Fruits are very important foods in the human diet since they play a fundamental role in nutrition due to their contribution of vitamins, minerals, antioxidants, fiber, and monosaccharides such as fructose, among other nutrients, so their frequent consumption and in recommended portions can be beneficial to health.
The wide spectrum of flavors, aromas, colors, textures, and shapes make them attractive to consumers of all ages and tastes; there are acidic, sweet, sour, bittersweet and, normally, depending on the area or region where we live, we have greater access to some than others.
In tropical climates we can find papaya, banana, coconut, mango, and pineapple, to mention a few. Pineapple is characterized by its sweet, sour taste and the itching sensation (or, as it is commonly known, "scalding") that it produces on the tongue when consumed fresh. You may wonder what is the reason for this effect?
Pineapple contains significant amounts of a proteolytic enzyme called bromelain, which is responsible for producing the scalding effect on our tongue. This is because in the saliva of our mouth there are proteins (recognized as responsible for the maintenance and protection of the mouth, as well as helping to digest food), which are hydrolyzed or "decomposed" when interacting with bromelain, generating the "scalding" sensation. In addition, the tongue is sensitized, and, due to the high acidity of pineapple, a more intense "burning or stinging" sensation is perceived.
Bromelain, besides helping to digest food, has been shown to have beneficial health effects, such as its antioxidant function, protecting cells from oxidative stress and free radicals. It also has anti-cancer potential (against a wide range of cancers such as breast, colon, stomach, rectal, pancreatic, skin, liver, etc.) and has anti-inflammatory, anti-microbial, immunomodulatory, and anti-ulcerative effects, among others, so that its consumption of adequate doses could have such health effects.
Likewise, the use of this enzyme in the industrial sector is wide; for example, it can be used for the treatment of food samples for amino acid analysis, as an additive for cattle feed, food supplements, production of bioactive peptides, softening of meat products, detergent additive, and cosmetic preparations.
Not only does pineapple contain this type of protease, but also kiwifruit and papaya; within their composition, actinidin and papain stand out, respectively. Proteolytic activity has also been demonstrated in figs; however, due to their high sugar content, we may not perceive the chemical interactions in our mouths. Eating is a sensory experience full of different flavors and it is interesting to understand why we perceive certain sensations when consuming different foods and beverages.
Authors: Luis Alfonso Jiménez Ortega (student of the Master of Science program) and José Basilio Heredia (research professor) of the Regional Coordination of CIAD Culiacán.