Featured Research

from universities, journals, and other organizations

Tough And Spongy: University Of Arkansas Researchers Uncover The Reasons For Mushroom Degradation

Date:
September 8, 2000
Source:
University Of Arkansas
Summary:
After a few days on the refrigerator shelf, the small, white button mushrooms from the grocery store turn brown and spongy, but when you try to cut them they seem tough as nails. University of Arkansas food science researchers have discovered the reason mushrooms become unusable so quickly and hope the information may one day be used to extend the shelf life of mushrooms in the market.

FAYETTEVILLE, Ark. -- After a few days on the refrigerator shelf, the small, white button mushrooms from the grocery store turn brown and spongy, but when you try to cut them they seem tough as nails. University of Arkansas food science researchers have discovered the reason mushrooms become unusable so quickly and hope the information may one day be used to extend the shelf life of mushrooms in the market.

Graduate student Svetlana Zivanovic and food science professor Ron Buescher will present their findings on Monday, Aug. 21 at the American Chemical Society's 220th national meeting in Washington, D.C.

Americans consume more Agaricus bisporus, or white button mushrooms, than any other kind. Last year people devoured over 8 million pounds of mushrooms, and 85 percent of those consumed were fresh.

Mushroom producers harvest the fruit-bodies at the "close cap" stage, when stems are still short and the caps are closed. They must pluck the mushrooms from the compost pile within a window of a few hours so they can preserve desirable traits. Desirable traits in mushrooms include short stems, closed caps, a white color and firm but tender texture.

Soon after harvesting, however, the mushrooms elongate, producing a flat, thin cap, long stem, a brown color and a spongy and tough texture that is difficult to cut or chew.

Little is known about why mushrooms degrade in quality in this manner. Although mushrooms appear next to carrots and tomatoes in the produce section, they are microorganisms, not vegetables. Most vegetables either soften or toughen over time, but they don't do both. Zivanovic set out to find out why mushrooms exhibit these two seemingly opposite qualities.

Unlike vegetables, mushrooms contain chitin in their cell walls, a substance commonly found in insects and shellfish.

While the mushroom grows, the chitin gets everything it needs from the compost pile, forest floor or tree of its choice. But once picked, the chitin begins to seek those substances from within the cells.

Zivanovic measured the presence of chitin in mushrooms at different stages, and discovered that mushrooms toughen as chitin increases.

At the same time that the caps open, cells stretch and elongate, increasing the spaces between them and leaving a spongy texture in its wake.

Zivanovic hypothesized that mushroom degradation may start when enzymes begin to break down proteins in the cell walls.

She infiltrated discs from mushroom caps with different hydrolyzing enzymes that break down proteins, and analyzed their effects on chemical composition of cell walls and on texture of the tissue. When structural proteins were hydrolyzed, cell wall construction was loosened and resulted in altered texture.

The next step in searching for a way to increase the shelf-life of fresh mushrooms would be to find a way to prevent proteolysis that rises after harvesting .

"If we could prolong their shelf life by even a day, it would be an accomplishment," Zivanovic said.


Story Source:

The above story is based on materials provided by University Of Arkansas. Note: Materials may be edited for content and length.


Cite This Page:

University Of Arkansas. "Tough And Spongy: University Of Arkansas Researchers Uncover The Reasons For Mushroom Degradation." ScienceDaily. ScienceDaily, 8 September 2000. <www.sciencedaily.com/releases/2000/09/000904124617.htm>.
University Of Arkansas. (2000, September 8). Tough And Spongy: University Of Arkansas Researchers Uncover The Reasons For Mushroom Degradation. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2000/09/000904124617.htm
University Of Arkansas. "Tough And Spongy: University Of Arkansas Researchers Uncover The Reasons For Mushroom Degradation." ScienceDaily. www.sciencedaily.com/releases/2000/09/000904124617.htm (accessed October 21, 2014).

Share This



More Plants & Animals News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins