Natural flavourings from biotechnology for foods and beverages - Natural Food Additives, Ingredients and Flavourings - page 248

that the ionones are important to red raspberry aroma (Klesk et al. 2004). Reported
uses include non-alcoholic beverages, ice cream, candy, baked goods, gelatins and
puddings, chewing gum, maraschino cherries (Burdock and Fenaroli 2010).
The biotransformation of some carotenoids to produce β -ionone has been
reported. The use of the enzymes lipoxygenase and xanthise oxidase, using
β -carotene as substrate, has been described by Wu et al. (1999), Gonçalves et al.
(2006) and Waché et al. (2006). Moreover, the use of integer cells was evaluated
by Zorn et al. (2003) using fi lamentous fungi to cleave β -carotene into fl avor
compounds. The production of β -ionone, β -cyclocitral, dihydroactinidiolide, and
2-hydroxy-2,6,6-trimethylcyclohexanone were observed.

Damascones and damascenones
The damascones are commercially important due to their low odor threshold values
and attractive sensory properties. α -Damascone occurs in the natural fl avor of tea
and tobacco, and has a very powerful fl oral complex fruity note reminiscent of
plum, rose and blackcurrant. β -Damascenone is found as a volatile constituent of
many natural materials such as rose oils. This ketone is a constituent of Bulgarian
rose oil, where it is an important contributor to the characteristic aroma, although
present in a concentration of just 500 ppm (Winterhalter and Rouseff 2001).
The microbial bioconversion of damascones has been studied. Bioconversion of
α -damascone was studied with four strains of Botrytis cinerea in grape must (pH 3.2).
The biotransformation products identifi ed were: 1,3-oxo- α -damascone, cis - and
trans -3-hydroxy- α -damascone, γ -damascenone, 3-oxo-8, 9-dihydro- α -damascone,
and cis - and trans -3-hydroxy-8,9-dihydro- α -damascone (Schoch et al. 1991).

11.3.6 Vanillin
Menthol, furaneol and vanillin are three of the most widely used compounds by
the fl avor industry. Vanillin (4-hydroxy-3-methoxybenzaldehyde) possesses a
sweet, fl oral and spice-like odor, and is quite bitter above 30-40 ppm. It is the
principal fl avor component of vanilla extract obtained from the cured pods (beans)
of the orchid Vanilla planifolia Andrews, at a level of about 2% by weight (Schwab
et al. 2008; Burdock and Fenaroli 2010). Its use includes non-alcoholic beverages,
ice cream, candy, gelatins and puddings, chewing gum, syrups, toppings and
margarine (Burdock and Fenaroli 2010).
Vanilla extracts are used extensively in chocolate and baked products, and
especially in ice cream (Bauer et al. 2001). Vanilla extract is valued as a natural
fl avor. However, due to its high cost and limited availability, less than 1% of the
annual world demand for vanillin is isolated from its botanical source (Walton et
al. 2003). Most of the vanillin used by the fl avor industry originates from chemical
methods that use guaiacol, eugenol or lignin as starting materials (Rao and
Ravishankar 2000; Schwab et al. 2008). However, the difference in price of the
natural compound and its chemically synthesized counterpart can be considerable.
For example, the price for synthetic vanillin is about USD 12 per kg with a market
of 12 000 tons/year, while vanillin extracted from vanilla pods costs about USD

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