Navigation Links
Illinois scientists put cancer-fighting power back into frozen broccoli
Date:8/6/2013

URBANA, Ill. There was bad news, then good news from University of Illinois broccoli researchers this month. In the first study, they learned that frozen broccoli lacks the ability to form sulforaphane, the cancer-fighting phytochemical in fresh broccoli. But a second study demonstrated how the food industry can act to restore the frozen vegetable's health benefits.

"We discovered a technique that companies can use to make frozen broccoli as nutritious as fresh. That matters because many people choose frozen veggies for their convenience and because they're less expensive," said Elizabeth Jeffery, a U of I professor of nutrition.

"Whenever I've told people that frozen broccoli may not be as nutritious as fresh broccoli, they look so downcast," she added.

As little as three to five servings of broccoli a week provides a cancer-protective benefit, but that isn't true for bags of broccoli that you pluck out of your grocery's freezer, she noted.

The problem begins when soon-to-be-frozen broccoli is blanched, or heated to high temperatures, to inactivate enzymes that can cause off-colors, tastes, and aromas during the product's 18-month shelf life, she explained.

The extreme heat destroys the enzyme myrosinase, which is necessary to form sulforaphane, the powerful cancer-preventive compound in broccoli, she said.

"We know this important enzyme is gone because in our first study we tested three commercially frozen broccoli samples before and after cooking. There was very little potential to form sulforaphane before the frozen broccoli was cooked and essentially none after it was cooked as recommended," said Edward B. Dosz, a graduate student in Jeffery's laboratory.

In the second study, the researchers experimented with blanching broccoli at slightly lower temperatures instead of at 86C, the current industry standard. When they used a temperature of 76C, 82 percent of the enzyme myrosinase was preserved without compromising food safety and quality.

Sulforaphane is formed when fresh broccoli is chopped or chewed, bringing its precursor glucoraphanin and the enzyme myrosinase into contact with each other. The researchers first thought that thawing frozen broccoli in the refrigerator might rupture the plant's cells and kick-start the enzymesubstrate interaction. It didn't work, Dosz said.

But they had previously had success using other food sources of myrosinase to boost broccoli's health benefits. So the researchers decided to expose frozen broccoli to myrosinase from a related cruciferous vegetable.

When they sprinkled 0.25 percent of daikon radishan amount that's invisible to the eye and undetectable to our taste budson the frozen broccoli, the two compounds worked together to form sulforaphane, Dosz said.

"That means that companies can blanch and freeze broccoli, sprinkle it with a minute amount of radish, and sell a product that has the cancer-fighting component that it lacked before," he said.

One question remained: Would sulforaphane survive the heat of microwave cooking? "We were delighted to find that the radish enzyme was heat stable enough to preserve broccoli's health benefits even when it was cooked for 10 minutes at 120F. So you can cook frozen broccoli in the microwave and it will retain its cancer-fighting capabilities," Dosz said.

Jeffery hopes that food processors will be eager to adopt this process so they can market frozen broccoli that has all of its original nutritional punch.

Until they do, she said that consumers can spice up their frozen, cooked broccoli with another food that contains myrosinase to bring the cancer-fighting super-food up to nutritional speed.

"Try teaming frozen broccoli with raw radishes, cabbage, arugula, watercress, horseradish, spicy mustard, or wasabi to give those bioactive compounds a boost," she advised.


'/>"/>

Contact: Phyllis Picklesimer
p-pickle@illinois.edu
217-244-2827
University of Illinois College of Agricultural, Consumer and Environmental Sciences
Source:Eurekalert

Related biology news :

1. University of Illinois researchers develop AFM-IR for nanometer scale chemical identification
2. Illinois town provides a historical foundation for todays bee research
3. University of Illinois receives grant to study ozone resistance in corn
4. University of Illinois to improve crop yield through photosynthesis in a new global effort
5. University of Illinois at Urbana-Champaign awarded 5-year grant from NASA
6. University of Illinois professor develops tool that helps dietitians deliver info clients need and can understand
7. Scientists learn how soy foods protect against colon cancer
8. Wistar scientists decipher structure of NatA, an enzyme complex that modifies most human proteins
9. Scientists uncover secrets of starfishs bizarre feeding mechanism
10. Geoscientists unearth mineral-making secrets potentially useful for new technologies
11. Scientists discover a molecular switch in cancers of the testis and ovary
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/11/2017)... , April 11, 2017 NXT-ID, Inc. ... technology company, announces the appointment of independent Directors Mr. ... to its Board of Directors, furthering the company,s corporate governance ... Gino ... we look forward to their guidance and benefiting from their ...
(Date:4/5/2017)... NEW YORK , April 5, 2017 ... security, is announcing that the server component of the ... is known for providing the end-to-end security architecture that ... customers. HYPR has already secured over 15 ... system makers including manufacturers of connected home product suites ...
(Date:4/3/2017)... , April 3, 2017  Data captured ... engineering platform, detected a statistically significant association ... prior to treatment and objective response of ... potential to predict whether cancer patients will ... treatment, as well as to improve both pre-infusion ...
Breaking Biology News(10 mins):
(Date:4/27/2017)... ... April 27, 2017 , ... ... name change to Fluence Analytics. , Fluence Analytics provides proprietary hardware ... biopharmaceutical manufacturing processes and R&D applications. The company’s patented technologies improve production ...
(Date:4/27/2017)... 2017  Pendant Biosciences, Inc. (formerly Nanoferix, Inc.), a ... drug delivery technologies, today announced that it has been ... Toronto . Shawn Glinter ... noted, "We are excited to become part of the ... are honored to be the first Tennessee ...
(Date:4/26/2017)... , ... April 26, 2017 , ... ... teamed up with NASA to showcase the future of deep space exploration and ... (SLS) rocket and Orion spacecraft and includes a guest appearance by former Shuttle ...
(Date:4/26/2017)... ... April 26, 2017 , ... Baltimore bio tech firm, ... security screening solution at the National Postal Forum 2017 in Baltimore, Maryland, May ... highly accurate, easy to use and low cost threat detection solution for government ...
Breaking Biology Technology: