They suggested that the thermal
degradation of catechins in various teas during processing, and
loss of catechins during storage may occur. Factors that affect
the stability of phenolic compounds include structure and
concentration, pH, temperature, light, presence of co-ingredients,
self-association, sugar and their degradation products, proteins,
and sulfur dioxide [19,20]. In addition, the delivery of bioactive
ingredients is challenging because of their limited solubility in
water and off-odor