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 25, 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 25, 2014).

Share This




More Plants & Animals News

Friday, July 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How to Make Single Serving Smoothies: Howdini Hacks

How to Make Single Serving Smoothies: Howdini Hacks

Howdini (July 24, 2014) Smoothies are a great way to get in lots of healthy ingredients, plus they taste great! Howdini has a trick for making the perfect single-size smoothie that will save you time on cleanup too! All you need is a blender and a mason jar. Video provided by Howdini
Powered by NewsLook.com
Boy Attacked by Shark in Florida

Boy Attacked by Shark in Florida

Reuters - US Online Video (July 24, 2014) An 8-year-old boy is bitten in the leg by a shark while vacationing at a Florida beach. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Tyrannosaur Pack-Hunting Theory Aided By New Footprints

Newsy (July 24, 2014) A new study claims a set of prehistoric T-Rex footprints supports the theory that the giant predators hunted in packs instead of alone. 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