Dairy Industry: Judging, Processing, Sanitation, and Standards
1. Judging and Grading of Milk Products
1.1 Milk
- Sensory evaluation: checking for fresh smell, creamy white color, and smooth
mouthfeel.
- Physical tests: density (specific gravity), freezing point (to detect dilution), and
sediment content.
- Chemical tests: fat % (Gerber test), solids-not-fat (SNF), acidity (0.12–0.15%), protein,
lactose.
- Microbiological tests: total plate count, coliform count, psychrotrophic count.
1.2 Butter
- Judging based on flavor (fresh, clean taste), texture (smooth, spreadable), salt content,
and color.
- Grading criteria include moisture content (<16%), fat content (>80%), and absence of
rancidity.
1.3 Cheese
- Evaluated for body (firmness), texture (smooth, no cracks), flavor (mild to sharp), and
color (uniform).
2. Cheese Spreads by Spray and Roller Drying
2.1 Spray Drying
- Cheese slurry atomized into hot air chamber.
- Quick drying at 160-200°C, retaining flavor and creating fine powder.
- Used in cheese spreads, soups, and seasoning powders.
2.2 Roller Drying
- Cheese slurry spread thinly over heated rollers.
- More intense heat gives a 'cooked' flavor profile.
- Results in coarser powder used in processed cheese products.
3. Enzyme Modified Cheese (EMC)
- Enzymes like lipases, proteases, and peptidases accelerate flavor development.
- Used in processed cheese spreads, bakery fillings, and flavoring agents.
- Reduces the traditional cheese aging period from months to days.
4. Enzymes in Dairy Processing
- Rennet (chymosin): coagulates casein to form curds in cheese-making.
- Lactase: converts lactose into glucose and galactose for lactose-free milk.
- Lipase: develops sharp cheese flavors.
- Proteases: aid in cheese texture and ripening.
- Catalase and peroxidase: natural enzymes indicating milk quality.
5. Sanitation and Cleaning in Dairy Plants
5.1 Cleaners and Sanitizers Selection
- Alkaline cleaners remove fat and protein residues.
- Acid cleaners remove milk stone (calcium deposits).
- Sanitizers used include chlorine compounds, peracetic acid, and quaternary
ammonium compounds (QUATs).
5.2 In-Plant Cleaning Systems (CIP)
- Clean-In-Place (CIP) systems automate the cleaning process.
- Cycle includes pre-rinse, detergent wash, intermediate rinse, final sanitizer rinse, and
post-rinse.
- Used in pipelines, pasteurizers, storage tanks.
6. Milk Supply Schemes & Organizations
- Milk Supply Schemes ensure milk collection from farmers, chilling, processing, and
distribution.
- Functions include quality testing, transportation logistics, and farmer support.
6.1 National Organizations
- NDDB: National Dairy Development Board, Operation Flood program.
- AMUL: India’s largest dairy cooperative.
- FSSAI: Regulates food safety and standards.
- Mother Dairy, Nandini, Vijaya: major state brands.
6.2 International Organizations
- IDF: International Dairy Federation.
- Codex Alimentarius Commission: sets international food quality standards.
- FAO, WHO: Develop global dairy safety guidelines.
7. Specifications and Standards in Milk Processing
- Governed by FSSAI and BIS standards in India, Codex internationally.
- Pasteurized milk: min. 3.0% fat and 8.5% SNF.
- Butter: min. 80% fat content.
- Paneer: 50% moisture, 20-30% fat based on milk source.
- Standards also cover microbial counts, contaminants, and labeling requirements.
8. Dairy Plant Sanitation and Waste Disposal
8.1 Sanitation
- Routine cleaning of floors, walls, and equipment.
- Scheduled sanitation protocols for all processing areas.
- Personal hygiene training for staff.
- Pest control measures to prevent contamination.
8.2 Waste Disposal
- Types of waste: whey, wash water, packaging waste.
- Treatment: Effluent Treatment Plants (ETP) to reduce BOD and COD.
- Reuse of whey in whey protein production.
- Composting of organic waste and recycling of packaging materials.
