Thou Shalt Not Commit Adulteration: Guarding Against The Dilution of Juice

The mission statement for the Technical Committee for the Juice Products Association, the major trade association of the juice industry, states that it is “dedicated to a level playing field for products containing juice” which means, as the statement goes on to say, that they “develop and validate methods for authenticating juice and juice products.”

The committee exists in response to the age-old problem of juice adulteration, which usually involves diluting “pure” fruit juice with other ingredients. Those ingredients may be water or sugar or sweeteners, as well as juices that are cheaper than the one being sold.

From a kosher perspective, the most serious concern is the (illicit) addition of non-kosher grape juice to a more expensive juice, such as pomegranate, raspberry, or cranberry juice that is marketed as “pure.” The incentive to adulterate is offset, of course, by the fact that adulteration is illegal. A tarnished name, especially in close-knit markets, can be enough to send a company into bankruptcy. Further, if a product is being touted as medicinal or therapeutic, a company will think twice before playing games.

Nonetheless, adulteration does take place. How would it be identified?

Contemporary laboratories have various methods to determine, or possibly determine, whether a juice product that claims to be one hundred percent juice is in fact that. Doing so requires the development of a “fingerprint” for that juice, which involves compiling a comprehensive database of a specific variety of juice and, based on that information, establishing a standard, or chemical profile,. That standard will be based on organic acids, sugars, proteins, and other constituents of a juice. Samples of juices that do not conform to the projection of what the juice ought to look like may be interpreted as being adulterated. To take a simple example: If the glucose content in a sample of apple juice exceeds the amount of glucose that is naturally in apple juice, a lab would conclude that glucose has been added to the apple juice.

The marker, or indicator, for grape juice is tartaric acid. Grape juice is rich in tartaric acid. Few other juices have any, and most have none.

There is no reported tartaric acid in raspberry juice. If a laboratory test on a sample of raspberry juice yielded the presence of tartaric acid, the laboratory would likely conclude that a) the raspberry juice has been adulterated and b) grape juice is the adulterant.

A juice’s “fingerprint” can also be developed through analysis of its pigment. Anthocyanins are a class of pigments that are red, purple, or blue. Grape juice has a distinctive anthocyanin profile (and that profile will differ depending on the variety). Pomegranate, raspberry, or strawberry juice each have a distinctive anthocyanin profile.
Tartaric acid and specific anthocyanins are the primary, and perhaps only, indicators for the presence of grape juice in other juices.

When a juice bottler suspects competitors of wrongdoing (usually because the price of a product is too good to be true) it will hire outside laboratories to analyze the product. Such testing is crucial in today’s regulatory environment, in which governments have limited capacity to test doctored products and policing is largely a function of self-regulation of industry. Testing not only discourages competitors from wrongdoing. It is a tool of quality assurance insofar as a corrupted or doctored product, even when it is someone else’s, can be disruptive for an entire industry.

It is important to note that the conclusions laboratories make are interpretations of data. The interpretations, to be sure, are based on norms hammered out through available literature and through discussions of, for example, the Juice Products Association’s technical committee. The presence of a non-conforming piece of data is not, however, proof-positive of adulteration. For example, high tartaric acid content in a sample of pomegranate juice could be interpreted to mean that grape juice is present in the sample. That conclusion would be based on the logic that there is no tartaric acid in pomegranate juice, and the only likely source for tartaric acid is grape juice.

What if, however, the database used to compile the chemical profile (the “fingerprint”) of pomegranate juice was not adequately comprehensive? What if the pomegranates used for the data were only of some varieties, and not others? Or only grew in certain types of soil, and not another? Or what if tartaric acid could be supplied from another juice, other than grape?

Generally, of course, laboratory interpretations are credible, or are thought to be credible in court. Recently, a juice company successfully sued another juice company for selling fraudulent product. The evidence used as basis for the judgment was the consensual conclusion of seven independent labs of wrong-doing. The defendant was severely penalized.

The global supply chain has created new challenges for beverage, food, and flavor manufacturers who expect the commodities they receive to cohere completely with the specifications they set forth to their suppliers. The most effective way to avoid problems with suppliers is to develop close-knit and long-term relationships with them.

Laboratory testing is not a great way to make sure your suppliers remain honest. But it is an important technique to be aware of, and invoking it from time to time is a way to make sure your product is exactly what it claims to be.

Rabbi Gavriel Price services the transportation, ingredients, and flavors industries at the Orthodox Union. He received rabbinic ordination from Breuer’s Rabbinical School in New York and a degree from Reed College, Portland, OR. A frequent contributor to BTUS, his “Vanilla, Hurricane Huddah, and the OU Flavor Department,” appeared in the Summer 2010 issue.