A continuation of a three part series, this second article will delve into cases for the use of metabolomics, a technology used to detect small molecules such as amino acids, organic acids, sugars, volatile metabolites and secondary metabolites such as alkaloids, phenolic components and also pigments such as carotenoids and anthocyanins present in food and food ingredients.

Case 1: Metabolomics and Shelf-Life Prediction

Reliable shelf-life determination and labeling is hugely important but is also hugely difficult. Too short times means losing potential business and increased wastage while too long can result in risking retailer trust and consumer preference in the long term. Erring on the side of caution is the norm. Having a better understanding of the processes involved in product deterioration and the factors influencing it would clearly provide us with a better model for shelf-life prediction. Such an improved understanding, together with a means to compensate for batch-related differences caused by unknown or invisible product pre-history (environmental perturbations, on-farm cultivation practices, sub-optimal transportation and storage, etc.) will enable more accurate and reliable determination of shelf life labeling.

In the META-PHOR project for example, metabolomics approaches were used to follow product deterioration under supermarket-identical conditions. Looking at both fresh melon and broccoli samples it could be shown that the transition between acceptable/suboptimal quality is remarkably sharp and the development of a lower quality product (containing e.g. off-flavors, showing color changes etc) occurs over a short period. What industry needs are quality/shelf-life predictors—so called “biomarkers” that are already present in the raw materials upon entering the factory. These biomarkers may represent either positive or negative attributes and as these are currently unknown molecules with unpredictable function, metabolomics would seem the most valuable approach to choose for their identification. However, once identified, metabolomics may no longer need to be used as the aim is to exploit subsequently the biomarkers in a simple kind of “predictor/dip-stick” type of test more suited to an industrial environment requiring cheap and rapid results on-site.

Case 2: Raw Material Sourcing—Tracing And Tracking

A culture of year-round availability has arisen in the Western world where previously seasonal products are continuously offered in our supermarkets. This internationalization of the food industry entails a major global logistical challenge to source materials from areas of the world with complementary seasons to our own. Raw materials are transported all over the world and blends from different sources are often made to maintain uniform quality expectations and manage price fluctuations. Quality control for food buyers is important and aspects of authentication grow in importance—especially in relation to industry and consumer demands for guarantees of sustainable production.

Tools are needed to ascertain if the product value meets required specifications and if the reported source is indeed correct. Metabolomics can provide a rapid analysis tool suited for aspects of source authentication. Suppliers and supermarkets must be able to confirm that their Blue Mountain coffee is exactly that and their wines do have guaranteed countries of origin—especially for the more exclusive, higher-priced products. We need source-specific biomarkers. Metabolomics now has the potential to identify such authentication biomarkers for tracing and tracking applications in the food industry.

Case 3: Raw Material Sourcing and Purity

Are my ingredients really from as is listed on the package? Are they pure? The food processing industry is continually being confronted with the need to guarantee purity of product and sustainability. Furthermore, higher quality products command higher prices. Orange juice concentrate is more expensive than that of mandarin juice; Basmati rice is three to four times more expensive than other non-fragrant long-grain rices; extra virgin olive oils from certain regions of Italy and Spain have been specially developed for exclusive markets; wine and coffee from one specific local region often costs more than others produced close-by. But how to know? Adulteration using cheaper variants is a constant problem—even a 10-20% dilution of an expensive product with a cheaper one can hugely bump up profit margins for the supplier.

Several metabolomics tools are currently in development to provide rapid, large-scale screening methods for basic raw materials. The Juice Screener as developed by Bruker is one such tool that is already on the market. With this tool a set of chemical biomarkers have been identified that can be used to both predict location of origin of fruit juice concentrates and also potential levels of adulteration down to 10%. Additional applications for other markets (e.g. the wine industry) are in development.

The next installment of this article will overview the use of metabolomics in the raw material production process. Please check back on Thursday, April 28 for the final part of this three part series.

*Acknowledgement: Both GKL and RDH kindly acknowledge financial support for this paper from the EU Framework VI project “Metabolomics for Plants, Health and OutReach,” or META-PHOR (No. FOOD-CT-2006-036296).

Gerard Klein Essink, MSc, is managing director of Bridge2Food in The Netherlands, and Dr. Robert D. Hall is managing director of Centre for BioSystems Genomics CBSG2012, Plant Research International, also in The Netherlands.