Writing in Flavour and Fragrance Journal the team behind the review noted that divanillin – which is a taste enhancer known to impart ‘pleasant impressions of creaminess to food’ – is naturally found in very low quantities in vanilla pods, but that production of the natural taste enhancer is possible at yields of greater than 95% using enzymatic reactions.
Led by Dr Ulrich Krings from the University Hannover, Germany, the team noted that in-depth sensory evaluations showed divanillin to possess “a pleasant, adherent and rich taste impression of creaminess, milk fattiness and sweetness, improving the quality of low-fat and reduced fat, semi-finished food products and ready-to-eat foodstuffs.”
“A subsequent patent claimed divanillin as a bitterness masking substance which extended the scope of applications for the food industry,” said the team.
Despite the strong promise of this natural taste enhancer and flavour masking agent, sourcing the ingredient has so far been tricky, said Krings and his team.
“Divanillin is primarily formed during the curing of the vanilla pods, a process of repeated wetting, warming ('sweating'), drying and conditioning aiming at the liberation of vanillin (1.5 to 2.5 % w/w) from its glucoside precursor,” they wrote. “The traces of natural divanillin present (5 to 50 mg per kg) are much too small to allow for an economic isolation.”
As a result, the German authors noted that many have tried to use biotechnologies to produce the taste enhancer.
Natural ingredients
“In a situation where consumers worldwide increasingly call for 'natural' food ingredients, and natural sources are economically unavailable, biotechnology can provide solutions without using toxic chemicals and harsh reaction conditions,” they said.
Indeed, the team noted that according to effective European law (EG 1334/2008) a 'natural flavoring substance' shall mean a compound 'obtained by appropriate physical, enzymatic or microbiological processes…', while The Code of Federal Regulation (CFR - Title 21) of the Food and Drug Administration of the United States contains the terms 'enzymolysis' and 'fermentation'.
“Transferred onto the divanillin case, a bioprocess could be envisaged mimicking the above pathway in the vanilla tissue, if a rich source of 'natural' vanillin as a precursor existed,” suggested Krings and his colleagues.
“This is the case,” they added, noting that biotechnological routes to the production of vanillin using strains of Amycolatopsis “has resulted in yields of 20 grams of 'biotech-vanillin' per liter of culture medium, presenting a rich source of the divanillin precursor.”