Possible Clues:

• Shoyu flavor
• Relative behind unionist institute gets a taste of Japan
• MSG taste
• Savory taste first identified in Tokyo
• Taste whose name means 'savoriness' in Japanese
• Meaty flavor
• Fifth flavor
• Savory food quality
• Savoury taste sensation produced by glutamates — I, a mum (anag)
• Miso soup quality