Crispness is very important to the pleasure of substantial eating. It appears to hold a particular place in the basic psychology of appetite and hunger satiation, spurring one to consume.
The Sensory Texture Profile technique developed in the early sixties does not specifically mention the term crispness. The technique regarded crispness as part of the brittleness scale and defined crispness as the ease of force with which a food crumbles, cracks, and shatters.
Food scientists have proposed that crispness is primarily an acoustical sensation. The frequency spectra and the amplitude characteristics of sounds produced by biting crisp foods cover a wide range and show irregular variations loudness with time.
Creating and maintain the desirable crispy texture is a very complicated task. The formulation and use of appropriate functional ingredients are probably the most important factors for food crispness.
For example, the type of flour or the use of gums in extruded snacks, the use of emulsifiers or enzymes in baking, or adding different hydrocolloids to coatings for crusted products, as well as interactions between different ingredients, all play a role in the crispness creation of the final products.