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Evaluation of Food, Agricultural and Biological Materials for Improved Characterization and Value-Added Utilization


<OL> <LI>Characterization of materials for better understanding of their processability and engineering functionality The goal of this research is to expand current knowledge on the behavior and properties of food, agricultural, and biological materials for new and improved utilization. Specific objectives of this research are to: (1) evaluate the physical, chemical, mechanical and functional properties of a wide range of potential food-substitute materials; <BR> (2) obtain relevant dose distribution data in selected food targets for mathematical model benchmarking. Will conduct tests on e-beam and gamma to establish comparions regarding effectiveness and safety. <BR>The outcome from this research will be critical knowledge in the area of material properties, functionality, and utilization. <LI> Feasibility of using current and new materials in alternative applications (such as food packaging). The main goal of this research is to design an effective biopolymeric antimicrobial carrier film for food packaging applications. Specific objectives of this research are: <BR>(1) develop film-forming processes for top-quality performance properties using biopolymers;<BR> (2) predict the antimicrobial mechanism/kinetics and the controlled-release profile of antimicrobial substances from the film into a food product using mathematical models of diffusion; <BR>(3) optimize carrier film design by modifying the thickness of the control layer to alter the diffusivity of antimicrobial agents (controlled release-rate).<BR> The outcome from this research should be a series of antimicrobial delivery systems with tailor-made properties to achieve a given effect. These systems could be widely applied for clinical uses in hospitals (as wound dressings or drug delivery systems), biological labware, biotechnology equipment, as well as food packaging. Other major positive outcomes from this effort will be reduced packaging costs, reduced overwrapping and expanded utilization of newly developed biodegradable packaging materials, which also reduce the problem of excessive waste.

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Non-Technical Summary: Complete characterization of rheological, physico-chemical and other engineering properties of food, agricultural and biological materials still remains a challenge to food process engineering and product development due to the complex nature of the materials. Many of these materials are complex in structure and in composition. Biopolymers polysaccharides and proteins) and/or colloidal particles (fat globules, water droplets, ice crystals, protein aggregates, sugar crystals) are typical examples of such systems. Properties of these materials which are important to consumers and manufacturers (appearance, shelf-life, quality and texture) depend on the structure, interactions and organization of the biopolymers and colloidal particles (Padua and Wang, 2000). Research is needed to understand the contribution that biopolymers and colloidal particles make to the overall physicochemical and mechanical properties of foods (natural and processed) and agricultural materials. This information is useful for the food and agricultural industries as it enables manufacturers to improve the properties of existing products, optimize processing conditions, develop new products and reduce manufacturing costs.? Packaging of food is a challenging task because foods are complex and diverse. Unlike inert packaged commodities, foods are dynamic systems with limited shelf life and very specific packaging requirements. Also, since foods are consumed to maintain life, the safety aspect is a critical packaging parameter. U.S. consumers benefit from the most affordable, nutritious and safe food supply in the world. However, the safety and quality of food is profoundly affected by potential microbiological contamination that can occur during handling and processing. Consequently, efforts to develop, refine, and implement measures to enhance assurances of food safety are critically needed (CATT, 1997; Tauxe et al., 1997). Several preservation methods including antioxidant treatment, modified atmosphere packaging (MAP), refrigerated storage, washing with chlorinated water or ozone, have been applied to extend shelf-life and inhibit microbial spoilage of minimally processed fresh produce (Ahvenainen, 1996; Tapia de Daza et al., 1996; Fan et al., 2003). Studies have shown that ionizing radiation could eliminate food-borne pathogens in fresh fruits and vegetables (Wiley, 1994; Farkas et al., 1997; Fan et al., 2003). However, little is known about the potential synergistic effect of antimicrobial packaging and irradiation in the quality and safety of fresh produce (Han, 2000). These active films could control microbial contamination by reducing the growth rate and maximum growth population and extending the lag period of the target microorganism to prolong the product shelf life and maintain its safety. For example, they must reduce microbial growth of nosterile foods or maintain the stability of pasteurized foods without post-contamination. The project will provide a research-intensive learning environment for students in science and engineering in the area of biopolymers, bioactive materials, materials properties and characterization, and food safety. <P> Approach: The experimental work to be carried out will, whenever possible, follow all the required testing standards and methodologies, such as AACC, AOAC and ASTM. Special attention will also be paid to make sure that the testing approach is scientifically sound. The results of testing and analyses will be documented and published in scientific journals. (1) Characterization of materials for better understanding of their processability and engineering functionality. Current efforts at our laboratory include testing of a wide series of materials. Our research plan is to: (1) identify an appropriate set of biopolymeric materials, blend biopolymers with greatly different viscosities, examine the effect of irradiation treatment on their properties, and understand polymer morphology and degradability; (2) characterize the shear behavior of starch-based ingredients for potential use in foods, energy and pacaging applications. Data Analysis: We will conduct steady shear and dynamic tests at a wide range of temperatures. Time-dependency will also be evaluated. 2) Feasibility of using current and new materials in alternative applications (such as food packaging). Current efforts at our laboratory include (1) modifying film barrier, structural, and mechanical properties by physical (UV, ultrasound, heat, e-beam irradiation), enzymatic, and chemical methods; (2) developing mechanical models of protein-matrix film structure to understand the relationship between structure and functionality; and more recently, (3) understanding the potential antimicrobial effects of natural active agents (proteins, natural oils, organic acids, flavors and nutraceuticals) on specific microorganisms, sensory properties, and quality of seasoned, precooked meats wrapped on films (this area is gaining considerable popularity as meat processors develop a variety of ready-to-heat products for quick meals with strict safety requirements) (Han, 2001). Our research plan is to: (1) investigate the effect of ionizing radiation on antimicrobial agent release rates; (2) determine whether the irradiation treatment functions as a release (anti-stick) factor or an anti-release factor into the foodstuff (Fan and Singh, 1989; Han, 2000); (3) establish whether irradiation can be the controlling factor for antimicrobial release; (4) carry out tests to predict performance of films; and (5) formulate a predictive model and a set of procedures for performance predictions. Data Analysis: Empirical/fundamental models or testing methodology will be used as a basis to predict film performance. Studies on these problems will provide information on the exact amount of antimicrobial agent and release rate of the antimicrobial substances required to achieve a given effect. Results from these studies will be expanded to other applications such as utensils.

Castell-Perez, Elena
Texas A&M University
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