Recipient Organization
OXFORD BIOMEDICAL RESEARCH, INC.
4600 GARDNER RD
METAMORA,MI 48455
Performing Department
Research and Development
Non Technical Summary
Oils and fats are essential nutrients for humans, providing fatty acids necessary for good health as well as being concentrated sources of calories. Fats enhance the taste, texture, and mouthfeel of many foods, and are functionally required in preparing a variety of food products. Frying in oil has been used as a cooking method for over 3,500 years, and has remained a popular way to prepare meals and snacks. However, as the populace becomes more educated and aware of the food they consume, fried foods have come under scrutiny due to their fat content and deleterious effects on health. With normal usage, frying oil degrades to form products that affect the taste and texture of the food, ultimately being discarded when it is "spent" and no longer suitable for cooking.We have developed a proprietary colorimetric technology that visually indicates the degradation of frying oil, changing from blue/black to yellow as the amount of total polar compounds (TPC) increases. These compounds are formed during the frying process, with a limit of 25% TPC being adopted in several countries. A high level of TPCs can cause the fried food to cook unevenly, absorb unwanted oil, and has shown to be deleterious to health. The level of TPCs in frying oil is considered to be the best indicator of its lifetime.Currently, the gold standard for measuring total polar compounds in frying fats is the American Oil Chemists' Society Official Method Cd 20-91 "Determination of Polar Compounds in Frying Fats". This is a laboratory-based method which requires special facilities, training, equipment, and takes approximately three hours to perform. Several hand-held conductivity tests have been developed to measure TPC, but are subject to interferences due to differences in types of fats and cost hundreds of dollars.We propose to complete the development of an inexpensive, easy-to-use dipstick prototype that measures % TPC and undergoes a drastic color change indicating when frying oils and fats should be discarded.Our preliminary work has produced a prototype dipstick which gives a very noticeable color change from 0% to 25% TPC. The work performed in Phase I will optimize this color change by evaluating several dye matrices, the effect of oil type, and by modifying the dye formulation. The objective of this work is to develop a convenient, inexpensive, and easy-to-use frying oil test which requires minimal training and undergoes a drastic color change with oils that are at the end of their usable life. This test will offer the fry operator a method for monitoring oil quality to improve taste, health, and alsoGoal 1: Evaluate several commercially-available glass fiber and/or polymer matrices to obtain the most robust formulation that will hold up to handling during manufacturing and also display the maximum color change when used in the assay.Goal 2: Modify the dye formulation, excipients, and synthesize new dye congener.Goal 3 Using a series of new and used oil samples standardized using the AOCS method, produce color charts correlating % TPC to end-point color for four commodity frying fats.Long-Term Objective: Create a suite of point-of-use tests which, with the aid of a portable cell-phone based instrument, measures the freshness and quality of food ingredients using chemical and/or immunosorbent assays converted to dipstick format.
Animal Health Component
30%
Research Effort Categories
Basic
(N/A)
Applied
30%
Developmental
70%
Goals / Objectives
Oils and fats are essential nutrients for humans, providing fatty acids necessary for good health as well as being concentrated sources of calories. Fats enhance the taste, texture, and mouthfeel of many foods, and are functionally required in preparing a variety of food products. Frying in oil has been used as a cooking method for over 3,500 years, and has remained a popular way to prepare meals and snacks. However, as the populace becomes more educated and aware of the food they consume, fried foods have come under scrutiny due to their fat content and deleterious effects on health. With normal usage, frying oil degrades to form products that affect the taste and texture of the food, ultimately being discarded when it is "spent" and no longer suitable for cooking.We have developed a proprietary colorimetric technology that visually indicates the degradation of frying oil, changing from blue/black to yellow as the amount of total polar compounds (TPC) increases. These compounds are formed during the frying process, with a limit of 25% TPC being adopted in several countries. A high level of TPCs can cause the fried food to cook unevenly, absorb unwanted oil, and has shown to be deleterious to health. The level of TPCs in frying oil is considered to be the best indicator of its lifetime.Currently, the gold standard for measuring total polar compounds in frying fats is the American Oil Chemists' Society Official Method Cd 20-91 "Determination of Polar Compounds in Frying Fats". This is a laboratory-based method which requires special facilities, training, equipment, and takes approximately three hours to perform. Several hand-held conductivity tests have been developed to measure TPC, but are subject to interferences due to differences in types of fats and cost hundreds of dollars.We propose to complete the development of an inexpensive, easy-to-use dipstick prototype that measures % TPC and undergoes a drastic color change indicating when frying oils and fats should be discarded. Our preliminary work has produced a prototype dipstick which gives a very noticeable color change from 0% to 25% TPC. The work performed in Phase I will optimize this color change by evaluating several dye matrices, the effect of oil type, and by modifying the dye formulation. The objective of this work is to develop a convenient, inexpensive, and easy-to-use frying oil test which requires minimal training and undergoes a drastic color change with oils that are at the end of their usable life. This test will offer the fry operator a method for monitoring oil quality to improve taste, health, and alsoGoal 1: Evaluate several commercially-available glass fiber and/or polymer matrices to obtain the most robust formulation that will hold up to handling during manufacturing and also display the maximum color change when used in the assay.Goal 2: Modify the dye formulation, excipients, and synthesize new dye congener.Goal 3 Using a series of new and used oil samples standardized using the AOCS method, produce color charts correlating % TPC to end-point color for four commodity frying fats.Long-Term Objective: Create a suite of point-of-use tests which, with the aid of a portable cell-phone based instrument, measures the freshness and quality of food ingredients using chemical and/or immunosorbent assays converted to dipstick format.
Project Methods
To complete the development of the current TPC dipstick prototype into a viable commercial product, it is critical to prepare a formulation that is mechanically and chemically robust and capable of consistent performance in spite of environmental differences in real world frying situations. The following Technical Objectives will be addressed during Phase I of this project:Objective 1: Attain maximal pad color development in less than two minutes.The current prototype undergoes a significant color change achieving, in 3-5 minutes a stable pseuo-plateau, with color stability for over an hour afterward. Based on feedback from food suppliers and restaurants, the ideal time from dip to a stable color ready to read is less than two minutes. The rate of color development can be accelerated by adjusting the concentrations of excipient, dye, and matrix pad material and/or adding an additional related congener of one of the present proprietary dyes which will be synthesized in-house.Objective 2: Obtain a non-interfering and visually-homogenous pad matrix.Simple cellulosic test pads have multiple hydroxyl groups that are not suitable for use for TPC testing. The current prototype uses a specific glass fiber matrix that does not have a chemical binder, which can interfere with the assay. However, due to the manufacturing process glass fiber matrices have a "stippled" appearance that can cause uneven absorption of the chemical formulation and thus some unevenness of the color upon exposure to oil samples.Further, glass fiber matrices without binders are more fragile, presenting difficulties for high throughput manufacturing methods, and are also less-than-ideal with regard to the uniformity of the color change. Several non-cellulosic matrices are available which may provide a more uniform color change. Based on our experience with the development of dry chemistry dipsticks involving many different chemistries, we anticipate that other matrices may help eliminate the occasional mottled color changes that we have thus far observed.Objective 3: Correlate AOCS %TPC to test pad color for various oil types.A wide range of plant materials are used as to produce for frying oils (see Figure 5). We have thus far tested our TPC dipstick prototypes on a limited number of frying oils and blends, including canola, commodity soy and high oleic soy oils. Although the selected dye mixture was selected to be responsive to polar functional groups, and has thus far shown a very strong correlation to the AOCS reference method, we recognize the possibility that the test method may exhibit some differences in color end-points or the progression of color change for some different frying oils and/or commercial frying oils or blends. Further, to reduce foaming and improve other characteristics, commercial cooking oils often include additives. These are typically present at parts per million levels, and are not expected to interfere with the color reaction. Nevertheless, it is important to evaluate and address these possibilities, especially for the oils, blends, and additives that are most commonly used for frying foods, Therefore, working with collaborators at Crystal Filtration, DuPont-Pioneer and others, we will obtain fresh oils as well as oils sampled at different stages in the frying process. We will measure the %TPC of each oil type or blend using the AOCS method, and will comparing the color of the test strip to other oils with the same %TPC value.If, for certain types of oils, blends or additives, differences are observed between the rates of change or end point values obtained using the dry chemistry dipstick vs. the AOCS method, then we will make adjustment the formulation to eliminate such variations. If significant differences are observed that cannot be addressed by reformulation, then we will identify groups of oils that perform similarly, and will be able to formulate two or more products for use with groups of oil types.Objective 4: Compare pad color change with various oil types.Differences in fatty acid composition lend diverse properties to each oil type, with coconut being a solid wax at room temperature and soy being a liquid. We hypothesize that these variations may cause different oils with the same TPC content to react differently with the dry chemistry components of our dipstick technology, either with a different color end-point or with a different rate of color change. During this phase of the project, four oils with significantly different physical/chemical properties will be evaluated for the performance of the TPC dipstick. Three calibrators, one new at 0% TPC, the second with 15% TPC and the third at 30% TPC by AOCS will be used, and the color response for each oil will be compared both visually and instrumentally using our Spectrocam® or requested Ocean Optics® reflectance spectrometers.Objective 5: Evaluate shelf life and stability after manufacture and during use:Upon deciding on a final formulation, several hundred dipsticks will be manufactured and placed into opaque plastic vials with oxygen scavengers and desiccants. While a majority of these will be placed at -20C for future use, 20 to 30 vials at 30 strips per vial will be placed at 50?C, 70?C and be measured on a weekly basis with known calibrators. The color response will be measured with the Spectrocam® or Ocean Optics® reflectance spectrometers.Objective 6: Compile data from Objectives 1 thru 4:This task will involve the compilation of the technical data from Tasks 4 and 5 to create a product manufacturing protocol (PMP) and a standard operating procedure (SOP). These two documents will be used to expand the dipstick manufacturing from hundreds at lab bench-scale to small batch runs numbering in the thousands.