Chromatographic techniques to build quality and support content claims


Dr DBA Narayana CSO Ayurvidye Trust, Bengaluru


The future of packaged food industry offers umpteen innovation possibilities due to more and more clarity emerging from regulatory provisions being notified by the Foods Authority in India. Any well-meaning compliant company would like to operate within the regulatory frame work.

Potential innovations in fortified foods and functional foods – supplements – nutraceuticals – FSDU – FSMP are immense. This also offers challenge to both innovators and the regulators including those involved in analytical aspects of such innovative products. Building quality and ability to support various types of content claims would necessarily be based on underpinning science and ability to analyse, trace, detect, evaluate changes during storage and above all provide reasonably convincing evidence on the product containing a particular nutrient / nutritional.

The nutrient / nutritional can come from a basket of – vitamins, minerals, amino acids, enzymes, and probiotics, and prebiotics, botanicals amongst others added to a food format or a food matrix to provide additional advantages. Chromatographic techniques be it Liquid Chromatography (LC) (High Performance, Ultra Performance) Gas Chromatography (GC) and innumerable technological advancements in terms of detectors, IT tools to attenuate, amplify, compute offer tools for substantiation.

Routine methods are available to separate vitamins and amino acids by such chromatographic techniques. Minerals do not get detected by these techniques and would need access to atomic absorption spectrometry or the latest Induction Coupled Plasma spectrometry (ICP) with either OES as detectors or MS as detectors.

The latter ICP has immense advantages of ability to detect and quantify more than 20 metals and minerals in one injection and that too many of them with detection limits in parts per billion. Claims on label of presence of vitamins, minerals, amino acids can be substantiated by these techniques with validated methods including when required quantitative estimations of them. Dr DBA Narayana CSO Ayurvidye Trust, Bengaluru Challenge on this front is of a high order when it comes to botanicals or their purified fractions or nutraceuticals added to food matrix.

Botanicals are likely to have many functional groups and minerals and sometimes pro-vitamins that can be present in the food matrix too. Potential interferences between the matrix and the botanical are generally seen giving a tough time to the analyst to segregate them while developing substantiation data. One approach for detecting / analysing botanicals in a food matrix is to take the conventional route of looking for marker compounds of the botanical added.

This is a standard technique adopted in most pharmacopoeial monographs for identification, assay and quantification of the purity of the botanical. The approach is to detect or analyse specific chemical compounds with known structure that are either novel or unique to that particular botanical or present in a few botanicals and not all botanicals (analytical markers).

If such marker compounds are also known in science to be responsible for specific therapeutic or pharmacological activity, then they are referred as biomarkers. One can look for these markers by chromatographic techniques and develop methods to detect or analyse them in the product using markers as reference substance. Often asked question is how many such markers of a botanical need to be analysed? Discussions may not be complete even after the cows have gone home.

A practical and pragmatic approach that balances science, knowledge, analytical ability in short time and preferably single sampling and injection and overall cost of analysis normally dictate the number of markers to be analysed. Some pharmacopoeias have also looked at negative markers to identify presence of potentially toxic compounds.

Indian Pharmacopoeial monograph adopts anywhere from a single marker to as many as 8 markers for a botanical. Expertise in developing analytical techniques involving LC or GC with or without MS would be a competency required to develop such methods. Ability to separate markers from the food matrix especially when present in very low proportions is a challenge that can be tried by extracting the markers from more than one serving sizes of the product. Knowledge of the proportions of marker selected in the botanical added to the food, quantum of botanical added and use of concentrating pre columns, guard columns to remove interfering chemical compounds from the matrix are basic requirements in such efforts.

Innovators would need to work in this area so that they are able to provide substantiation data when challenged by consumers or regulators on content claims made on labels. If a herbal tea is marketed claiming added ginger to the tea, innovators will need to demonstrate presence of ginger in the tea brew prepared using the product. If any benefits are being claimed due to presence of ginger in the tea, innovators may need to quantify and show adequate amount of ginger added, as per provisions in the Nutra Regulations where minimum and maximum proportions of ginger may be specified.

If proportions are not specified in the regulation the innovator will need in addition to demonstrate presence of ginger in the tea, data to support the level of addition of ginger. Dried ginger is known to contain more than 200 compounds that are characterized. One can adopt testing for – 6-gingerol, 8-gingerol, shagols, gingerones as potential markers. A number of such markers are available for use as reference substances supplied by global as well as Indian firms.

Many CSIR labs also claim ability to supply marker compounds. Indian Pharmacopoeia Commission supplies certified markers for those monographs present in IP. Other pharmacopoeial bodies globally also have a similar offerings of marker compounds for sale. Content claims need not be only the positive content claims. Negative content claims also need analysis and substantiation. Absence of heavy metal contaminants, pesticide residues, aflatoxins or presence of these potential contaminants below the prescribed limits of acceptance would also need substantiation.

Except for heavy metals contaminants chromatography offers techniques for such measurements. It is one thing for the innovator to have a good method to detect or analyse and also issue certification of such testing. More often than not certificate of analysis issued by the innovator laboratory is questioned for conflict of interest and not accepted fully. Innovators should in such situation share the method of analysis (if required confidentially) with an independent third party accredited test house and such laboratory should draw samples and analyse to provide the reports.

Readers of NuFFooDS are aware of case studies of published cases related to noodles, soft drinks and related controversies in India in the last few years which underwrite the importance of substantiating content claims. Content claims do not need prior approval of the Foods Authority and seems to be an easy way for providing marketable USP’s to the product. Innovators who wish to do so should invest and toil in ability to substantiate the content and have a analytical method to do so.

Given the scientific competency of Indian Scientists this challenge is achievable. The laboratories of the foods authority will also need to gear up to undertake such challenges.

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