Expanding Local Markets through Evaluating Sensory Characteristics and Agronomic Performance of Flint Corn Varieties

Progress report for ONE20-362

Project Type: Partnership
Funds awarded in 2020: $29,185.00
Projected End Date: 08/31/2022
Grant Recipient: University of Vermont and State Agricultural College
Region: Northeast
State: Vermont
Project Leader:
Roy Desrochers
University of Vermont and State Agricultural College
Expand All

Project Information


The objective of this project is to identify successful flint corn varieties, management practices, and key physical and sensory characteristics of flint cornmeal and products, to better understand farmer, food manufacturer, and consumer needs to expand the flint corn market in the Northeast.  Varieties will be evaluated for agronomic characteristics including vigor, disease and pest resistance, standability, and grain yield.  We will also investigate flint corn populations to optimize yield and quality.  Each variety will be assessed for milling quality including kernel size uniformity, proneness to cracked kernels, proportion of horny endosperm to soft endosperm, and amount of large bran flakes present in the cornmeal.  Cornmeal from each variety will be evaluated for sensory quality including aroma and flavor.  The evaluation will be made by a panel of trained tasters using established descriptive sensory analysis methods that allow us to objectively define and compare the aroma and flavor of the samples.  Select flint corn varieties will be used to prepare consumer products, such as tortillas, which will be evaluated for characteristics that support consumer acceptance and market success. The data generated by this sensory analysis on finished products will be correlated against the sensory data generated on the cornmeal samples, as well as the agronomic information, to meet the overall objective of identifying successful flint corn varieties that meet the needs of farmers, food manufacturers, and consumers in this emerging market. Information will be shared widely with farmers and end-users through print materials, video, online resources, and outreach events.

Project Objectives:

This project seeks to evaluate flint corn variety performance and suitability to this region’s climate and farming systems and their potential to be used by food and beverage manufacturers to produce successful consumer products.


The questions we will answer are:


  • Which flint corn varieties are best suited for growing in the Northeast?
  • Are the production practices (i.e. populations) for flint corn different than dent corn?
  • What consumer food products are each flint corn variety suitable for producing?
  • Which flint corn varieties result in food products that best meet consumer aroma and flavor preferences?
  • What metrics can be used at the farm-level to predict processing performance and suitability in addition to sensory quality of end products?


Answering these key questions will help local farmers employ successful production practices and select flint corn varieties that are suitable for local processors. This will help develop strong relationships between local farmers and processors enhancing local food system resiliency. It will also provide insight into consumer preferences related to flint corn food products and will begin to determine characteristics of seed quality required by processors require to make products that meet these consumer preferences to ensure successful markets.


In 2019 there were almost 90 million acres of corn planted in the US (USDA NASS). This acreage is primarily dedicated to growing dent corn for feeding livestock. However, it is also used for food ingredients and products such as corn starches, corn syrups, tortillas, and tortilla chips. There are other types of corn, such as flint, that we also use in food products. It gets its name from the hard, glassy, and flint-like nature of its kernels and was originally cultivated by Native Americans prior to colonization. Although flint corn has been grown in the Northeastern US for centuries, its use outside of small specialty and cultural markets has been limited. There is growing interest from food manufacturers to make products such as tortillas and tortilla chips using flint corn. However, these companies lack critical information on the suitability of flint corn varieties, and seed quality parameters, to successfully make these products. In addition, they lack an understanding of consumer preferences for the aroma, flavor, and texture characteristics of products made with flint corn. Lastly, they often lack needed access to locally grown, high quality flint corn. Farmers interested in growing flint corn for these companies lack much needed information on farming practices, and variety selection, and have limited access to the quantity of high-quality seed needed for commercial cultivation.


Therefore, there are a number of factors contributing to the limited use of flint corn in our region: 1) the majority of corn breeding has centered around dent corn which holds the largest market share in the US; 2) farmers and food companies lack information on growing flint corn and using it as an alternative to dent corn, or other grains, in products that meet consumer needs; and 3) farmers lack access to suitable flint corn seed and genetics for their region.


This project aims to evaluate and identify flint corn varieties that are suitable to the growing conditions in the Northeastern US, and that have the physical and sensory characteristics to successfully produce value-added corn products that meet the needs of consumers. We will meet the aims of this project by conducting flint corn variety trials with our farm partners to determine production practices and varieties that thrive in our climate to produce high quality yield and fit our agricultural systems and scale. We will work with a local food manufacturer to understand the challenges of using flint corn to make food products such as tortillas and define the quality parameters that indicate suitability of use for a flint corn variety. Finally, we will use a trained descriptive sensory panel to objectively measure the sensory characteristics of flint corn varieties, products made with them, and interpret the results relative to known consumer preferences. This research will increase the opportunities for growers to supply flint corn to food manufacturers, who will be able to produce food products that better meet the needs of consumers to expand the current market.


Click linked name(s) to expand
  • Joseph Bossen, II (Researcher)
  • Dr. Heather Darby - Technical Advisor (Educator and Researcher)
  • Sam Fuller (Researcher)
  • Paul Rainville - Producer
  • Roger Rainville - Producer


Materials and methods:

Variety Evaluation


The overall objective of our project is to use flint corn field trials and a sensory directed product development approach to expand the flint corn market in the Northeast, while sharing the approach and results to the benefit of other grain growers in the United States.

The timeline and task updates are as follows:

August 2020:                          Project kick-off and logistics planning

A virtual meeting was held with the UVM Extension Northwest Crops and Soils Program team and staff from the All Souls Tortilleria to discuss the award and review overall project activities and timing, including the fall 2020 and winter 2021 preparations for the 2021 growing season.

Fall 2020:                                Preparation for the 2021 growing season 

The team began identifying flint and dent corn varieties, and seed sources, that are of interest for the project’s 2021 agronomic trial.  An initial list was created and the seed will be ordered in winter 2021, with germination tests conducted as necessary.

In addition to the identification of the corn varieties to be used in this project, the descriptive sensory analysis piece was kicked-off and cornmeal sample preparation and sensory method development for its evaluation was initiated. One of the aims of this project is to develop new and effective ways to prepare cornmeal samples on which objective descriptive sensory analysis can be conducted to generate data that can be successfully correlated with both practices at the farms and sensory performance of final products such as corn tortillas and chips. We plan to adapt the standard approach used by many large international food companies to conduct sensory screening on grains such as corn. Typically, a 10% aqueous solution of each cornmeal sample is produced and submitted for objective descriptive sensory analysis.

First Quarter 2021:                 Sensory Orientation and Training

We plan to continue sample preparation development for cornmeal in the first quarter of 2021 using existing flint corn samples and the trained descriptive sensory panel at the UVM Extension. Our aim is to have a standard approach well defined by the end of the first quarter.

In addition, we plan to orient the trained descriptive sensory analysis panel at UVM Extension to corn products such as tortillas and tortilla chips in preparation for the trials scheduled for the fall of 2021.

Early in January 2021, we collected corn tortilla chip samples produced by All Souls Tortilleria in Burlington, Vermont, to use in a sensory orientation of the trained descriptive sensory analysis panel at the University of Vermont Extension. Due to Covid-19 restrictions, individual samples were distributed to the UVM Extension trained tasters, and representatives from All Souls Tortilleria, and a virtual sensory orientation taste session was facilitated by Roy Desrochers on January 8, 2021. Participants used standard sensory methods to assess the headspace aroma of each sample bag and then record both flavor and texture data.

A modification of the Flavor Profile Method (FPM) of Sensory Analysis called Total Intensity of Aroma (TIA) was used for the bag headspace aroma analysis. FPM and TIA are standard sensory methods well defined and accepted through the American Society for Testing and Materials (ASTM), specifically committee ASTM E-18 which develops standard sensory methods.   (Reference: ASTM ML 13)

The flavor and texture of the samples was assessed using another modification of FPM call Profile Attribute Analysis (PAA) which is another standard ASTM method. These sensory methods will be used by the UVM Extension descriptive sensory analysis panel in the fall of 2021 to evaluate flint corn meal samples at the farm level, as well as flint corn tortillas and tortilla chips produced by All Souls Tortilleria using the trial flint corn samples.

In addition, planning is underway for a virtual hands-on flint and dent corn demonstration as a component of the 2021 Northern Grain Growers Association Annual Conference. 

Second Quarter 2021:             Plant Flint Corn Trials and Sensory Training

We plan to plant the flint corn trials in the second quarter of 2021 at the Borderview Research Farm in Alburgh, VT., and the Rainville Farm in Highgate, VT. using the experimental design outlined in the grant proposal. As plots germinate, they will be visually assessed for vigor and populations. Throughout the growing season, dates when each variety reaches target growth stages (i.e. tassel and silk formation, physiological maturity, etc.) will be recorded. Scouting for insect and disease presence and severity will be conducted early, mid, and late into the season. The UVM Plant Diagnostic Laboratory will assist with the identification of disease issues noted in the field.

Fourth Quarter 2021:              Harvest, Physical Testing, and Sensory Directed Product Development

The flint corn trials will be harvested in the fourth quarter of 2021. Prior to harvest, plots will be assessed for populations, number of ears fully formed, number of plants forming ears, lodging presence and severity, ear orientation and husk cover. Plots will be hand harvested and yield, average ear length and number of kernel rows will be recorded. A subsample of ears will be shelled, and harvest grain moisture and test weight measured using a Dickey-John Mini-GAC Plus meter. Ears from each variety will then be fully dried in a grain bin, shelled, and a subsample submitted to the UVM Cereal Grain Testing Lab for a basic corn nutrient analysis via NIR (Near Infrared Reflectance) procedures and Deoxynivalenol (DON) content.

Cornmeal samples will be prepared for each of the flint corn trail varieties and assessed by the UVM Extension descriptive sensory analysis panel using the sample preparation and analysis methods developed in the first quarter of 2021.

We will then select samples of flint corn from the variety trials, based on agronomic performance and DON concentrations, and deliver them to All Souls Tortilleria for processing into food products. The samples will be nixtamalized, a process of cooking in a hot water bath with culinary lime to remove the pericarp and alter the proteins to create a malleable dough. The trained panel will conduct descriptive sensory analysis on a small portion the whole kernel, nixtamalized corn, known as hominy. Remaining hominy will be wet milled into a masa dough and rolled into tortillas.  The tortillas will be both baked into whole tortillas and cut and fried into tortilla chips. Objective descriptive sensory analysis will be conducted on both tortilla and tortilla chips samples. The trained sensory panel will also generate texture profiles for all the finished corn product samples. Aroma, flavor, and texture results for the end-products will be correlated with all other farming, flint corn variety, and flint corn sensory data, to connect these variables to end-product performance, which will be interpreted using the Flavor Leadership Criteria. (FLC) The FLC are a powerful set of sensory criteria, developed by ADL, to identify products with market leading potential. These criteria include early identifiable flavor, amplitude, mouthfeel, off-notes, and aftertaste.


Research results and discussion:

No measurements or observations recorded, no analysis conducted to date.

Research conclusions:

No results or conclusions have been generated to date as we are still in the planning, acquisition of seeds, and planting stage.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

Planning is underway for a virtual hands-on flint and dent corn demonstration as a component of the 2021 Northern Grain Growers Association Annual Conference. 

In addition, once we have results for this project, we plan to disseminate them as follows:

  • Flint corn production will be highlighted at the NWCS field day held each July with Roger Rainville at Borderview Research Farm. Agronomic and sensory results will be shared with attendees who will engage in corn product tastings (200 attendees)
  • Research reports will be generated at the end of each year summarizing agronomic and sensory results. Reports will be posted to our website (uvm.edu/extension/nwcrops) and made available at outreach events.
  • Researchers and collaborators will present research results that highlight practices that will help farmers produce flint corn that is high quality and desirable for end-use markets at the 2022 Annual Grain Growers Conference (120 attendees)
  • A short YouTube video, approximately 5-10 minutes in length, will be made with All Souls Tortilleria describing the process of nixtamalization for tortillas and tortilla chips and the corn qualities that lead to high quality tortilla products. The video will be posted to our YouTube channel https://www.youtube.com/user/cropsoilsvteam(2, 390 subscribers)
  • A factsheet outlining considerations for flint corn variety selection and quality parameters for specialty food markets based on the findings of this research project will be created.
  • At least two 4-hour sensory workshops for local farmers and food manufacturers will be held to educate and train attendees in sensory methods, terminology, and information review in addition to reviewing our project and its findings. The locations of the workshops will be selected to be convenient for both farmers and manufacturers, and to allow for networking and knowledge transfer between the groups. We expect to have up to 25 participants at each workshop.
  • A one-page sensory screening document describing terminology and sensory screening methods specific to flint corn will be created and shared with local farmers and food manufacturers. It will also be made available on our website.

Learning Outcomes

Key areas in which farmers reported changes in knowledge, attitude, skills and/or awareness:

None to date as we are still in the planning and planting stage

Project Outcomes

Project outcomes:

None to date as we are still in the planning and planting stage

Assessment of Project Approach and Areas of Further Study:

No assessment possible at this point.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.