astringency differences other two samples. The high performance liquid chromatography (HPLC) was used to evaluate the recovery of free catechin from catechin-milk samples. Catechin was combined with 9% skim milk, 4.5% lactose, and whey. These samples were following acid precipitation and centrifugation, supernatants were recovered and the total catechin content was determined by HPLC. Though the recovery of catechins was markedly decreased about 95% by skim milk, lactose and whey caused decreases of about 5-25%. The influence of various casein proteins on recovery of catechins was examined, alpha- and beta-casein showed equal recovery effects of about 45% when each casein concentration was the same formation for whole milk. beta-Casein showed the highest recovery of about 35% when each casein concentration was the same molar concentration. These results indicate that the astringency of the catechin is suppressed by the milk component.
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