Sensory Activation in the Eating Experience
Why do people choose to eat certain foods over others, even when they know the food might be unhealthy? What are the product attributes that make Oreos and Doritos cash-generating machines, year after year? The harsh but simple truth is that the biochemical mechanisms which drive food choices are not widely understood by the companies that manufacture, market and sell food. Flavor is only a small part of what could be called the “Cravability Product Design Theory;” overall, these techniques are not intuitive. This speaks directly as to why there are a relatively small number of food products, amongst a universe of thousands, which are truly cravable; in marketing vernacular--cash cows.
There are several parts to the application of the theory. A mastery of each technique is required to holistically define and engineer product attributes that manifest truly competitive points of difference.
The secret of food selection is complex and is not typically taught in food science programs. Many food companies, both manufacturers and foodservice companies, lack a fundamental understanding of the way the experience of eating unfolds. They fail to grasp the power of techno-emotional product design. A great food product developer understands how to craft all these parts together into a whole that is greater than the sum of its parts.
A critical precept to understanding the key drivers of food choice and intake principles lies in a simple fact: the relentless role of genetics directs people to respond to food pleasure. What stands as a formidable barrier to this concept is the myth of intelligence. That is, people are commonly taught their choices are logically and systematically processed, analyzed and selected by the conscious brain. But, humans are pleasure-seeking creatures. The truth is that food choices are mainly neurological responses to activate the subconscious pleasure centers of the brain. Certain food attributes trigger extremely strong biochemical responses. Typically, humans seek to activate those pleasure centers as frequently as possible, often subjugating more rational choices.
The Experience of Eating
There is a defined and observable sequence of events when eating a food. Some sequence steps are learned, but become habituated behavior over time; they are so automatic, one is not aware they are taking place. When evaluating the experience of eating a food, it is essential to understand the sequence of events that occurs in the analytical centers of the brain. Only then can the potential of a food or beverage’s design be maximized.
Appearance.First, people eat with their eyes. Chefs, among others, have espoused this mantra for many years. The presentation elements of color, size, proportion and visual intrigue are basic for culinary success. When a food is placed in front of a person, the eyes immediately begin an evaluation process. Is the food familiar? Is it the right color; the right shape? Has it been eaten before—most importantly, do we trust it? As with several steps in this sequence, primary visual analysis is a genetic trait that ensured survival in man’s early years, when the food supply was always changing, always suspect. Certainly, the cranial database of food is learned, but there is evidence that visual analysis, as the first step in the eating experience, is universal among geography and culture. When there is a food choice, the brain, through the eyes, calculates how much pleasure will be generated during the eating and digestion of any food. It then immediately assigns a “cravability factor” to the food.
Expectations.If the visual observation of the food is congruent with a positive memory, one will jump to the next step; but, if it is unfamiliar or does not (in every way) match up with the memory, one proceeds with caution. This is a learned behavior that serves as an important defense mechanism. A good product developer knows the “right” color is a critical first step in trial and acceptance. From their perspective, if a food product can meet the expectations formed by this point, the experience is usually positive and satisfying. Any food or beverage delivering to, or preferably surpassing, the expectations will normally be successful, by any metric. These first two steps gain “trial.” Great execution of the remaining steps is awarded with repeat purchase and customer loyalty (a form of cravability).
Temperature.Another important defense mechanism, the lips are an incredibly sensitive thermometer. Based on visual observation, the brain calculates an expectation of the temperature of the incoming food. If the lips sense a disconnect, a danger signal is sent to the motor mechanisms. Sometimes, a food may not have a dangerous temperature, but, once it gets in the mouth, if it is different than the expectation predicted, it is generally perceived as unpleasant. In culinary school, this dictum is taught: “cold food cold, hot food hot.” A warm beer or lukewarm pizza, or anything lukewarm for that matter, is often a disappointing experience. It may be that, inherently, the brain knows a food should be definitively hot or cold; any food in between resides in the food-safety “danger zone.” Thus, it may be pathogenically harmful.
Texture.Once the food product enters the oral cavity, the tongue and trigeminal nerves begin to evaluate the texture. It is here that mediocre food design often falls short. The brain loves textural contrast. Great food and beverage design results in a “tactile symphony.” Inter-oral variety, over the course of an eating event, increases sensory arousal and pleasure. Name some of the world’s most popular foods, and generally, textural contrast will be found--such as pizza, which has a crunchy, chewy crust, combined with soft cheese. Chocolate enters the mouth hard, but it immediately begins to melt into luscious, decadent creaminess. Ice cream is first perceived to be semi-hard and cold, but immediately warms and surrenders its dairy fats and sugar to the senses. The sensory experience is further enhanced, when hot fudge and nuts are added to the ice cream. The pleasure centers of the brain light up, opiate-like neuro-compounds are released, and life is very good for a while.
Aromas.Some are “programmed,” essential survival indicators of the environment-- detecting food and danger. Smoke is a great example. Smoke from the BBQ is pleasing and triggers a salivation response; whereas, the smoke of a forest fire is not at all pleasant and normally triggers a flight response. Aroma detection and perception guide humans to nutrients, such as vitamins, minerals and fatty acids. While these aromas are programmed, most aromas are learned over time and through experience. They acquire significance through food ingestion and are important in the formation of food memory. Fat and sugar best form memories! If one reflects on their own best food memories, this statement will likely be validated. Aroma preferences, once formed, are resistant to extinction. A little-appreciated element of great food and beverage design seeks to incorporate aromas targeted to elicit a positive food memory.
Recently, the author has done research on incorporating aromatic compounds into packaging materials that are activated and released upon heating. The concept seeks to create an emotional bond with the consumer; great aroma rarely disappoints. This effectively moves aroma to the very front of the event sequence, ahead of visual. And, since aroma rarely disappoints the expectation, trust factor is immediately established. Many food products face the commodity challenges of price and function. One way to overcome this is connecting with the customer on an emotional level. Before Starbucks, coffee for many was a commodity. Now, Starbucks has helped coffee become an emotional experience.
Sensations.Chefs and food technologists often focus enormous resources on getting the flavor right. While flavor is important, there are many other sensory mechanisms that come into play, once a food enters the oral cavity and before flavor is even perceived by the brain. These mechanisms are not widely understood outside the community of sensory scientists, but offer an area of fertile development for the knowledgeable food designer.
Some have estimated only 4% of the cells in the gustatory cortex respond to taste. Of course, that begs the question:What are all the rest of the neurons responding to? The answer: orosenation. Orosensation is detected and evaluated by the trigeminal nerve system. It involves a variety of sensations, such as touch (tactile), temperature, pain and pressure. In school, children are taught that humans have five senses. That is not quite the whole story. In the mouth alone, there are more than 20 different senses. Osmolality receptors detect solute concentrations; other receptors evaluate stretch (think caramel); there are senses that calculate position and orientation (critical to avoid choking); and, other receptors are triggered by MSG, hot peppers, vanilloid compounds, and heat and cold. The intentional design of food that activates several of these senses is far more interesting to the brain.
Taste.Finally, not until all the previous evaluation steps have been completed and approved, does the brain focus on flavor—or more accurately, taste. Flavor is a contributor to taste, but it is only a piece. There are several classifications of taste, including:
- Sensients are chemical activators of physical sensations in the mouth. Some examples are astringent, alcohol, electric and alkaline. Szechuan buttons (not to be confused with Szechuan peppers) are an interesting, if unusual, illustration of electric. They cause mild electric “jolts,” as they are being chewed. In small amounts, they can provide a new and exhilarating eating experience.
- Water has its own taste.
- Aversive: bitter and sour--another defense mechanism signaling the content of potentially harmful toxins.
- Energy: fatty acid taste--a powerful predictor of cravability. Potato chips, French fries, fried chicken or bacon are all some of the world’s favorite foods.
- Hedonic: these are powerful pleasure triggers that are most often associated with fat and sugar, but also from certain amino acid complexes that signal the presence of essential-for-survival protein. One reference for these types of amino acids is glutamates. Glutamates define umami. Salt and glutamates in combination yield powerful hedonics. Remember the Doritos example? They are loaded with both. Glutamates can be concentrated and enhanced in foods that are aged, dried, cured, fermented, roasted and toasted. Parmesan, soy sauce, fish sauce, MSG, oyster sauce, cured ham and bacon are foods illustrative of this. Their widespread popularity is no accident.
The powerful synergy of salt and glutamates becomes problematic, when attempting to reduce sodium, a subject of great attention these days. When it comes to enhancing flavor to overcome the lack of salty taste, adding umami impact can often provide sensory satisfaction contributing a generic savory character. Ingredients to accomplish this include monosodium glutamate (MSG), autolyzed yeast extracts, hydrolyzed vegetable protein and soy sauce. While MSG contains 13% sodium, table salt is 40%, so it can be helpful in reduced sodium applications where its high level of flavor impact makes it possible to get “more bang for the buck.”
For more information on this topic, type “taste perception” or “sensory testing” into the search field at PreparedFoods.com.