Kokumi! If you want a whole picture on umami, there's the core concept of glutamate, then a second level of umami boosting from ribonucleotides like IMP. There's a third layer that's not Glutathione Homeostasis and Functions: Potential Targets for Medical Interventions Lushchak 2012 Journal of Amino Acids Wiley Online Library Glutathione Gsh Antioxidant Plants Animals Fungi Stock Illustration 1320541694 Shutterstock Catabolism of extracellular glutathione supplies cysteine to support tumours Nature Optimizing Glutathione's Component Amino Acids Without Supplements JaypeeDigital eBook Reader