Source: CRAFT TECHNOLOGIES, INC. submitted to NRP
COMMERCIALIZATION OF A RAPID FIELD TEST TO MEASURE VITAMIN A IN FORTIFIED FOODS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
Reporting Frequency
Annual
Accession No.
0192858
Grant No.
2002-33610-12318
Cumulative Award Amt.
(N/A)
Proposal No.
2002-03047
Multistate No.
(N/A)
Project Start Date
Sep 15, 2002
Project End Date
Sep 14, 2005
Grant Year
2002
Program Code
[8.5]- (N/A)
Recipient Organization
CRAFT TECHNOLOGIES, INC.
4344 FRANK PRICE CHURCH RD.
WILSON,NC 27893
Performing Department
(N/A)
Non Technical Summary
Internationally there are 250 million children whose health is compromised in varying degrees due to the deficiency of vitamin A (VAD) in their diets. One of the most accepted methods for sustained remediation of VAD has been through food fortification. Currently more than 40 countries have implemented VA fortification of foods. The effectiveness of fortification programs and the stability of fortified foods in various environments must be measured. If this does not occur the VA may not be added uniformly or at all; or it may become inactive before the food is consumed. There is a need for a rapid economical means to measure the fortification of foods with vitamin A. The purpose of this project is to develop a rapid field-test (Craft Rapid vitamin A Field Test) to measure vitamin A in four types of fortified foods (sugar, rice, flour, and dairy products) based on the use of a modified portable fluorometer, the CRAFTi.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7023450101050%
7023450202050%
Goals / Objectives
The overall objective for this proposal is to prepare the CRAFTi, a portable fluorometer, for commercial production including finalized extraction methods and kits for fortified sugar, rice, flour, and milk. This will include accessories, packaging and a marketing/distribution plan. Specific objectives for this proposal include: 1)Refined modifications to the CRAFTi fluorometer. a)Evaluate type and source of lamps, power supply and filters to insure ease of manufacture. b)Test the utility of multiple power options including solar, AC, and DC. c)Modify software or install shutter to eliminate the flaring due to stray light. d)Modify software to test correctly during instrument initialization. 2)Finalization of extraction methods for sugar, rice, flour. a)Finalize sugar extraction using selected solvents and measuring utensils. b)Refine rice extraction and test with more replicates of actual samples. c)Refine flour extraction and test with more replicates of actual samples. d)Refine corn meal extraction and test with more replicates of actual samples. 3)Development of an extraction method for milk. Spend concerted effort to extract VA from milk without the presence of fluorescent interferences. 4)Analyze at least 25 samples of each matrix obtained from countries fortifying that matrix for statistical comparison of CRAFTi results to HPLC results 5)For each matrix, to analyze the same sample ten consecutive times on the same day using the CRAFTi to determine within-day reproducibility. For each matrix, to analyze the same sample in duplicate on ten consecutive working days using the CRAFTi to determine between-day reproducibility. 6)If the power supply should be modified, recertification of instrument safety using the altered power supply. 7)Identification/development of accessories for measuring, mixing etc. 8)Identification of vendors to supply parts for the instrument modification. 9)Identification of vendors for the solvents and consumable kits. 10)Identification of packaging materials and marketing strategies. 11)Production of documentation in the form of written manuals and training videos.
Project Methods
Instrument Modification An instrument measuring 6" x 13" x 5" and weighing less than 15 pounds has been modified and laboratory-tested for the measurement of VA. During a field-test, exposure of the sample compartment to bright sunlight resulted in oversaturation of the diodes. We propose to correct this problem by modifying the software or introducing a shutter to block light from the optics. The instrument must be operable with a rechargeable battery power supply. Present modifications have made it operable using a 12-volt battery in addition to AC current. Since the original power supply automatically senses 110 or 220 V AC, it is capable of being used worldwide for AC operation. We will test the use of a voltage inverter that converts DC to AC current. The inverter would only be used during battery operation. Field-Friendly Extractions Extracts of each matrix will be prepared using saponification and measured by HPLC and the CRAFTi. A portion of the FF extract measured on the CRAFTi will be analyzed by HPLC. Using this comparison between methods and sample preparation, we will be able to choose the approach with the highest extraction efficiency. The measurement of FF extracts using HPLC with fluorescent detection will allow us to determine if fluorescent interferences contribute to the CRAFTi readings. If food matrix components are found to interfere, methods to exclude the matrix fluorescence will be developed. The samples may require filtration or solid phase extraction (SPE) to exclude interfering components. These can both be accomplished using disposable syringes and filters or SPE discs. Sample preparation should be designed to eliminate refrigeration and centrifugation. We have identified a cuvette-shaped block embedded with a very stable component that fluoresces under the same conditions as VA. This makes the calibration simple and reproducible. Simulated field tests will be used to mimic adverse conditions. Measuring Dairy Products The ability to measure VA in dairy products will greatly increase the market for the CRAFTi. Preliminary tests indicate that the triglyceride content may interfere with VA fluorescence. We will test ionic and nonionic detergents, enzymes, and SPE to obtain an acceptable sample clean-up. Since this test would occur at the dairy processing plant, many of our concerns regarding field use are not essential for this application. They are essential, however, if this test is to be used to measure VA in breast milk of VAD women in developing countries. Testing Field Samples We have already demonstrated the CRAFTi?s utility with fortified sugar from Nicaragua. We will request samples of fortified flour from the Philippines or Africa, corn meal from Mexico, rice from Asia, and milk from the USA. In exchange for the samples, we will perform the analysis at no cost to them and provide results using the two methods. In this way, we will supplement our proof of CRAFTi accuracy. First, these products will be analyzed by HPLC to determine sample size. Then, analysis of the same samples will be done on the CRAFTi using the sample size determined as optimal by HPLC.

Progress 09/15/02 to 09/14/05

Outputs
A commercial portable fluorometer has been adapted for quantitative measurement of vitamin A, by substitution of the excitation lamp and excitation filter. Commercially available plastic blocks with an embedded fluorescent dye are used for calibration of the instrument. Inexpensive borosilicate test tubes, or conventional fluorometer cuvettes, can be used as cuvettes. Electrical power is provided from mains current (115 or 230V AC, automatically detected and switched by the circuitry of the fluorometer), or from a rechargeable 12-V battery through a power inverter. Simplified ("field-friendly") methods have been tested for extraction and analysis of vitamin A (retinyl palmitate) from commercial fortified sugar and from lab-fortified wheat flour, corn meal, corn starch ("Maizena"), and rice ("Ultra Rice(TM)," PATH). "Field-friendly" methods for extraction of vitamin A from fortified sugar and Ultra Rice do give good recoveries from these food products, and give very good correlations with HPLC analyses. Endogenous fluorescence associated with plant oils has complicated analysis of vitamin A at the low concentrations typically anticipated in fortified foods such as cooking oils and grain flours. In general, saponification reduces the endogenous fluorescence to levels which do not interfere with the assay. However, "field-friendly" (nonsaponification solvent extraction) techniques are not yet fully satisfactory for routine field use. We have attempted a variety of approaches to avoid or remove these fluorescent interferences: solvent pre-extraction, backwashing the solvent extract, enzymatic hydrolysis of sample triglycerides, chromatography on mini-columns. Although some of these approaches have been helpful in reducing the amount of fluorescent interference from specific food matrices, none of them has brought down the level of endogenous fluorescence to a level that ensures a robust method for field use for analysis of the low levels of vitamin A encountered in fortified foods. To that extent we have not been able to meet all of the goals of this project. It should be noted, however, that the fluorometer itself has very good sensitivity for the levels of vitamin A used in fortified food products. The premixes used in preparation of these consumer products, with 1000x greater concentrations of vitamin A, are readily analyzed with the CRAFTi because the relative contribution of the endogenous fluorescence is reduced to insignificant levels. Ancillary to this project, a method has also been developed for determination of retinol in blood samples to assess human vitamin A status. We intend to pursue patenting.

Impacts
The CRAFTi portable fluorometer was designed to provide rapid, inexpensive quantitative analysis of vitamin A in fortified foods in field settings, furnishing rapid verification that intended levels of vitamin A have been met. Its use can also help assure that adequate mixing (homogeneity) of vitamin A in fortified foods has been achieved. The instrument is rugged and portable, and has performed satisfactorily in the laboratory and in field testing.

Publications

  • No publications reported this period


Progress 10/01/02 to 09/30/03

Outputs
Progress Report: Instrument Modification: An instrument measuring 6" x 13" x 5" and weighing less than 15 pounds has been modified and laboratory-tested for the measurement of vitamin A (VA). Since the original power supply automatically senses 110 or 220 V AC, it is capable of being used worldwide for AC operation. For field use the instrument is powered from a 12-V battery by means of a small power inverter. It is not necessary to modify the internal power supply or software. A suitable Calibration Block (incorporating a stable dye which fluoresces very similarly to vitamin A) has been identified, making instrument calibration simple and reproducible. Field Friendly Extractions: Extracts of various matrices have been prepared by saponification and the vitamin A content has been measured by HPLC and by the CRAFTi. Other extraction methods which are more field friendly (FF) have been compared. The measurement of FF extracts by HPLC with fluorescence and absorbance detection allows evaluation of possible interferences which might give erroneous values on the CRAFTi. Methods for removal of interfering fluorescent matrix components (such as are found in plant oils) are under development; these methods include solid-phase extraction using disposable cartridges or disks. Sample preparation is designed to eliminate refrigeration and centrifugation as much as possible. Measuring Vitamin A in Fortified Sugar and Maize Flour: Vitamin A content of fortified sugar has been measured by spectrophotometry, HPLC, and CRAFTi fluorescence in our laboratory, with correlation coefficients of 0.97-0.99 between methods, over the range 0 to 25 ug retinyl palmitate/g sugar. A major analytical problem was lack of homogeneity of vitamin A mixing in the sugar product, exactly the sort of problem the CRAFTi is intended to identify. Vitamin A-fortified sugar was analyzed by an independent laboratory in Zambia; the correlation between spectrophotometric results and CRAFTi fluorescence results was 0.73-0.85 over the range 0 to 20 ug retinyl palmitate/g sugar. Vitamin A-fortified maize flour from Uganda is currently being analyzed in our laboratory. Vitamin A-fortified sugar from Nicaragua has previously been tested satisfactorially. Measuring Dairy Products: The ability to measure VA in dairy products will greatly increase the market for the CRAFTi. Preliminary tests indicate that the triglyceride content may interfere with VA fluorescence. We will test ionic and nonionic detergents, enzymes, and SPE to obtain an acceptable sample clean-up. Since dairy samples would be analyzed at processing plant, many of our concerns regarding field use are not essential for this application. They are important, however, if this test is to be used to measure VA in breast milk of VAD women in developing countries. Documentation: A general instruction manual for use of the CRAFTi fluorometer has been developed, with separate guidelines for preparation and analysis of specific products.

Impacts
Impact: The CRAFTi portable fluorometer is intended to provide rapid, inexpensive quantitative analysis of vitamin A in fortified foods, furnishing rapid verification that intended levels of vitamin A have been met but not exceeded. Its use can also help assure that adequate mixing (homogeneity) of vitamin A in fortified foods has been achieved.

Publications

  • No publications reported this period