African berries

Monellin, an intensively sweet protein from the West African berries Dioscoreophyllum cumminsii. On a weight basis, monellin is several thousand times more potent in sweetness than sucrose. It consists of two non-covalently associated polypeptide chains, A and B, with 44 and 50 residues, respectively. According to the X-ray crystal structure, the natural protein consists of an anti-parallel /S-sheet with five strands and an a-hdix. Single-chain moneUin (SCM), an engineered 94 aa polypeptide, has been proven to be as sweet as the native two-chain molecule, and is more stable in both high-temperature and acidic environments compared to the native monellin [T. Mizukoshi et al., FEBS Lett. 1997, 413, 409 ... 

Monellin an intensely sweet tasting dimeric protein the A-chain contains 44, the B-chain SO amino acid residues. M. tastes 3,000 times (weight basis) or 90,000 times (molar basis) sweeter than sucrose. It was discovered in the tesh fruits of an African berry, DioscoreophyUum cumminsU ( wild red berry ) of the Menispermaceae. Another sweet protein is Thaumatin (see). 

Taste also registers differences between enantiomers. L-Glutamic acid imparts a meaty flavor and has been sold as taste intensifier for meats. The D-isomer, however, is almost tasteless. The proteins thaumalin (MW about 21,000) and monellin (MW about 10,700) have been observed to exhibit intense sweetness. An even more potent taste modifier is miraculin (MW about 44,000), found, like the other two, in African berries, which causes acids to taste sweet. Monellin contains 92 amino acid residues. Its intact tertiary (three-dimensional) structure is necessary to produce sweetness. The protein is in fact composed of two noncovalently bound chains of 50 and 42 residues. When separated, neither shows sweetness. This represents a case of molecular recognition at a conformational level. 

The roots of pharmacology extend backward in time to our earliest Pleistocene hominid ancestors on the African savanna, approximately five to ten million years ago. These primitive forebearers grubbed for existence in the brush, where berries, shoots, leaves, tubers, flowers, seeds, nuts, and roots were plentiful. Our predecessors became specialized vegetarians who only later acquired an appetite for meat. It was their vegetarian diet that served to join gastronomic needs with pharmacological discovery. 

Additional evidence that the exterior surface of the taste receptor cell plasma membrane is the location of the sweet receptor is provided by the action of the chemostimulatory proteins, monellin and thaumatin. Monellin occurs in the fruit of the African serendipity berry (Dioscoreophyllum cumminsii), and thaumatin is found in the fruit of Thaumatococcus daniellii, also... 

The fruit of the African Miracle Berry bush (Synsepalum duldficum) has no flavor. But after it has been chewed, acidic foods taste sweet and not sour. A lemon tastes delicious, and a tomato is sweeter than an apple. The active substance appears to be a protein, and the mechanism has not been discovered. What are some possible mechanisms ... 

The edulans and dihydroedulans were first identified in passionfruit (Whitfield and Stanley, 1977 Prestwich et al., 1976). Subsequently, edulans were seen in human urine (Mills and Walker, 2001), while dihydroedulans have also been found in male scent organs of African butterflies (Schulz et al., 1993). The theaspiranes have been identified in green and black tea, as well as in a number of finits and berries (Schmidt et al., 1992). Later, a theaspirane was observed by SPME/GC-MS in urine from a female Asian elephant (Rasmussen, 2001). Recently, a dihydroedulan and a theaspirane were reported from giant panda urine (Dehnhard et al., 2003). 

Thaumatin (also called thalin) is a mixture of sweet proteins extracted from the fruit of the tropical West African flowering plant Thaumatococcus danielli (Marantaceae), known as miracle fruit or miracle berry. It is the only protein sweetener approved in the EU (E957). The main components with sweet notes resembling... 

Later, African tribes made wine from coffee, by fermenting the ripe berries and adding water to the juice. 

The A to Z of African American Cinema by S. Torriano Berry and Venise T. Berry, 2009. 

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