Dela broccoli eller tillaga hel?

[RobinEH]

Jag brukar ångkoka min broccoli i microvågsugn. Dessförinnan så brukar jag dock alltid dela broccolin i relavit små bitar för att slippa göra detta efter tillagning samt för att förkorta tillagningstiden. Nu undrar jag dock hur detta påverkar broccolins innehåll av vitaminer och mineral, och specifikt vitamin C. Vitamin C och andra vitaminer påverkas ju av kontakt med syre och vid tillagning. Att då dela broccolin i små bitar kommer ju att öka den direkta exponeringen av syre medan större bitar kommer att öka tillagningstiden.

Vad är bäst för att bevara så mycket vitaminer som möjligt. Kortare tillagningstid eller mindre syreexponering?

[King Grub]

Broccoli förlorar upp till 97% av vissa mikronäringsämnen om den tillagas i mikrovågsugn.

För att undvika större förluster av vitamin C bör man undvika lång tillagningstid.

[Mazr]

Ska man koka den istället då?

[Sir Beef A Lot]

Steam that shit, brah!
http://livethemma.ikea.se/sites/livethemma.ikea.se/files/angkok_fix.jpg

[RobinEH]

Broccoli förlorar upp till 97% av vissa mikronäringsämnen om den tillagas i mikrovågsugn.

För att undvika större förluster av vitamin C bör man undvika lång tillagningstid.

Just "97%" finner jag i denne (http://onlinelibrary.wiley.com/doi/10.1002/jsfa.1585/abstract) :
Clear disadvantages were detected when broccoli was microwaved, namely high losses of flavonoids (97%), sinapic acid derivatives (74%) and caffeoyl-quinic acid derivatives (87%). Conventional boiling led to a significant loss of flavonoids (66%) from fresh raw broccoli, while high-pressure boiling caused considerable leaching (47%) of caffeoyl-quinic acid derivatives into the cooking water.

Då jag inte har tillgång till fulländaren så får jag flika in med vad andra har skrivit.
But when you look into the test conditions around the research, you'll find that the conclusion can be a bit misleading. The broccoli was microwaved in 10 teaspoons of water for 10 minutes. The greatest factors in the lost of nutrients in the broccoli were more likely the seeping of nutrients into excessive amounts of water (just like boiling) and the really long time of the microwave cooking (excessive heat does break down the nutrients). (http://answers.yahoo.com/question/index?qid=20100608180828AAF900c)
But there's more to this story. While heat from any cooking reduces the levels of certain nutrients, the length of cooking time and the amount of water used are major factors too.

When vegetables are cooked in water, nutrients get leached out and thrown away with the water. The broccoli in this study was cooked in 10 tablespoons of water. That’s a lot.

Plus the fact that flavonoids are water-soluble antioxidants. And, according to Dr Cristina García-Viguera, leader of the study, "During microwave heating they leach into the cooking water, removing their nutritional benefits from the foodstuff."

The broccoli was also cooked in the microwave way longer than necessary. The longer cooking time and the excess use of water caused greater loss of nutrients. (http://www.bellaonline.com/articles/art52758.asp)
That research isn’t relevant to household microwaving. Basically, the researchers added far too much water and microwaved the living daylights out of the broccoli. (http://medvetenskap.wordpress.com/2009/01/10/forstor-mikrovagsugnen-naringen-i-din-mat/)

Dessutom så ångkokar jag broccolin i microvågsugnen.