Enzymes in Fruit Juice
Extraction
2009 Cluster 1
Biotechnology
Jody Zhang
Enzymes
Engineering
digestive enzymes
catalyze hydrolysis of
polymers into monomers
in food products
alter the structure of a
protein to consequently
modify function
family shuffling –
recombining
structurally similar
proteins of sections of
sequences
Cell Wall
glycan-rich
polysaccharide or oligosaccharide
primary and secondary walls
for structure
primary cell wall consists 80-90%
polysaccharide, 10-20% protein
cellulose-xyloglucan (type of
hemicellulose) network
embedded in matrix of pectin
secondary cell wall less pectin,
more cellulose, different class of
hemicellulose, lignin
Pectin
structural heteropolysaccharide –
monosaccharides are different
complex set of polysaccharides
present in primary cell walls, binds cells together
in middle lamella between plant cells
insoluable protopectins, polymers of galacturonic
acid, give structure; as fruit ripens, protopectin
breaks down into pectin, pectinic acid, and pectic
acid --> fruit softens
α-(1-4) polygalacturonic acid backbone, acetylated
and methylated
Pectin Structure
Pectinase/History
polygalacturonase
enzyme that breaks
down pectin
used for degradation
of cell walls = helps in
extracting fruit juices
1930s - first use of
pectinase in fruit juice
processing
1950s - purified,
standardized pectic
enzymes commercially
available
1970s – pectolytic
enzymes used during
mashing of apples
Cellulose and Cellulase
structural
polysaccharide
found in cell
walls, most
abundant
biopolymer in
nature
enzyme that
catalyses
hydrolysis of
cellulose
Polyphenol
group of chemical substances, common in
plants, consisting of molecules containing
one or more phenols – organic compounds
of phenyl rings, C6H5-, attached to a
hydroxyl group in aromatic ring
Flavonoid
most common group of polyphenols,
common in plants, known for antioxidant
activity
apple consumption correlate with reduced risk
of lung cancer in Europe