1. School of Biotechnology & Microbiology
Program MSc
Semester 1st
semester
Subject Microbiology
Student Code
Paper
Paper Code
Topic
Scientific overview of Ghee
and butter preparation
Submitted By Priyabrata Karmakar
Submitted To
( School of Biotechnology &
Microbiology)
2. Table of Contents
Ghee Production: Scientific Overview
Introduction
Nutritional Value
Science behind ghee preparation
Various Methods of Ghee Preparation
Indigenous or Desi method
Creamery butter method
Pre-stratification method
Direct cream method
Continuous method
Conclusion
Butter Production: Scientific Overview
Introduction
Nutritional Information
Classification of Butter
Butter Making Process
References
3. Scientific Overview Of Ghee & Butter Production
Page | 1
Ghee Production: Scientific Overview
Ghee is a specialized form of clarified butter indigenous to South Asia, usually prepared from
milk of cows or buffalos. It forms an important component of the diet of human beings due to
its rich flavor and high nutritive value. Several commercial products (such as clarified butter,
butter-oil and other indigenous milk products) commonly used in different regions are closely
related to ghee.
Butterfat is the most expensive constituent of milk and ghee is essentially the constituted of
butterfat.
All efforts are made to minimize losses of butterfat while making ghee and butter. Another
important aspect is to maintain the organoleptic and analytical properties of butterfat to an
acceptable level in the final product.
Nutritional Information Value /100g
Fat Content (%) 99.2-100
Energy 3644 kJ or 886 kcal
Introduction
Nutritional Information
0
10
20
30
40
50
60
70
Value/100g
Fig: Nutritional value of Ghee
4. Scientific Overview Of Ghee & Butter Production
Page | 2
The science behind ghee production involves following points
Concentration of lipid phase - Butterfat in milk is present in form of fat globules, which are
properly emulsified by fat globule membrane and dispersed in serum phase. For efficient
separation of butterfat from the continuous phase (serum), it has to be concentrated inform of
cream or malai. Further concentration of butter fat is possible by converting it into a
continuous phase as in case of butter. The purpose of concentrating butterfat in a
discontinuous (cream) or continuous phase (butter) is to reduce the amount of water contents
in the raw material and facilitate ghee preparation.
Sometimes, some intermediate operations such as fermentation of milk prior to concentration
of lipid phase or of cream to emanate desired acidic flavor is also adopted
Heat clarification of cream or butter- Removes practically all the moisture and to generate
typical flavor and granulation, and
Removal of residue from the heat clarified butterfat- To meet the legal requirements and
also to improve the storage ability.
Different methods are used for the preparation of ghee. The adoption of a particular method is
mainly dependent on the scale of production.
Indigenous or Desi method
Creamery butter method
Pre-stratification method
Direct cream method
Continuous method
Various Methods of Ghee Preparation
Science behind ghee preparation
5. Scientific Overview Of Ghee & Butter Production
Page | 3
Indigenous or Desi method
It is an age-old process and largely adopted in rural areas/villages and also at urban
household levels because of simplicity in equipment and technique. This traditional method
of making ghee contributes about 80% of the total ghee produced in the country. This method
usually involves two routes, i.e.
(1) Lactic acid fermentation of raw or heated milk is followed by churning of curd into
makkhan or butter.
(2) Separation of malai (clotted cream) from the boiled milk and its churning into butter.
Dahi or buttermilk of previous day is used as starter culture for fermentation of milk.
Churning of curd or malai is done with hand wooden churn. Now-a-days electrically operated
butter churns are available and used by many housewives or makkhan producers. Makkhan is
stored at room temperature for days together and when sufficient quantity accumulated, it is
converted into ghee. For this purpose, makkhan is heated in a earthen pot (now-a-days metal,
Fig: Flow diagram of manufacturing of ghee by various methods
6. Scientific Overview Of Ghee & Butter Production
Page | 4
particularly steel or aluminum containers are also used) on slow fire. The scum gathered on
the top of melted butter is continuously removed with perforated ladle. The heating is
discontinued on complete removal of scum and froth and getting clear fat (ghee). There are
several limitations in this process which are mentioned here:
The quality of ghee is highly inconsistent in terms of chemical and sensory quality.
Method is incompatible to large-scale production.
Recovery of fat is low.
Acidity is high and hence keeping quality is low.
Manufacture and storage of ghee is done in undesirable containers.
Ghee residue being acidic in nature cannot be used.
Creamery Butter Method
This is the standard method adopted in almost all organized dairies, where the raw material
used is unsalted creamery butter, commonly known as ghee or white butter The butter is
heated in an improved ghee boiler, which consists of a stainless steel jacketed pan (vessel)
provided with a manual stirrer.
There may be provision for a movable, hollow, stainless steel tube, centrally bored through
the bottom of the pan for emptying the pan-contents when required; alternatively, the pan
may be emptied by providing a simple pan-tilting device. A steam control valve, pressure and
temperature indicator, etc., are also provided in the boiler.
In the beginning, the solid mass of butter (which may be cut into small pieces to facilitate
melting) is heated over a low fire and carefully stirred so that it melts. Later, the steam
pressure in the jacket is raised so that the liquid mass starts boiling, with a re-moval of the
water vapour from the pan-contents at a temperature of over 90°C.
This temperature remains constant as long as the moisture is being driven out. The contents
are constantly agitated throughout the process of conversion of butter into ghee, to prevent
scorching.
The scum which gathers on the top surface of the boiling mass is removed from time to time
by a perforated ladle. Usually, there is profuse effervescence (1st), accompanied by a
crackling sound in the early stages of boiling, but both gradually decrease if the moisture
content is reduced.
7. Scientific Overview Of Ghee & Butter Production
Page | 5
When practically all the moisture has been driven out, the temperature of the liquid mass
suddenly shoots up and the heating at this stage has to be carefully controlled. The endpoint
is indicated by the appearance of effervescence (2nd), which is much finer than the first,
together with a browning of the curd particles. At this stage a characteristic ghee flavor also
emanates, and this is an indication that it has been heated sufficiently.
The final temperature of heating/clarification usually ranges from 110 to 120°C, depending
upon the region. (In some parts of the country, it is finally heated to a still higher temperature,
which yields a burnt or overcooked flavor relished in those areas; a recent trend in other parts
of the country is to use lower heating temperatures, around 107°C.
After cooling and sedimentation, the ghee is filtered through a muslin cloth so as to separate
it from the sediment known as ghee-residue (consisting mostly of burnt casein). It then goes
on for granulation and packa-ging.
Pre-stratification method
In the creamery method, as also in the country method, the high acidity of the raw material
(especially true of makkhan) at high clarifying temperatures, makes the product greasy and
also reduces its shelf- life. Research work has led to the evolution of a modified technique
capable of yielding a higher grade product at lower cost of clarification.
Main theme of the pre-stratification method is when butter is left undisturbed at a temperature
of 80-85°C for 15 to 30 minutes, it stratifies, i.e., separates into 3 distinct layers, viz., a top
layer of floating denatured particles of curd, a middle layer of fat, and a bottom layer of
buttermilk. This separation into layers has been called pre-stratification.
The bottom layer of buttermilk contains 60-70 per cent of solids-not-fat and also over 80
percent of the moisture originally present in the butter. The buttermilk is mechanically
removed without disturbing the top and middle layers. Afterwards, the temperature of the
remaining two upper layers (of denatured curd and fat) is raised to the usual clarifying
temperature of 110-120°C.
Advantages of this process are-
Economy in fuel consumption as compared to direct clarification
8. Scientific Overview Of Ghee & Butter Production
Page | 6
Production of ghee with a lower acidity and longer shelf-life (acid removed in
buttermilk).
Direct cream method
In this method, the cream obtained by usual separation of milk, is heated in a ghee boiler,
which consists of a stainless steel jacketed pan provided with a manuals tirrer. The cream
meant for ghee making is taken in the ghee boiler and the heating in the beginning is a
controlled one. Later the steam pressure in the jacket is raised so that the liquid mass starts
boiling with the removal of water vapour from the pan contents at a temperature of over
90°C.The temperature remains constant as long as the moisture is being driven out. The
contents are constantly agitated throughout the process of conversion of cream into ghee to
prevent scorching.
Continuous Method
The batch methods for making ghee are highly suitable for small and medium scale
production of ghee. With the increase in demand and scope for export of ghee, some very
large organized dairies prefer to adopt a continuous ghee making methods. Some of the
problems associated with the current batch methods of ghee making are
Unsuitable for large-scale production
High-energy consumption
Excessive strain and fatigue on the operators
Product exposed to the environment
Cleaning of equipment is done manually
All the limitations of the conventional batch methods given above are obviated by continuous
ghee making plants. These systems work on the basis of two principles- (a) moisture
evaporation from cream/butter using thin film scraped surface heat exchanger (TSSHE) and
(b) de-emulsification of cream using high speed clarifixator and oil concentrator followed by
moisture evaporation.
9. Scientific Overview Of Ghee & Butter Production
Page | 7
Five different methods are adopted to manufacture ghee in our country. These methods are:
Indigenous (desi) method, direct cream method, creamery butter method, pre-stratification
method and continuous method.
Indigenous method is most important because 90% of ghee is produced by this method. It is
adopted on a small scale in rural areas. Milk is converted into curd followed by its churning
into makkhan and finally heating to obtain ghee. High fat cream (60-80%) is preferred in
direct cream method.
Creamery butter method is commonly used by organized sector in which cooking butter is
boiled to get ghee.
Pre-stratification method is highly energy efficient method, because by stratifying melted
butter into three layers, a major portion of buttermilk is removed from it, thereby drastically
reducing the heating time. The large organized dairies prefer to adopt continuous method
owing to several benefits.
Conclusion
10. Scientific Overview Of Ghee & Butter Production
Page | 8
Butter Production: Scientific Overview
Butter is essentially the fat of the milk. It is usually made from sweet cream and is salted.
Traditionally it is being made from cream that had been allowed to stand and sour naturally.
The cream is then skimmed from the top of the milk and poured into a wooden tub. Butter
making is done by hand in butter churns. The natural souring process is, however, a very
sensitive one and infection by foreign micro-organisms often spoiled the result.
Today's commercial butter making is a product of the knowledge and experience gained over
the years in such matters as hygiene, bacterial acidifying and heat treatment, as well as the
rapid technical development that has led to the advanced machinery now used.
Chemically butter fat consists essentially of a mixture of triglycerides, particularly those
derived from fatty acids, such as palmitic, oleic, myristic, and stearic acids. The fatty acid
composition of butter fat varies according to the producing animal's diet. A measure of the
amount of these acids, the Reichert-Meissl, or Reichert-Wollny, number is important in the
analysis of butter fat.
Fat, % 80
Moisture, % 16 - 18
Salt, % 0 - 2
Protein, % 0.7
Specific energy, kJ/100 g 3140
Introduction
Nutritional Information
Fig: Nutritional Value of butter
11. Scientific Overview Of Ghee & Butter Production
Page | 9
Many types of butter are found in the market. These differ with the type of cream from which
they are made and with variations in the manufacturing process. Unless specifically
mentioned, the different kinds of butter may or may not have been salted. A brief description
of several kinds of butter is as follows-
Pasteurized cream butter- Usually made from pasteurized sweet cream. Such butter has a
milder flavor than that made from similar cream not pasteurized.
Ripened cream butter- Made from cream in which a pleasant delicate aroma has been
developed before churning by ripening (i.e., inoculating the cream with a lactic culture and
holding it at a desired temperature). Properly made, ripened cream butter has a delicate
flavor.
Unripened cream butter- Made from unripened cream. The flavor of such butter is usually
mild.
Salted butter- Butter to which salt has been added.
Unsalted butter- Contains no added salt.
Sweet cream butter- In this case, the acidity of the churned cream does not exceed 0.20%.
Sour cream butter- Made from cream which has more than0.20% acidity.
Fresh butter- Such butter has not undergone cold storage.(Usually, fresh butter is not kept
for more than 3 weeks.)
Cold storage butter- This butter has been stored at a temperature of about -18°C for some
time. (Generally cold storage butter is from 1 to 6 months old when offered for retail trade.)
Dairy butter (USA)- This is butter made on a farm. It is usually made from unpasteurized
sour cream, which has not been standardized for acidity. This butter generally has a sour
flavor due to the high acid content of the cream.
Creamery butter- This is butter made in a creamery or dairy factory. It is more uniform in
quality than dairy butter.
Classification of Butter
12. Scientific Overview Of Ghee & Butter Production
Page | 10
Milk & cream
Milk is collected from cows. Butter can also be produced from the milk of buffalo, camel,
goat, ewe, and mares. Cream is separated from the milk. The cream can be either supplied by
a fluid milk dairy or separated from whole milk by the butter manufacturer. The cream should
be sweet (pH greater than 6.6), not rancid, not oxidized, and free from off flavors. The cream
is pasteurized at a temperature of 95°C or more to destroy enzymes and micro-organisms.
Ripening
Sometimes, cultures are added to ferment milk sugars to lactic acid and desirable flavor and
aroma characteristics for cultured butter. This is more common in European butters.
Aging
Cream is held at cool temperatures to crystallize the butterfat globules, ensuring proper
churning and texture of the butter. In the aging tank, the cream is subjected to a program of
controlled cooling designed to give the fat the required crystalline structure. As a rule, aging
takes 12 - 15 hours. From the aging tank, the cream is pumped to the churn or continuous
butter maker via a plate heat exchanger which brings it to the requisite temperature.
Churning
Cream is agitated, and eventually butter granules form, grow larger, and coalesce. In the end,
there are two phases left: a semisolid mass of butter, and the liquid left over, which is the
buttermilk.
Draining & washing
Thus the cream is split into two fractions: butter grains and buttermilk. In traditional
churning, the machine stops when the grains have reached a certain size, whereupon the
buttermilk is drained off. With the continuous butter maker the draining of the buttermilk is
also continuous.
Butter Making Process
13. Scientific Overview Of Ghee & Butter Production
Page | 11
After draining, the butter is worked to a continuous fat phase containing a finely dispersed
water phase. It used to be common practice to wash the butter after churning to remove any
residual buttermilk and milk solids but this is rarely done today. This washing process would
ensure that all the butter milk is washed out of the butter. Otherwise the butter would not
keep and go rancid.
Salting & working
Salt is used to improve the flavor and the shelf-life, as it acts as a preservative. Further, the
butter is worked to improve its consistency.
Packing & storage
The butter is finally patted into shape and then wrapped in waxed paper and then stored in a
cool place. As it cools, the butterfat crystallizes and the butter becomes firm. Whipped butter,
made by whipping air or nitrogen gas into soft butter , is intended to spread more easily at
refrigeration temperatures.
https://www.sciencedirect.com/science/article/pii/S0975947619300579
https://www.researchgate.net/publication/294787393_Butter_Manufacture
https://www.researchgate.net/publication/340918193_Design_and_Development_of_
an_Automated_and_Quality_Controlled_System_for_Traditional_Butter_and_Ghee_
Production
https://www.academia.edu/32937861/Butter_Production_Technology_and_Process_B
utter_Production_Technology_and_Process
https://www.slideshare.net/fiona_tormey/butter-making?next_slideshow=1
https://www.goma.co.in/blog/cream-butter-ghee-processing-plant/
https://nir-for-food.com/butter-overview/
https://www.uoguelph.ca/foodscience/book/export/html/1687
https://en.wikipedia.org/wiki/Butter
https://en.wikipedia.org/wiki/Ghee
http://wiki.zero-emissions.at/index.php?title=Butter_production
References