Biocatalytic process for upgrading of grape pomace
Fecha
20172017
Institución
Resumen
Grape pomace consists in the skin, stems and seeds of grapes that remain after processing
in the distilleries, wineries and juice industry. Grape processing wastes can be an important
economic problem to producers besides the environmental impact caused by the large
amount of these types of residues generated during the harvest season. In the latest years,
important efforts has done to obtain high added values products of waste grape by-products.
The main example is the extraction of polyphenols with antioxidant properties for use in food,
cosmetic or pharmaceuticals products 1.
However, the grape pomace has others interesting compounds which ones have been less
explored, as monoterpenes. Monoterpenes are present in grapes in free and glycosidic
conjugates forms, playing an important role in wine aroma. The glycoside conjugated form is
odourless and can be found in much higher concentrations than the free form, especially in
the skin of the grape. These compounds can liberate all its potential aroma under enzymatic
hydrolysis, based on a sequential and multienzymatic process using different glycosidases 2.
Recently using a commercial extract, different glycosidases were co-immobilized as a
combi-CLEA (Cross Liked Enzyme Aggregate) and successfully applied for aroma enhanced
in wine 3.
The objective of this work has been the recuperation of monoterpenes from grapes pomaces
based on a two stages biocatalytic process. As a first stage, pomace of muscat grape variety
from the production of pisco (Chilean Brandy) was hydrolysed using a commercial extract of
pectinases (Lafazym press) followed by solid-phase extraction of the conjugated
monoterpenes. The enzymatic hydrolysis was carry out adding 6 g of pectinases to 1 kg of
pomace (49% of humidity) suspended in distilled water, maintaining this suspension at
constant agitation for 24 h. After that, the hydrolysed was centrifuged to obtain a supernatant
enriched in sugars and conjugated monoterpenes. In a second stage, 10 g combi-CLEA of
glycosidases (22.3 and 18.3 UI/g of β-galactosidase and arabinoside activity, respectively)
was used to hydrolyse the conjugated monoterpenes.
After the whole process is possible to obtain free monoterpenes and moreover an effluent
with high content of reducing sugars that could be reincorporated into the main fermentation
process for pisco production.
This process shows an interested alternative for the revalorization of agro-wastes and to
obtain free monoterpenes for food and cosmetics applications.
Acknowledgements: Fondecyt 1160768
1. Yu J, Ahmedna M. International Journal of Food Science and Technology 2013, 48, (2), 221-
237.
2. Ahumada K, Urrutia P, Illanes A, Wilson L. Food and Bioproducts Processing 2015, 94, 555-
560.
3. Ahumada K, Martínez-Gil A, Moreno-Simunovic Y, Illanes A, Wilson L.. Molecules 2016, 21,
(11).