With a growing body of research into the nutritional value of lemons, oranges and other citrus fruits, it’s no wonder that consumption is up worldwide.
It’s no secret anymore that citrus fruits, including vitamins, minerals, and the phytochemicals that give them their unique color and taste profiles, have great value when it comes to the human diet. Because of their high concentrations of polyphenols, which include antioxidants and flavonoids, citrus fruits have gotten a lot of attention from both scientists and the public.
Because of the way fruits are processed and consumed, however, it has led to an unavoidable issue: a growing problem with citrus waste.
- Citrus peels and seeds need to be specially treated in order to be disposed of;
- Processing citrus for juice results in waste of about 50% of the fresh fruit mass;
- Waste includes peels (50–55% of the total fruit mass), seeds (20–40% of total fruit mass), pomace (the pulpy residue), and wastewater;
- Citrus processing worldwide creates about 10 million metric tonnes of waste annually.
The question is, why throw it away when almost all of that waste can be used productively?
A recent study by Indian researchers looked into the various ways that the “waste” – which actually constitute nutrient and polyphenol rich material – can be used.
With essential oils and fragrance, the beauty and cosmetic industries could use citrus waste in many ways.
- Skincare: with natural oils, citrus seeds are already used in the cosmetic industry in soaps, lotions and sprays.
- Citrus sinensis seed oil can be used to produce medicinal soaps;
- Seed oil also contains linoleic acid (36%) as well as oleic acid (27%);
- The soap they developed with it in one study had anti-microbial, anti-fungal, anti-parasitic and anti-oxidant properties.
The paper names many other possible uses.
- Use in the food industry as additives for nutrition – to create “designer foods”;
- A source of pectin, coloring or flavoring;
- The pharmaceutical industry can use it;
- It can be used an as organic material in biofuels and biofertilizers, as well as packaging material.
In their conclusion, the researchers note that more study is needed to determine the best ways to recoup the citrus waste material and use it, eliminating the environmental pollution it can create. They mention the concept of a circular economy – one where there is zero waste because everything is used.
In the case of citrus, the benefits are clear.