National Organic Standards Board

Handling Subcommittee

Petitioned Material Discussion Document

Zein

February 16, 2021

SUMMARY 

This document includes a brief review of the petitioned use of zein, or corn protein, as a “Nonorganic 

agricultural substance[s] allowed in or on processed products labelled as organic,” as well as the 

recently submitted technical review. 

INTRODUCTION

The NOSB was petitioned in February of 2020 to consider zein, otherwise known as “maize protein”, 

“protein coating” or “confectioner’s glaze”, for addition to the National List. The full petition may be 

found here. The petitioner, Flo Chemical Corporation, asked for inclusion of zein under “Nonorganic 

agricultural substance[s] allowed in or on processed products labeled as “organic” (§ 205.606).” The 

NOSB asked for a technical report which was produced in January 2021 and deemed sufficient in 

February 2021. 

Zein is the protein component of corn, which has the useful quality of being hydrophobic, but easily 

dissolved in an alcohol solution. This allows zein to be dissolved into the solution and then sprayed or 

otherwise applied on the food item. The alcohol then evaporates off and leaves behind a thin layer of 

zein that acts as a protective coating. This zein layer serves as a moisture barrier and effectively extends 

the shelf life of dried nuts and fruits, candies, and fresh fruits and vegetables much in the same way 

plastic wrap would. In contrast to plastic sheeting, the zein layer is fully edible and adds nothing but a 

small amount of protein of poor nutritional quality to the consumed product. 

BACKGROUND

This is the first time that zein has been petitioned for inclusion on the National List. It was first 

designated as GRAS (generally recognized as safe) by the FDA in 1984. The petitioner states that there is 

currently only one North American manufacturer of zein, the petitioner - Flo Corporation. Their stated 

manufacturing process is: 

“ Zein is derived from dent corn gluten meal. All of our zein production for the food industry comes from 

USA sourced, non-GMO corn. In addition, all of our production is certified OU Kosher. 

Manufacturing: Flo Chemical Corporation manufactures (isolates) zein utilizing a proprietary process 

(Freeman Process), which was developed in 1976 by the company’s founders. Process starts with the 

following raw materials: non-GMO CGM, water and ethanol.” 

While it would be possible to manufacture organic zein with organic starting products, the manufacturer 

states that sourcing certified organic corn gluten meal for the production of organic zein is not currently 

possible. In addition, organic ethanol is reported by the petitioner to be prohibitively expensive.

RELEVANT AREAS OF THE RULE, NOP GUIDANCE, NOP POLICY MEMO, and OMRI 

The TR states, “Zein is a food substance Generally Recognized as Safe (GRAS) by FDA [21 CFR 184.1984] 

as a direct human food ingredient, for use as a surface-finishing agent, and for technical effects (i.e., as 

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an anticaking agent or free-flow agent, a drying agent, and a humectant). Zein also is allowed as an 

indirect food additive used as a component of adhesives [21 CFR 175.105]. A major use of zein is for 

coating foods and pharmaceutical products. The most common production process for zein uses corn 

gluten, also known as corn gluten meal, as the starting material. Corn gluten itself is a GRAS food 

ingredient [21 CFR 184.1321].”

Zein has not been previously considered for addition to the National List. There are no current NOP 

policy memos that relate to zein or its category of proposed use. Despite this, the rulings that have been 

made on corn steep liquor (CSL) are directly relevant to any review of zein as they are different products 

created during the same wet-milling process. The bulk of the corn gluten meal is produced via wetmilling with sulfur dioxide as the alternative wet milling strategies are not cost-competitive and drymilling produces very little of the desired zein protein in the end-product.

In determining whether or not to allow corn steep liquor as a non-synthetic agricultural product, The 

Organic Materials Review Institute (OMRI) reported the following decision-making process: 

“For technical questions such as these, OMRI relies on our Advisory Council, an independent body 

made up of experts in their fields, to determine the status of a substance. The Advisory Council 

was provided with peer-reviewed literature, patents, manufacturing processes and a copy of the 

2006 NOSB synthetic/nonsynthetic decision tree catered to CSL to help inform their votes. In May 

2009, the Advisory Council voted 8-2 that corn steep liquor is synthetic. 

Later, OMRI received additional information that lent to the argument that it was not synthetic; 

mainly that lactic acid is the driving force for the chemical change rather than sulfurous acid. 

Lactic acid is produced naturally in the steeping process through the conversion of dissolved 

sugars. The Advisory Council was asked to vote again, taking into account the new information. 

Again, the council voted that CSL was synthetic, 7-3. This comment from an Advisory Council 

member summarizes the prevailing argument: “As long as any of the active species [Sulfurous 

acid] is present, it can react with the proteins. Breaking of disulfide bonds is an irreversible 

reaction that goes to completion. Once the sulfite ion reacts, more of it is produced by the 

ionization process to maintain equilibrium conditions. The suboptimal pH of the industrial 

process does not stop breaking of disulfide bonds by sulfite ion. It only slows it down. In the 

industrial process some of the bonds are probably broken by lactic acid, but it is unreasonable to 

assume that the entire degradation process is due to unilateral action of lactic acid produced in 

the fermentation reaction.” 

In a memo on November 12, 2009, the NOP asked the organic industry to consider CSL 

nonsynthetic and allowed for use in organic agriculture until the NOSB can discuss it at the 

Spring 2010 meeting. Although the OMRI Advisory Council voted twice that CSL is synthetic, 

OMRI has followed the NOP directive and currently lists products with CSL.” 

In 2011, the NOSB reviewed corn steep liquor and through a similar rationale, came to the same 

conclusion.

“Recommendation: The Crops Committee recommends that Corn Steep Liquor produced via the 

traditional countercurrent corn wet milling process be considered as non-synthetic and allowed for use in 

organic crop production. 

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Committee Vote Motion: Consider CSL to be non-synthetic when produced via the traditional 

countercurrent corn wet milling process only. 

Motion: Jeff Moyer Second: Tina Ellor Yes: 4 No: 3 Abstain: 0 Absent: 0” 

PREVIOUS PUBLIC COMMENT AND TECHNICAL REPORT

SUMMARY OF REVIEW

As this is the first time zein has been considered, there are no previous public comments or reviews to 

draw upon. For questions of whether or not the product should be allowed and/or how to classify it, 

referencing the relevant discussions surrounding corn steep liquor is useful. The NOSB determination 

on how to categorize corn steep liquor can be found here. 

DISCUSSION

The potentially contentious areas for understanding zein’s suitability for inclusion on the National List 

fall under three main categories: a) the environmental impacts of the corn wet-milling process used to 

create the corn gluten meal, b) whether the zein product can be considered non-synthetic and c) 

whether zein fills a unique functionality not already filled by currently allowed substances. 

Corn wet-milling 

There are legitimate concerns regarding the environmental impacts of the corn wet-milling process. 

Corn wet-milling is the primary means used to create the corn gluten meal that is the starting product 

for zein. As evidence that it is a concern to the regulatory agencies, from 1999-2004 the Agricultural 

Research Service Southern Regional Research Center received a grant from the USDA titled, 

“Development of environmentally acceptable technologies for processing corn.” A specific aim of the 

research was to reduce the use of sulfur dioxide in wet-milling of corn as it was determined to be 

environmentally detrimental. (Full text of the grant report can be found here.) If and when sulfur dioxide 

is released into the air through the drying process, it reacts with air and water to form sulfuric acid and 

becomes one of the major contributors to acid rain. While there are steps that can be taken to remove 

the sulfur dioxide before exhaust is released into the environment, the potential for negative 

environmental effects exists.

The previous decision-making on that point is outlined above. Having summarized that, it is important to 

note that there does seem to be an effective pathway to avoiding the wet-milling process entirely in the 

production of zein. Researchers from the University of Illinois have developed another zein product that 

is created directly from whole corn. They plan to market this product under the name Amazein and 

point to the fact that direct production from corn bypasses need for sulfur dioxide or the other caustic 

chemicals that are used during the wet milling process that creates much of the corn gluten meal on the 

market. This method of direct extraction from whole organic corn may also allow for the creation of a 

truly organic zein product as organic ethanol is available in the US, though perhaps prohibitively 

expensive (see questions regarding expense of organic ethanol.)

Classification as a non-synthetic

There has been ongoing debate about whether the end products of the corn wet-milling process can be 

considered non-synthetic. Wet-milling steeps the corn for 24-48 hours in a hot water solution that is 

0.1% - 0.2% sulfur dioxide, allowing the sulfur dioxide to break protein bonds and add itself to the 

resulting molecule. This means that a chemical reaction has occurred, raising debate as to whether the 

zein should be considered an agricultural product or a synthetic. As the NOSB has evaluated this 

question previously for corn steep liquor, the precedent has been established to consider these end 

products as non-synthetics.

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Alternatives

There are products currently on the National List that can serve a similar role to zein in forming a 

protective coating around foodstuffs. Examples of this include beeswax, shellac, vegetable proteins and 

carnauba wax. Zein’s functionality is unique because it offers a vegan/vegetarian option to replace

shellac and beeswax as coatings. As opposed to other vegetable proteins (such as wheat), zein is not a 

major food allergen. The final other option, carnauba wax, can be sourced and grown only in Brazil. 

Questions for Stakeholders

1. If zein is made from cornmeal that is wet-milled, how much (if any) sulfur residue is left in the 

final product? 

2. What are the hurdles to achieving organic zein?

3. What sectors of the organic food market would benefit the most significantly from the addition 

of zein to the National List and how much will shelf-life be improved?

4. Do we need to revisit the classification as a non-synthetic, or is the established precedence 

sufficient rationale?

Subcommittee vote:

Motion to accept the petition discussion document on zein 

Motion by: Jerry D’Amore

Seconded by: Steve Ela 

Yes: 6 No: 0 Abstain: 0 Absent: 1 Recuse: 0

Approved by Jerry D’Amore, Handling Subcommittee Chair, to transmit to NOP February 17, 2021.

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