Lab tests: a mushroom peptide boosts saltiness by 70.59%

On a lab bench, three short chains of amino acids were tested against a simple question: can they make salt taste stronger? The answer, in this study, is yes. Researchers at Gannan Medical University in China report that a peptide isolated from the edible Hypsizygus marmoreus mushroom boosted perceived saltiness by 70.59% over the test window, measured in the 75-105-second range.

The starting point is familiar. Salt carries flavor, and cutting it is difficult. The team did not propose a low-sodium diet as the only answer. Instead, they looked for a blend of peptides that could let a smaller amount of salt do the same job. From a pool of 6,000 candidates, mass spectrometry narrowed the list to five. Those five were synthesized and tested on human tasters and on an electronic tongue, an instrument that measures taste with sensors.

Three peptides held up: ASHGEGF, GDDWT and LDDGF. ASHGEGF was the strongest, with 70.59% enhancement, followed by LDDGF at 49.02% and GDDWT at 47.06%. At the molecular level, all three target the transmembrane channel-like protein 4 (TMC4), the receptor that detects saltiness and passes the signal to the brain. Earlier work had suggested mushrooms could interact with this receptor, but the mechanism had not been pinned down until now.

What changes, and for whom? The people who gain most are those who eat a lot of processed and fast food, where salt is often hard to see. The authors point to a further problem: studies have shown for decades that people underestimate how much salt goes into these foods, and that older people face a particular challenge. A food ingredient that makes salt register more strongly could, in principle, reduce intake without a noticeable change in taste. That is still a hypothesis. The peptides have so far been tested as isolated synthetic compounds, not in a finished product. The researchers will next examine how ASHGEGF performs in a low-sodium mix and in real food, and the source does not give a timeline for those tests or for any product.