Featured Research

from universities, journals, and other organizations

Microwave Blanching Superior In Vegetable-Preservation Process

Date:
April 13, 1998
Source:
University Of Illinois At Urbana-Champaign
Summary:
Blanching freshly picked vegetables in a microwave not only speeds the freezing process but also maintains the foods' nutritional value better than traditional blanching does.

CHAMPAIGN, Ill. -- Blanching freshly picked vegetables in a microwave not only speeds the freezing process but also maintains the foods' nutritional value better than traditional blanching does.

What began as a project by senior food-science students at the University of Illinois has grown into a series of published graduate-level experiments -- green beans (1994), broccoli (1995) and, now, asparagus -- that are setting the standards for efficient microwave blanching.

"In my years of conducting food-preservation classes, I found out that a lot of people are not very interested in using traditional food-preservation methods, because they are time consuming and they heat up the house," said Susan Brewer, a U. of I. food scientist. "People were trying to particularly get away from having to blanch anything. The idea was to simply take something out of the garden, put it in a storage bag and stick it in the freezer."

But that's not a good practice, she said. Vegetables taken straight from the garden to the freezer, without blanching, deteriorate within a month. "Four weeks later, they are going to be of such poor quality that you are not going to want to eat them," she said.

Blanching is very short exposure to high heat -- typically two to five minutes in boiling water or live steam. The heat inactivates enzymes in the vegetables. Preparing for and using traditional steaming or boiling makes for messy kitchens and a lot of unwanted heat. Microwaving has been discouraged because of uncertainties on temperature, time and resulting quality.

"A lot of the recommendations used today are based on USDA guidelines developed in the 1940s and 1950s, and they were used for large quantities," Brewer said. "Our lifestyles have changed a lot. We've got microwave ovens in the kitchen and women in the work force. Women are no longer spending a lot of time in the kitchen doing these things anymore."

The most recent findings -- published in the December issue of the Journal of Food Quality by Brewer and Shahnaz Begum, a graduate student in food science and nutrition -- indicate that microwave-blanched asparagus keeps its nutritional value, taste and texture, as well as and often better than, asparagus blanched using traditional methods.

The success of microwave blanching depends mostly on quantity, timing and wattage. In this case, researchers blanched two to three servings at a time in a covered casserole dish with about two tablespoons of water. They blanched the asparagus, which had been picked within four hours of the process, at 700 watts for four minutes, then sealed it in plastic and put it into the freezer immediately.

In arriving at the optimum time for microwaving, the researchers identified the minimum amount of heating needed to inactivate both peroxidase and ascorbic-acid oxidase activities, which break down a vegetable's quality and vitamin C content, respectively, during storage.

Quality testing was done three months later on the asparagus, cooked in the microwave.


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Microwave Blanching Superior In Vegetable-Preservation Process." ScienceDaily. ScienceDaily, 13 April 1998. <www.sciencedaily.com/releases/1998/04/980413000021.htm>.
University Of Illinois At Urbana-Champaign. (1998, April 13). Microwave Blanching Superior In Vegetable-Preservation Process. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/1998/04/980413000021.htm
University Of Illinois At Urbana-Champaign. "Microwave Blanching Superior In Vegetable-Preservation Process." ScienceDaily. www.sciencedaily.com/releases/1998/04/980413000021.htm (accessed July 22, 2014).

Share This




More Plants & Animals News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Michigan Plant's Goal: Flower and Die

Michigan Plant's Goal: Flower and Die

AP (July 22, 2014) An 80-year-old agave plant, which is blooming for the first and only time at a University of Michigan conservatory, will die when it's done (July 22) Video provided by AP
Powered by NewsLook.com
San Diego Zoo Welcomes New, Rare Rhino Calf

San Diego Zoo Welcomes New, Rare Rhino Calf

Reuters - US Online Video (July 21, 2014) An endangered black rhino baby is the newest resident at the San Diego Zoo. Sasha Salama reports. Video provided by Reuters
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
$23.6 Billion Awarded To Widow In Smoking Lawsuit

$23.6 Billion Awarded To Widow In Smoking Lawsuit

Newsy (July 20, 2014) Cynthia Robinson claims R.J. Reynolds Tobacco Company hid the health and addiction risks of its products, leading to the death of her husband in 1996. Video provided by Newsy
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:
from the past week

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