Why Are the Oils Liquid and the Fats Solid?

Oils and fats

Oils are liquid if they melt below ambient temperatures, and fats are solid if they do not melt at ambient temperatures.  At the usual room temperatures in the United States, lamb tallow is one of the hardest fats, butter is a soft fat, chicken fat is almost liquid, lard can be a hard fat or a soft fat depending on what kind of a diet the animals ate, palm oil is a soft fat, and olive oil is a liquid. Canola, corn, cottonseed, peanut, safflower, soybean, or sunflower oils are very liquid and they have not been partially hydrogenated. Thus the natural fats range from very hard fats to very soft fats to viscous oils to liquid oils.

Whether these food lipids are called fats or oils sometimes depends on the ambient temperature where they originate. Palm Oil and Olive Oil are fruit oils, and Coconut Oil is from a fruit, which is also a seed; they are liquids at the ambient temperature where they are produced. Palm kernel oil is a seed oil that is liquid in the tropics. Some of the oils like olive oil are very solid when they are stored in the refrigerator. Some like palm oil are separated into several semi-solid forms for use in foods. Figure 1.4 shows what these fats and oils look like at different temperatures.

Figure 1.4:Melting Characteristics of Oil

The practice of calling animal fats “saturated” is not only misleading, it is just plain wrong. For example, beef fat is 54 percent unsaturated, lard is 60 percent unsaturated, and chicken fat is about 70 percent unsaturated. This makes these animal fats “less than half” saturated. Therefore, they really should be called unsaturated fats. In fact, none of the naturally occurring fats and oils is made up of only all saturated or all unsaturated fatty acids; rather they are mixtures of different amounts of various fatty acids.

SOURCE:  Know Your Fats : The Complete Primer for Understanding the Nutrition of Fats, Oils and Cholesterol; Mary G. Enig, PhD

The Five Major Taste of Food

Taste of Food

The taste of a food is a combination of five major tastes—salt, sweet, sour, bitter, and umami. It is complex and hard to describe completely. Sweet and salt tastes are detected primarily on the tip of the tongue, and so they are detected quickly, whereas bitter tastes are detected mainly by taste buds at the back of the tongue. It takes longer to perceive a bitter taste and it lingers in the mouth; thus, bitter foods are often described as having an aftertaste. Sour tastes are mainly detected by the taste buds along the side of the tongue.

Sugars, alcohols, aldehydes, and certain amino acids taste sweet to varying degrees. Acids (such as vinegar, lemon juice, and the many organic acids present in fruits) contribute the sour taste, saltiness is due to salts, including sodium chloride, and bitter tastes are due to alkaloids such as caffeine, theobromine, quinine, and other bitter compounds.

Umami is a taste that recently has been added to the other four. It is a savory taste given by ingredients such as monosodium glutamate (MSG) and other flavor enhancers. The umami taste is significant in Japanese foods and in snack foods such as taco-flavored chips.

- “The beasts have memory, judgment and all the faculties and passions of our mind, in a certain degree; but no beast is a cook.”

This quip by the eighteenth-century Scottish biographer James Boswell defines the essence of humanity in a way his contemporaries would have found humorous but also thought provoking. It is neither an immortal soul, reason, nor powers of abstraction that separate us from animals but the simple ability to use fire to transform our daily fare into something more palatable and nutritious.

THE ORIGINS OF COOKING

ancient cookery

We are nothing more than cooking animals. Archaeological evidence bears this out; it is our distant Neanderthal relatives, whose sites offer the earliest incontrovertible evidence of cooking. From those distant times down to the present, the food we eat and how it is prepared has become the decisive factor in the survival of both individuals and whole civilizations, so what better way to approach the subject of history than through the bubbling cauldron?

Growing and preparing food has also been the occupation of the vast majority of men and women who ever lived. To understand ourselves, we should naturally begin with the food that constitutes the fabric of our existence. Yet every culture arrives at different solutions, uses different crops and cooking methods, and invents what amount to unique cuisines. These are to some extent predetermined by geography, technology, and a certain amount of luck. Nonetheless every cuisine is a practical and artistic expression of the culture that created it. It embodies the values and aspirations of each society, its world outlook as well as its history.

Cooking is full of questions that science can help answer — questions you might not have even thought about asking but that can make you a better cook.

When two not-so-friendly-with-each-other liquid joins together

when eggs become mayonnaise

In the simplest terms, an emulsion is a stable mixture of two liquids—such as oil and water—that normally separate from each other. Emulsions can be temporary (measured in seconds or minutes), semi permanent (hours), or relatively permanent (days, months, and sometimes years).

Mayonnaise is the best known and most widely consumed emulsified sauce. Basically, it is an emulsion comprising oil, egg yolks, and either lemon juice or vinegar. Related sauces include chantilly (mayonnaise mixed with whipped cream), gribiche (a piquant mayonnaise made with hard-boiled yolks), and rémoulade (mayonnaise plus chopped pickles, mustard, and other flavoring agents).

Hollandaise is the most celebrated emulsified sauce. It is an emulsion consisting of butter, egg yolks, and lemon juice combined with a little water, salt, and cayenne pepper.  Well-known derivatives include béarnaise (hollandaise enlivened with shallots, tarragon, and vinegar),choron (flavored with tomato), maltese (infused with orange), and mousseline (combined with whipped cream). Other world-renowned emulsified sauces include beurre blanc and sabayon (zabaglione).

Sauces are not the only emulsions. Whole milk, for example, is one, too. If milk fresh from the cow is left to stand, the emulsion breaks down and the cream (butterfat) rises to the top. Homogenization, a process that creates a relatively stable emulsion, prevents this separation.