Purpose :Suppress yeasts/molds on the rind during brining and early ripening without inhibiting starter cultures inside the cheese.

Key principles:

• Natamycin is poorly water‑soluble; use as a low‑ppm dispersion in the brine with continuous gentle agitation/recirculation.
• Maintain typical brine specs independently (NaCl 18–24% w/w, pH ~5.2–5.6, Ca2+ balanced), then overlay natamycin control.

Typical working range in brine: Active natamycin: 10–40 mg/L (ppm) in the brine liquor. Many plants run 20–30 mg/L as a starting point.

Formulations

Option 1: Using 50% natamycin powder

• Target 20 mg/L active in a 5,000 L brine tank:
• Required active: 20 mg/L × 5,000 L = 100,000 mg = 100 g active.
• With 50% powder: 100 g active ÷ 0.50 = 200 g powder.
• Slurry preparation:
• In a side vessel, add 10–20 L of cold brine (same salt concentration as tank) at 5–10°C.
• Start gentle mixing; slowly add 200 g of 50% natamycin powder while stirring to make a uniform slurry.
• Optionally add 0.01–0.03% polysorbate 80 to the slurry to improve wetting/dispersion (check labeling/regulatory).
• Add the slurry to the main brine tank at an inlet with high circulation; keep the tank covered and shaded.
• Maintain mild continuous agitation or recirculation to minimize settling.

Option 2: Using liquid type natamycin aqueous solution (40,000–55,000 ppm)

• Target 20 mg/L active in 5,000 L:
• Required active: 100 g active.
• Volume of solution at 50 g/L: 100 g ÷ 50 g/L = 2.0 L.
• Meter the measured volume directly into the brine return line or high‑turbulence zone; keep the drum protected from light and keep the tank covered.

B) Shredded cheese mold inhibition

Purpose : Suppress mold/yeast growth in refrigerated distribution on high‑surface‑area cheese shreds.

Two common approaches

1. Powdered anti‑caking blend carrying natamycin (dry application).
2. Fine mist spray of an aqueous natamycin dispersion onto shreds before tumbling/bagging.

Target finished‑product dose (active):10–20 mg/kg (ppm) natamycin active in finished shredded cheese is common.

Approach 1: Dry blend with anti‑caking powder

• Anti‑caking base: potato starch or microcrystalline cellulose (MCC) ± small CaCO3 or cellulose powder. when dosed at 1.0–1.5% of cheese weight, it delivers 10–20 ppm natamycin active.
• Anti‑caking carrier(s): 9,970 g
• Natamycin powder 50%: 30 g
• Dose this blend at 1.0% w/w of cheese to deliver ≈15 ppm active.

Approach 2: Aqueous spray onto shreds

• Aim for a spray that delivers 10–20 mg/kg active evenly with minimal added moisture (≤0.5% added water).

Option 2A: Using 50% natamycin powder

• To make 100 L at 1,000 mg/L active:
• Active required: 100 g.(50% powder needed: 200 g.)
• Fill tank with 100 L cold, dechlorinated water (5–10°C).
• Optional wetting aid: polysorbate 80 at 0.02% (20 g) to improve wetting; avoid ethanol in high‑shear spray zones if vapor control is poor.
• Sprinkle in 200 g 50% natamycin powder under gentle agitation; mix 10–15 minutes.
• Keep recirculating; fit 100–200 μm inline screen; keep tank covered and shaded.

Option 2B: Using natamycin aqueous solution (40,000–55,000 ppm)

• To make 100 L at 1,000 mg/L active: need 100 g active → 100 g ÷ 50 g/L = 2.0 L of the stock solution; q.s. with water to 100 L.

Spray application math:

• If shreds line runs 1,000 kg/h and you target 15 ppm active:
• Required active per hour: 15 g.
• With 1,000 mg/L spray: need 15 L/h spray volume.
• Added moisture: 15 L to 1,000 kg = 1.5% w/w moisture. If that’s too high, double concentration to 2,000 mg/L and spray 7.5 L/h (0.75% added moisture).
• Use fine mist nozzles (e.g., 0.3–0.5 mm orifice), low pressure, and position above a cascading curtain of shreds for full coverage.
• Immediately tumble in a perforated drum 10–20 seconds; then proceed to bagging.

Important compliance note

• Many jurisdictions only permit the use of natamycin for surface treatment. When used in brine, the intention is to protect the surface. Ensure that migration into the interior remains minimal and meets local limits (often defined as 'not detectable' at a distance of 5 mm from the surface, with a maximum surface residue of about 1 mg/dm²). Always check your country's regulations.
• Some markets explicitly allow natamycin on shredded cheese; others restrict or require label declarations. Confirm your local rule and any maximum finished‑product limits (often around 10–20 mg/kg active in the cheese).