Adding Value to Oilseed Crops by Producing Food Quality Oils

Final Report for LNE11-309

Project Type: Research and Education
Funds awarded in 2011: $143,131.00
Projected End Date: 12/31/2014
Grant Recipient: Pennsylvania State University
Region: Northeast
State: Vermont
Project Leader:
Dr. Douglas Schaufler
The Pennsylvania State University
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Project Information


Oilseeds are a potential crop in the Northeast that can increase farmer crop diversity and provide an alternative energy source and niche edible oil products. This project worked to provide information and find ways of processing edible oils on a small scale that would work for farmers. An oilseed processing guide, seven fact sheets, a comparison of six small-scale oilseed presses, and video information on oilseed processing and oil quality were compiled and presented to 650 farmers at seven trainings. Additionally, online webinar and video resources have been viewed by 1,244 viewers.

Oilseed presses have been purchased by at least two farmers involved with this project, and others have added filtration with a greater understanding of the filtration process. Known edible oil production has not increased as a result of this project. Farmers continue to access the information created and consider edible oil production as a potential market for their farm.


Oilseed crops can provide a niche market and provide for energy needs of farms in the Northeast. Crops such as sunflower, canola, safflower and other crops raised for the oil contained in the seed produced can be grown in the northeastern United States. The oil produced can be used for fuel, either as straight vegetable oil or chemically changed into biodiesel, or the oil can be used as edible oil. When used as edible oil, the oil may be used as produced or refined to varying degrees. Refining the oil may make it more suitable for some uses, such as frying.


Farmers have sometimes started growing oilseed crops for the energy use, then realized that the value of the oil as an edible oil is greater than the value of the diesel fuel or heating fuel that the oil is replacing. Questions then arise as to what the difference is in the process of producing the oil, or what needs to be done differently to sell the oil as edible oil. While information is readily available for producing edible oils on a large commercial scale, there is little information available on producing edible oils on a small scale. This project attempted to answer some of those questions and provide guidance to farmers interested in small-scale edible oil production.


The two universities that partnered for this project came into the project with differing backgrounds. The University of Vermont has been growing various oilseed crops for a number of years, looking at the agronomic methods and crop yields. Farms throughout Vermont, usually working with Vermont Sustainable Jobs Fund, purchased equipment and set up systems to grow oilseed crops, extract the oil, and produce biodiesel for on-farm use. As a result, these were projects that had energy production as a focus and had processing located on farms. This provided a rich background in farmer grown and produced oilseed crops and energy. Primarily these farms focused on sunflowers as their oilseed crop.


Penn State grew oilseed crops (primarily canola) for 4 years with the intent of using the canola oil as a straight vegetable oil (SVO) fuel. This required pressing and filtering the oil for use as a direct replacement for diesel fuel in two tractors modified for this purpose.


It was inevitable that the production of oil for energy also brought up the questions related to producing edible oils. The value of the oil produced for energy as a replacement for diesel fuel is reflected in the current price of diesel fuel, as the value for edible oil is reflected in the price paid for the edible oil. As the price of fuel fluctuates, interest in the production of alternatives to petroleum fuels also fluctuates. At one point, the cost for diesel fuel was $4.00/gallon while the cost for edible canola oil was $7.00/gallon. Both oils start off as the same oil, so it makes sense for a farmer producing the oil to be interested in selling all or a portion of the oil as edible oil.

Performance Target:

By the end of March 2014, 200 farmers will learn how to safely and profitably produce edible oils, and 20 of these farmers will engage in edible oil production increasing the value of their product $10.00/gallon resulting in a profitable enterprise documented with the oilseed calculator.

As noted above, an oilseed processing guide, seven fact sheets, a comparison of six small-scale oilseed presses, and video information on oilseed processing and oil quality were compiled and presented to 650 farmers at seven trainings. Additionally, online webinar and video resources have been viewed by 1,244 viewers.

Oilseed presses have been purchased by at least two farmers involved with this project, and others have added filtration with a greater understanding of the filtration process. Known edible oil production has not increased as a result of this project. Farmer intererest was more focused on producing biodiesel.


Click linked name(s) to expand/collapse or show everyone's info
  • Chris Callahan
  • Dr. Heather Darby


Materials and methods:

Evaluation of the oilseed presses was of interest to the project. A fact sheet listed in the publications section shows the evaluation of six small oilseed presses currently used at farms in the northeast. Because this type of evaluation had not been carried out before, the protocol for doing this testing did not exist. Project personnel developed a protocol for evaluating these small presses, including seed used, temperatures, press operating speeds, and other factors that affect the output of these small presses. This protocol is included as an upload to this report, and details the measurements recorded for each press. It is important to note that although an attempt was made to make all measurements the same for each press, operating an oilseed press is as much an art as it is a science. After operating a press for some time, operators have a feel for the press and will tweak the various parameters of speed or press clearances for what they feel is necessary for good quality oil. The evaluation of these presses was an important portion of this project, and the resulting fact sheet is the first commentary on these presses pulled together into one place.


Filtration of the oil produced is important or not important, depending on the ultimate use of the oil. Although this project was intent on the use of oil as an edible product, much of the experience and interest in oil production is in using the oil for energy. Experience showed that using bag filters (25 micron followed by 5 micron) did not consistently produce oil that was free from particulates. Oil with particulates used as edible oil does not result in consequences; users may perceive a layer of sediment on the bottom of the bottle as “poor oil”. Others wanted to see the sediment because to them this meant the oil was not overly processed, and therefore a more “natural” product. When using the oil for SVO engine fuel, visible particulates in the oil meant shortened fuel filter life and the possibility of a vehicle stalling because of fuel filter clogging. When making biodiesel, sediment in the oil is removed during the biodiesel production process and so is not as much of a concern. This project investigated the filtration of oils, particularly the use of the filter press. Recommendations for using the filter press are presented in a fact sheet listed in the publications section.


Edible oils available commercially are often referred to as RBD oils: Refined, Bleached and Deodorized. Refining includes filtration, which this project covered primarily with the use of the filter press. Bleaching refers to removing colorants from the oil, and deodorization refers to removing odors present in the oil. Edible oils found on the grocery store shelf have been subjected to RBD, and thus appear uniform and light in color and have no appreciable odor. In reality, these oils as pressed have differences in color and differences in odor. Some oils have what people perceive as good odors while others may not smell so good. This is, of course, dependent on differences between people and what they perceive as a “good” odor.


Commercially bleached oils are usually heated to a high temperature and have a measured amount of bleaching clay introduced to this hot oil. Stirring the oil/clay mixture for a certain amount of time results in the clay absorbing and holding the colorants in the oil. When filtered again, the clay and absorbed colorants are removed from the oil resulting in lighter, more uniform colored oil. This process takes place under a blanket of inert gas such as nitrogen or argon, because if oxygen is allowed to contact the oil at this higher temperature the oil oxidizes quickly resulting in rancid tasting oil. For a commercial operation this setup works well, but for a smaller operation it was felt this would be a difficult process to replicate. A smaller scale bleaching apparatus was built as described in the next paragraph.


As a part of this project a small bleaching apparatus that operated under a continuous flow was built. The bleaching unit consisted of stainless steel tubes with a 2 inch outside diameter. Oil was pumped slowly through the tubes. The first tube had 3 external electric heaters on the outside of the tube, heating the oil to approximately 95° C. This heated oil continues on through another tube of the same diameter, approximately 1 meter long. Bleaching clay of a particular makeup of relatively large particles was inside of this tube and absorbs the oil colorants as the oil passed through. A heating cable wrapped around the outside of this tube kept the oil hot as it passed through the apparatus. A small opening mesh screen at the end of the bleaching clay tube held the bleaching clay inside the tube, not allowing the bleaching clay to move past the screen.


Oil then was deposited into a receiving container, where it was blanketed with an inert gas (nitrogen or argon or similar gas) and allowed to cool. The resulting color of the final product depended on how fast the oil was being pumped through the apparatus; faster movement of the oil resulted in a lower retention time and less color removal. A slower flow of oil through the apparatus resulted in greater color removal and a lighter colored oil. Oil was pumped through the tubing with an air operated diaphragm pump. Using this pump allowed an even pressure to be maintained on the oil, resulting in a uniform flow through the bleaching clay media. The media used was an Oil Dri UltraClear, with an 8/16 mesh size.


Although this bleaching apparatus worked, farmers attending the project workshops were dismayed with the extra effort and cost of setup involved with bleaching the oil. Ultimately this work was not continued because there was no interest from the farmers with bleaching any oil that they might sell as edible oil. Any of the farmers interested in selling oil as edible oil decided that they would either settle the oil for a short time to remove the majority, but not all of the particulates, or use a filtration method such as the filter press to produce a clear, but darker colored, product. A picture of this bleaching apparatus is uploaded as a part of this final report.


One of the project personnel works within the Food Science department at Penn State. Dr. Elias has worked with the raw oils produced by the oilseed press, and has done experimentation to start looking at the differences between these raw oils and commercially available oils. Interesting results of this work are uploaded as a file and included:

  1. In an accelerated comparison of shelf life, the raw oil showed better stability than a bottle of commercial oil purchased off the shelf from a local grocery store
  2. A creamy-style Italian salad dressing formulated using raw canola oil showed no significant difference in a blind taste-test between this salad dressing and a commercial salad dressing
  3. The salad dressing made with the raw oil showed better stability than the commercial salad dressing


A separate trial looking at the effect of bottle color on oil quality during storage has been completed. The data compared oil degradation within clear, brown and green bottles with the thought that a darker bottle may provide increased protection to oil quality while the bottle sits on the shelf waiting for purchase. Data analysis shows that there is no significant difference in oil shelf life between the different bottle colors. This may change depending on the type of oil in the bottle. This study looked at raw canola oil which is very stable oil. It is suspected that the additional colorants in the raw oil reduce the amount of light reacting with the oxidants in the oil, resulting in the oil stored in the different bottle colors having the same shelf life.

Research results and discussion:

  1. Six hundred farmers receive inquiry about interest in learning about edible oil production. Achieved 03/2012


  1. 300 farmers reply to inquiry about what informational needs are and best way(s) to present information.

Fewer farmers expressed interest in producing edible oils than expected. Vermont has a history of contacting and collecting oil producers and have added new names to their current list of about 200 interested farmers. Pennsylvania has a listing of 44 names in the Mid-Atlantic region as a result of the contacts above. This total of 244 still falls short of the 300 sought for informational gathering purposes. The same body of interested farmers continued through 2014 with few additions.


  1. 250 farmers check off and return edible oil information delivery methods most useful to them. Farmers expressing an interest in edible oils were directed to a survey posted on the University of Vermont oilseed website. Only 26 farmers responded to this survey, though the information they presented was useful in guiding project publications. In general, webinars were seen as least useful with online publications and YouTube videos seen as the most useful. Requests were made in 2014 to try and add to these numbers, but responses were minimal. Again, it seems those interested in responding did so by the end of 2014.


  1. Printed information materials (fact sheets) received by 250 farmers and read by 220 farmers.

Achieved 12/2014


  1. 100 farmers attend day-long workshop on edible oil production.

Achieved 08/2012


  1. 95 farmers respond to survey of workshop attendees with specific questions about their potential edible oil operation.

25 of 41 attendees at the 2014 oilseed workshops completed the post workshop survey. We did not have a total of 95 completed surveys, but did obtain information that will be useful in guiding future projects. Initally project surveys were sent out following the workshop, with minimal response. Later workshops had the survey integrated into the final portion of the workshop and response was better. Learned to integrate surveys into the workshop rather than expecting survey completion after everyone has gone home.


  1. 100 farmers attend day-long workshop on edible oil production with updated information on bleaching and degumming.

78 farmers attended workshops that featured increased information on degumming and bleaching. Overall, farmers were not interested in adding these processes to their processing; the belief was that producing oil on a local scale was more important than mimicking the production of commercially available oils.


  1. 50 farmers review new information available on YouTube and through Webinars developed by the project and available through extension websites.

Achieved: 12/2014

Videos were created on four subjects with links at the University of Vermont oilseed website.

Analytics for these videos show good acceptance:

Identifying and Quantifying Rancidity in Food-Grade Oil: 167 views

Refining Food-Grade Oil: 197 views

What Makes a Food-Grade Oil Unstable or Rancid: 244 views

Small-scale Oilseed Presses: 481 views

On-Farm Oilseed Pressing for Fuel and Food—Northeast Bioenergy Webinar: 155 views

  1. 20 farmers purchase equipment to produce or partner with existing operations to press edible oils for sale.

This milestone was not met. We know of two new oilseed presses in the northeast since this project began. Farmers are not lining up to purchase and start operating new oilseed operations. To both change to an unknown crop and produce edible oil from that crop seem to be two hurdles for farmers rather than the production of a new product from an already grown crop. Also, fuel prices play a part in growing oilseeds either for fuel or for edible oils. Fuel prices were relatively steady with a large downturn at the end of this project. Historically, lower petroleum prices reduces the current interest in alternative sources of energy. Many of the farmers interested in the production of edible oils are initially drawn to the production of alternative fuels, then into the production of edible oils.

Participation Summary


Educational approach:

Print publications from this project:

Small-Scale Oilseed Processing Guide – this is a compilation of the following fact sheets:

Oilseed Fact Sheet: Overview of Small-Scale Oilseed Processing

Oilseed Fact Sheet: The Regional Picture

Oilseed Fact Sheet: Processing Edible Oils

Oilseed Fact Sheet: Storage and Cleaning

Oilseed Fact Sheet: Oilseed Presses

Oilseed Fact Sheet: Oil Filtration

Oilseed Fact Sheet: Processing Regulations

Small-Scale Oilseed Presses: An Evaluation of Six Commercially-Available Designs


Videos from this project:

Small-Scale Oilseed Presses:

What Makes a Food Grade Oil Unstable or Rancid:

Refining Food Grade Oil:

Identifying and Quantifying Rancidity in Food-Grade Oil:



On-Farm Oilseed Pressing for Fuel and Food--Northeast Bioenergy Webinar:


Oilseed grower meetings

Vermont has a history of holding an “Oilseed Producer” meeting in late winter/early spring. During the duration of this project personnel from both Vermont and Pennsylvania presented at these grower meetings combined with workshops. Known oilseed producers in Pennsylvania and other Mid-Atlantic states were invited to these meetings, though none attended.

03/26/2012: White River Junction, VT: 22 attendees (poor weather reduced attendance)

03/19/2013: Berlin, VT: 26 attendees

03/03/2014: Burlington, VT: 46 attendees


Field days/Workshops

02/2012: Penn State University Farm: Oilseed processing workshop: State College, PA: 32 attendees

08/2012: Field Day: Borderview Farm, Alburgh, VT: 250 attendees

08/2013: No-till oilseed cropping and pressing, filtering, bleaching: Byers Farm, Liverpool, PA: 37 attendees

08/2013: Field Day: Borderview Farm, Alburgh, VT: 237 attendees


Oilseed processing demonstrations

08/2012: Pennsylvania Ag Progress Days: oilseed pressing with popcorn popped in oil produced

01/2013: Pennsylvania Farm Show: oilseed pressing demonstrated

08/2013: Pennsylvania Ag Progress Days: oilseed pressing with popcorn popped in oil produced

01/2014: Pennsylvania Farm Show: oilseed pressing demonstrated

08/2014: Pennsylvania Ag Progress Days: oilseed pressing with popcorn popped in oil produced

No milestones

Additional Project Outcomes

Project outcomes:

Impacts of Results/Outcomes

By the end of March 2014, 200 farmers will learn how to safely and profitably produce edible oils, and 20 of these farmers will engage in edible oil production increasing the value of their product $10.00/gallon resulting in a profitable enterprise documented with the oilseed calculator.


We consolidated the experiences of many of the current oilseed press operators through the evaluation of presses used on current farms, and created informational publications and videos that provide important information to those considering raising oilseeds. We are not aware of the twenty new producers that we had hoped to bring into production, though we did reach the 200 farmers with information through the printed publications and videos. Many farmers we are in contact with are still considering oilseed production “when we get our ancient grains (or substitute another enterprise) work completed”. Most farmers we are in conversation with are looking at oil production as a niche market to complement other niche markets under development or already up and running. This week (03/2015) requests were received for information developed under this project from farmers in Tennessee and Nebraska; the information pulled together under this project is unique and is being used throughout the northeast and the country.

Economic Analysis

An oilseed cost calculator is available through the University of Vermont Oilseeds website ( This calculator was originally developed for estimating the cost of biodiesel production from oilseed crops, but was modified so that oil production costs can also be estimated. Because the oil production is one step in the biodiesel production cost, the calculator can be used for both purposes. Using a calculator such as this is always an open ended process because of the variables used as inputs. How someone values their time can play an important part in whether an operation is seen as viable or break-even, so it is difficult to compare operations as different operators see their costs differently. The calculator does, however, allow an operator to look at their operation and change parameters to see the effect of the variable costs of inputs.

Farmer Adoption

Many of the farmers met before and during the life of this project openly shared their experiences of pressing and processing oils. Others did not wish to share the processing methods they had developed, believing that what they had learned on their own gave them an edge in the marketplace.

While our objectives/performance target mentions new oilseed presses specifically, filtration of the oil was a topic that was of interest to many. Both for fuel use and edible oil use, the filtration of oil is necessary to either make fuel useful or remove the burden of clogged fuel filters, or for producing an edible oil product that does not result in sediment in the bottled product. As a result of this project at least one farmer added additional filtration capacity, and others understand the function of the filter press.

Assessment of Project Approach and Areas of Further Study:

Areas needing additional study

There remain a number of questions about the usefulness of “raw” pressed oils. Because these oils do retain the flavor and odor present in the pressed oils, the use of these oils brings these flavors through to the resulting product. When making a salad dressing, for example, raw canola oil brings a unique flavor through to the salad. While this is a flavor that is not disagreeable to most, it is a flavor that most people are not going to be familiar with and must be worked with as products are developed. Tasting of a salad dressing made with raw canola oil was shown to have no significant difference from a commercially produced salad dressing, but the recipe was tailored to the use of the raw oil.

Consumer acceptance of raw oils is another area needing additional study. While some consumers view the sediment at the bottom of a jar of oil as meaning the oil is more “natural”, others will view this as undesirable. Consumer preferences need to be looked at more closely. In addition to the sediment issue, the acceptance by consumers of oils with an actual smell to them should be investigated. Some oils smell what some say is good, while other people may not think the same oil smells “good”. It will be interesting to quantify this and find out which oils produce a more agreeable odor to a majority of potential purchasers.


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.