The best available definition of quality was one stabilised in the 1951 USDA Marketing Workshop Report. This definition alludes to quality being a concept, but describes it in terms that are definable in their own right. Quality was defined as being ‘a combination of attributes or characteristics of a product, which have significance in determining the degree of acceptability of the product to a user’.

Because this definition mentions characteristics or attributes, which can be defined, and mentions a user, who will purchase the product or use the service, let this be considered a working definition of quality. Do not forget, however, quality is a concept.

Building a quality program involves a long-term commitment of time and resources.
Management should, however, look at their quality efforts not as expenditure, but as a cost-savings centre. The benefits of producing and distributing products of the same consistency or quality are enormous. Failure to maintain standards can result in severe economic loss, or, depending on the product and problems encountered, injury or worse to the user, and in the worst-case scenario, the economic death of a company or label.

• Management support,
• Solid quality philosophy/policy,
• Communication/education, including Free exchange of information; employee self improvement; written procedures; specifications and standards; and professional societies and meetings,
• Committed staff/team approach,
• Independent quality management function,
• Process control/documentation, including product and raw materials specifications; packaging materials specifications; equipment maintenance; product coding, tracking, and recall procedures; and microbiological procedures and standards,
• Innovation.

Each of these elements is dependent on the others for successful program development and management.

Quality control of fragrance and flavour substances, as well as the products derived from them, comprises the comparison of sensory, analytical, and if necessary, microbiological data with standards and specifications. To a large extent these have been established in official specification collections (Pharmacopoeias, ISO, Essential Oil Association, Merck Index).

In the past few decades, a precise analytical methodology has been developed for sensory evaluation and has proved to give reliable results. Analytical determination of identity purity aids greatly in establishing the acceptability of fragrance and flavour materials.

Single fragrance and flavour compounds are characterised by generally accepted physical constants, such as density, refractive index, optical rotation and melting point. The advantages of these parameters are their speed of measurement and the possibility of comparison with other laboratories; therefor, they will continue to be indispensable.

Determinations of content by chemical parameters, such as ester and carbonyl numbers, are being increasingly supplemented by chromatographic procedures such as GC and HPLC and by spectroscopic techniques (UV, IR, and NMR).

Standardisation of specifications for complex fragrance and flavour materials, such as essential oils and animal secretions, is far more difficult than for single compounds. In addition to organoleptic and physical properties, the content of certain typical components is determined. Problems concerning the natural, using modern chromatographic and spectroscopic analytical techniques (and combinations such as GC-MS) solves botanical and geographical origins of these products.

The analysis of trace components (halogens, heavy metals, and pesticides) in flavours and fragrances that are used in foods and cosmetics is becoming increasingly important. Radioactivity values in materials of natural origin are also monitored.