pH measurement (direct or in solution)

pH measurement is an essential parameter in the physicochemical analysis of food, cosmetic, nutraceutical, plant-based, and animal feed products. It allows for the evaluation of a product's acidity or alkalinity and is a determining factor for stability, safety in use, formulation compatibility, and, in some cases, regulatory compliance.

An unsuitable pH can affect texture, shelf life, microbial activity, the solubility of active ingredients, and the bioavailability of certain ingredients. In cosmetic formulations, it must remain compatible with skin pH. In the food industry, it plays a key role in fermentation, microbiological safety, and the stability of finished products. In plant extracts or nutraceuticals, it determines the stability of sensitive compounds such as curcumin, berberine, and palmatin.

pH analysis methods: direct or after dissolving

Two analytical approaches are proposed depending on the nature of the matrix.

• Direct pH
  measurement is performed on liquid, semi-liquid, or pasty samples. A suitable electrode is immersed directly in the matrix, ensuring a measurement that accurately reflects the product's native state. This approach is ideal for cosmetic creams, gels, lotions, beverages, aqueous solutions, sauces, or liquid extracts.
• pH after dissolution:
  Solid, powdery, or highly concentrated matrices require controlled dissolution. This method ensures homogeneous and reproducible measurement for plant powders, tablets, nutritional ingredients, dry extracts, solid raw materials, or additives.

Technical characteristics of pH measurement

The analyses are performed in accordance with applicable standards (ISO 4316, ISO 10523, or industry equivalents). Technical aspects include:

• Multi-point calibration with certified pads
• temperature control to ensure reliability
• Electrode selection based on matrix (viscous, aqueous, low conductivity)
• Repeating measurements to verify signal stability

pH analysis can be integrated into a more comprehensive physicochemical characterization. YesWeLab, for example, offers density analysis for liquids or solids, allowing for the correlation of pH with structural parameters. For plant-based or nutraceutical matrices, pH measurement is often combined with the measurement of active molecules such as curcumin, berberine, or palmatin.

Industrial applications and relevant matrices

pH measurement is used in many fields:

Human food:
Control of acidity, stability, and microbiological safety of beverages, juices, fermented products, sauces, dairy products, or functional drinks. This measurement can be supplemented by the total antioxidant capacity (TAS) measurement for products enriched with bioactive compounds.

In cosmetics,
pH is an essential measurement to guarantee skin-product compatibility in creams, gels, serums, shampoos, and lotions. pH also determines the stability of formulations containing gelling agents, which are analyzed, for example, through gelation studies.

Plants and nutraceuticals:
Evaluation of the acidity of plant extracts, stability of active ingredients, and optimization of formulations. pH can influence the stability of alkaloids or polyphenols measured in the YesWeLab catalog, such as curcumin, palmatin, or berberine.

Animal nutrition:
Quality control of raw materials, additives and formulations. pH is often combined with the measurement of Strong Ion Difference (SID), essential for assessing the electrolyte balance of a ration.

Integration into a comprehensive analytical strategy

pH measurement is often a first step before further characterizing a product. It can guide the investigation towards:

• stability analyses
• material-product compatibility studies
• additional nutritional analyses

YesWeLab supports manufacturers by selecting the appropriate techniques and laboratories according to the nature of the matrix, the regulatory context and the quality control objectives.

Analysis performed using YesWeLab

Thanks to its network of ISO 17025 and COFRAC accredited partner laboratories, YesWeLab offers reliable, reproducible pH testing suitable for all industrial matrices. You can order, track, and centralize your analyses directly through the YesWeLab platform.

For any specific request or quote, our scientific team is available to assist you.