supplemented with 20 and 35% glucose. A prominent pineapple aroma resulted due
to the production of 6.58 and 5.24 mmol/L/g total volatiles (TV) in the respective
media. Different aromatic compounds such as acetaldehyde, ethanol, isopropanol,
ethyl acetate, ethyl isobutyrate, isobutyl acetate, isoamyl acetate and ethyl-3hexanoate were identified in the headspace of the cultures. When leucine was
added, the total volatiles increased to 8.29 mmol/L/g. A strong banana odour was
detected as ethyl acetate and isoamyl acetate were found to be produced. However,
the biosynthesis of volatile compounds was not improved by the addition of soybean
oil and in fact it was reduced due to the addition of mineral salts (Soares et al. 2000).
In a study, five different agro-industrial residues were evaluated as substrate for
cultivating a strain of Kluyveromyces marxianus. The yeast produced fruity aroma
compounds when cassava bagasse and giant palm bran (Opuntia ficus-indica) were
used as substrates. In the experiment, the influence of different parameters on the
production of volatile compounds was tested. The parameters included initial pH of
the substrate, addition of glucose, incubation temperature, initial substrate moisture
and the size of inoculum. Using a 2
5 factorial design, both the parameters, namely
addition of glucose and initial pH of the substrate, were found to be statistically
significant for the production of aroma compounds when palm bran was used as a
substrate. The addition of glucose did not have a significant role when the substrate
was cassava bagasse, but 2
2 factorial designs showed the addition of glucose to be
statistically significant at higher concentrations. Nine and eleven aroma compounds
were found to be produced from palm bran and cassava bagasse, respectively, when
headspace analysis of the culture was done by gas chromatography. These
compounds included alcohols, esters and aldehyde. Ethyl acetate, ethanol and
acetaldehyde were the major compounds produced, while two compounds remained
unidentified in both the cases. Esters produced were responsible for the fruity aroma
in both the cases. When the substrate was supplemented with 10% glucose, 418 and
1395 μmol L
À1 headspace g
À1 of ethanol (palm oil) and ethyl acetate (cassava
bagasse) were produced at highest concentration (Medeiros et al. 2000).
Trichoderma viride has been reported to ferment the fruits of Pandanus tectorius
by using SSF approach. The aromatic compounds produced belonged to the classes
of alkanes, alcohols, ketones, pyrones, furanes, monoterpene and sesquiterpenes.
GC/MS analysis showed 17 peaks which corresponded to alkenes hydrocarbons
(tetradecane, tetracosane, tetracosahexaene, pentadecane, hexacosane, heptadecane
and octadecane), alcohol (phenol), amide (9-octacenamide) and monoterpene aldehyde (9-octadecenal) (Darmasiwi et al. 2016).
Following solid-state fermentation and distillation of sorghum, a fermented
product Kaoliang is prepared, further blended and aged by yeasts Saccharomyces
cerevisiae, Kazachstania exigua and Candida humilis) to form yellow water, a
by-product of fermentation. The optimization of fermentation process led to the
enhanced production of aroma compounds, such as ethyl acetate, isoamyl acetate
and 2-phenylethanol in the yellow water (Lai et al. 2019). Boratyński et al. (2018)
carried out solid-state fermentation (SSF) on linseed and rapeseed cakes inoculated
with different strains of filamentous fungi producing aroma lactone such as
1-phenylethyl acetate, a mixture of ‘trans’ and ‘cis’ whisky lactones,
7 Biotechnological Interventions for Production of Flavour and Fragrance. . .
149
to the production of 6.58 and 5.24 mmol/L/g total volatiles (TV) in the respective
media. Different aromatic compounds such as acetaldehyde, ethanol, isopropanol,
ethyl acetate, ethyl isobutyrate, isobutyl acetate, isoamyl acetate and ethyl-3hexanoate were identified in the headspace of the cultures. When leucine was
added, the total volatiles increased to 8.29 mmol/L/g. A strong banana odour was
detected as ethyl acetate and isoamyl acetate were found to be produced. However,
the biosynthesis of volatile compounds was not improved by the addition of soybean
oil and in fact it was reduced due to the addition of mineral salts (Soares et al. 2000).
In a study, five different agro-industrial residues were evaluated as substrate for
cultivating a strain of Kluyveromyces marxianus. The yeast produced fruity aroma
compounds when cassava bagasse and giant palm bran (Opuntia ficus-indica) were
used as substrates. In the experiment, the influence of different parameters on the
production of volatile compounds was tested. The parameters included initial pH of
the substrate, addition of glucose, incubation temperature, initial substrate moisture
and the size of inoculum. Using a 2
5 factorial design, both the parameters, namely
addition of glucose and initial pH of the substrate, were found to be statistically
significant for the production of aroma compounds when palm bran was used as a
substrate. The addition of glucose did not have a significant role when the substrate
was cassava bagasse, but 2
2 factorial designs showed the addition of glucose to be
statistically significant at higher concentrations. Nine and eleven aroma compounds
were found to be produced from palm bran and cassava bagasse, respectively, when
headspace analysis of the culture was done by gas chromatography. These
compounds included alcohols, esters and aldehyde. Ethyl acetate, ethanol and
acetaldehyde were the major compounds produced, while two compounds remained
unidentified in both the cases. Esters produced were responsible for the fruity aroma
in both the cases. When the substrate was supplemented with 10% glucose, 418 and
1395 μmol L
À1 headspace g
À1 of ethanol (palm oil) and ethyl acetate (cassava
bagasse) were produced at highest concentration (Medeiros et al. 2000).
Trichoderma viride has been reported to ferment the fruits of Pandanus tectorius
by using SSF approach. The aromatic compounds produced belonged to the classes
of alkanes, alcohols, ketones, pyrones, furanes, monoterpene and sesquiterpenes.
GC/MS analysis showed 17 peaks which corresponded to alkenes hydrocarbons
(tetradecane, tetracosane, tetracosahexaene, pentadecane, hexacosane, heptadecane
and octadecane), alcohol (phenol), amide (9-octacenamide) and monoterpene aldehyde (9-octadecenal) (Darmasiwi et al. 2016).
Following solid-state fermentation and distillation of sorghum, a fermented
product Kaoliang is prepared, further blended and aged by yeasts Saccharomyces
cerevisiae, Kazachstania exigua and Candida humilis) to form yellow water, a
by-product of fermentation. The optimization of fermentation process led to the
enhanced production of aroma compounds, such as ethyl acetate, isoamyl acetate
and 2-phenylethanol in the yellow water (Lai et al. 2019). Boratyński et al. (2018)
carried out solid-state fermentation (SSF) on linseed and rapeseed cakes inoculated
with different strains of filamentous fungi producing aroma lactone such as
1-phenylethyl acetate, a mixture of ‘trans’ and ‘cis’ whisky lactones,
7 Biotechnological Interventions for Production of Flavour and Fragrance. . .
149