Shulaev (who eschews the term foodomics, saying “We have enough –omics already”) uses this hardware to probe the plant metabolic pathways that ultimately produce nutritionally useful metabolites, such as flavonoids and anthocyanins. His model system is the wild woodland strawberry, and his ultimate goal is to understand the biosynthesis of metabolites sufficiently to be able to tweak the plants into more nutritionally useful strains.
Towards that end, he is working with a mathematician to model flux through the flavonoid pathway—a problem that is harder than it sounds. “The whole flavonoid metabolism [pathway] is not really so tremendously big,” he explains; it contains maybe a few dozen components. “But since there are many entry and exit points and branching and many regulatory points, it's … a very difficult and quite ambitious task.”
Fulvio Mattivi has used MS approaches to characterize the many chemical changes that occur when red wine is micro-oxygenated, one step in the wine-making process. In that study, Mattivi's team was able to detect and characterize in a single reverse-phase separation (and without sample preparation) some 1,000 compounds in the wine samples, 4 times more than most oenology references even mention.
Mattivi's lab also recently developed a high-throughput method for extracting and characterizing some 135 plant metabolites, especially phenolics, and analyzing them by MS.
Because analytical chemists often concentrate on known compounds, such broad and unbiased analyses can still yield surprises. For instance, while studying the metabolite composition of strawberries, Mattivi realized that the fruit's single most abundant ellagitannin (a kind of polyphenol) was one that had never before been described in strawberries.
The compound, called agrimoniin, was thought to be found mostly in Asian medicinal plants, while similar compounds had been identified in pomegranate. But strawberries are far more widely consumed in the West. “This compound in strawberry has on average a content of 200 mg/kilo,” Mattivi says. “That means that most probably this is the single most important ellagitannin in the human diet. And one year ago, it was still unnoticed.”
But before you run out and gorge yourself on strawberries, remember: Researchers still must consider the compound's bioavailability. As Bordoni notes, the nutritional content of raw food does not necessarily reflect what the body gets out of it. “Really, I hope that in the future I can eat 100 kilos of chocolate every day without having any problem of weight,” she says. That seems unlikely, but the science will tell. In the meantime, bon appetit!