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United States Department of Agriculture

Agricultural Research Service


Location: Quality and Safety Assessment Research Unit

2010 Annual Report

1a.Objectives (from AD-416)
A goal of this project is to develop and compare rapid, accurate, improved (nondestructive)and environmentally benign spectral methods to replace invasive, less accurate and less rapid current methods of analysis to determine the quality and functional end product use of agricultural commodities and food products and to assist regulatory agencies in objectively measuring and predicting quality and functionality. Another goal is to enhance the value of fiber commodities, such as cotton and flax through the design, development and testing of woven and non-woven materials for composites with specific properties and industrial applications.

Specifically this involves sub-objectives to:.
1)Develop an accurate method for determining starch amylose/amylopectin ratios as a measurement of grain quality to facilitate its genetic development/functionality for foods, biobased products, and biofuels..
2)Facilitate compliance with the Nutrition Labeling and Education Act (NLEA) by the development of rapid, accurate and environmentally benign spectroscopic methods for: total dietary fiber in mixed foods; for rapid analysis of fats in cereal and snack foods; and rapid analysis of trans-fatty acids in snack foods..
3)Develop methods for cotton to detect stickiness and identify trash, factors that adversely affect quality..
4)Develop methods to determine the fiber content of the standing flax plant to predict proper harvesting time and for the assessment of retted flax that provides a measurement of shive (trash) content..
5)Determine the relationships among sensory, physical, and chemical properties of poultry meat that result from non-traditional processing, such as applications that hasten the onset of rigor or air-chilling to reduce water use..
6)Determine the relationships among sensory, physical, and chemical properties of poultry meat that result from further-processing treatments, such as marination to increase yield and improve sensory quality..
7)Design and produce woven and non-woven flax fiber products for construction of composites for specific industrial applications and develop methods to utilize flax and agricultural process by-products into usable bio-based co-products.

1b.Approach (from AD-416)
1) Proton high-resolution magic-angle-spinning (HR MAS) nuclear magnetic resonance (NMR) will be used to measure branching in grain starch based on the ratio of the areas of the anomeric protons (1-4/1-6). The data obtained will serve as reference data for use in chemometric calibrations for vibrational spectroscopic techniques (nearinfrared [NIR], mid-infrared [MIR] and Raman) to provide more accurate rapid analysis methods..
2)Analysis of dietary fiber in mixed meals will be conducted by homogenizing samples and analyzing sub-samples for total dietary fiber (TDF) by Association of Official Analytical Chemists (AOAC) Method 991.43 as the reference method. Off-the-shelf cereal and snack foods will be milled and analyzed for total fat using AOAC Method 996.01 as the reference method. Fatty acids will be extracted and analyzed for proportion of trans-fatty acids by gas chromatography (GC) as the reference method. Samples will be scanned with diffuse refection NIR and/or MIR spectrometers. Chemometric models will be developed to relate spectra to reference data and used to predict: dietary fiber; total, saturated, and trans-fat in test mixed meals; cereal products; and snack food samples. .
3)Obtain stickiness values on cotton fiber samples by mini-card system as reference values. Scan samples with high-resolution NIR spectrometers. Develop spectroscopically based classification models. Export model to field analysis based system. Integrate system with remediation technologies..
4)Collect samples of all foreign matter present in cotton. Scan samples using attenuated total reflectance/Fourier transform-infrared (ATR/FT-IR). Build database of spectra. Validate with known samples and test the database using unknown samples. Identify unknown foreign matter in cotton. Develop a set of samples prepared from physically separated pure fiber and shive of flax. Grind and prepare weighed mixtures of components. Scan these samples using laboratory based NIR spectrometers. Develop a chemometric calibration for fiber and shive content of the samples. Use this calibration to predict the fiber and shive content of as-is and retted flax..
5)Develop comprehensive profiles of the measurable sensory attributes of foods and food products and relate these profiles to the food's physical and chemical properties in order to enhance product development and accurately predict end-use quality. Develop indexes, methods, or strategies to predict, evaluate, modify, and control end-use quality based on data-relationships..
6)The overall framework of the research involves six steps; (a) Develop specific sensory objectives relating to the commodity problem; (b) Select the range of characteristics encompassed by the problem that will be tested; (c) Develop the appropriate databases of sensory, chemical, physical properties; (d) Pre-process the data using multivariate methods; (e) Develop and test models to explain and predict sensory quality; (f) Test selected variables in more stringent experimental designs..
7)Develop composites from flax fibers and renewable polyesters. The tensile properties of these bio-composites will be evaluated to obtain strength and flexibility values.

3.Progress Report
Completion of the previous project provided the opportunity to develop the new research project plan and begin investigations for the redirected assignment on poultry meat and egg quality. Recruitment of personnel and acquisition of instrumentation were priorities during this transition period with one of two vacant research positions filled and several major pieces of equipment purchased. Technical progress on poultry meat quality focused on the effects of sample preparation and water-holding capacity of poultry breast meat. The water-holding capacity (WHC) of meat directly affects meat yield and shelf life in the retail market. The effects of storage, marination and moisture contents on WHC measurements showed that 24-h aging can significantly affect WHC measurement. This result suggests that marination with 24-h aged chicken breast meat will have significant impact on marination yields and/or marination retention. The relation of sample preparation to sensory evaluation of poultry meat quality was also evaluated. Sensory quality directly impacts purchase and use of food by consumers. Current methods used by sensory panels to evaluate quality of poultry breast meat are affected by meat variations and panelist errors. In order to reduce variations and facilitate the development of instrumental methods to predict the sensory quality, we investigated the differences in sensory quality attributes between whole fillets (more variations) and meat patties (more consistency). Our results showed that relative sensory evaluation values for some texture properties, such as hardness and cohesiveness of mass, were not affected by the sample preparation methods (patties vs. whole fillets). The results from the study are critical for success in developing instrumental methods to predict sensory quality. Efforts to develop these methods began with the application of chemometric techniques to spectral data. Such models remove the subjectivity associated with human panels to determine the sensory quality of meat.

Enhancements to the Egg Micro-Crack Detection System continued. Human graders are having trouble finding small hairline cracks in table eggs. A modified-pressure imaging system to detect hairline cracks in shell eggs was developed to assist the human graders. The system uses digital images of eggs at atmospheric pressure and under a slight vacuum to detect the cracks. The system must image the entire egg so each egg is rotated at least three times for full coverage. The existing system was further automated with a programmable stepper motor integrated with the control program such that the capture and rotation of the eggs were fully automated. A database that takes the system results and populates the USDA Agricultural Marketing Service’s (AMS) PY-75 form, the official egg-grading form for AMS, was also developed. Additionally, an enhanced image processing algorithm, that improves individual egg images under varying lighting conditions, was implemented. These automations and enhancements made it easier for humans to grade the eggs and reduced the overall processing time without affecting system accuracy.

1. Spectroscopic technique to measure fatty acid degradation. A spectroscopic method was developed to detect the degradation of long-chain polyunsaturated acids that are used as nutritional supplements in foods and animal feeds. These supplements provide benefits to cardiovascular and nervous system health but are susceptible to oxidation and generate malodorous compounds. Conventional analysis requires expensive instrumentation, skilled technicians, and significant sample preparation time. The spectral technique is rapid and requires no sample preparation. The method could be implemented for quality assessment and quality control during production.

2. Degradation rates of flax/polyester composite materials. Composites prepared from renewable materials are expected to degrade in the environment at different rates. This is a significant design parameter for product development. Tests were conducted to measure the breakdown of several composite formulations. The results demonstrated that the degradation rate could be controlled by the composite formulation and adjusted for specific applications. The composites degraded completely with the release of simple organic compounds that would fertilize soil. This information can be used to prepare composites for geotextile and landscape applications.

Review Publications
Zhuang, H., Savage, E.M. 2010. Comparisons of sensory descriptive flavor and texture profiles of cooked broiler breast fillets categorized by raw meat color lightness values. Poult. Sci. 89: 1049-1055.

Zhuang, H., Savage, E.M., Lawrence, K.C. 2010. Effect of Three Postmortem Electrical Stimulation Methods on the Quality of Early-deboned Broiler Breast Meat. Poult. Sci. 89: 1737-1743.

Last Modified: 4/15/2014
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