In the Garden: Tart and Sour Foods Pack a Potent Punch
Learn about what it is that makes an apple a day keep the doctor away, such as polyphenols and their protective properties against chronic diseases.
I have always preferred savory over sweet. Is this a genetic predisposition or some sort of learned behavior? Maybe a little bit of both, as it turns out.
I am likely what is termed an average taster or non-taster (which almost seems like an insult for someone who thinks so highly of food). I am the opposite of the super-tasters, who tend toward being picky eaters because they have more “taste buds” on the tongue. Super-tasters have a heightened sense of taste when it comes to sweet, salty, sour, bitter, umami and fat. This hypersensitivity makes it hard to like bitter and tart.
“The ability to sense each of these tastes is believed to have evolved to improve the chances of survival for our earliest ancestors,” Guy Crosby, PhD, of CookingScienceGuy.com, explains in a scientific review that explores the connection between taste and smell. “The sweet taste of fruit indicates a source of sugars for energy. Umami is believed to have evolved as a means to detect protein and essential amino acids. Salt is required for regulating the level of bodily fluids. Sour indicates the presence of spoiled food, as we might find in old milk. Many toxic compounds found in plants produce a very bitter taste. And fat is another important source of energy as well as essential fatty acids. Our sense of taste evolved to detect non-volatile molecules that we cannot smell.”
I am not a picky eater (as long as it is real food). I love bitter and tart—we have been raising our own fruit since I was a child and I think being around ripening fruit taught me to appreciate tart. I realized quite early on that fruit is not necessarily sweet in that sugary sort of way. Blueberries, blackberries and apples are best with a little bit of tartness. Tartness, to me, represents tannin, antioxidants, pectin and polyphenols: These are all buzzwords in health circles, yet commerce is trying to sweeten these fruits up, either in flavor or messaging.
Take, for example, the apple. The old varieties that ripen in our orchard turn brown quickly after we slice them. I am delighted, because browning is simply a reaction between enzymes in the fruit and oxygen. The more browning, the more polyphenol oxidase. The more polyphenol oxidase, the better. Plant polyphenols have protective properties against chronic diseases and plant polyphenols as a group contribute to bitterness, astringency, color, flavor, odor and oxidative stability (meaning browning).
So far science has identified more than 8,000 different polyphenols in plants. Some of the classifications might sound familiar: phenolic acid, which gives onions the ability to last in the pantry for months; flavonoids, which represent color like the anthocyanins in blueberries; stilbenes, which account for the resveratrol in red grapes and red wine; and lignans, a phytoestrogen found in legumes, seeds and nuts.
It is estimated that the average adult consumes 30 teaspoons of sugar each day, although the recommendation is just six. So, the question becomes: Should we train ourselves to tone down our pursuit of sweetness and refine our palates to appreciate tart and all of its associated antioxidant benefits? Probably so.
Let’s go back to the apple. Malic acid makes fruit tart tasting and it also helps our bodies to produce energy. The sweeter the fruit, the less malic acid. Pectin is the soluble fiber; generally the more pectin a fruit has the tarter it will be. This soluble fiber is one of the reasons we are encouraged to eat fruit (and it is one of the reasons it is better to eat whole fruit than a smoothie that has blended the soluble fiber to bits).
New varieties of apples have been developed that do not brown after being sliced. This, quite frankly, annoys me. We are effectively making healthy food less healthy in pursuit of aesthetics. Let’s instead applaud the browning apple because it tastes a little tart as it delivers some fantastic nutrients in its own edible wrapper.
-An apple a day keeps the doctor away” was an early-20th-century slogan developed by cider apple growers fearing that the temperance movement would adversely impact apple sales.
-The tart peel of citrus fruits is loaded with polyphenols, so consider zesting lemon, lime and grapefruit into recipes.
-Different polyphenols are absorbed by the body in different parts of our digestive tracts, and their bioavailability depends on healthy gut microbiota.
For a more comprehensive reading on the subject of polyphenols read the 2016 scientific review in the online journal Nutrients: “The Reciprocal Interactions between Polyphenols and Gut Microbiota and Effects on Bioaccessibility” by Tugba Ozdal , David A. Sela , Jianbo Xiao, Dilek Boyacioglu, Fang Chen and Esra Capanoglu. MDPI.com/2072-6643/8/2/78
Illustration: Amanda Almira Newton, 1906. U.S. Department of Agriculture Pomological Watercolor Collection. Rare and Special Collections, National Agricultural Library, Beltsville, MD 20705