These parameters do not only reflect nutritional composition; they also help detect adulteration, blending or quality de
1. Moisture
- Meaning: affects freshness, shelf life and the risk of microbial growth.
- Test method: oven-drying the sample at 105°C to constant weight (TCVN/ISO), infrared drying or Karl Fischer (for c
2. Ash content
- Meaning: reflects the total mineral content, helping establish nutritional value and detect inorganic impurities.
- Test method: incinerating the sample at 550–600°C to constant weight.
3. Protein content
- Meaning: a key nutritional index in protein-rich foods (milk, meat, seafood…).
- Test methods:
+ Kjeldahl: determines total nitrogen, converted to protein.
+ Dumas: nitrogen analysis by automated instrument, fast and accurate.
4. Lipid (fat) content
- Meaning: defines the energy value and quality of the food.
- Test methods:
+ Soxhlet extraction with organic solvent.
+ Gerber method (in milk and dairy products).
5. Acid parameters in food
- Meaning: assess sourness, storage quality and fermentation progress.
- Test methods:
+ Total acid titration: titrate the sample with 0.1N NaOH using phenolphthalein as indicator.
+ pH: measured directly with a pH meter.
+ Applies to soft drinks, yogurt, fruit juice, fish sauce…
👉 See the article Determining acid content in food by the enzymatic method
6. Sugar parameters in food
- Meaning: establishes nutritional value, controls quality and detects adulteration.
- Test methods:
+ Reducing-sugar analysis (glucose, fructose): by the Lane-Eynon method (Cu²⁺ titration).
+ Total sugar analysis: acid hydrolysis followed by Lane-Eynon quantification.
+ High-performance liquid chromatography (HPLC): detailed, accurate analysis of each sugar type.
+ UV-VIS spectrophotometry: DNS reagent used to quantify reducing sugars.
👉 See the article Determining sugar content in food by the enzymatic method
7. Vitamin and mineral parameters
- Meaning: backs up the nutritional value information on food labels.
- Test methods:
+ Vitamin C: iodine titration or HPLC.
+ Minerals (Ca, Fe, Zn, Na, K): analyzed by AAS (atomic absorption spectrophotometry) or ICP-MS.
8. Fibre content
- Meaning: assesses the nutritional value of vegetables, tubers, fruit and cereals.
- Test method: the enzymatic – gravimetric (AOAC) method.
9. Salt content (NaCl)
- Meaning: affects salty taste, preservation and consumer health.
- Test methods:
+ Mohr titration (AgNO₃ titration with K₂CrO₄ indicator).
+ Cl⁻ ion-selective electrode.
10. Peroxide value (PV) – fats
- Meaning: assesses how far fats and oils have oxidized, affecting safety and flavour.
- Test methods:
+ Iodometric titration.
+ AOAC titrimetric method.
11. Water activity (aw)
- Meaning: linked to microbial growth potential and shelf life.
- Test method: an aw meter working on the principle of moisture equilibration between sample and air.
12. Heavy metal content (Pb, Cd, Hg, As, Sn, Cu, Zn…)
- Meaning: mandatory safety limits under QCVN / Codex.
- Test methods:
+ AAS (atomic absorption spectrophotometry).
+ ICP-MS (inductively coupled plasma mass spectrometry).
+ ICP-OES (inductively coupled plasma optical emission spectrometry).
13. Chemical residues and toxins
- Pesticide residues: GC-MS, LC-MS/MS.
- Mycotoxins (aflatoxin, ochratoxin…): ELISA, HPLC or LC-MS/MS methods.
- Nitrite and nitrate content: UV-VIS spectrophotometry, ion chromatography.
So the key physicochemical parameters in food include: moisture, ash, protein, lipid, carbohydrate, fibre, acid/pH, salt, peroxide value, water activity, heavy metals and chemical re. Depending on the food type, choose the parameter set according to QCVN, Codex, ISO or AOAC.
Testing the physicochemical parameters in food not only safeguards health safety; it also preserves brand reputation and meets quality-management requirements under te acids and sugars in food deserve particular attention because they directly affect flavour, shelf life and consumer acceptance.