Journal of Bioprocessing & Biotechniques

Flavors production by enzymatic esterification is an important scientific and technological issue due to the numerous inconveniences related to the acid catalysis, mainly due to not be a clean technology. In this sense, this work used an alternative technology that describes the maximization of the enzymatic production of eugenyl acetate and linalyl acetate esters via enzymatic esterification of eugenol, a major component of clove oil (Caryophyllus aromaticus), and tertiary alcohol linalool, by using acetic anhydride and immobilized enzyme Novozym 435 as the catalyst in an organic solvent-free system. The best reaction condition with 100% of eugenyl acetate conversion was obtained at 60°C with an excess of acetic anhydride (1:5 molar ratio) and 10% of enzyme concentration (w/w in relation to the substrates). Higher yields of linalyl acetate (5.6%) were achieved with the enzyme concentration of 5%, at 70°C and molar ratio acid to alcohol of 9:1, with 6 hours of reaction time for the both esters production. The data analysis showed a positive effect of molar ratio associated with the temperature to the eugenyl acetate conversion, and the effect of the temperature to the linalyl acetate conversion. The tertiary alcohol characteristic in esterification it was also discussed.

Colocynthis citrullus is a species of melon, popularly called ‘Egusi’ in West Africa. It belongs to a large family
called Curcubitaceae, which consist of 119 genera and about 925 species. In order to assess variations in nutritional
value of Egusi Melon (Colocynthis citrullus) seeds, proximate and fatty acid composition of eight accessions of the
crop were carried out. The accessions were selected from collections of family curcubitaceae made across Nigeria.
The analyses of shelled Melon seeds were done using the standard Method of Association of Analytical Chemists.
The data collected from the proximate and fatty acid constituents were used for Analysis of variance and Duncan
multiple range test (DMRT) was used to separate the means. The results of the proximate and fatty acid composition
showed significant differences (p < 0.05) among the different melon accessions. Accession NGR-NG-02 had highest
value of ash (8.71%), crude fibre (6.43) and crude protein (35.37%) contents. The highest stearic (10.03%) and oleic
(18.49%) values were recorded for NGR-NG-02 and NGR-NG-20 respectively. While the highest palmitic (61.33%)
and linoleic (65.84%) values were recorded for NGR-NG-29. The high significant variation observed among the
accessions could be an indication of high genetic diversity among Nigerian Egusi melon.