How To Keep Potatoes From Turning Brown Before Cooking

Potatoes are one of the virtually versatile foods out there. You lot can broil, fry, boil or mash them. Eat them warm or cold, with plenty of seasonings, or just plain. You lot can eat them months later on they're harvested, or fresh out of the basis. The options are literally endless.

At that place is one common thread though that binds most potato dishes together: they're all cooked in some mode. It's very rare to come across a raw murphy dish, raw potato juice being but i of those few exceptions, merely almost all dishes involve heating that potato some way.

There's a good reason for this. Raw potatoes aren't very digestible (nor delectable) for humans. But once information technology'southward cooked, a murphy will never be the same once more. So what happens during cooking? What transforms this raw hard irish potato, into something eaten all over the world?

1. What is a murphy fabricated of?
   • Chemical Composition
2. What happens when cooking a murphy?
   • Heating the white potato
   • "Killing" the potato
   • Chemical reactions
   • Moisture redistribution
3. Why exercise Mealy & Waxy Potatoes Cook and so Differently?
   • White potato Cells Rupture (Waxy) vs Intermission Apart (Mealy)
   • Starch content
4. How to Cook a Potato
   • Boil potatoes in h2o
   • Cook in the microwave
   • Mashed potatoes
   • Submerge in oil
   • Fry in some oil
   • Bake a whole white potato
5. Sources

What is a potato made of?

Before the potato is cooked, it'southward a raw part of a plant, more specifically, it's a tuber. It is meant to be planted and grow into a new potato plant. A raw potato is 'alive'. It might sprout during storage and it will be animate.

The inside of a murphy is quite homogeneous, fabricated up of cells that are full of food to serve as a starting point for that plant. The skin protects the inside and is pretty thin, especially for recently harvested and smaller potatoes.

The cells within a white potato all have the same basic structure: the cell contains a sack of water, a nucleus, and diverse other structures ("factories") to keep the cell running. Surrounding every cell is a cell wall which protects the within. These cell walls hold everything together and provide compactness to a potato thanks to a phenomenon chosen turgor. This turgor is caused past h2o within the jail cell pressing against the cell walls. If a irish potato dries out and loses wet you will discover it turning soft, it'south losing its turgor.

Both the cells themselves and the prison cell walls play an of import office in the texture and structure of a potato. In raw potatoes, most cells are intact and the cell walls are firm. Notwithstanding, in one case you start cooking a murphy, that changes, causing the texture of the potato to change.

Did you lot know that potatoes originated in S America? A couple of centuries ago potatoes were introduced to other regions in the world. By now, it's 1 of the world's master staple foods.

Chemical Composition

Peradventure unsurprisingly, nearly of a spud is water, most eighty%. This is very common for fruits and vegetables. The residue of the tater is more often than not carbohydrates (>15%), of which nigh is potato starch (more than 85%). Starch is a mode for plants to shop energy (glucose). In the case of a irish potato, this energy is stored to be available when growing into a new constitute. Starch sits in the cells in the form of granules of 1-100 micrometer in size. Each granule is made up of a lot of starch molecules.

There'due south barely any fat in a potato and simply a few percent is protein. Potatoes as well comprise a lot of other minor components such as vitamins and minerals.

Even though all starches have the aforementioned basic chemical composition, they practise differ in their beliefs. Corn, potato, rice, and wheat starch, for instance, are all a little dissimilar! Even the starch from two different potato varieties might behave differently.

The Cells Walls

The composition of the cell walls is quite different compared to the cells themselves. They don't contain this big reservoir or h2o, nor the big quantities of starch. Instead, the prison cell walls are mostly fabricated up of large molecules such as cellulose, hemicellulose, and pectins. These molecules aid give the potato structure and keep everything together.

What happens when cooking a spud?

When y'all melt a white potato, no matter the method, whether it's boiling, frying, baking, or steaming, your potato will visually change. It turns from a hard tuber into a softer, crumblier production, that's easier to mash, seize with teeth through, cut, and chew. So what causes these transformations?

Heating the potato

Of course, information technology all starts by heating the potato. This can become very fast (east.thousand. deep frying thinly cut pieces in oil), or more than slowly (e.g. steaming a whole potato). The heat will nigh ever (using a microwave is the exception) showtime heat up the outside. The oestrus and then penetrates throughout, until the whole potato is hot. The energy that the rut brings initiates transformations and reactions within the potato.

Why does information technology take longer for a big spud to melt than it does for a pocket-size one?

The main reason for the difference in cooking time between small-scale and large potatoes (pieces), is that information technology takes time for the potato to heat upward. When a potato is heated from the outside, that heat will slowly have to penetrate throughout the potato.
The shortest altitude within the potato determines how fast the heat gets in. This is why a long french fry volition cook just as apace equally a short french fry, information technology's the thickness of the fry that limits the rut transfer (of course, assuming that the fry is longer than it is thick!).

Ever bought par-boiled, pre-cooked potatoes and noticed how all the pieces tend to be of a like size? This helps ensure that all your potatoes cook in a similar time frame!

A large whole baked irish potato takes significantly longer to bake than a pocket-size one.

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"Killing" the potato

One of the outset things that happen when a spud is heated is that it gets 'killed'. A raw potato is alive, you lot can bury that tater in the ground and abound a plant. Notwithstanding, the estrus will inactivate and destroy several crucial components of the potato, losing its ability to grow into a plant again. An important part of living organisms (humans included) are enzymes, which catalyze a lot of reactions necessary for living. Heat inactivates these enzymes. One time inactivated, they tin't exist reactivated. You can try planting a cooked irish potato, just it won't practice much!

Chemical reactions

The deactivation of these enzymes is simply the showtime. Once a potato is hot enough several other chemic reactions will accept place that will irreversibly change the murphy. You will have passed the point of no return, your potato will never be the same again!

As with any food, a lot of unlike processes happen simultaneously, and we can't discuss all. Instead, nosotros'll focus on three major processes that occur that explain a lot of the transformations you'll see:

1. The heat volition pause down and soften jail cell walls. Private cells are no longer held together equally tightly anymore. Cells themselves may suspension and rupture, causing the molecules within to be released. The molecules tin react and cause further changes.
2. Starch absorbs water and gelatinizes.
3. At high plenty temperatures sugars and proteins in the potato volition react in the Maillard reaction. This makes a potato plough brown and become lots of delicious flavors.

Chemical reactions don't just happen once a potato is heated. During storage various chemical reactions take identify. For instance, it is well known that storing a potato in the refrigerator results in starches breaking down into sugars.

Breaking downward the jail cell structure

The jail cell walls are the glue that keeps the cells in a potato together. However, when a potato is heated this 'glue' starts to dissolve and thus the construction starts to atomize. Especially the pectins in the cell wall are known to dissolve.

Once the 'glue' betwixt the cells has started to soften the eating feel of the potato volition also exist very dissimilar. Information technology will be easier to bite into a irish potato since the cells move apart from one some other more easily. It is one of the reasons why a cooked potato is softer than a raw ane.

The increase in temperature also changes the permeability of the cell walls of a potato. At higher temperatures more small molecules can travel through the jail cell walls and jail cell membranes (specially above 60°C, 140°F), changing their composition.

In some cases, not just the jail cell walls, but also the cells themselves might weaken and even rupture. If cells do rupture they release their components into the remainder of the murphy, changing the structure of the overall potato.

Starch gelatinization

A major function of a potato is made up of starch and and then the changes that tater starch undergoes during cooking have a major impact on the backdrop of a cooked potato. Nosotros've discussed the changes potato starch undergoes during cooking extensively in some other post, simply will requite a short recap here.

Upon heating the potato, the starch granules in the cell will beginning to blot more and more water, swelling up as a result. At some point, the starch granules burst. Each starch granule contains a lot of individual starch molecules made upwards of amylose and amylopectin. These are then 'freed' in the cell and some will even leave the cell if the jail cell has broken or is sufficiently porous.

Does cooking potatoes remove potato starch?

It's a commonly asked question, simply no, cooking potatoes does not remove the potato starch. Certain, some starch might leach out during cooking, but the majority volition remain within the spud. What'southward more than, if y'all'd remove all of the starch out of the potato you'd be left with very niggling potato! All you'd have was water with a few proteins and some micronutrients.

Browning of a potato

In some grooming methods, a potato doesn't just soften and change texture, information technology also turns brownish: think chips or chips. You will merely find this transformation in training methods where y'all utilise high temperatures, well in a higher place 100°C (212°F), and where the moisture content is not too loftier.

The transformation itself is caused by the Maillard reaction which is a reaction between proteins and sugars. How fast and whether the reaction takes place is influenced by several factors. Get-go of all, temperature, the higher the temperature the faster it volition proceed (which is why a potato chip fried at 180°C volition plough brown faster than one fried at 140°C). Moisture content, the Maillard reaction is very slow in a very boiling environment. The amount of sugar and protein in your potatoes. If your spud contains more sugars, the reaction volition continue more than rapidly and your potatoes will brownish more quickly.

Especially this terminal factor causes for a lot of differences between potatoes. If potatoes are stored differently, are from a dissimilar cultivar, etc. the amount and rate of browning will be different.

Moisture redistribution

Apart from all these reactions taking place that permanently alter the murphy, another of import process is taking identify, accelerated past the heat: moisture motility.

A raw white potato contains a lot of h2o. During cooking, some of this water might evaporate from the potato, depending on the cooking method. The extent to which wet is driven out of has a huge impact on the final production. Moisture leaves the potato when it's heated above the boiling point of h2o (100°C/212°F), equally is the case when deep-frying for case.

Driving off plenty wet can make a murphy crunchy (we've done a deeper dive into crispiness hither). To make the whole irish potato crispy enough moisture needs to exist riven out of the whole piece. Of course, this is a lot easier for a thin potato piece (e.g. a scrap), than it is for a large potato. This is why a chip is crispy equally a whole, whereas a large baked potato will simply be crunchy on the outside and remain soft and juicy within.

The Challenge: Keeping information technology Crispy!

Making a potato crispy is ane thing, keeping it crispy is another challenge!

There is a lot of moisture in the air around united states of america, even more so in boiling environments. Energetically water wants to distribute itself evenly over separate phases/components (read more on this miracle here). As a result, moisture from the air will desire to enter your murphy once again. Too, if the inside of your murphy still contains a lot of moisture, this volition migrate to the exterior, softening the crust. It is why chips are packaged in special air-tight packaging and why you had amend consume your fries quick!

An open handbag of potato chips, the chips will commencement softening presently after opening!

Why practice Mealy & Waxy Potatoes Cook and then Differently?

There are a lot of different potato varieties. They differ in size, season, shape, color, and mealiness vs. waxiness. This last descriptor especially is unique for potatoes and refers to how potatoes acquit one time they're cooked. A waxy potato tends to exist firmer and hold its shape better, it will exist harder to mash. A mealy (also called starchy) potato, on the other mitt, falls apart more easily when y'all attempt to mash it.

Now that we know what happens while cooking a potato, we can explain this difference past looking at how the cells walls and cells intermission and how the starch within those varieties behaves.

Annotation, most potatoes aren't completely mealy OR purely waxy. It's more of a continuous scale where some are very mealy, others slightly waxy, etc. Also, if you lot want to actually draw potatoes well, you'll need other descriptors such as firmness and moistness as well. However, for sake of simplicity, nosotros'll focus on waxy & mealy potatoes.

Potato Cells Rupture (Waxy) vs Interruption Apart (Mealy)

The processes we just discussed that occur when you lot're cooking potatoes all influence whether a white potato is waxy or mealy. Interestingly, in the case of mealy potato especially the connections between cells are weakened. The cells themselves remain in contact but the 'mucilage' property them together weakens helping them to fall apart.

In the instance of waxy potatoes these weakened connections between cells all the same occur, simply to a lesser extent. Likewise, more actual cells get damaged during the cooking process, causing some of the starch to leak out which adds to the waxy, moist mouthfeel.

Whether a potato is mealy or waxy is determined by its variety. That determines the limerick of the cell walls and cells and just how they comport when being heated.

Starch content

As we discussed, cooking starch plays an important role when you're cooking potatoes. Starch isn't just important during cooking, but also afterward, when the tater cools down and starch 'recrystallizes'. This recrystallization can provide boosted compactness to the irish potato. Generally speaking, a mealy potato contains more starch than a waxy variety.

A lot of researchers take also looked at the type of starch (east.g. amylose vs amylopectin content), the shape and size of the granules and how these tin can impact mealiness vs. waxiness. Conclusions in this area contradict each other sometimes, so no clear relationships have been plant.

How to Cook a White potato

There are literally endless ways to tweak and command these scientific processes to make potatoes just a little different every time. How much moisture exercise you lot remove? How long do you cook a potato for, so how much time do y'all give chemic reactions to take place? At what temperature practice you initiate these processes? Even though the basics remain the aforementioned, the resulting potatoes can vary a lot!

There isn't one perfect style to cook a potato, of course. But there are a few basic techniques that are slap-up starting points. We'll highlight a few, focusing on discussing but exactly which transformations take (or don't have) identify!

Eddy potatoes in water

How?

Bring a pot of water to the boil and add potatoes (mayhap with some table salt). They can be peeled or unpeeled, cut into pieces, or placed in whole. Cook until the potatoes are tender (test with a fork/knive).

Transformations

Cells walls soften and some cells break down, the starch cooks.

No Maillard reaction (not hot plenty, also much water)

Cook in the microwave

How?

Identify whole (unpeeled!) potatoes in the microwave and heat until fully cooked. Fourth dimension depends on size and wattage, typically 5-12 minutes.

Nosotros accept an extensive mail on microwaving potatoes.

Transformations

No Maillard reaction (not hot plenty, besides much h2o)

Gives a drier potato compared to boiling in water, which is great if you want to broil/fry them side by side.

Mashed potatoes

How?

Cook your murphy (e.m. by humid in h2o, or in the microwave) and and so mash with a fork/masher into a puree. You can make them every bit luxurious as you want (e.thou. by adding butter).

Utilise mealy potatoes for mashed potatoes, these fall apart more smoothly!

Transformations

The heat disintegrates the cell walls, loosening the cells from one another, making information technology easy to mash.

No crunch hither, you don't want to dry out your mash. Total of smoothness, thanks to the tater starch!

Submerge in oil

How?

Submerge in hot oil until cooked through, crunchy, and slightly brown. Tin can involve just 1 frying stride, or several (e.g. start at 160°C, then at 180°C). Tin can also be combined with pre-cooking in the microwave or boiling water. Best washed with pre-cut/sliced potatoes

Read all about this method for making French fries here.

Transformations

Oil is hot enough for the Maillard reaction to accept place and for the potatoes to dark-brown (slightly).

The oestrus and speed give a practiced contrast betwixt crunchy & moist.

Fry in some oil

How?

Use a flat pan with only a little hot oil and fry your potatoes in the thin layer of oil. It will take longer than fully submerging them and it's best combined with a pre-cooking method (east.g. using the microwave). Best done for potato pieces (not whole potatoes, unless they're small ones!).

Transformations

Oil is hot enough for the Maillard reaction to take place and for the potatoes to brown nicely.

Can make a nice crunchy outside with a moist inside.

Broil a whole white potato

How?

Place a whole potato in a hot oven or barbecue (wrap in aluminum foil to continue heat within). Information technology takes time for the whole potato to become hot. The foil helps to keep the rut and moisture in so the outside doesn't dry out out before the inside is fully cooked.

Transformations

In one case y'all've opened the foil and leave the tater to bake a trivial longer it can plow crispy on the outside!

Sources

D. Kumar, An overview of the factors affecting saccharide content of potatoes, 2004, Ann. Appl. Biological science, 145:247-256

N. van Marle, Characterization of changes in potato tissue during cooking in relation to texture development, 1997, ISBN: ninety-5485-661-0, link

McComber, Diane R.; Horner, Harry T.; Chamberlin, Marker A.; and Cox, David F., "Potato Cultivar Differences Associated with Mealiness" (1994).Botany Publication and Papers. 55. http://lib.physicianiastate.edu/bot_pubs/55

Jaspreet Singh, Lovedeep Kaur, Advances in Potato Chemistry and Engineering, 2016, Bookish Press, Chapter 2,3 & fourteen, link

5.A. Vaclavik, Essentials of food science, 2008, tertiary edition, Affiliate 4 Starches in Food link

Source: https://foodcrumbles.com/science-of-cooking-potatoes/

Posted by: MillerConfled.blogspot.com

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