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Fatty Acids

By Rabbi Dovid Cohen, Administrative Rabbinic Coordinator

Q. A Mashgiach said that something needs hashgacha because it contains “fatty acids”.  What are those?  Can they really be treif?  

A. Most people think of oil as something they can use in cooking, but food scientists realized that they could break apart oil and fat molecules into their constituent parts and use those components for other purposes.  One group of valuable items they can obtain are called “fatty acids”, so called because they come from fat/oil and have a certain structure, i.e., a carboxyl group, that chemically identifies them as an “acid”.  The carboxyl group is there in each fatty acid, and it is always attached to a chain of carbon atoms, so that main difference between one fatty acid and the next is how long that chain is.

Fatty acids with between 6 and 14 carbons generally come from inherently kosher sources such as coconut, palm, or vegetable oil.  Nonetheless, they are kosher-sensitive because the equipment used to “split” the acids from the oil, segregate one fatty acid from the next, and purify the fatty acids, might also be used to do the same processes for fatty acids made from animal fat.  One use for the fatty acids with these chain lengths is in the production of flavors; for example, hexanoic/caproic acid is a fatty acid with 6 carbons, and when reacted with ethyl alcohol it produces ethyl caproate, which has an apple-like flavor.

However, the fatty acids with 16 or 18 carbons – palmitic acid, stearic acid, and oleic acid – are much more kosher-sensitive, since they can be produced from animal fat (i.e., non-kosher).  These might also be used in flavors, such as ethyl palmitate in buttery or vanilla flavors, or oleic acid in meat or chicken flavors.  Another common use is that magnesium stearate is added to pills/tablets because it helps them slide in and out of the machinery more easily.  The good news is that magnesium stearate is typically used in small amounts that it is batel b’shishim, so a person taking a pill does not have to concern themselves with it.

Flavor chemicals are also used in tiny amounts; theoretically, they would be batel b’shishim, but since they change the taste of the food (avidah lit’amah), they cannot be batel.  That means that if animal-fat-based oleic acid was used to create the chicken flavor in an instant noodle soup, that soup would be forbidden, even b’dieved.  However, a significant limitation of the halacha of “avidah lit’amah” is that it is only a concern when the food is inherently forbidden.  But if the only issue is that the avidah lit’amah might, itself, have been produced on non-kosher equipment, then it can be batel.  [The concept is called melach habaluah m’dam.]  This means, that if the fatty acid was from the earlier group – containing 6-14 carbons – where we know the fatty acid comes from a kosher source, and the concern is just that it might have been processed on non-kosher equipment, the food will b’dieved be permitted.

One last notable use of fatty acids is in the production of polysorbates, which serve as emulsifiers that allow water and oil to mix.  They are made by reacting ethoxylated sorbitan (which binds with water) together with a fatty acid (which binds with oils), and polysorbates are categorized by which fatty acid they are made with: polysorbate 20 – lauric acid; polysorbate 60 – stearic acid; and polysorbate 80 – oleic acid.  In most cases, an emulsifier plays such a significant role in the food that it also cannot be batel (davar hama’amid) regardless of how little of it there is.  Once again, that strict status only applies when the emulsifier is inherently forbidden, such as with polysorbates 60 or 80, but not if it was polysorbate 20 made with lauric acid, since that comes from vegetable oil.

Of course, all these points regarding bitul are only applicable in situations of b’dieved, but our first choice is always to ensure that all ingredients we eat are 100% kosher.

This article first appeared in the Let’s Talk Kashrus column, Yated Ne’eman, February 9, 2024.