What is SNF in Milk? (SNF Full Form & Meaning)
SNF stands for "Solids-Not-Fat" (वसा रहित ठोस).
In dairy chemistry, milk is composed of two primary parts: Water (~85%–88%) and Total Solids (~12%–15%). Total Solids are further divided into:
- FAT (वसा / चिकनाई): The butterfat present in milk globules.
- SNF (Solids-Not-Fat): All the nutritious solid components of milk remaining after removing the butterfat.
$$\text{Total Solids (TS)} = \text{FAT} \% + \text{SNF} \%$$
What Nutrients Make Up SNF?
SNF represents the true nutritional core of milk. It consists of:
- Milk Proteins (~3.2%–3.8%): Casein (80% of protein) and Whey proteins (Albumin and Globulin). Essential for muscle growth and paneer recovery.
- Milk Sugar / Lactose (~4.5%–5.0%): Gives milk its natural mild sweetness and provides instant energy.
- Minerals & Salts (~0.7%–0.8%): Calcium, Phosphorus, Magnesium, Potassium, and Zinc. Crucial for bone density.
- Water-Soluble Vitamins: Vitamin B-Complex (B1, B2, B6, B12) and Vitamin C.
FSSAI Legal Minimum Standards for FAT & SNF in India
The Food Safety and Standards Authority of India (FSSAI) mandates legal minimum standards across states:
| Milk Category | Minimum FAT % | Minimum SNF % | Minimum Total Solids (TS) % |
|---|---|---|---|
| Cow Milk (गाय का दूध) | 3.2% to 4.0% (State-wise) | 8.5% | 12.0% |
| Buffalo Milk (भैंस का दूध) | 5.0% to 6.0% | 9.0% | 14.5% |
| Mixed Milk (मिश्रित दूध) | 4.5% | 8.5% | 13.0% |
| Standardized Milk | 4.5% | 8.5% | 13.0% |
| Toned Milk (टोन्ड दूध) | 3.0% | 8.5% | 11.5% |
| Double Toned Milk | 1.5% | 9.0% | 10.5% |
Note: If milk tests below 8.5% SNF at a collection center, dairy cooperative systems flag it for water adulteration or low-density milk, resulting in severe rate deductions.
How to Calculate SNF: The Richmond Formula
When a collection center or dairy booth tests milk, they determine:
- FAT % using a Gerber Centrifuge or Electronic Milk Analyzer.
- CLR (Corrected Lactometer Reading) using a standard ISI Zeal Lactometer at 27°C (or 29°C with temperature correction).
From CLR and FAT, SNF is calculated using the standard Richmond Equation:
$$\text{SNF } \% = \left(\frac{\text{CLR}}{4}\right) + (0.21 \times \text{FAT } \%) + 0.36$$
Step-by-Step Calculation Example:
- Measured CLR: 28
- Measured FAT: 4.0% (Cow Milk)
$$\text{SNF} = \left(\frac{28}{4}\right) + (0.21 \times 4.0) + 0.36$$
$$\text{SNF} = 7.0 + 0.84 + 0.36 = \mathbf{8.20\%}$$
Because 8.20% is below the 8.5% standard, the dairy cooperative deductions will apply.