Most fruits have a typical C3 stable carbon isotope ratio around -25 on our scale. Addition of HFCS to juices and concentrates as well as other fruit products can often be determined with ease by looking at the stable carbon isotope ratio. The same is true for freeze dried fruit chips. Dried fruit which is claimed to be free from added sweeteners can exhibit the addition of HFCS just as juices can.
The oxygen isotope ratio can reveal whether a juice is reconstituted from concentrate or “not from concentrate”. Wines, vinegars, alcohols, malts and other products are easy targets for adulteration and misrepresentation concerning sugar sources and good candidates for stable isotope analysis to determine origin and purity