Butter | Animal Husbandry & Veterinary Science Optional for UPSC PDF Download

Butter-making Overview

• Historical Significance: Butter-making holds a rich historical background, with mentions even in ancient texts like the Old Testament.
• Symbol of Wealth: In earlier times, butter was not just a commodity but also a symbol of affluence.
• Butter in Modern Times: Today, butter stands out as a primary dairy product in developed dairy nations. Notably, India contributes significantly, producing around eight percent of the world's total butter.

Definition of Butter

• Composition: Butter can be described as a concentrated fat, derived by churning cream, consolidating the fat into a dense mass, and subsequently processing it.

PFA Rules on Butter (1976)

• Product Description: Table (creamery) butter originates from cow or buffalo milk, cream, or curd, possibly in combination. It might include common salt, annatto, or carotene as coloring agents.
• Composition Standards: It must exclude other animal fats, wax, mineral oils, and vegetable oils. Preservatives are limited to common salt, while colorants are restricted to annatto or carotene. The butter should contain at least 80% milk fat, up to 1.5% curd, and a maximum of 3% common salt.
• Additional Additives: Flavor enhancers like diacetyl can be incorporated within limits, not surpassing 4 parts per million. Additives such as calcium hydroxide, sodium bicarbonate, or sodium polyphosphates are permissible, provided they do not exceed 0.2% of the butter's total weight.

Types of Butter

Sweet Cream Butter

• Pasteurized cream butter: Typically made from pasteurized sweet cream, offering a milder flavor compared to unpasteurized varieties.
• Ripened cream butter: Developed from cream with a delicate aroma before churning, achieved through ripening the cream with specific cultures.
• Unripened cream butter: Produced from unripened cream, usually characterized by a mild flavor profile.

Salted and Unsalted Butter

• Salted butter: Butter enriched with added salt for flavor enhancement.
• Unsalted butter: Butter without any salt content.

Other Varieties of Butter

• Sour cream butter: Crafted from cream with acidity exceeding 0.2 percent.
• Fresh butter: Butter not subjected to cold storage, typically consumed within three weeks of production.
• Cold storage butter: Stored at around -19°C (0°F) and aged between one to six months before sale.
• Dairy butter: Produced from unpasteurized sour cream without acidity standardization, often with a sour taste.
• Creamery butter: Manufactured in a creamery or dairy factory, known for its uniform quality compared to dairy butter.

Indian Butter Composition and Manufacture

Composition of Indian Butter

• Butter fat: Indian butter typically contains 80.2% butter fat.
• Moisture: It has a moisture content of 16.3%.
• Salt: The salt content in Indian butter is about 2.5%.
• Curd: A small percentage, around 1.0%, consists of curd.

Nutritive Value

• Butter is rich in fat and fat-soluble vitamins such as A, D, E, and K.

Manufacture of Butter

• Upon receiving milk at the dairy plant, various processes are undertaken:
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  • Grading, sampling, weighing, and testing of the milk.
  • Preheating the milk to enhance cream separation efficiency.
  • Separation of cream using centrifugal methods.
  • Neutralization of cream to reduce acidity.
  • Standardization, pasteurization, cooling, aging, ripening, and churning of cream.
  • Washing, settling, working, and final packaging and storage.

Flow Diagram of Butter Manufacture

• Receiving milk
• Preheating (35-40°C)
• Cream separation (centrifugal)
• Cooling (20-22°C)
• Ripening (20-22°C)
• Grading, weighing, sampling, and testing
• Neutralization of cream to adjust acidity
• Standardization of cream
• Pasteurization or vaporization
• Cooling and aging
• Churning of cream
• Washing, salting, and working
• Packaging and storage at -23 to -29°C

Summary of IAS(M) Processes

• Standardization of Cream

  Standardizing cream involves adjusting the fat content to a specific percentage as per standards. This adjustment is achieved by adding a calculated amount of skim milk. The aim is to minimize fat loss in buttermilk during churning.

• Pasteurization of Cream

  Pasteurization serves several purposes: destroying harmful microorganisms in cream to ensure safety for consumption, extending the shelf life of cream and butter by neutralizing enzymes, eliminating undesirable flavors, and enabling the removal of off-flavors during processing.

  • Methods of Pasteurization

    • Holder Pasteurization: This batch process involves heating cream to 71°C for 20 minutes and then rapidly cooling it.
    • HTST (Plate) Pasteurization: A continuous process suitable for large-scale operations, heating cream to 95-100°C for 15-16 seconds.
    • Vacuum Pasteurization (Vacreation): Another continuous process involving dilution of cream, reducing fat content by 6-8%.

• Cooling and Ageing of Cream

  After pasteurization, cream must be cooled and aged to facilitate churning. Proper solidification of butterfat is essential for successful churning, resulting in satisfactory butter quality.

• Ripening of Cream

  Ripening involves fermenting cream with starter cultures to enhance flavor and aroma, leading to thorough churning and reduced fat loss in buttermilk.

Butter Production Process Overview

• Starter Culture and Cream Preparation:
  • Butter production begins with the addition of a butter starter culture containing specific bacteria like Streptococcus lactis and Streptococcus cremori, along with aroma producers such as Streptococcus diacetilactis, Leuconostos citrovorum, and Leuconostoc dextranicum, to standardized, pasteurized, and cooled cream at a specific percentage.
  • The cream is then thoroughly mixed and incubated at a controlled temperature for a specific duration, typically around 15-16 hours.
• Cream Ripening and Flavor Enhancement:
  • Cream ripening is a meticulous and time-consuming process where flavor compounds are introduced to enhance the taste of the butter.
  • To impart the desired flavor profile, starter cultures, starter-distillates, or synthetic flavor compounds are added during the production process.
  • However, using these additives may result in drawbacks like unnatural aroma, lack of desired mellow flavor, and aroma instability.
• Churning Process:
  • Churning involves agitating the cream until fat globules adhere together to form larger masses, leading to the separation of butterfat from buttermilk.
  • Key aspects of good churning include ease of churning, completeness, washing, and optimal churning duration.
  • The churning operation includes preparing the churn, filling cream, and adding butter color for uniformity.
  • Butter color, derived from sources like annatto or carotene, is added to maintain consistent color throughout the year.
  • Operating the churn involves initial rotation, removal of liberated gas, fat testing, temperature monitoring, and the breaking stage where butter granules form.

Butter Making Process

• Churning Process

  • Churning continues until butter grains reach desired size.
  • Factors causing churning difficulties include excessive hard fat, small fat globules, thin cream, overloading the churn, low churning temperature, and abnormal cream.
  • To prevent fat losses in buttermilk, factors like high churning temperature, high fat content in cream, small fat globules, overloading of the churn, and under-churning need to be controlled.

• Washing Process

  • Washing aims to remove buttermilk from butter grains, improve butter quality, correct firmness defects, and reduce certain off-flavors.
  • Chilled water is added to butter grains after draining buttermilk, followed by draining out the wash water.
  • Salting is crucial for enhancing butter's keeping quality, taste, and overrun, typically added at a rate of 2 to 2.5% of butter fat.

• Working Process

  • Working involves kneading butter to dissolve salt evenly, bring butter grains together, and form a compact mass for handling and packing.
  • Methods of salting include dry salting, wet salting, and brine salting, each serving specific purposes based on the desired outcome.

Butter Manufacturing Process

• Working of Butter

  • Moisture in butter reduced to microscopic droplets
  • Key goals of working: compact body, tough waxy texture, even salt and moisture distribution
  • Avoid free moisture to prevent microbial migration and weight loss
  • Overworking damages texture, underworking leads to leaky butter
  • Working increases air content, impacting spoilage and density

• Moisture and Fat Content

  • Legal limits: Moisture content typically 16%, Fat content 80% in India and some countries

• Overrun in Butter

  • Definition: Weight of butter exceeding fat content in cream
  • Importance of overrun in creamery business for financial stability
  • Factors influencing overrun: moisture, curd, salt
  • Theoretical overrun: 25% maximum butter from 100 kg fat, practical overrun around 20%

• Packaging of Butter

  • Bulk packaging in boxes/cases/lubs in developed countries
  • Retail packs range from 1 oz to 500 g
  • Materials used: vegetable parchment paper, cellophane, polythene, etc.
  • Tin plated cans used in tropical regions for heat and odor prevention

Butter Packaging and Storage Summary

Types of Packaging Methods

• Packaging methods for butter can be manual (hand moulding) or mechanical.
• Hand moulding is suitable for small-scale operations but is slow and inefficient.
• Mechanical moulding, packing, and wrapping are ideal for large-scale operations, reducing labor costs and losses.

Storage of Butter

• Commercial cold storage of butter is typically maintained at temperatures ranging from -23°C to -29°C (-10°F to -20°F).
• Flavor deterioration occurs during commercial cold storage, with chemical deterioration being a significant factor.
• Shrinkage of stored butter is mainly due to moisture evaporation from the butter pat.
• Butter packs must contain the correct weight marked on the package to ensure accuracy for consumers.

Factors Affecting Keeping Quality

• Storage temperature directly impacts the keeping quality of butter, with higher temperatures leading to lower quality.
• Higher levels of copper, iron, acidity, salt content, curd, and air in butter reduce its keeping quality.
• Pasteurization of cream and proper sanitary packaging methods enhance the keeping quality of butter.
• Exposure to light can lower the keeping quality, so it's recommended to store butter in a dark, dry place.

Distribution Process

• Butter is distributed from the factory to wholesalers in bulk packages and to retailers in wrapped pats.
• Ideal distribution temperatures should be maintained between -18°C and -29°C (0°F and 20°F).
• Butter may also be sold in retail trade from deep freeze or refrigerated butter boxes.

Judging and Grading of Table Butter

• Butter Composition Standards in India:
  • Table and creamery butter in India must have a minimum of 80% fat, a maximum of 1.5% curd, and not more than 3.0% common salt.
  • Moisture content is typically around 16.3% but not specifically mentioned in the regulations.
• Moisture Content Standards:
  • In some countries, the legal standard sets the moisture content at 16%.
• Bacteriological Standards:
  • According to the PFA Rules, there are no specific bacteriological standards for butter.
• Sanitary Grades Based on Yeast and Mold Content:
  • Recommended grades based on yeast and mold content per ml are categorized into different ranges.
  • These ranges determine the quality and cleanliness of the butter product.
• ISI Score-card for Butter:
  • Defines characteristics such as flavor, body texture, color, appearance, and finish.
  • Assigns points for specific attributes like cleanliness, moisture content, and overall quality.

Understanding Butter Grades and Defects

Butter Grades:

• Butter grades are assigned based on the following point system:
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  • Excellent: Butter scoring 95 and above
  • Very Good: Butter scoring between 90 and 94
  • Good: Butter scoring between 85 and 89

Criteria for High-Grade Butter:

• The packaging should be neat, clean, tidy, and well-finished.
• Salt must be properly dissolved.
• Uniform color throughout.
• Firm, compact body with a closely knit texture.
• Desired flavor should be clean, aromatic, and pleasant.

Defects in Butter:

• Butter defects can result from poor milk or cream quality and faulty manufacturing/storage methods.
• Defects can be categorized into:
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  • Flavor defects
  • Body and texture defects
  • Color defects

It is essential to maintain high quality throughout the butter production process to ensure the best product for consumers.