GIFSQ Tools · Module 10 — Packaging & Shelf-Life · Tool 197 of 500
Track peroxide value (PV) against its limit: the PV on a given day, the days left to the limit and the status at a steady oxidation rate.
Try sample values — fills the form with the worked example below.
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PV on that day (meq/kg)
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Days to the limit
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Days left from that day
Equation: PV on day t (meq/kg) = PV₀ + rate × t. Days to limit = (limit − PV₀) ÷ rate. Days left from day t = days to limit − t.
Method: Oxidation tracking by peroxide value: PV rises roughly in a straight line while oxidation is steady, and the product is judged at the PV limit set in the specification.
Assumptions: oxidation runs at a constant rate over the tracked period; PV is measured by the same method each time.
Limitations: PV only tracks primary oxidation — it falls again as peroxides break down, so a low PV late in storage does not mean the fat is fresh; check secondary oxidation too.
Rounding: PV to 2 decimal places; days to 2 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: Oxidation tracking by peroxide value: PV rises roughly in a straight line while oxidation is steady, and the product is judged at the PV limit set in the specification.
Assumptions: oxidation runs at a constant rate over the tracked period; PV is measured by the same method each time.
Limitations: PV only tracks primary oxidation — it falls again as peroxides break down, so a low PV late in storage does not mean the fat is fresh; check secondary oxidation too.
Rounding: PV to 2 decimal places; days to 2 decimal places; intermediates unrounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: PV 2 meq/kg at day 0, limit 10, rate 0.2 per day: on day 20 the PV is 2 + 0.2 × 20 = 6.00 meq/kg; the limit is reached at day 40.00, so 20.00 days remain.
Enter values above to see results.
Typical PV limits: 10 meq/kg for refined oils in many specifications — always use the limit in your own product specification. Tool 197 of 500 — GIFSQ
