CONCEPT 27: PRECOOKING MAKES VEGETABLES FIRMER Flashcards Preview

THE SCIENCE OF GOOD COOKING > CONCEPT 27: PRECOOKING MAKES VEGETABLES FIRMER > Flashcards

Flashcards in CONCEPT 27: PRECOOKING MAKES VEGETABLES FIRMER Deck (45):
1

Can almost any vegetable be roasted in a pan or oven?

Yes

2

Whats the problem with roasting vegetables in the oven?

Their very high water content causes significant moisture loss when browned in the oven. This concentrates flavor but can leave you with a batch of wrinkled, dry vegetables.

3

How do you get vegetables tender without moisture loss?

Steam them.

4

Precooking is especially important for vegetables such as...

Potatoes, sweet potatoes, carrots, Brussels sprouts, asparagus and cauliflower; vegetables that can become firm and stay firm during cooking when exposed to short cooking times and low heat.

5

Vegetables (such as Potatoes, sweet potatoes, carrots, Brussels sprouts, asparagus and cauliflower) contain an enzyme that becomes most active at what temperatures?

Between 120 and 160 degrees Fahrenheit.

6

What is this vegetable enzyme called?

Pectin methyl esterase.

7

What does pectin methyl esterase do?

Causes pectin in cell walls to more readily link with calcium ions, which are already present in the vegetables structure. This link causes pectin to become stronger, making the vegetables much less prone to breaking down.

8

Though use interchangeably, are brown and caramelize the same thing?

No

9

What is caramelization?

Describes the chemical reactions that take place when sugar is heated to the point that its molecules begin to break apart and generate hundreds of new flavor, cold and aroma compounds. Example: crème brûlée.

10

Name three vegetables that are high in natural sugar.

Onions, carrots and squash.

11

Describe browning.

The process that involves the interaction of not just sugar molecules and heat but also proteins and their breakdown products, amino acids--and is called Maillard reaction. Browning creates a tremendous number of flavors and color, but they're not the same as caramelization because protein is involved.

12

Do meats and bread benefit from caramelization or browning?

Browning

13

Do vegetables benefit from browning or caramelization?

Since vegetables contain little or no protein they technically caramelize.

14

What do pectin strands and calcium bond look like?

Pectin is like a wire fence, calcium ions are dots at each point.

15

What does a gentle start and hot finish do for vegetables?

Vegetable cells maintain a strong pectin network due to the work of enzyme pectin methyl esterase, which causes pectin to link with calcium ions.

16

What happens when you cook vegetables at high heat alone?

Pectin methyl esterase is not active, and the pectin network within the vegetables cells is more prone to breaking down.

17

TEST KITCHEN: VEGETABLES COOKED ON HIGH HEAT, COVERED THEN UNCOVERED, COOKED IN A WATER BATH AT 150 DEGREES FOR 30 MINUTES AND ROASTED.

Roasted were wrinkled and lost 62% of their weight; covered then uncovered were less wrinkled and lost 60% of their weight; water bath and roasted weren't wrinkled and lost 53% of their weight.

18

What does covering a vegetable with aluminum foil in the oven do?

It steams them in the oven until it's removed.

19

Do the shiny and dull sides of aluminum foil work the same? Mashed potato test.

Yes, heating mashed potatoes with shiny side facing the food heated up a bit faster; difference was so slight they concluded no difference.

20

How is aluminum foil made? Why does one side shine?

By passing two layers of foil through a rolling mill at the same time. The side in contact with the rolling mill comes out shiny, while the other side is dull.

21

Describe the perfect roasted sweet potatoes.

Nicely caramelized exterior, a smooth, creamy interior and earthy sweetness.

22

What does "cold start, finish sweet" mean when cooking mashed potatoes?

The less sweet potatoes browned, the sweeter they became.

23

Why are sweet potatoes noticeably sweeter with lower oven temperatures?

The starch in sweet potatoes is converted to sugar between 135 and 170 degrees. Once the internal temperature exceeds 170, no further conversion takes place. Thus, the lower the temp, the longer they will stay within this range; this is called the "sweet zone."

24

What happens when you store sweet potatoes in the refrigerator?

It can cause them to develop a tough interior, even when cooked for long period of time.

25

How should sweet potatoes be stored?

At room temperature, away from light.

26

Why do sweet potatoes develop hard centers when refrigerated?

During chilling stage, sweet potatoes' cell walls become more permeable, allowing the calcium ions located between cells to enter into the cell walls. Warming them to room temperature activates an enzyme called pectin methyl esterase. The enzyme alters pectin in a way that allows it to react with the calcium ions, strengthening the pectin molecules in the cells' walls so they can't be broken down.

27

What draws out carrots natural sugars and intensifies their flavor?

Roasting

28

Carrots contain more _____ than any other vegetable.

Pectin

29

Do Brussels sprouts taste overly bitter and sulfuruous at times?

Yes

30

Broccoli, radish, cabbage, Brussles sprout and mustard green are all part of what family?

Crucifer family

31

Brussels sprout are rich in flavor precursors. What does this mean?

Flavor precursors react with the vegetable's enzymes to produce pungent new compounds when cut, cooked, or even eaten.

32

Handling Brussels sprouts just right helps them take os what flavor?

Nutty sweetness

33

How should you arrange cut Brussels sprouts when cooking? Why?

Cut side down for optimal browning and extra flavor.

34

Why do you sprinkle Brussels sprout with oil AND water before roasting?

Each piece hold on to a little water that acts like a steam chamber when covered with foil, helping the interior to cook through.

35

As with oven-raosted vegetables, should you also precook before browning on a stove?

Yes

36

Is the oven really your best choice for larger vegetables such as cauliflower and sweet potatoes?

Yes

37

How do you steam smaller vegetables on the stove if they're not cooked in water first?

Cover them with a lid before browning.

38

Can pencil thin asparagus be covered and cooked?

Not really, it cannot withstand the heat and overcooks too easily.

39

When sautéing, how does butter help cook asparagus?

The moisture inside helps steam the vegetable.

40

Why is asparagus better when steaming before sautéing?

Raw asparagus is dry and waxy; the sugars necessary for browning are locked up inside the plants tough cell walls--cooking is required to release these sugars.

41

What is a cooking medium?

Instrument by which something is accomplished.

42

Does a crowded pan help increase the steam effect?

Yes

43

When using a small sauté pan, what direction should asparagus spears be facing for maximum browning?

Half facing one way, half facing the other.

44

Best way to store asparagus?

Trimmed, standing upright in a glass, with a bit of water (1 inch up the stalk) in the refrigerator.

45

TEST KITCHEN: STORED ASPARAGUS IN PLASTIC BAG, PAPER BAD WITH WET TOWEL AND STANDING UPRIGHT IN WATER.

Plastic bag was slimy, paper bag had shriveled tips and limp stalks, standing in water were bright and fresh.

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