We have investigated the effect of the continuous supplementation of silicate in the drinking water of broilers and layers on the taste of meat and eggs. In a follow-up experiment, we here examined the influence of rearing method, hen age, and layer type on the effects of silicate supplementation on the taste and texture of the egg. Free amino acids were analyzed by ODS pre-column high-performance liquid chromatography. Sensory evaluation of egg yolk and egg white of boiled eggs was conducted by panelists. The results showed that many free amino acids related to sweetness, umami-taste, and bitterness were significantly increased in the high dose (0.24 mg/mL)-supplemented group compared to the control, although the specific amino acids that varied between groups differed from those identified in previous experiments. Moreover, the sensory evaluation showed that silicate supplementation decreased the egg smell, and increased the umami and preference for the egg yolk, while the stiffness score of the egg white increased. These findings suggest that silicate supplementation in hen drinking water could have beneficial effects on the egg taste, although further detailed studies are needed to clarify the specific amino acids that are increased according to test conditions.
