Fruit peel or fruit skin is the outer protective covering of fruits. In general, the skin in some tough-layered fruits such as pomegranate, passion fruit, mangosteen, etc., is known as the rind while in citrus fruits such as in oranges, it is better termed as peel (zest). Apart from protecting the underlying edible portion of fruit from harsh environmental factors as well as micro and macro organisms, it indeed holds some of the vital health-benefiting constituents such as dietary fiber and phytonutrients that help fulfill overall wellness.
Photo courtesy: fdecomite
|Mango peel with a fruit peeler.
Photo courtesy: ms.Tea
Fruit peel is either firmly adherent to its underlying flesh as in berries, and apples or rather loosely as in oranges, bananas, etc. Its thickness varies widely, even in the same family fruits, ranging from paper-thin to very thick shell-like cover as in the mangosteen.
In some raw fruits, the peel has a neutral taste as in grapes and apples. However, in papaya and unripe sapodilla, it can be bitter and inedible because of the high tannin content. As the fruit ripens, the peel becomes easily separable from the pulp (bananas). In addition, its components turn sweeter and become pleasant-tasting as in sapodilla, guava, kiwifruit, and kumquat.
Fruit ripening is purely an enzymatic process, which brings certain characteristic changes to the fruit color, aroma, taste, maturity (hardening) of seeds, etc.
The peel in some fruits like guava is firmly cohesive to its pulp, and indeed, in some fruits, it turns tastier and nutritious than the flesh itself as the fruit ripens.
Fruit peel is very rich in essential oils that give a characteristic aroma to the fruit. The oil glands are spread all over the peel but denser near its pits. These oil glands have prominently developed in citrus fruits like lemons and oranges.
Most often, the fruit peel is discarded even when it is found safe for human consumption. Research studies suggest that the fruit peel holds many vital nutrients and non-starch compounds that play a vital role in health and wellness. Here are some salient points to highlight why the fruit skin is recognized as one of the essential components of our diet.
fruit peel of some of the common fruits like blueberries, grapes, guava, and kumquat carry higher concentration of anti-oxidants such as anthocyanin pigments, tannins, catechins…etc than in their flesh (pulp). Blue or purple color fruit peels are rich in anthocyanidin glycosides while yellow color fruits have xanthin, carotenes and lutein pigments. Major components of these pigments are present just underneath its outer layer of skin.
Peel is rich source of rough dietary fibers, also known as NSP (non-starch polysaccharides), such as hemi-cellulose, pectin, tannins, gum…etc. These compounds increase the bulk to the food, and help prevent constipation by reducing gastro-intestinal transit time. They further bind to the toxin chemicals in the food and protect their expose to gut mucus membrane and thereby offer protection from colon cancer risk. Furthermore, dietary fibers bind firmly to bile salts (produced from cholesterol) and eliminate them from the gut, thus in turn help lower serum LDL cholesterol levels.
Peel is low in calories, sugar, and fats; and is free from cholesterol. It adds bulk to the food and helps cut down overall calorie intake.
The fruit peel of some fruits, indeed, contains considerable amounts of mineral and vitamins, especially in guava and citrus category fruits.
For example, in the orange, the peel holds rather higher levels of vitamin C (ascorbic acid) than its juice. 100 g of fresh orange-peel provides 136 mg per 100 g of vitamin C while its flesh contains just about 71 mg/100 g. Please refer the nutrtion database chart below.
Likewise, fruit peel is a rich source of vitamin A, B-complex vitamins, minerals such as calcium, selenium, manganese, zinc...etc., several fold more than its pulp. Please read the orange peel USDA nutrition data table below, for example, and then compare it with nutrition facts table in orange fruit.
Recent scientific trial studies suggest that certain compounds in passion fruit peel has bronchodilator effect and can help relieve bronchospasm in asthma patients. A trial study conducted by Watson RR and his colleagues at Tuscon University AZ, suggests that oral administration of the purple passion fruit peel extract reduces wheeze and cough and improves shortness of breath in adults with asthma. (Related link-Pubmed.gov)
|Principle||Nutrient Value||Percentage of RDA|
|Total Fat||0.20 g||1%|
|Dietary Fiber||10.60 g||28%|
|Pantothenic acid||0.490 mg||10%|
|Vitamin C||136 mg||226%|
|Vitamin A||420 IU||14%|
|Vitamin E||0.25 mg||2%|
While it is advised to eat fruits along with its peel in some allowed fruits, however, some caution should be kept in mind while eating whole fruits.
1. Multiple insecticide sprays are commonly employed on fruit orchards. Certain amounts of this may enter and embed deep in their skin cells. So, wash fruits thoroughly before use. Organic-farmed fruits are, therefore, recommended for the safe use of their peel.
2. Oftentimes, insects lay their eggs/cysts on the fruit skin. Eating raw, unwashed fruits may pose health-risk because these egg/cysts may enter the brain, and cause a condition known as neuro-cysticercosis.
3. Too much fiber content in the peel may cause indigestion in some people, especially in children. (Medical disclaimer).
Before you decide to use fruits for peel preparation, it is advised to select fruits that are fresh, organic without surface cuts, blemishes, and bruises. Wash the fruit thoroughly in running water to remove surface dust, soil…etc. Place the fruit in a bowl of saltwater for about half an hour. Then wash them again in cold water. This way, you would be made sure any surface insect eggs/larvae are removed. Gently pat dry using a soft cloth.
To prepare: use the fruit peeler machine. In the case of citrus fruits, one may peel them very easily out of hand. Store dried zest/peel powder in a cool, dry place in an air-tight glass container away from moisture.
Here are some recipes of fruit peel you can enjoy while getting most of their health benefits.
|Orange peel candy with chocolate.
Phot courtesy: grongar
Fruit peel, especially of citrus fruits, can be candied.
Citrus fruit zest is added to flavor confectionary.
Lemon peel is used to pickling.
Citrus fruit peel like lemon, tangerines can be dried, powdered, and stored for future usage.
In India, unripe, green mango along with their peels are sun dried and ground to powder (Aamchoor). It is basically used as condiment. Aamchoor is generally mixed with a pinch of turmeric and black pepper powder and added to curries, sauces and chutneys.
In some fruits, the peel is bitter in taste and may contain toxic compounds which when eaten may cause some serious adverse reactions. These fruits can only be eaten after its peel removed. For example, raw, unripe mango peel latex contains urushiol, a compound which may cause mango-latex allergy syndrome in some sensitized persons. (Medical disclaimer).
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USDA National Nutrient Database. (opens new window)
Stanford School of Medicine Cancer information Page- Nutrition to Reduce Cancer Risk (Link opens in new window).