Natural low-calorie sweeteners - Natural Food Additives, Ingredients and Flavourings - page 67

3.5.3 Mabinlin
Mabinlin is a sweet protein from the Chinese plant Mabinlang ( Capparis masaikai
Levl.). It is a heterodimer and exists in several isoforms of which four have been
characterised (Liu et al. 1993; Nirasawa et al. 1994). Mabinlin I is heat labile,
losing sweetness after incubation for 30 minutes at 80°C and pH 6 (Kinghorn and
Compadre 2001); the other forms are more stable, particularly mabinlin II. This
heterodimer (the A chain of mabinlin II contains 33 amino acids; the B chain
contains 72, the whole is 10.4 kDa) is still sweet after 48 hours at 85°C. However,
the sweetness of mabinlin II is only about 10 times that of sucrose on a weight
basis (Liu et al. 1993; Nirasawa et al. 1994), which is so low that the protein has
no prospect of becoming a commercial high-potency sweetener.

3.5.4 Monellin
There are fi ve sweet proteins known as monellins isolated from the West African
serendipity berry, Dioscoreophyllum cumminsii Stapf. 'Monellin' is actually
monellin 4, a protein of 11 086 Daltons, occurring at 0.3-0.5% of the fruit and
comprising two, non-covalently associated polypeptide chains, A and B. Chain A
has 44 amino acid residues; B has 50. Separately the chains are not sweet, but in
the native form they have a potency of 1500-2000 at 7%SE (Kinghorn and
Compadre 2001).
Monellin has been of considerable academic interest but little commercial
signifi cance. It has a slow onset of sweetness, coupled with a persistent aftertaste.
It is not stable to heat.

3.5.5 Pentadin
Like brazzein (see Section 3.4.2), pentadin is a sweet protein isolated from
Pentadiplandra brazzeana Baillon. Much less attention has been paid to it than to
brazzein, but it has a molecular mass around 12 000 Daltons and a potency quoted
as 500 under unknown conditions (van der Wel et al. 1989). Pentadin was extracted
from smoked, dried berries (Hellekant and Danilova 2005) and it is unclear if it is
indeed distinct from brazzein obtained from fresh fruit.

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3.5.6 Phyllodulcin
Phyllodulcin is a dihydroisocoumarin sweetener, occurring as a glycoside in the
leaves of Hydrangea macrophylla Seringe and other hydrangeae. The sweet
aglycone is produced by enzymatic hydrolysis when leaves are crushed or
fermented.
Phyllodulcin is reported to have a potency of 400 at 2%SE. It has a delayed
sweetness onset and a liquorice aftertaste (Kinghorn and Compadre 2001). As
well as these sensory issues, the pure sweetener has low solubility.
The fermented leaves are used to make a sweet ceremonial tea in Japan and
the preparation is also used in confectionery and other foods in that country.