Tuesday 27 April 2021

Cooking denatures protein - Lower heat sources bring up the temperature of the meat more uniformly than hotter heat sources

Lower heat sources bring up the temperature of the meat more uniformly than hotter heat sources.

Getting the center cooked while not overcooking the outside—has to do with the rate at which heat energy is transferred to the core of a food. Since cooking applies heat to foods from the outside in, the outer portions will warm up faster, and because we want to make sure the entire food is at least above a minimum temperature, the outside will technically be overcooked by the time the center gets there. This difference in temperature from the center to outer edges of the food is referred to as a temperature gradient.

All parts of our example steak are not going to to reach temperature simultaneously. Because grill environments are hotter than ovens, the temperature delta between the environment and the food is larger, so foods cooked on the grill will heat up more quickly and have a steeper temperature gradient.

Carryover

Carryover in cooking refers to the phenomenon of continued cooking once the food is removed from the source of heat. While this seems to violate a whole bunch of laws of thermodynamics, it’s actually straightforward: the outer portion of the just-cooked food is hotter than the center portion, so the outer portion will transfer some of its heat into the center. You can think of it like pouring hot fudge sauce on top of ice cream: even though there’s no external heat being added to the system, the ice cream melts because the hot fudge raises its temperature.

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Lower heat sources bring up the temperature of the meat more uniformly than hotter heat sources.

https://www.oreilly.com/library/view/cooking-for-geeks/9781449389543/ch04.html


In summary, nutritional value of legumes, meats, fish, grains/cereals, and vegetables [with oil] is improved by slow cooking. 

Many books have been written on this topic. In the popular press a good and recent example is 'Cooked' by Michael Pollan. Cooking, or food preparation using heat, is considered by anthropologists to be a positive influence in human evolution. Nutritionally, cooking techniques are very different. While some nutrients are heat sensitive, particularly those in fruit, slow cooking at low heat improves bioavailability of various essential nutrients, e.g. preformed vitamin A from meat, and beneficial phytochemicals, e.g. carotenoids from vegetables and leafy greens, particularly in the presence of fat or oil, such as olive oil.

Furthermore, as mentioned in Munira Husain's excellent response to your comment and query 'Cooking is required not only for destroying microorganisms, but it also denatures many natural toxicants, enzymes, facilitates chemical reactions and enhances food palatability - taste, texture, flavor, digestibility and assimilation, which are most vital for proper nutrition.'

However, some domestic cooking techniques - browning, smoking and charring - create undesirable by-products, such as advanced glycation products. Many industrial cooking techniques have created foods with high concentrations of undesirable products, such as trans-fats and high-fructose corn syrup.

In summary, nutritional value of legumes, meats, fish, grains/cereals, and vegetables [with oil] is improved by slow cooking. By contrast, nutritional value of most fruits is not improved by cooking. One cuisine that embodies these cooking concepts is the traditional Greek Mediterranean diet, as explained in the recent book 'The Mediterranean Diet' by Catherine Itsiopoulos.


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7th Nov, 2013
Aman Paul
Protix, Netherlands
The best thing is to classify foods into 3 categories:
1. Foods in which cooking destroys important nutrients (fruits, non starchy vegetables, etc)
2. Foods in which cooking destroys some of important nutrients (starchy vegetable, milk, meat, etc)
3. Foods in which cooking has no effect on nutrients (most of the cereals)
So we start from the third category, we can see that there is almost no effect of cooking on nutrients so we dont need to tailor new methods. For the second category we need to optimize existing methods or develop new methods to prevent nutrient spoilage. For the first category its always better to go for minimal processing.
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13th Nov, 2013
slow cooking at low heat improves bioavailability of various essential nutrients

Laima Brazionis
University of Melbourne
Many books have been written on this topic. In the popular press a good and recent example is 'Cooked' by Michael Pollan. Cooking, or food preparation using heat, is considered by anthropologists to be a positive influence in human evolution. Nutritionally, cooking techniques are very different. While some nutrients are heat sensitive, particularly those in fruit, slow cooking at low heat improves bioavailability of various essential nutrients, e.g. preformed vitamin A from meat, and beneficial phytochemicals, e.g. carotenoids from vegetables and leafy greens, particularly in the presence of fat or oil, such as olive oil.
Furthermore, as mentioned in Munira Husain's excellent response to your comment and query 'Cooking is required not only for destroying microorganisms, but it also denatures many natural toxicants, enzymes, facilitates chemical reactions and enhances food palatability - taste, texture, flavor, digestibility and assimilation, which are most vital for proper nutrition.'
However, some domestic cooking techniques - browning, smoking and charring - create undesirable by-products, such as advanced glycation products. Many industrial cooking techniques have created foods with high concentrations of undesirable products, such as trans-fats and high-fructose corn syrup.
In summary, nutritional value of legumes, meats, fish, grains/cereals, and vegetables [with oil] is improved by slow cooking. By contrast, nutritional value of most fruits is not improved by cooking. One cuisine that embodies these cooking concepts is the traditional Greek Mediterranean diet, as explained in the recent book 'The Mediterranean Diet' by Catherine Itsiopoulos.

https://www.researchgate.net/post/Food-cooking-degrades-around-30-40-of-nutrition-So-what-is-the-way-to-preserve-the-nutrition-of-food

chicken can cook as quickly as 10 minutes (skinless chicken breasts) to as much as 30 minutes (mixed chicken parts, specially from a large chicken).

Contrary to what you may think, chicken takes the same amount of time to cook, whether the cook is Indian or European or Chinese. Or which country the kitchen is located in.

The two major variables in cooking time are which part of the chicken you're cooking, and the age of the bird.

Chickens get tougher as they age. If you live in a western country, your chicken probably comes from a factory farm and the age of slaughter is standardized and uniform. The meat will usually be tender and will cook fast, unless you buy an atypically large bird instead of the standard broiler. In Asian countries, chickens may be less standardized and more variable. You can tell if a bird is older by looking at the raw meat, which will be tougher and stringier.

The part of the chicken matters. Chicken breasts are usually more tender because chickens don't fly much and those muscles don't see hard exercise. Chicken legs and drumsticks are harder working muscles and take longer to cook.

Skin-on chicken will take longer to cook than skinless chicken because skin is an insulator and delays heat from entering. Conversely, bone-in chicken cooks faster because bone is a conductor and helps heat penetrate.

Generally, these differences are minor and people account for them by slight overcooking.

One difference in Indian recipes is that they often deliberately overcook the chicken. Overcooking dissolves connective tissue, separating muscle fibers and allowing the spicy gravy to soak in and flavor the meat. Western cooks have more of a fetish for cooked "just right". One reason why Indians care less about this is because the majority of recipes stew the chicken in liquid, so overcooking won't dry the meat and make it less juicy. If you're baking or dry roasting, you should care more about not overcooking.

In my kitchen, chicken can cook as quickly as 10 minutes (skinless chicken breasts) to as much as 30 minutes (mixed chicken parts, specially from a large chicken). This is stewing time only, I am not counting time used in roasting the meat with the masala and bringing the liquid to a boil. Make sure the pot is covered with a tight-fitting lid and the stove maintains a proper simmer throughout.

Dry cooking always takes longer than moist cooking. In a 350 F oven, it takes at least 25 minutes even for a single layer of drumsticks. A whole chicken roast can easily take an hour.

Deep frying is fastest, and can take as little as 5 minutes for chicken parts. Whole chicken may take 10-15 minutes.

Because of these variables, nobody can give you an exact time accurate to the minute. The best advice is to be consistent - use the same pot, lid, stove, heat setting, so you can learn how your equipment works. And always check for doneness beginning 5-10 minutes before you think it'll be ready, so you can turn off the heat at the right time.

Signs of doneness include:

  • the chicken will no longer have any hint of pinkness, it'll be dark brown

  • If you slide a knife tip into some thick meaty part, it will slide in easily without meeting resistance

  • but the chicken pieces will still be intact and not falling apart.

If all this is too much trouble, buy a meat thermometer with a long probe, stop cooking when the internal temperature reaches 160-165 F.


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don't boil chicken. For the sake of good tasting chicken, just roast it 


What r u doing, u don't boil chicken. For the sake of good tasting chicken, just roast it and it'll taste fine


I was going to say the same thing. Boiling a chicken is disgusting.



https://www.quora.com/How-long-does-chicken-need-to-be-boiled-to-be-cooked-all-the-way-through




Friday 16 April 2021

The Great Influenza - book - insights

 

just finished reading this book
Few insights
1918 influenza happened in 3 waves
Spring 1918 (March) - The first wave
Fall 1918 (October) - The second wave. The most lethal wave. By Nov 1918, the second wave was over.
Dec 1918 - The third wave. Third wave was lethal but not as much as second wave. Late December 1918, the influenza receded from around the world.
*
While the above 3 waves were most prominent. The influenza continues for the next two years sporadically.

Spring 1919 - in Feb 1919, influenza deaths in Paris were 2700 (half of peak of 4600 in Oct 1918 in Paris). In Feb, US President’s daughter caught influenza. In March 1919, another 1500 Parisians died.
April 1919 - US President Woodrow Wilson gets influenza. It affects his mind. It influences in how World War I treaty is negotiated and signed by him. Influenza usually affects brain quite adversely. This is the invisible havoc played by influenza.
Jan 1922 - quarantine in Washington state
In a city or town, the cycle from 1st case to end of local epidemic generally lasted from 1.5 months to 2 months.

In army camps, the men are packed so closely that it ran from 3 weeks to 1 month before it subsided.
People who were exposed to first wave usually developed immunity by second wave. Second wave usually affected second set of people. Gradually, the influenza mutated to become milder by each wave.
There are no reliable figures for total death rate. The range is from 2 crores to 5 crores to 10 crores. As per one estimate, death toll in Indian subcontinent alone may have been 2 crores.
In the US, 6.75 lakh people died out of 10.5 crore population in the US then.
It led to 0.65% deaths in US. In Italy, death rate was 1% of their population. Surprisingly, Italy had the highest death rate among developed nations even then like now.
The 1918 influenza mostly affected people less than 40 years age unlike the present one which affects mostly old people. Perhaps, in 1918, the old people may got some immunity because of the 1880-90 flu (my view). Perhaps, now old people are dying and young people have immunity because young people have been vaccinated by various vaccines like polio etc which may be proving some immunity. While the old people may not have had such vaccines.
In the afterword, the author mentions SARs was infinitely easier to control than influenza.
He further mentions that Manufacturing and distributing a vaccine would take months at best and ativiral drugs are not very effective.