Transcript Baker`s Yeast

YEAST EXTRACTS FOR THE PRESENT
AND FUTURE
Tilak Nagodawithana. Ph.D
ADVANTAGES FOR USING YEAST
EXTRACTS
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To provide or modify flavor
To provide flavor enhancement
To create new process flavors
To reduce Sodium usage
As alternative to MSG
Cost reduction
For friendly ingredient statement
For use in fermentation media
DIFFERENT YEAST SOURCES FOR EXTRACT
PRODUCTION
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Saccharomyces cerevisiae
- Baker’s Yeast
- Brewer’s Yeast
- Distiller’s Yeast
Candida utilis (Torula Yeast)
Kluyveromyces marxianus (fragilis)
Saccharomyces lactis
APPROXIMATE ANALYSIS OF YEAST
%
Protein
Total Carbohydrates
Nucleic Acid
Fat (Ether extractable)
Total Lipids
Moisture
Ash
51.0
24.7
7.0
1.2
6.8
5.0
7.5
KEY STEPS IN AUTOLYSIS
YEAST
AUTOLYSIS
CENTRIFUGATION
CELL WALL
EXTRACTS
TYPICAL EXTRACT PROCESSING
PROCEDURE
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Adjust yeast slurry to 12 - 14% solids
Adjust pH to around 5
Raise the temperature to 50ºC
Run for 24 - 36 hours
Centrifuge - discard underflow (cell wall*)
Filter the supernatant
concentrate the clear supernatant
Dry
Package
* Cell wall may be used to produce value-added products
WHAT TAKES PLACE DURING AUTOLYSIS
DEFINITION OF AUTOLYSIS: SELF DIGESTION DUE TO ITS
OWN ENZYMES
- Proteins degraded by enzymes namely proteases
- Glycogen and Trehalose are degraded by carbohydrases
- Nucleic acid is degraded by nucleases
- Fat is degraded by lipases
- Glucan is degraded by glucanases
YEAST AUTOLYSIS
START OF AUTOLYSIS
CELL WALL RUPTURE DURING AUTOLYSIS
STATE AT END OF AUTOLYSIS
ENZYMATIC HYDROLYSIS
ENZYMATIC HYDROLYSIS
PAPAIN
PAPAIN
ACID HYDROLYSIS
NUTRALIZE WITH BASE AFTER
ACID HYDROLYSIS
EMPTY YEAST CELL
AFTER
CENTRIFUGATION
CELL WALL
EXTRACT
MAJOR PRODUCTS OF
AUTOLYSIS/HYDROLYSIS
YEAST
AUTOLYSIS OR HYDROLYSIS
CENTRIFUGATION
CELL WALL
EXTRACTS
CURRENT/FUTURE TRENDS
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Develop extracts with high 5’-levels (Natural)
Produce 5’- extracts from Brewer’s
Develop low-sodium flavor extracts
Develop high glutamate extracts (Natural)
Develop extracts with characteristic flavors
-Reaction flavors
-Additives
Cut processing cost
Develop extracts for fermentation media
FLAVOR ENHANCERS
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MONOSODIUM GLUTAMATE (MSG)
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DISODIUM 5’-INOSINATE (5’-IMP)
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DISODIUM 5’-GUANYLATE (5’-GMP)
THRESHOLD VALUES: GMS/100ML
(EFFECT OF SYNERGY)
Threshold values: gms/100mls
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50 : 50 5’-IMP 5’-GMP MSG
5’-GMP:5’-IMP
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Distilled water
0.8 %. MSG
* with 0.1% MSG
0.0063 0.025 0.0125 0.03
0.00001 0.0001 0.0003* -
METHODS OF 5’-NUCLEOTIDE
PRODUCTION
(1) Direct fermentation of sugars into 5’-GMP
and 5’-IMP
(2) Direct fermentation of sugars into
nucleosides with subsequent phosphorylation
into corresponding nucleotides.
(3) Degradation of RNA using phosphodiesterase
enzyme. Subsequent conversion of 5’-AMP to
5’-IMP using adenylic deaminase enzyme.
(4) Any combination of above three procedures
CRITICAL STEPS IN 5’-NUCLEOTIDES
PRODUCTION
Yeast
Heat to 95ºC
To release RNA
Papain Treatment
to increase yield
Centrifugation
RP-1 Treatment
Deamizyme Treatment
Filtration
Pasteurization
Concentration
5’- GMP + 5’- AMP
5’-AMP to 5’-IMP
Drying
PROCESS FLAVORINGS
OR
REACTION FLAVORS
MAILLARD REACTION - UP-STREAM
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REDUCING SUGAR + AMINO ACID
N-GLYCOSYLAMINE
OR
N-FRUCTOSYLAMINE
AMADORI OR
HEYNS
REARRANGEMENT
AMINO ACIDS
FLAVOR
COLOR
STRECKER
DEGRADATION
AMADORI OR
HEYNS COMPOUNDS
(DICARBONYLS)
SOME EXAMPLES OF PROCESSED FLAVOR
DEVELOPMENT
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XYLOSE + CYSTEINE + PROLINE + IMP + ASCORBIC ACID
BEEF FLAVOR
121°C, pH 6, 1.5hrs
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GLUTAMIC ACID +CYSTEINE +ALANINE +IMP + GLYCINE +
VEG. OIL
CHICKEN FLAVOR
100°C, pH 6, 4hrs
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GLUCOSE + GLUTAMIC ACID + CYSTEINE + ALANINE +
GLYCINE + THIMINE +IMP + VEG. OIL
PORK FLAVOR
100°C, pH 6, 4hrs
SUMMARY
WE COVERED:
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DIFFERENT YEASTS USED IN PRODUCTION OF EXTRACTS
TECHNIQUES APPLIED FOR AUTOLYSIS & HYDROLYSIS
DOWN-STREAM PROCESSING
PRODUCTION OF FLAVOR ENHANCERS
SYNERGESTIC EFFECT OF FLAVOR ENHANCERS
PROCESS FLAVORINGS
CURRENT AND FUTURE TRENDS