Module 9 

Methods of Cooking

  9.01: 
Module
Summary
  9.02: 
Module Objectives

9.03: How to Make Meringue

An almost real-time look at the stages of whipping egg whites and making meringue. From egg whites, froth and foam, to creamy meringue.

9.04: Gastrophysics

From a purely physical point of view, foods need to be treated as a multi-scale system. This becomes obvious from the sensory qualities of the food felt while we are eating. By biting, chewing and swallowing, foods are destroyed by the teeth, aroma gets released, taste becomes released, broken food pieces are wetted by the salvia and are transformed to a partially liquid bolus that can be swallowed with pleasure. By translating these processes into physical ideas, the relations to materials sciences become visible. The texture of the food is defined by its physical structure including the swelling and lubrication agents, water and oil. The rupture and breakdown of the structure determine, together with the water content and oil concentration, the aroma and taste release. The temperature of the food yields the perception intensity of the culinary sensation. Finally, size, surface states, wettability, and composition of the damaged food in the mouth determine volume and viscosity of the bolus, as well as the satiation.

The unconscious way of eating involves more than is visible on a macroscopic scale. Of course, its macroscopic shapes and its surfaces determine the first impression when the food is taken into the mouth, but only a number of non-visible processes lead the overall pleasure and the flavor of the foods. Figure 1 illustrates the hierarchy involved during  the process of eating. At the lowest level, some of the macroscopic properties are listed. They concern surface properties, such as roughness, properties like hardness or softness of the state of the food (i.e. the foaminess or creaminess of meringue).

 

The next level in Figure 1 shows another form of the complexity -- most foods are composite and structured materials that contain more than one aggregate state of the matter. Gases inside bubbles form with liquids or solids inside the boundaries foams. ‘Solid’ chocolate consists of solid spherical crystals with liquid cores of fatty acids of higher unsaturation degree.


 

Both the water and fat content of the foods determine the solution properties of aroma and taste-relevant compounds and ions, exploit spreading on the tongue and stimulate taste buds and trigeminal channels. At the highest level and smallest scales in the scheme shown in Figure 1, aroma release takes place. Characteristically shaped volatile aroma compounds are detected by its receptors in the olfactory bulb.
 

‘Eating with pleasure’ involves thus the entire length scales ranging from macroscopic dimensions down to molecular scales almost simultaneously. Consequently, gastrophysics similarly involves many time scales, which are not independent and cannot be clearly separated from each other, since at the perception level all length and times matter - unlike in food processing where time and lengths scales can be selected to design certain properties of foods.

Figure 1: The hierarchy in length scales and of the different sensory sensations.

9.05:Molecular Hierarchies

From the physicist’s point of view, foods are hierarchical complex systems where structure and texture can be related to structural polymers, such as proteins and carbohydrates with different solvability. Figure 2 shows the basic building blocks of all foods. Every food consists of proteins, carbohydrates, oil, and water. Proteins and carbohydrates form the basic structure. The two contrary solvents water and fat (oil) determine their self-organization in the foods.

 

Carbohydrates are mainly water soluble, proteins, which consist of hydrophilic and hydrophobic amino acids, accept partially water and oil as solvent, depending on their function and their primary structure, that is, the arrangement of the amino acids along the backbone of the protein chain contour.

 

There are five basic tastes which include the following: sweet, sour, salty, bitter and umami. These foods govern a number of small molecular compounds, which are in most cases water soluble. All sugars and sweeteners are ions or dipolar molecules, salts dissociate in their ions. The acid taste is related to proton activity and umami to a number of water-soluble molecules, the most well-known glutamic acid. Moreover, the ions and the overall ionic strength (salt content) in foods have some implication for the structure and texture of the foods. Monovalent ions contribute to the screening of electrostatic interactions. Bivalent ions can, under certain circumstances, provoke liquid-to-solid phase transitions like calcium or magnesium ions in certain alginates.

Aroma compounds are, in contrast, weakly water soluble but dissolve strongly in a fatty environment. Indeed, their odor activity is more or less determined by the volatility (a thermodynamic property defined by the corresponding vapour pressure) and the odor threshold (a physiological-chemical property). Both quantities can be easily measured in defined solvents at a certain temperature. Nevertheless, odor impressions turn out to be more complicated in real foods; many proteins in food have special (hydrophobic) binding sites for aroma compounds that define a ‘local’ vapor pressure. Thus the same aroma compound will appear with different odor activity values in different foods.

Figure 2: Classification of Food Constituents

Spices

When selecting spices, it is a good idea to keep in mind quantities. Buy smaller quantities and more often. Spices are sensitive to light and air as it will affect their flavor, so it is important to keep them dry and sealed in individual containers to preserve their freshness. 

Additionally, when selecting spices for your kitchen, start with the basics. You can always add to your collection once you start experimenting.

Pantry Essentials

  • Black Pepper

  • Sea Salt

  • Paprika

  • Nutmeg

  • Red Chili Flakes

  • Cumin

  • Coriander

Vinegars

Sweet, sour, and packed with umami: vinegar is an indispensable ingredient in any chef’s pantry. 

Vinegar is a condiment derived from a second bacterial fermentation of alcohol or other raw ingredient containing sugar, like wine, beer, or rice.

This fermentation produces an acetic acid that lends vinegar its tangy taste. The word comes from “sour wine” in French: vinaigre: vin (wine) and aigre (sour).

Pantry Essentials

  • Rice Vinegar

  • White Vinegar

  • Apple Cider Vinegar

  • Balsamic Vinegar

A stroll through the cooking oils section of the grocery store offers many options—olive, coconut, corn, hemp, to name a few—and all have roughly 120 calories and 14 grams of fat per tablespoon.

The proportion of the different types of fats that make up these oils—monounsaturated, polyunsaturated, and saturated—is what matters, and that can vary dramatically from oil to oil. 

However, the type of cooking you are planning is a concern, too. High-heat cooking requires an oil with a high smoke point (the temperature at which the oil begins to burn). Additionally, for some dishes you want a neutral or mild flavor, while others call for a specific taste. 

Pantry Essentials

  • Extra Virgin Olive Oil

  • Canola Oil

  • Coconut Oil

  • Ghee

Oils

9.06: Review/Critical Thinking

Please complete the following questions. It is important that you use full sentences and present the questions and answers when you submit your work.

 

Go to the Assessment area in the course to complete the assignment Review and Critical Thinking and submit the work as a file attachment.

 

The answers to the Review and Critical Thinking Questions are worth 10 points.

9.07: Cooking Assignment #9

This is your opportunity to bake ANYTHING that includes meringue. You can choose Pavlova, Baked Alaska, lemon meringue pie, banana pudding, meringue cookies, etc. It is entirely up to you. Just be sure to take pictures of your process and the final product!

*Remember, there are vegan meringue versions of most everything.

Here is some inspiration to get your creative juices flowing:

1- Mad for Meringue

2- 22 Heavenly Meringue Desserts

Chef's Choice

9.08: Module 9 Quiz

Before you take the quiz for this unit take a moment to review what you have learned.

Before you take the quiz for this unit take a moment to review what you have learned.

When you feel that you are ready to complete the Module 9 Quiz, Methods of Cooking, click HERE.

The Lost Art of Meringue