A small sign hanging above the produce in a local supermarket reads, “Fruits and vegetables have been coated with food-grade vegetable, petroleum, beeswax, and/or lac-resin based wax or resin to maintain freshness… No fruits or vegetables have been coated with animal-based wax”. The sign is the result of efforts by citizens groups demanding disclosure of ingredients in coatings used on fresh produce. The produce industry, citing the impracticality of constantly changing signs and claiming that disclosure would compromise the confidentiality of coatings ingredients, resisted these demands. The FDA regulation that emerged in 1994 is the result of a compromise between the two groups. Although the sign does disclose some information, it only tells part of a much larger story.1

The sign is not required by law to declare the additives put in coatings, some of which raise kashrus concerns. That doesn’t mean that coatings on fresh produce are not acceptable. This article will present information relevant to evaluating the kashrus of coatings. .

First, a note about where the information came from: Coatings manufacturers, careful to guard trade secrets, are unusually tight-lipped about the ingredients they use. Jewish law, in any event, limits the credibility of company spokespeople, particularly when there is no way of verifying their claims.

Reading literature written by and for people in the produce industry is halachically similar to overhearing a conversation, and, in some instances, is reliable according to the parameters of maysiach l’fi tumo, which means that the person talking is unaware of the halachic significance of his report.2

Much of the literature comes out of government and academic research. Coatings extend the shelf life of fresh fruit and vegetables and, in some instances, make fruits and vegetables look more attractive. The technology is critical to agribusiness. The USDA has several scientists researching and developing more effective and less expensive coatings. These scientists, whose salary is paid for by tax dollars, consider it part of their job to speak to the public. Food Science departments also invest in research into coatings. The annual conference of the Institute of Food Technologists has featured sessions discussing progress in coatings manufacture from various materials.3

The most straightforward way of knowing what actually goes into coatings is by reviewing the product lines of major manufacturers. Those products typically contain two major components: the base, or resin, which is the majority ingredient of a coating (and which are broadly listed on the supermarket sign), and several different additives (which are left out).

In terms of bases, shellac (the “lac-based” resin referred to in the sign), and carnauba wax are by far the most commonly used. Shellac is a secretion of the lac bug, which is found in Thailand and India. Some kashrus agencies follow the ruling of Iggeros Moshe Yoreh Deah I:24, which offers several reasons why shellac is acceptable as a confectionary glaze.4

Carnauba wax is formed on the leaves of the Brazilian palm tree, from which it is mechanically removed. It is inherently kosher.5

A sucrose-ester base is also available on the market, but sold on a much smaller scale.6 Other likely materials include Candellila wax, also botanical in origin, cellulose based materials (botanical), and petroleum, which is inherently kosher. Beeswax is also considered inherently kosher.7

Research and development of new coatings bases include whey or casein-protein (dairy derivatives),8 wheat (chametz),9 rice-bran (kitnios), corn zein,10 acetylated monoglyceride11 (which can be either from a kosher vegetable or non-kosher animal source), or from a triglyceride emulsion12 (also from vegetable or non-kosher animal sources).13 Coatings containing these materials are not commonly, if at all, produced commercially.

As far as additives are concerned, information can be taken from the industrial product labels of the coatings. These labels are found on the coating containers in the produce packinghouses, where coatings are actually applied to fresh produce. These labels have ingredient declarations that list many of the additives found in coatings. These additives help the base be evenly dispersed and conform smoothly to the shape of the produce. Some of the additives can be of animal, vegetable, or dairy origin.

Morpholine oleate is an additive commonly found on ingredients labels. Morpholine is an innocuous ammonium based ingredient that is used to raise the pH. The “oleate” suffix indicates the presence of oleic acid, a fatty acid. Sometimes oleic acid is used for legal reasons (it’s necessary in the presence of morpholine) and in other applications it is an emulsifier, critical to the production of the coating.

An emulsifier helps a material like carnauba wax mix with water. The coating is sprayed onto fruits, which means that it must be in a water-solution.14

Stearic acid, another fatty acid, is also commonly added to coatings. This additive is a plasticizer, which means it increases the flexibility and adds toughness to a coating.

Fatty acids are one of the two major components of a fat or oil. Although some fatty acids can come from a vegetable source only, others, like oleic and stearic acids, can come from either a vegetable or an animal source. How do we know whether the oleic acid that companies are using is from the vegetable source or the animal source?

Some companies claim that they have used vegetable based oleic acids. A chemist from a major coatings manufacturer suggested that it is the “climate” to purchase vegetable-derived ingredients, and, therefore, kosher consumers can rest assured that oleic acid is from a vegetable source. On the other hand, tallow derivatives are typically cheaper than their vegetable counterparts.15 Although American companies do like to declare the use of vegetable-based ingredients for the health-conscious consumer, that possibility does not exist with fresh produce, since no comprehensive ingredient statement is provided to the retail consumer. One manufacturer acknowledged that additives such as oleic or stearic acid were not necessarily from kosher sources. When the non-kosher alternative is cheaper, and no affirmative duty compels manufactures to declare the origin of their ingredients, it is hard to assume that the oleic acid being used in coatings is from a vegetable source.

Whey (dairy) and soy (kitnios) proteins are also often used as thickeners in coatings. Apparently the presence of dairy is not an allergen concern, nor it is an allergen concern that manufacturers are willing to risk. Finally, the coating solution sometimes contains alcohol (isopropanol or ethanol).16

Table I shows both the ingredients used in coatings and their typical proportions.17

TABLE I

IngredientProportion
Water65-80%
Alcohol
(isopropanol and/or ethanol)0-15%
Carnauba wax/shellac15-18%
Oleic acid and other fatty acids3-5%
Morpholine 1.5-2.5%
Soy or dairy protein0-4%

Coatings at this stage taste terrible, and are not fit even for an animal.

The coating is sprayed onto fruits or vegetables using a method called wet casting. After the coatings have been sprayed onto produce, they go through a drying tunnel and the alcohol and water evaporate. The drying tunnel operates at temperatures considerably less than yad soledes bo, and is typically 105 degrees Fahrenheit.18

What is left on the fruit or vegetable after drying is the base and additives, minus the water and alcohol. The significance of this fact is that whatever percentage a given additive is in the original solution, that figure is approximately four to five times that percentage of the actual coating on the fruit. In other words, if a given ingredient would be only 1% of the coating in the original solution, it would constitute 5% of the coating that is actually found on the fruit.

After drying, the range of ingredient proportions in a coating, based on the numbers cited in Table I, is:

TABLE II

IngredientProportion
Carnauba wax/shellac75-80%
Fatty acids
(mostly oleic acid)11-14%
Morpholine Difficult to estimate since it gradually evaporates
Stearic acidLess than 1%
Soy or dairy protein0-25%

A dried shellac or carnauba wax based coating at this stage tastes mildly unpleasant. The presence of coatings on fresh fruits or vegetables is so minimal that any off-taste in the actual coating is undetectable.

Based on all of the above, if in fact the oleic acid is from a non-kosher source, would such a coating be acceptable? There are various reasons to be lenient. One of them is that, according to some poskim, in a non-food product such as toothpaste, a non-kosher ingredient such as animal-derived glycerin would be batel b’rov. Here too carnauba wax and shellac, the standard bases for coatings, are considered halachically to be a non-food product. Therefore any possible non-kosher additive would be, like the case of the toothpaste, batel b’rov.19

A dairy protein would similarly be batel b’rov.

Ideally, it would be best to use kosher certified coatings on fresh produce. However, since the kosher consumer and kosher agencies have no practical way to determine what coating was used, one should consult his or her posek.