Virginia Polytechnic Institute and State University

UPDATES AT VIRGINIA TECH

MILES Program

Students and faculty members at Virginia Tech are hoping to find solutions to some of our most pressing health issues by creating a better understanding of free-radical and oxidation processes through interdisciplinary training. This training is being conducted through the Macromolecular Interfaces with Life Sciences (MILES) program, funded by a National Science Foundation Integrative Graduate Education and Research Traineeship (IGERT) award. The program uses free radical and oxidation processes as the thematic basis for research and education at the chemistry-biology interface.

Oxidation is a process that involves free radicals, which cause food to spoil or taste bad and damage cellular processes in living things. Oxidative stress is implicated in many chronic diseases such as cancer, diabetes, and obesity as well as the compromise of immune function.

MILES is led by a team of researchers: Susan Duncan, professor of Food Science and Technology in the College of Agriculture and Life Sciences; Tim Long, professor of Chemistry in the College of Science; and Craig Thatcher, Large Animal Clinical Sciences professor in the VA-MD Regional College of Veterinary Medicine.

“The scientific scope of the program is broad, crossing traditional boundaries of science from the oxidation of fats to understanding disease mechanisms,” says Long. “The program bridges the gap between traditional macromolecular science and biological disciplines.”

MILES supports the interdisciplinary training of doctoral scientists and engineers. Twenty core faculty members from 5 of VA Tech's colleges – Agriculture and Life Science, Engineering Science, Natural Resources, and the VA-MD Regional College of Veterinary Medicine - provide cooperative research, interdisciplinary education, and outreach experiences to more than 30 students. Other departments, institutes, universities, and national laboratories are affiliated with the program as research collaborators or internship opportunities. The MILES program encourages collaboration that may not have traditionally formed among faculty members and students in multiple disciplines.

“We are focused on training the future scientific leader, one who functions in an ever increasingly interdisciplinary field at the intersection of biology and chemistry,” says Long. “We also hope to develop leaders who can convey scientific advances to the general public and who are involved in the educational process from an earlier point in their training.”

To facilitate the development of these skills, students take a set of core courses, which help establish the foundation for their research. Students learn the fundamentals of oxidative processes at the interface of chemistry and biology. They also receive training in grant writing and ethics. The program also encourages outreach activities and mentoring as well as leadership opportunities through committees and presentations at scientific meetings.

MILES students are required to seek knowledge beyond their specific research focus and work collaboratively with students and faculty members in other disciplines to create novel projects. For example, graduate students Sharlene Williams (chemistry) and Ben Lepene (biomedical and veterinary science) are working together on research projects focused on polymer-based drug delivery systems designed to reduce oxidative damage present in many conditions associated with human aging and disease. One aspect of their research is the development of antioxidant delivery systems with unique polymer architectures that allow the systems to target specific cell receptors. They have worked together to synthesize a new polymer drug delivery system, conducted in vitro testing to quantify cellular uptake and bio-compatibility, as well as conducted efficacy studies designed to investigate the impact these antioxidant delivery systems have on oxidative damage to lipids, proteins and DNA.

Understanding the process of oxidation and its effects on food and health is important to scientists and non-scientists alike. Faculty members and students have developed the Mentoring Academic Growth in the Community (MAGIC) program and have collaborated with the Science Museum of Western Virginia to create educational modules about oxidation and its impact on society for K-12 audiences.

“The key to teaching kids about oxidation is to find examples that make concepts relevant in their own lives,” says Duncan . “Food tastes better if oxidation is prevented or minimized. Everyone can relate to food, so demonstrating improvements to flavor, appearance, and shelf life as a result of oxidation control methods is interesting on a personal level.”

CURRENT TOPICS AND DAIRY ISSUES

Edible Films Made From Dairy, Biofuel Byproducts

A method developed by Agricultural Research Service (ARS) scientists uses byproducts—not only from dairy processing, but also from biofuel production—to create biodegradable protective films.

The technology was developed by research leader Peggy M. Tomasula and her colleagues at the ARS Eastern Regional Research Center 's Dairy Processing and Products Research Unit in Wyndmoor , Pa. They found that combining the milk protein casein with water and glycerol, a byproduct of biofuel production, produces a water-resistant film that can be used as an edible coating for food products.

The scientists used carbon dioxide as an environmentally friendly solvent to isolate dairy proteins from milk, instead of harsh chemicals or acids that can be difficult to dispose of, according to Tomasula. Carbon dioxide (CO2) is another byproduct of the glucose fermentation that is used to make ethanol. Using CO2 makes the edible film more water-resistant and biodegradable.

The resulting food coatings are glossy, transparent and completely edible. Like conventional food packaging, edible films can extend the shelf life of many foods, protect products from damage, prevent exposure to moisture and oxygen and improve appearance. By using renewable resources instead of petrochemicals, the scientists can create more biodegradable products and reduce waste.

Tomasula has been working with food technologist Kirsten L. Dangaran and chemist Phoebe X. Qi to improve the appearance and protective properties of the casein films.

At one point in the production process, CO2 dissolves into the milk, decreasing its pH level and causing casein to form particles of a substance known as CO2-casein. The researchers found that decreasing the size of the CO2-casein particles improved the films' ability to block moisture and increased their glossiness.

They also found that coating a low-density polyethylene film with the CO2-casein increased the film's ability to block oxygen permeation. Adjustments like these could make the films more competitive with existing, less eco-friendly products.