A strong debittering agent was discovered in fermented skipjack tuna​,​ also known as bonito in Japanese. The compound​,​ known as N-acetylglutamic acid​,​ is a derivative of glutamic acid​,​ the principal flavor compound that activates umami. Despite being found in small quantities in most foods​,​ N-acetylglutamic acid is easily synthesized by acetylation of glutamic acid. Many supplements are acetylated​,​ like N-acetylcysteine or N-acetyltyrosine​,​ and so this could be an easy to produce ingredient.

Taste is one of the ways our ancestors gathered information about our food. It’s part of our decision-making process that determines what we should or should not eat. Taste influences our thinking​,​ emotions​,​ and behavior when it comes to what we choose to ingest. Taste even drives unconscious ways our bodies metabolically handle the food when we ingest it. That’s because​,​ beyond our tongue​,​ there are taste receptors that line our gastrointestinal system. 🧠

When animals have specialized diets​,​ their genes for certain taste buds can dwindle. They have fewer dietary decisions to make and do not require a full set of taste buds. For example​,​ pandas eat only bamboo. Many of their genes for the umami taste receptor are no longer functional. Animals that eat exclusively meat​,​ such as cats​,​ have lost their genes for sweet taste receptors all together. Aquatic carnivores have even fewer taste buds​,​ as they consume prey whole. 🐬

There are five types of taste for humans – sweet​,​ sour​,​ bitter​,​ salt​,​ and umami. Of these​,​ salt and sour are picked up by proteins called ion channels. On the other hand​,​ sweet and umami are made up of a family of proteins called taste receptor type 1 (T1Rs). Bitterness is detected by another family of taste proteins called taste receptor type 2 (T2Rs). The types of compounds that cause bitterness​,​ mostly toxic compounds​,​ are by far the most complex and diverse. ☣️

Taste is one of the most rudimentary senses in our genetic toolbox. The biochemical machinery to sense chemicals in water may have evolved as far back as 500 million years ago. And the first complete taste bud to appear in evolutionary history is believed to be for umami. Genes that encode for a sensor to the amino acid glutamate were found in the genome of elephant sharks​,​ which branched off from fish some 400 million years ago. The taste of umami is quite ancient. 👅

Ribonucleotides are intense umami enhancers. Inosinates in particular are found in high concentration in organ meats and animal protein. These RNA-based umami molecules raise the levels of uric acid in blood. During the Miocene age​,​ humans developed a mutation in the uricase enzyme​,​ resulting in steadier uric acid blood levels during times of famine. The need for ribonucleotides drives the taste for umami. But nowadays​,​ elevated blood levels of uric acid can lead to gout. 👅

There are literally hundreds of molecules that make up meat flavor. The dominant classes are sulfur compounds​,​ ketones​,​ and aldehydes. Sulfurous aromas are formed when cysteine and methionine react with ribose​,​ a type of sugar that makes up DNA and RNA​,​ during cooking. Ketones and aldehydes are formed from the break down of unsaturated fats. The diet of animals​,​ which contributes to the levels and types of fats​,​ amino acids​,​ and sugars in tissues​,​ plays a large in the final flavor. 🍗

Glutathione-enriched yeast is a powerhouse of flavor. Boasting high levels of glutamic acid​,​ nucleotides​,​ glutathione​,​ sugars​,​ and peptides​,​ yeast is the complete package for savory flavors. The Maillard reaction offers a way to design meat-like flavors using glutathione-enriched yeast. As an excellent source of sulfur precursors​,​ this yeast produces a wide variety of sulfur-based flavor products when heated with cysteine and ribose. Beef-like flavors can even be optimized. 🐄

Glutathione is a peptide made up of three amino acids - glycine​,​ cysteine​,​ and glutamic acid. During cooking and heating​,​ glutathione undergoes the Maillard reaction with reducing sugars to produce meat-like flavors. The cysteine contains a sulfur atom​,​ which participates in the reaction by producing sulfur-rich molecules such as 2-furfurylthiol​,​ thiophene​,​ and dimethyl disulfide. These are some of the molecules that give roasted meat its characteristic aroma and flavor. 🥩

One of the most abundant antioxidants found in all animal tissue is glutathione. This compound is especially concentrated in beef​,​ chicken​,​ pork​,​ and scallops. The molecule activates the intense taste of kokumi​,​ the sixth taste that enhances the intensity and longevity of savory flavors. Glutathione at 0.04% of the mass is needed to initiate this effect on our tongue. When combined with umami-eliciting compounds​,​ much less glutathione (0.01%) is needed to create the same taste effect. 🐖