As much as “food integrity” has been part of nearly every discussion related to the food supply chain, the term is in itself unclear to many stakeholders in this arena. On one hand, food integrity implies a global perspective that includes food production, distribution, and everything in between (procurement, processing, packaging, testing, etc.); on the other hand, it could simply mean the absence of any fraudulent, unknown ingredient in the food supply chain that would impact food safety and public health.
At U.S. Pharmacopeial Convention (USP), we try to confine food integrity to the food ingredient level, and that means we develop tools to help manufacturers, formulators, regulators, and other parties to assert food ingredient quality (identity, purity, strength, as well as absence of contaminants). The analogy is that our Food Chemicals Codex (FCC) can be seen as a dictionary for food trade. The FCC is not a specialty dictionary, but it aims to establish a common language and to facilitate communication among the many players in this field. Just as an example, even though a manufacturer of potato chips may have a very nuanced understanding of what “salt” means and how important granularity and crystal flow are from a technological production perspective, his/her understanding of the identity and purity of this ingredient should not differ from how “salt” is described in the FCC. The logic seems simple, when applied to describe ingredients such as those consisting of well-defined simple salts or single molecules, but the more complex the chemical composition of a food ingredient, the more difficult it is to determine its integrity.
Food integrity is intrinsic to food safety in the FCC context. Being able to determine the safety of food and its ingredients at the basic level depends on the knowledge of its composition. One can only make a safety assessment of those components that are known. Hence, if and when an unknown ingredient is introduced in the food supply chain, it is impossible to establish whether the ingredient and any food produced with it is safe or not, until the presence of such an unknown ingredient becomes transparent. Unfortunately, in some cases this happens only when consumers experience a negative health impact.
The development and application of identity and purity standards for food ingredients is no easy task. Vitamin A is an example that illustrates what goes into deciding which test methods to use. It is an ingredient used both as a dietary supplement and in food formulations. Often, the term “vitamin A” is used to refer to a group of different compounds (including retinol, retinoic acid, and several carotenoids, of which beta-carotene is arguably the best known). All these various compounds have their own features regarding stability, bioavailability, isomerism, and other important parameters. An analyst will have to tailor his/her analytical methods to the specific compound (e.g., provitamin A or beta-carotene to adequately assess its purity and identity). Right there, the definition of what compound exactly is meant by “vitamin A” will trigger a decision about the types of tests necessary to accurately establish authenticity. Questions that feed into the very definition of the somewhat loose term “vitamin A” are: Which are the criteria we want to capture with vitamin A? For which purpose are we testing? The analyst would measure vitamin A by international units if the purpose was related to biological activity and bioavailability rather than a milligram/milliliter concentration, which is how food ingredients are usually measured.
Moisture, or water content, as simple as it sounds, is an important residue to consider and a good example to demonstrate the challenges of setting standards. Moisture is important because it often impacts the chemical stability of an ingredient (e.g. too much water and your ingredient may disintegrate); and, more importantly, it determines the risk of microbiological spoilage. If only very little water is available to microorganisms, this can be measured through determining water activity, which will predict microbiological growth and spoilage. Keeping water activity low is a control mechanism to minimize risks from potentially harmful microorganisms.