According to pubmed.ncbi.nlm.nih.gov, Miraculin (MCL) is a homodimeric protein isolated from the red berries of Richadella dulcifica. MCL, although flat in taste at neutral pH, has a taste-modifying activity to convert sour stimuli to sweetness. Once MCL is held on the tongue, the strong sweetness is sensed over 1 h each time we taste a sour solution. Nevertheless, no molecular mechanism underlying the taste-modifying activity has been clarified. In this study, we succeeded in quantitatively evaluating the acid-induced sweetness of MCL using a cell-based assay system and found that MCL activated hT1R2-hT1R3 pH-dependently as the pH decreased from 6.5 to 4.8 and that the receptor activation occurred every time an acid solution was applied. Although MCL per se is sensory-inactive at pH 6.7 or higher, it suppressed the response of hT1R2-hT1R3 to other sweeteners at neutral pH and enhanced the response at weakly acidic pH. Using human/mouse chimeric receptors and molecular modeling, we revealed that the amino-terminal domain of hT1R2 is required for the response to MCL. Our data suggest that MCL binds hT1R2-hT1R3 as an antagonist at neutral pH and functionally changes into an agonist at acidic pH, and we conclude this may cause its taste-modifying activity.
Known as the taste modifier, Miraculin, a glycoprotein extracted from the fruit of Synsepalum dulcificum or better known as the Miracle Berry, in short, it makes the sour flavour tastes sweet without the intervention of artificial flavourings.
People who love to eat and drink sour-tasting food and beverages such as citrus fruits, alcohol, and the rest of the strongly flavoured meals, would somehow try to defy the taste without even the use of added-sugar. Thus, having miracle berries on your table wouldn’t hurt much on your calorie-conscious body.
Yes, miracle berries can replace your table sugar and any artificial flavourings that could possibly harm your health. Experts say that anything artificial is never good. Knowing that table sugar is almost used every day in our households, it is better to keep this stuff away especially from our kids before it’s too late.
Another research from PubMed said that Miraculin (MCL), a tropical fruit protein, is unique in that it has a taste-modifying activity to convert sourness to sweetness, though flat in taste at neutral pH. To obtain a sufficient amount of MCL to examine the mechanism involved in this sensory event at the molecular level, we transformed Aspergillus oryzae by introducing the MCL gene. Transformants were expressed and secreted a sensory-active form of MCL yielding 2 mg/L. Recombinant MCL resembled native MCL in the secondary structure and the taste-modifying activity to generate sweetness at acidic pH.
Also, they emphasized that Miraculin differs from other sweet-tasting proteins because it is a taste-modifier having the unusual property of modifying sourness to sweetness. It shows its taste-modifying activity at acidic pH, with a maximum at pH 3.0, while it is flat at neutral pH. Previous studies suggested the importance of two histidine residues for the taste-modifying activity of miraculin.
Citation:
www.pubmed.ncbi.nlm.nih.gov
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