Czech researchers published a paper in 2019 that looked at a variety of citrus fruits, and the mineral content of both the flesh and skin. Citrus fruits are frequently studied for their rich vitamin and antioxidant content, as well as bioflavonoids. Citrus fruits, however, and importantly, the peels, are also rich in minerals.
- The researchers analyzed orange (Citrus sinensis), pomelo (Citrus maxima), mandarin (Citrus reticulata Blanco), lemon (Citrus limon), key lime (Citrus aurantifolia), and grapefruits (Citrus paradisi).
- In virtually all cases, they found higher concentrations of minerals in the peel than in the flesh.
“The content of macro- and micronutrients in the peel of most of the fruits far exceeded their quantity in the pulp,” they note.
Mineral content in fruit and peel
- Limes and oranges contained the highest potassium content.
- Limes contained the most sodium by far of the citrus fruits.
- Limes had the highest concentration of calcium by far, with the orange coming in second.
- Oranges contained the most phosphorus of all the citrus fruits studied.
- Pummelos ad the highest iron content, as well as the highest magnesium content.
- Red and green grapefruits, limes, and mandarins had the most zinc content in this study.
- Pummelos and oranges had the highest copper content – in pummelos, about 80% of it was found in the peels.
- Pummelos, oranges and mandarins showed the highest content of manganese.
- Lemons and green grapefruits were noted to have the highest levels of selenium.
Eat your peels
“With regard to nutrition and health, increased consumption of specific citrus fruits may help to meet the body’s ongoing demand for individual minerals,” the researchers write. They recommend adding the derived nutrients to foods such as breakfast cereals.
- With the most iron and copper, oranges and pummelos can be recommended for people with hemoglobin production disorders, and other conditions that stem from deficiencies of those minerals.
- Pummelos, with their rich iron content, could be recommended for patients with anemia, oxidative stress, and other conditions.
- The low sodium content of citrus fruits other than limes makes them a good dietary choice for people with hypertension, kidney problems, or other conditions where sodium intake is an issue.
- All citrus fruits are a valuable source of potassium, required by the body to balance water and electrolytes.
As the researchers note, despite its high nutritional value, most citrus peels end up processed and used in cattle feed, or worse yet, dumped as waste. Yet, even in an everyday household, there are so many ways to use citrus peels to add flavor and goodness to almost any type of dish.