Extension Ag Update
 May/June  2002
Articles Research Resources Internet Links Ag Facts Education

Research Results

Straw-Fiber Packaging Within Grasp Soon

ARS News Service. Agricultural Research Service, USDA, Marcia Wood, (301) 504-1662, MarciaWood@ars.usda.gov

Today's leftover rice and wheat straw might tomorrow be used in making environmentally friendly packaging materials or other biobased products. The molded polystyrene forms that hold computers or electronic components snugly in their shipping cartons, for example, could be replaced with biodegradable inserts made--in part--from straw fiber. That's according to Agricultural Research Service chemist William J. Orts. He is leader of the Bioproduct Chemistry and Engineering Unit at the ARS Western Regional Research Center in Albany, Calif.

Orts directs studies that are revealing how cellulose-rich fibers from straw hold up during pulping. The pulping process results in a slurry of straw, water and additives, such as clays and starches, that are dried and molded into rigid shapes. Straw fibers must perform predictably so that the finished pulp product is uniform, according to Orts. Otherwise, manufacturers might opt to stay with familiar raw materials instead of choosing straw.

Orts is collaborating in the studies with Regale Corporation, a California-based designer and manufacturer of customized packaging made from recycled materials. In new tests at the Western Regional Research Center, Orts and co-researchers are putting rice and wheat straw through a modified hot-water and a conventional chemical-based pulping process. The researchers hope to discover variations that could lower costs. That could boost the appeal of rice or wheat straw as an economical manufacturing option.

Packaging materials and other biobased products from straw could give growers a new, profitable market for straw that today is plowed under or perhaps sold for animal feed or bedding. The amount of straw produced each year is enormous. In California alone, the annual rice crop generates more than 300,000 tons of straw. And the state's wheat crop yields an estimated 400,000 tons of straw.

New Process for Tenderizing Meat

Scientist: James Claus (608) 262-0875, jrclaus@facstaff.wisc.edu
Source: George Gallepp (608) 262-3636, Agricultural and Consumer Press Service College of Agricultural and Life Sciences, 440 Henry Mall, Research Division, Madison WI 53706, (608) 262-1461, University of Wisconsin-Madison

A new process that instantly tenderizes boneless meat could help packing houses produce consistently tender, moist cuts of beef, according to a University of Wisconsin-Madison meat scientist. "We can take cuts such as top rounds, eye of rounds, or rib and loin steaks and improve their tenderness by 25 percent to 30 percent in the blink of an eye," says James Claus of the Department of Animal Sciences. "This could have an enormous impact on the meat industry's ability to produce more tender products.

"Cuts that are already tender, such as filet mignon, don't need to be more tender," Claus says. "The new process increases the tenderness of cuts from the least tender animals the most. The greatest improvement is in meat cuts that are leaner and less marbled, which are typically from the lower USDA beef quality grades. The result is that meat treated this way will be more consistently tender." Tests show that the method also works well on pork and chicken breasts. Claus found a 28 percent improvement in the tenderness of pork loins, for example. To tenderize beef, the industry currently may age meat for one to two weeks, use blades or needles that slice into or puncture meat cuts, or add plant enzymes to the meat. Claus's tests at the UW-Madison's Meat and Muscle Biology Laboratory showed dramatic increases in tenderness of unaged meat.

The new method performs as well as or better than blade tenderization, he says, and it doesn't break the surface of meat. (Processes that break the meat surface increase the risk of bacterial contamination.) Another advantage of the process is that nothing is added, such as plant enzymes, which may give meat an undesirable flavor or texture. The new process uses electrically generated hydrodynamic shock waves. Like a sonic boom traveling through the atmosphere, the shock wave speeds through the meat breaking apart some of the tiny fibers in the muscle cells. In addition to improving tenderness, this process also improves the ability of meat to absorb and retain moisture, according to Claus. He says the method does not change the meat's flavor or color. Hydrodyne Incorporated of San Juan, Puerto Rico holds patents for tenderizing meat with electrically created hydrodynamic shock waves. The company provided the machine Claus evaluated. His experiments at the College of Agricultural and Life Sciences were supported in part by grants from the Wisconsin Beef Council.

The concept of tenderizing with shock waves is not new. An earlier Hydrodyne method attempted to tenderize meat using explosives to generate the shock waves. The new electrical-based system produces higher shock wave pressures and allows an operator to treat meat more than once if needed for greater tenderness. The unit Claus used takes as much space as a small pickup truck and does not require any unusual electrical current. Claus says the meat industry may find the process especially useful in tenderizing what are known as sub-primals and individual muscles used to produce case-ready steaks. Claus also used the machine to tenderize beef and pork cuts before injecting marinade. The treated cuts retained five percent more marinade, which improved their juiciness.

The process also could be used in preparing broilers for market. "It would allow that industry to remove breast meat from bone immediately rather than storing the birds in ice first. We found that breasts removed immediately and subsequently treated post-rigor with this shock-wave method were as tender as breasts harvested using the current method," Claus says.