This document discusses cheese ripening and methods to accelerate the process. Cheese ripening refers to physical and biochemical changes that occur when cheese is held under controlled conditions. Key changes include proteolysis which transforms the rubbery curd into a mellow product and lipolysis which creates a velvety texture. Technological approaches to accelerate ripening involve manipulating conditions like temperature and moisture content, while biotechnological methods include using exogenous enzymes, genetically modified starter cultures, and adjunct bacterial strains. The goal of accelerated ripening is to develop flavor compounds in days rather than the typical months through enhanced microbial activity and biochemical reactions.

1. Cheese Ripening
To My Presentation Entitled-
Presented By
Mst. Tasmim Sultana
Reg. No: 12-04913
Department of Dairy Science
Sher-e-Bangla Agricultural University
Dhaka-1207 1/15

2. Ripening of cheese
Ripening of cheese refers to physical and biochemical changes that take place in cheese when it
is being held under specific and controlled conditions. Ripening process is considered as the
most crucial step in cheese making as it has greater influence on the development of
characteristic cheese flavor
 Most varieties of cheeses require 6-12 months of ripening period depending on the type of
cheese and/or conditions of ripening.
 Two important parameters that influence cheese ripening are temperature and relative
humidity.
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4. Changes During Cheese Ripening
 A series of microbiological and biochemical changes that occur during
ripening process are responsible for final mellow, waxy product having a
characteristic taste, aroma and texture.
Physical Changes
Proteolysis-rubbery curd of green cheese to the mellow, waxy ripened product
Lipolysis- velvetiness of cheese
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5. Chemical Changes
 Glycolysis: lactose-lactic acid
 Proteolysis: proteins-amino acids-amines (Histamine etc.)
 Lipolysis: fats-fatty acids-keto-acids
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6. Different Approaches for Accelerating Cheese Ripening
Two important approaches employed or tried by the cheese industry for
accelerating the cheese ripening process include
 Technological
 Bio-technological.
Controlled and accelerated cheese ripening
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7. Technological approaches
Technological approaches involve the manipulation of curing conditions such as
-Elevated temperatures
-Increasing the moisture content of cheeses
 Cheese is ripened at elevated temperature i.e. at 15°-20°C for 2-3 weeks
 Temperature enhanced bacterial growth resulting increased release of enzyme for
bringing about enhanced proteolytic and lipolytic changes.
 By adding moisture, cheese slurries are prepared by incubating at higher temperatures
30°C for 7-10 days.
 The slurries containing 40% total solids are being reported to have developed strong
flavor in days rather than in months.
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8. Biotechnological approaches
Biotechnological approaches involve-
 Exogenous microbial enzymes
 Methods of enzyme addition
 Microencapsulation
 Manipulation of starters
 Genetic engineering
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9. Exogenous microbial enzymes
 β-galactosidase
 Proteinases
 Lipases
 Mixtures of enzymes
Methods of enzyme additions
 Addition of enzymes to milk in solution form
 Enzymes are mixed with salt and sprinkled
Microencapsulation
 In this method, enzyme of interest is encapsulated in some type of artificial sacs usually with the object of
protecting it from particular environment. The sac dissolves at the required target site and stage, and releases
the enzyme for its designated action.
 Various substances have been used for the encapsulation of enzymes but most widely used ones are
liposomes. These are artificial sacs/capsules in micro vesicle form consisting of a central aqueous core
surrounded by one or more eccentric layers of fat
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10. Manipulation of starters
Many of starter organisms produce proteinases and peptidases. For accelerated cheese
ripening, addition of increased volumes of starter culture or enhancing their growth is
necessary for producing more proteinases or peptidases.
Attenuated starters
Attenuated starters are the modified lactic acid bacteria that lack the ability of
producing sufficient levels of acid during the cheese making but provide active
enzymes which can play a significant role in maturation and flavor development in
cheese
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11. Mutant starter strains
It consists of lactase negative proteinases negative or lactase negative proteinases
positive derivatives which have also been found to significantly influences ripening
changes in cheeses.
Adjunct starters
the use of lactobacilli which intensify the cheese flavor production when used in
combination with lactococci. It is believed that addition of small volumes of these
adjunct lactobacilli modify the proteolysis resulting in higher concentration of amino
acids
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12. Genetic Engineering in Cheese Ripening
 The genetic engineering of starter cultures as the best options available for finding a
viable, sustainable and promising tool for accelerating the cheese ripening. Most of the
strains of starter cultures used in cheese industries can be modified by DNA
recombination mechanisms.
 For example, more proteolysis producing strain can be allowed to take up lactose
utilizing plasmid (if it is lac- ) and thus two characters can be combined.
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13. Conclusion
 Cheese is a biochemically dynamic product that undergoes significant changes during ripening.
 Freshly made curds of various cheese varieties have bland and largely similar flavors and aroma
and, during ripening, flavoring compounds are produced that are characteristic of each variety.
 The biochemical changes occurring during ripening are grouped into primary events including
glycolysis, lipolysis, and proteolysis followed by secondary biochemical changes
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14. References
1. Sunita Grover & V. K. Batish and V. Padmanabha Reddy. (2019), Dairy Biotechnology, Dairy
Microbiology Division. NDRI, Karnal. pp. 141-146.
2. Brown, J. A., Foegeding, E. A., Daubert, C. R., Drake, M. A. and Gumpertz, M. (2003),
Relationships among rheological and sensorial properties of young cheeses, J.
Dairy Sci. 86, 3054-3067.
3. Benfeldt, C. and Sorensen, J. (2001), Heat treatment of cheese milk: effect on
proteolysis during cheese ripening, Int. Dairy. J. 11, 567-574.
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Department of Dairy Science
Sher-e-Bangla Agricultural University
Dhaka-1207