GIFSQ Tools · Module 2 — Food Chemistry & Physicochemical Testing · Tool 40 of 500
Checker: enter the measured pH, Brix, acidity, salt and water activity with the specification limits for each, and get a pass or fail for every parameter.
Try sample values — fills the form with the worked example below.
pH
Soluble solids (Brix)
Titratable acidity
Salt
Water activity
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Parameters passed
–
Parameters failed
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Overall result
Equation: A parameter passes when minimum ≤ measured ≤ maximum (limits inclusive). Overall pass = all five parameters pass. Fail count = the number of parameters outside their limits.
Method: Specification check against the product specification — pH by AOAC 981.12, soluble solids by refractometry (AOAC 932.12 / ISO 2173), titratable acidity by titration (AOAC 942.15), salt by titration (AOAC 937.09), water activity by chilled-mirror or capacitance meter (AOAC 978.18 / ISO 18787). The limits themselves come from your product specification, not from this tool.
Assumptions: each measured value was taken by its named method; the limits entered are the current specification for this product.
Limitations: a pass here is a check against limits, not a full quality judgement — a product can pass all five and still fail on flavour, colour or microbiology; limits at the boundary pass, so a value sitting on a limit deserves a re-check.
Rounding: pass and fail counts are whole numbers; measured values are shown to 2 decimal places (water activity to 2 decimal places); intermediate values are not rounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Method: Specification check against the product specification — pH by AOAC 981.12, soluble solids by refractometry (AOAC 932.12 / ISO 2173), titratable acidity by titration (AOAC 942.15), salt by titration (AOAC 937.09), water activity by chilled-mirror or capacitance meter (AOAC 978.18 / ISO 18787). The limits themselves come from your product specification, not from this tool.
Assumptions: each measured value was taken by its named method; the limits entered are the current specification for this product.
Limitations: a pass here is a check against limits, not a full quality judgement — a product can pass all five and still fail on flavour, colour or microbiology; limits at the boundary pass, so a value sitting on a limit deserves a re-check.
Rounding: pass and fail counts are whole numbers; measured values are shown to 2 decimal places (water activity to 2 decimal places); intermediate values are not rounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: A juice is checked against pH 3.00–4.00, Brix 11.00–13.00, acidity 0.50–1.00 %, salt 0.00–0.50 %, aw 0.00–0.85. Measured: pH 3.50, Brix 12.00, acidity 0.70 %, salt 0.20 %, aw 0.80 — all five inside their limits, so 5 passed, 0 failed, overall PASS.
Enter values above to see results.
Enter the limits from your own product specification for every batch — do not reuse another product's limits. A value exactly on a limit passes, by the inclusive rule above. Tool 40 of 500 — GIFSQ
