enzyme technology in dairy
TRANSCRIPT
-
8/2/2019 Enzyme Technology in Dairy
1/72
Click to edit Master subtitle style
4/15/12
Ezyme Technology
For Dairy Industry
Lecturer: Dr. L H NG P
-
8/2/2019 Enzyme Technology in Dairy
2/72
4/15/12
Group
3Nguyn Tt Hon V BTFTIU10208Nguyn Ngc Mai Trinh BTFTIU10215
L Th Hng Nhi BTFTIU10229
Hong H Thanh Hi BTFTIU10210
Trn Th Mai Hng BTFTIU10
-
8/2/2019 Enzyme Technology in Dairy
3/72
4/15/12
CONTENTS
INTRODUCTION INDIGENOUSENZYMES OF
BOVINE MILK
EXOGENOUSENZYMES USED IN THE
DAIRY INDUSTRY
-
8/2/2019 Enzyme Technology in Dairy
4/72
4/15/12
INTRODUCTI
-
8/2/2019 Enzyme Technology in Dairy
5/72
4/15/12
.In the dairy industry, enzymes are widely used inthe production of milk, cheeses, yogurt and other dairyproducts
-
8/2/2019 Enzyme Technology in Dairy
6/72
4/15/12
q Enzyme technology in the dairy industrycan be divided into two main areas:
1. INDIGENOUS ENZYMES in milk andtheir impact on dairy products
2. The use ofEXOGENOUS ENZYMESin the manufacture of dairy products.
-
8/2/2019 Enzyme Technology in Dairy
7/72
4/15/12
INDIGENOUS
ENZYMES OFBOVINE MILK
-
8/2/2019 Enzyme Technology in Dairy
8/72
4/15/12
INDIGENOUS ENZYMES OF BOVINEMILK
-
8/2/2019 Enzyme Technology in Dairy
9/72
Click to edit Master subtitle style
4/15/12
INDIGENOUS ENZYMES OFBOVINE MILK
- Microorganisms in Bovine milk are a potential enzymatic source
have positive or negative impacts in dairy applications.- Most microorganisms do not survive pasteurization limited toproducts produced mainly from raw milk.- The microflora of raw cold stored milk is dominated by Gram-negative, nonlactose fermenting psychrotrophic bacteria, with more
than 70% of milk microflora consisting of Pseudomonas species.
-
8/2/2019 Enzyme Technology in Dairy
10/72
4/15/12
Approximately sixty indigenous enzymes are present inraw milk have been reported.
q Indigenous milk enzymes arise mainly from three potentialsources:
1. Blood
2. Secretary cell cytoplasm3. The milk fat globule membrane.q. Most indigenous enzymes are inactive in milk due to
inappropriate environmental conditions or lack of suitable
substrates Enzyme Technology and destroyed by pasteurizationto create a standardized product.q. Those indigenous enzymes that can be exploited to aid certain
dairy applications, or those that could have a major negative
impact in dairy applications if not controlled.
-
8/2/2019 Enzyme Technology in Dairy
11/72
4/15/12
LIPASES Lipase is an enzyme that catalyzes the formation or cleavage (
hydrolysis ) of fats ( lipids ). Low levels of lipolysis can have a marked
impact on flavor. For example: In general the lower chain
FFAs (C4 C8) impart rancid flavors, whilelonger chain FFAs impart soapy flavors.
The fat globules are surrounded by a thinmembrane called the milk fat globulemembrane (MFGM).
be damaged by agitation, homogenization,foaming, or poor handling, which can result inthe rapid interaction of enzyme and substrate,causing the development ofoff flavors.
http://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipases&hl=vi&client=firefox-a&hs=wwj&rls=org.mozilla:en-US:official&prmd=imvnsb&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Enzyme&usg=ALkJrhhHZ9oelqNuvUUm5FIAQLmUJeK1ZQhttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipases&hl=vi&client=firefox-a&hs=wwj&rls=org.mozilla:en-US:official&prmd=imvnsb&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Catalyze&usg=ALkJrhgg0z_GQz8mbuVAGL3wxeQ6OX3bCAhttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipases&hl=vi&client=firefox-a&hs=wwj&rls=org.mozilla:en-US:official&prmd=imvnsb&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Hydrolysis&usg=ALkJrhimh_9WDbkldKvpP2kX75aeV_ficghttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipases&hl=vi&client=firefox-a&hs=wwj&rls=org.mozilla:en-US:official&prmd=imvnsb&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Lipid&usg=ALkJrhjfhzsop9d8W4Czrdgrp9faeHICtwhttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipases&hl=vi&client=firefox-a&hs=wwj&rls=org.mozilla:en-US:official&prmd=imvnsb&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Lipid&usg=ALkJrhjfhzsop9d8W4Czrdgrp9faeHICtwhttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipases&hl=vi&client=firefox-a&hs=wwj&rls=org.mozilla:en-US:official&prmd=imvnsb&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Hydrolysis&usg=ALkJrhimh_9WDbkldKvpP2kX75aeV_ficghttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipases&hl=vi&client=firefox-a&hs=wwj&rls=org.mozilla:en-US:official&prmd=imvnsb&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Catalyze&usg=ALkJrhgg0z_GQz8mbuVAGL3wxeQ6OX3bCAhttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipases&hl=vi&client=firefox-a&hs=wwj&rls=org.mozilla:en-US:official&prmd=imvnsb&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Enzyme&usg=ALkJrhhHZ9oelqNuvUUm5FIAQLmUJeK1ZQ -
8/2/2019 Enzyme Technology in Dairy
12/72
4/15/12
Lipoprotein Lipase It is a water soluble enzyme that
hydrolyzestriglycerides in lipoproteins. Indigenous LPL is present in milk via
leakage through the mammary cellmembrane from the blood where it is
involved in the metabolism of plasmatriglycerols.
LPL is activated by an apolipoprotein activator, apo-CII, and ispresent in high enough concentrations in milk to be of real dangerin terms of its spoilage capability.
LPL is susceptible to standard high temperature short time (HTST)pasteurization; however it is thought that it is not completelyinactivated and may be active in some milk products.
http://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipoprotein+Lipase&hl=vi&client=firefox-a&hs=L15&rls=org.mozilla:en-US:official&prmd=imvns&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Enzyme&usg=ALkJrhhPX-rSdYQkgYTSaHxNGBsslbSWWAhttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipoprotein+Lipase&hl=vi&client=firefox-a&hs=L15&rls=org.mozilla:en-US:official&prmd=imvns&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Hydrolyze&usg=ALkJrhiaEY68V2LRb-mYbu3wHQhBOys41whttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipoprotein+Lipase&hl=vi&client=firefox-a&hs=L15&rls=org.mozilla:en-US:official&prmd=imvns&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Triglyceride&usg=ALkJrhgJLR7BMGVjlTlvABU6Eoj2aeKp6Ahttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipoprotein+Lipase&hl=vi&client=firefox-a&hs=L15&rls=org.mozilla:en-US:official&prmd=imvns&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Lipoprotein&usg=ALkJrhimbQmcBkAF7R-dF3V2uCnyqDzy3whttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipoprotein+Lipase&hl=vi&client=firefox-a&hs=L15&rls=org.mozilla:en-US:official&prmd=imvns&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Lipoprotein&usg=ALkJrhimbQmcBkAF7R-dF3V2uCnyqDzy3whttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipoprotein+Lipase&hl=vi&client=firefox-a&hs=L15&rls=org.mozilla:en-US:official&prmd=imvns&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Triglyceride&usg=ALkJrhgJLR7BMGVjlTlvABU6Eoj2aeKp6Ahttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipoprotein+Lipase&hl=vi&client=firefox-a&hs=L15&rls=org.mozilla:en-US:official&prmd=imvns&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Hydrolyze&usg=ALkJrhiaEY68V2LRb-mYbu3wHQhBOys41whttp://translate.googleusercontent.com/translate_c?hl=vi&prev=/search?q=Lipoprotein+Lipase&hl=vi&client=firefox-a&hs=L15&rls=org.mozilla:en-US:official&prmd=imvns&rurl=translate.google.com.vn&sl=en&twu=1&u=http://en.wikipedia.org/wiki/Enzyme&usg=ALkJrhhPX-rSdYQkgYTSaHxNGBsslbSWWA -
8/2/2019 Enzyme Technology in Dairy
13/72
4/15/12
Bacterial Lipases Extracellular lipases produced by psychrotrophic bacteria
have the potential to cause hydrolytic rancidity in milkand milk products as these dominate in typical cold bulkmilk storage conditions.
Lipases of psychrotrophicbacteria have varying heatstability and some can survive
pasteurization, however
lipolytic spoilage rarely occursin pasteurized milk.
Pseudomonas is the most frequentlyreported psychrotroph in raw milk
-
8/2/2019 Enzyme Technology in Dairy
14/72
4/15/12
Phospholipases
Phospholipase activity has been identified in milk LPLand in several bacteria.
Phospholipases are potentially very important in milkas they degrade the phospholipids of the MFGM,thereby making the fat susceptible to hydrolysis.
These enzymes are also quite heat stable and are notdestroyed by pasteurization.
-
8/2/2019 Enzyme Technology in Dairy
15/72
4/15/12
PROTEINASES
A few indigenous milk proteinases have beenidentified in bovine milk, but only two appear tobe of importance in the dairy industry:
1. Plasmin or Milk Alkaline Proteinase.
2. Cathepsin D or Acid Milk Proteinase.
-
8/2/2019 Enzyme Technology in Dairy
16/72
4/15/12
Proteinase Plasmin (EC 3.4.21.7) is an alkaline serine proteinase
and is secreted as plasminogen that is activated inblood and milk.
Its role in blood is to break
down blood clots and is a partof a complex systemconsisting of activators andinhibitors.
The concentration of plasmin and plasminogen inmilk increases with advancing lactation, mastiticinfection, and number of lactations.
-
8/2/2019 Enzyme Technology in Dairy
17/72
4/15/12
Plasmin has a high specificity for peptide bonds with a
carboxyl group supplied by lysine or arginine.
It has an optimumactivity at pH 7.5 and
35C, and still exhibitsabout 20% activity at5C.
It is active over a widepH range from pH 4 to9 and is quite heatstable.
LYSINE ARGININE
-
8/2/2019 Enzyme Technology in Dairy
18/72
4/15/12
Plasmin can have a positive or
negative effect on cheesemaking as it is involved inproteolysis during ripening.
It is also linked to poor curd
formation in cheese made fromlate lactation milks.
Plasmin is also associated with the generation of gluey and
bitter off flavors during storage of UHT milks and is a majorfactor affecting their shelf life.
It can accelerate cheese ripening by the activation of
plasminogen to plasmin in the cheese.
-
8/2/2019 Enzyme Technology in Dairy
19/72
4/15/12
Proteinase
Cathepsin D (EC 3.4.23.5) is a lysozomal enzyme thathas a similar specificity to chymosin, but has very poormilk clotting activity.
It is relatively heat labile as it is inactivated by 70Cfor 10 min, and may contribute to proteolysis incheese, but not significantly.
A a ine P osp omonoesterase
-
8/2/2019 Enzyme Technology in Dairy
20/72
4/15/12
A a ine P osp omonoesterase(Phosphatase)
v Phosphatase enzymes are ableto split specific phosporic acidesters into phosphoric acid andthe related alcohols.
v It has a pH and temperatureoptima differing from
physiological values; pH of9.8.
v The enzyme is destroyed byminimum pasteurizationtemperatures.
Alkaline
-
8/2/2019 Enzyme Technology in Dairy
21/72
4/15/12
v The enzyme is a glycoprotein and
has a lower optimum pH than that ofalkaline phosphatase (pH 5).
v Acid phosphatase hydrolysesaromatic phosphomonoesters.
v The enzyme is active against caseins.
v This enzyme affects casein micelleformation through dephosphorylation
of casein, which destroys interchainbridging via phosphate groupsbetween casein polypeptides andcalcium ions.
AlkalinePhosphomonoesterase(Phosphatase)
-
8/2/2019 Enzyme Technology in Dairy
22/72
4/15/12
LACTOPEROXIDASE
v Peroxidases have beenshown to be involvedin antibacterial
activity.v Lactoperoxidase
requires H2O2 andthiocyanate to causebacterial inhibition.
v The mode of action ofthis system has beenused to cold pasteurize
SO S
-
8/2/2019 Enzyme Technology in Dairy
23/72
4/15/12
LYSOZYMES
Lysozyme hydrolyses the(1-4)-linkage betweenmuramic acid and N-acetylglucosamine of
mucopolysaccharides of thebacterial cell wall.
Lysozyme is fairly heatstable in acid conditions, but
heat labile at pH 7 or above. Lysozyme is effectively an
antibacterial agent .
-
8/2/2019 Enzyme Technology in Dairy
24/72
4/15/12
XANTHINE OXIDASE It concentrated in the MFGM where
it is one of the principal proteins. All of the major milk proteins can
act as either activators or inhibitorsof xanthine oxidase.
The pH optimum is about 8.5 , theenzyme requires flavin,adenine,dinucleotide, othercofactors.
It in milk is associated with oxidativerancidity.
Xanthine oxidase has been
implicated as having bacteriostatic
GLUTAMYL TRANSPEPTIDASE
-
8/2/2019 Enzyme Technology in Dairy
25/72
4/15/12
- GLUTAMYL TRANSPEPTIDASE(Transferase)
-Glutamyl transpeptidase catalyses thetransfer of _ -glutamyl residues from - glutamyl-containing peptides.
It plays an important role in amino acidtransport in the mammary gland
-
8/2/2019 Enzyme Technology in Dairy
26/72
4/15/12
EXOGENOUS
ENZYMES USED IN THEDAIRY INDUSTRY
-
8/2/2019 Enzyme Technology in Dairy
27/72
4/15/12
-
8/2/2019 Enzyme Technology in Dairy
28/72
4/15/12
-GALACTOSIDASE
-Galactosidases (commonly referred to as lactase),which hydrolyse lactose to glucose + galactose, areprobably the second most significant enzyme in dairytechnology
-
8/2/2019 Enzyme Technology in Dairy
29/72
4/15/12
Roles: Getting easy to consume milk and dairy products for
people who are lactose-intolerant
Limiting many defects in refrigerated foods such as
crystallization in dairy foods, development of sandy orgritty texture, and deposit formation.
LIPASE
-
8/2/2019 Enzyme Technology in Dairy
30/72
Click to edit Master subtitle style
4/15/12
LIPASE
The principal application of lipases in dairy technology is incheese
-
8/2/2019 Enzyme Technology in Dairy
31/72
4/15/12
LIPASE
a
b
c
Rennet P t
-
8/2/2019 Enzyme Technology in Dairy
32/72
4/15/12
a combination ofthe milk clotting enzyme rennet andpregastriclipases, which contribute to the required flavor and aromadevelopment
Produced by grinding the semi-dry stomach of the dairy animal
into a paste + NaCl. Rennet pastes contains
chymosin which coagulates
the milk + a potent lipase +
pregastric esterase, which
leads to much lipolysis
during ripening.
Rennet Paste
-
8/2/2019 Enzyme Technology in Dairy
33/72
4/15/12
(PGE) The lipase in rennet paste, generally referred to as
pregastric esterase (PGE), is secreted by a gland at thebase of the tongue, which is stimulated by suckling; thesecreted lipase is washed into the stomach with theingested milk.
Pecorino Provolone
-
8/2/2019 Enzyme Technology in Dairy
34/72
4/15/12
The physiological significance: to assist in lipiddigestion in the neonate which has limited pancreaticfunction
Provide the sharp piquant flavorwhich is is primarily
due to short chain FFAs arising from the action of PGE For example : lipases that primarily release short chain
fatty acids lead to the development of a piquant, sharp,spicy, tangy flavour, while release of medium to long
chain fatty acids can lead to a soapy taste
-
8/2/2019 Enzyme Technology in Dairy
35/72
4/15/12
-
8/2/2019 Enzyme Technology in Dairy
36/72
4/15/12
PGEs are regioselective for the Sn1 and Sn3 positions of
milk triglycerides and have a particular affinity for shortchain fatty acids at the Sn3 position.
This ensures the
release of the mostvolatile free fattyacids, which by theirnature have the
greatest impact onflavor and aromadifferences in thecheeses
Mi bi l Li
-
8/2/2019 Enzyme Technology in Dairy
37/72
4/15/12
Microbial Lipases
Microbial lipases are lipolytic enzyme preparations,which are derived from yeasts, molds, and bacteria
MOLDS
-
8/2/2019 Enzyme Technology in Dairy
38/72
4/15/12
MOLDS play a direct role in flavor and aroma development
The lipases originate from the mold Penicillium roquefortiused in the manufacture of the cheese. The cheeses are then
pierced using rods, which enables carbon dioxide to bereleased from the curd and oxygen to penetrate. This together
with the correct humidity, salt, and oxygen facilitatesgermination of the spores
LACTIC ACID
-
8/2/2019 Enzyme Technology in Dairy
39/72
4/15/12
LAB initiate the production of lactic acid, their primary
role in natural cheese making Secondary role: contribute to the cheese ripening
process by the release of cell wall or intracellularenzymes
LACTIC ACIDBACTERIA (LAB)
The lipolytic activity of these bacteriais very low, but lipase activity has
been identified in many LAB.nonstarter lactic acid bacteria
(NSLAB) which are predominant inthe microbiological content of manycheese varieties during ripeninghave a role in the level of lipolysis in
these cheeses
YEAS
-
8/2/2019 Enzyme Technology in Dairy
40/72
4/15/12
Yeasts contribute to lipolysis levels in these cheeses.
YEASTS
Geotrichum candidum is
commonly found on somecheese varieties beforesalting and is veryacylspecific for cis-9
unsaturated fatty acids
-
8/2/2019 Enzyme Technology in Dairy
41/72
4/15/12
RIPENINGv Cheese curd can be made from raw or pasteurized milk.
Raw milk cheese should be ripened for 60 days or more asa safeguard against pathogens.
Cheddar, where a mature cheese is typically 12 to 18months old, costs associated with ripening become a
major issue.
Methods for accelerated cheese
-
8/2/2019 Enzyme Technology in Dairy
42/72
4/15/12
Methods for accelerated cheeseripening
v
Non-enzymatic method Elevated ripening temperatures
High Pressure
v Enzymatic methods
Exogenous enzymes
Attenuated starter cultures Adjuncts
Genetic modification
Nonenzymatic Methods For
-
8/2/2019 Enzyme Technology in Dairy
43/72
4/15/12
Nonenzymatic Methods ForAccelerating Cheese Ripening
The first is elevated temperatureripening, which provides a betterenvironment for the enzymes towork,thereby accelerating ripening.Should care needs to be taken to
ensure microbial safety and toprevent textural defects.
The second method is high pressuretreatment, which still in its infancy,but may have the potential toaccelerate cheese ripening
Ri i U i E
-
8/2/2019 Enzyme Technology in Dairy
44/72
Click to edit Master subtitle style
4/15/12
Ripening Using EnzymeTechnology
1. Exogenous Enzymes2. Commercial Enzymes for Accelerating Cheese Ripening3. Attenuated Starter Cultures and Adjuncts
Exogenous Enzymes
-
8/2/2019 Enzyme Technology in Dairy
45/72
4/15/12
Exogenous Enzymes
Adding increased amounts of enzymes during thecheese making process.
=> Quicker hydrolysis of the major milk components.=> Reducing its ripening time
i i b l d fl d t t
-
8/2/2019 Enzyme Technology in Dairy
46/72
4/15/12
ieving a balanced flavor and texture pro Using this technology has proven difficult.
Enhancing hydrolysis of the major casein proteinscauses:
1. Bitterness
2. Losses in yield3. Weakness in texture
Exogenous lipases
-
8/2/2019 Enzyme Technology in Dairy
47/72
4/15/12
Exogenous lipases
Lipolysis to be important in Cheddar cheeseflavor development. Small increases in the level of lipolysis can have
major negative sensory impacts.
=> The correct dosage level of lipase is critical forsuccess.
Blends of enzymes or enzyme
-
8/2/2019 Enzyme Technology in Dairy
48/72
4/15/12
Blends of enzymes or enzymecocktails
They are available to accelerate cheeseripening without negative effects.
However, problems can still occur with
unbalanced ripening because:1. The enzymes have not been added to the curd
uniformly.
2. Differences in production techniques amongdifferent factories.
Liposome technology
-
8/2/2019 Enzyme Technology in Dairy
49/72
4/15/12
Liposome technology
The enzymes would then fully partition withthe curd and not negatively affect yield.
It would be easy to use, but also ensure even
distribution of the enzyme in the curd. Encapsulating water soluble enzymes in the
aqueous phase between phospholipid layers in
liposome globules.
ro ems ex s e w posome
-
8/2/2019 Enzyme Technology in Dairy
50/72
4/15/12
ro ems ex s e w posometechnology
1. Maximizing enzyme encapsulation rates.
2. High costs due to the expense of using soya lecithinin the production of liposomes.
3. Increased moisture4. Changes in rheological characteristics of the cheese
5. Most soya lecithin is derived from genetically
modified soya which further limits its use in certaincountries.
ng exogenous enzymes a e
-
8/2/2019 Enzyme Technology in Dairy
51/72
4/15/12
ng exogenous enzymes a esalting stage
Adding exogenous enzymes at the saltingstage (milling) of the cheese making processoffers the best route for Cheddar cheese
production. It has shown an increase in the indices of
ripening.
Many different types of exogenous enzymeshave been added to different cheeses, despiteproblems associated with uneven enzymedistribution in the curd.
C i l E f A l ti Ch Ri i
-
8/2/2019 Enzyme Technology in Dairy
52/72
4/15/12
Commercial Enzymes for Accelerating Cheese Ripening
Few commercially successful enzymesystems to accelerate cheese ripeningexist.
Ex:
Attenuated Starter Cultures and Adjuncts
-
8/2/2019 Enzyme Technology in Dairy
53/72
4/15/12
Attenuated Starter Cultures and Adjuncts
q Cheese curd :retain up to 3 times the level of startertypically used in cheese making, therefore opening the
possibility of enabling extra starter culture, containingmore enzymes, to be added to the curd to accelerate itsripening.
q Using sublethal heat treatments or freeze-thawtreatments, which do not affect the enzyme activity of thestarter bacteria. Lactose-negative strains may also beused, as these occur naturally, because they cannot
produce acid they can also be used to accelerate cheeseripening.
Attenuated Starter Cultures and Adjuncts
-
8/2/2019 Enzyme Technology in Dairy
54/72
4/15/12
Attenuated Starter Cultures and Adjuncts
The advent of genetic modification (GM) has enhanced thepossibility of using cultures for the acceleration of cheeseripening. Not only has the taxonomy of cultures been
advanced but also their enzyme complement, activities,
ENZYME TECHNOLOGY IN CHEESE
-
8/2/2019 Enzyme Technology in Dairy
55/72
4/15/12
AS AN INGREDIENTq Cheeses have been used as ingredients in foods for years and used in
the retail, food service (catering), and industrial sectors.
q This aspect has driven suppliers to develop cost effective alternativesto using natural cheese in ingredient formulations.
q Natural cheese is an essential ingredient in many products, providing
flavor, aroma, color, texture, and functionality, but it can be quiteexpensive.
Fast Ripened Cheese
-
8/2/2019 Enzyme Technology in Dairy
56/72
4/15/12
Fast Ripened Cheese
q It s defined by their high moisture content and short ripening
times, which can be weeks rather than months.
q The enzymes and starter cultures used in their production aresimilar to those outlined in the accelerated cheese ripeningsection and are added at levels higher than that found in naturalcheese.
-
8/2/2019 Enzyme Technology in Dairy
57/72
4/15/12
q These cheeses are high moisture cheeses, which aretypically ripened at 15 to 20C to increase the rate ofenzyme reaction and thus hydrolysis .Once anacceptable flavor profile has been reached- stored
(shredded)
q A variation of this type of cheese involves shredding thecheese and adding enzymes, then reblending it in afashion similar to processed cheese, and ripening it athigh temperatures.
Enzyme Modified Cheese
-
8/2/2019 Enzyme Technology in Dairy
58/72
4/15/12
Enzyme Modified Cheese
Cheese with flavor enhanced by enzyme treatment
Typically lipolytic and proteolytic enzymes used
More intense flavors than naturally ripened cheese, with
values of greater than 30X noted in many examples
-
8/2/2019 Enzyme Technology in Dairy
59/72
4/15/12
Factors Influencing EMC Flavor
Starting material e.g. Fresh curd, immature cheese, cream,milk
Free fatty acids produced (using lipases)
Peptides and free amino acids (proteases and peptidases)
Reaction conditions (time, temperature, pH and enzymeused)
-
8/2/2019 Enzyme Technology in Dairy
60/72
4/15/12
EMC Preparation
Use of Lipases
-
8/2/2019 Enzyme Technology in Dairy
61/72
4/15/12
Extensively used to enhance the flavor of EMC, due toformation of fatty acids from milk fat
Short chain fatty acids are key component incheese flavor
Animal pregastric esterase widely used in naturalcheese and EMC production, but microbial lipases are
becoming more desirable
Use of Lipases
Lipases Reaction
-
8/2/2019 Enzyme Technology in Dairy
62/72
4/15/12
Lipases Reaction
Use of Proteases
-
8/2/2019 Enzyme Technology in Dairy
63/72
4/15/12
Used to improve taste of EMC Liberation of low-molecular peptides and amino acids
create umami or savory flavor
Produces less bitter notes (usually found due tohydrophobic amino acids within peptides)
Use of Proteases
Glutamin
-
8/2/2019 Enzyme Technology in Dairy
64/72
4/15/12
Converts glutamine into glutamate Glutamine is a flavorless amino acid, butconversion to glutamate can increase taste
intensity without addition of separateingredients or raising sodium content Glutaminase DAIWA SD-C100S acts on freeglutamine and can be used in combination withUmamizyme to improve EMC taste
Glutaminase
Substitute or Imitation
-
8/2/2019 Enzyme Technology in Dairy
65/72
4/15/12
Substitute or ImitationCheeseq These are cheese products which, as opposed to natural cheese, are not
made directly from milk. Two types of imitation cheese are producedin very high volumes: processed and analogue cheese. Neitherimitation cheese uses enzymes directly in its manufacture, but eithermay contain ingredients produced using enzymes.
PROTEINS
-
8/2/2019 Enzyme Technology in Dairy
66/72
4/15/12
PROTEINSHYDROLYSIS
q Enzyme hydrolysis is generally seen as a noninvasive technology,
and is an extrapolation of many natural processes. Two milkproteins, casein and whey, are used in the food industry forspecific flavor, functional, or nutritional applications. A widevariety of commercial enzymes are useful in the preparation ofhydrolysates that are very soluble, and stable at low pH and whenheated
-
8/2/2019 Enzyme Technology in Dairy
67/72
4/15/12
However, a major problem associated with protein hydrolysis,
particularly for casein and whey proteins, is the development ofbitterness, which is associated with the accumulation of hydrophobicpeptides
Generally, a number of key peptidase activities are important in
bitterness reduction. General aminopeptidase activity, which cleavessingle amino acids from the N-terminal of a peptide (Pep N and Pep Cactivity) is important. The removal of the amino acid proline from a
peptide can greatly reduce bitterness, because it alters the peptidesthree-dimensional structure, changing its solubility and increasing its
susceptibility to hydrolysis .
-
8/2/2019 Enzyme Technology in Dairy
68/72
4/15/12
Key peptidase activities involved in removing proline are prolinespecific peptidases such as: postprolyl dipeptidyl dipeptidase (Pep X),which releases N-terminal dipeptides from prolyl peptides; prolineaminopeptidase (Pep P), which exclusively hydrolyzes
the N-terminal amino acid from peptides that have proline in the secondposition; proline iminopeptidase (Pep I) which removes unsubstitutedN-terminal proline residues from tri- , oligo-, and polypeptides;prolinase (Pep R) which cleaves N-terminal Pro-X dipeptides; andprolidase (Pep Q) which hydrolyzes X-Pro dipeptides
LACTOSE HYDROLYSIS
-
8/2/2019 Enzyme Technology in Dairy
69/72
4/15/12
The Galactosidase can used accelerating cheeseripening. Hydrolysis of milk lactose for its use in ice
cream to prevent crystallization has been shown to besuccessful. The treatment of hydrolysed whey for animalfeed removes problems associated with crystallization oflactose on drying and makes the whey more useful as a
feed component
LACTOSE HYDROLYSIS
LYSOZYM
-
8/2/2019 Enzyme Technology in Dairy
70/72
4/15/12
Lysozyme is used in some Dutch, Swiss, and Italian cheese
varieties to prevent late gas blowing and off flavors causedby the growth of Clostridium tyrobutyricum. Mostcommercial lysozyme is derived from chicken egg white
LYSOZYMES
TRANSGLUTAMIN
-
8/2/2019 Enzyme Technology in Dairy
71/72
4/15/12
Transglutaminase (TGase) is an enzyme which catalyzes an
acyl-transfer reaction introducing a covalent cross linkbetween glutamine and lysine residues.
TGase has found applications throughout the food sectorparticularly in improving functional properties of variousproducts. The use of TGase in the dairy industry at present isgenerally limited to research.
TRANSGLUTAMINASE
-
8/2/2019 Enzyme Technology in Dairy
72/72
ThankYou