As explored in part 1, citrus is one of the world’s most important ingredients in foods and flavors. But these incredible fruits also play a critical role in our fragrances, health and beauty products, and even pharmaceuticals. Let’s look at the other side of lemons.
The Power of Citrus Scents
The fragrances of citrus have powerful aromatherapy benefits. Citrus fragrances are known for being mood-enhancing and stress-reducing, and studies have shown that aromatherapy activates the limbic system, with a wide range of calming, stress-reducing, pain-fighting effects. Some of the emotions associated with citrus fragrances are:
- Sweet orange: energizing
- Lemon: uplifting
- Lime: refreshing and purifying
- Grapefruit: mood balancing
- Bergamot: mood enhancing
- Mandarin: calming
- Yuzu: reduces anxiety
Many of these effects are due to the benefits of limonene, a terpene found in the rind of citrus fruits, and also found in plants like lemongrass and lemon myrtle. Limonene is an important compound not just in fragrances, but in a wide range of other products.
Most Common Uses for Limonene
Perfumes
Naturally, limonene is important in the fragrance industry. Chemically, the terpenes in citrus are closely related to the terpenes in mint and conifers, so citrus fragrances blend well with both mint and pine aromas. Citrus fragrances are typically used to brighten scents and add a lighter top note to earthy scents.
Household cleaning products
The scent of citrus is strongly associated with feelings of fresh cleanliness, for good reason. Citrus oils are natural solvents, and help to break down oil and grease.
Personal care products
Many citrus oils are known for their ability to help reduce acne, due to their gentle cleaning power, and limonene is often used in personal hygiene and beauty products.
Organic insecticide
Limonene is a known ingredient in many organic, botanical pesticides and herbicides.
Powerful solvent
Limonene can be used as a solvent powerful enough to remove glues and adhesives, or clean grease and oil from machine parts. It is a natural, better smelling alternative to turpentine.
Health benefits
Limonene, and many compounds in citrus fruits, have a huge range of health benefits. Limonene alone has been shown to boost liver enzymes that detoxify carcinogens, working in the liver and small bowel to reduce the risk of cancer. In animal studies, limonene has reduced the growth of tumors, with extremely low toxicity compared to other treatments.
Drug delivery
Limonene is a sorption promoter that improves delivery and absorption of transdermal drugs, decreasing barrier resistance.
Biotech Citrus: the Next Wave
Because citrus fruits are of such global importance, both economically and nutritionally, citriculture is a flourishing field for biotechnology. Biotech solutions, notably CRISPR and gene editing, are being used to make citrus plants more disease resistant and more productive. Genetic research also gives us the opportunity to further develop citrus fruits specialized for certain health and commercial purposes, while meeting consumer demand for sustainability and quality.
The CRISPR/Cas9 genome editing technique is the most promising and most widely used genetic modification technique in citrus, and the Cas9 engineering technique pioneered by Jennifer Doudna and Emmanuelle Charpentier was recently awarded the Nobel Prize in Chemistry. Cas9 has been successfully used to improve resistance to citrus canker, a citrus disease that has spread around the world and causes millions of dollars in lost fruits and trees every year. Citrus canker has cost over $1Billion USD between 1995 to 2006 in Florida alone, eliminating 87,000 acres of citrus crops, and eradicating the lime industry in the Miami area.
Because of the high heterozygosity of citrus fruits, and the wide host range of Xanthomonas citri, the bacterium that causes citrus canker. However, the precision of gene targeting enabled by Cas9 can create disease resistance where selective breeding cannot. Recent years have seen a dramatic improvement in canker-resistant citrus in laboratory settings, but GMOs remain controversial in commercial crops. The debate about when and how to introduce and regulate GMO crops, as well as the discussion about whether CRISPR edited organisms should be included in the “GMO” category remains ongoing.
Citrus fruits are beautiful and fragrant, and have a powerful ability to affect our mood and our health. They are the source of many important chemical compounds with a wide range of uses in food and beverage, medications, health and beauty, and even industrial applications. The critical importance of these crops cannot be overstated, so if you want to work on the cutting edge of food and beverage development, biotechnology and medicine, or health and hygiene, contact grapefrute today.
