Love it or hate it, rocket is popular all over the world. Also known as arugula, roquette and rucola, its known for its pungent and peppery flavours. It might look like an unassuming leafy vegetable, but the reasons for its taste, health benefits and whether we like it all comes down to genetics.
Rocket actually encompasses several species, all of them part of the same family as broccoli, cabbage, kale, mustard and watercress the Brassicales. Its distinctive aroma and flavours are created by chemical compounds produced by its leaves, called isothiocyanates. Some of these compounds can be eye-wateringly hot, whereas others can have a radishy flavour or none at all.
In the wild, isothiocyanates are thought to help defend plants from herbivores and disease, and also help it tolerate environmental stress. But for humans, eating isothiocyanates confers health benefits. Studies have shown them to have anti-cancer properties, and anti-neurodegenerative effects against diseases such as Alzheimers.
Sharing the full story, not just the headlines
For this reason, plants containing isothiocyanates interest scientists particularly those with little taste and flavour. One such compound is sulforaphane, which is found in rocket and broccoli. Several years ago, researchers produced a super broccoli with high amounts of sulforaphane. Consumers couldnt taste the difference, and it was later shown to be effective in preventing and slowing prostate cancer and in lowering cholesterol.
But one advantage with rocket is that it doesnt need cooked to be eaten. Heating other Brassicales, like broccoli, to over 65C inactivates myrosinase, which is an enzyme in their tissues that converts compounds called glucosinolates into sulforaphane and other isothiocyanates when people chew these plants. If the myrosinase is inactivated, consumers will receive little or none of the associated health benefits, no matter how much is bred into the plants.
Chewing aside, theres some evidence to suggest that our gut microflora possess their own myrosinase and can convert glucosinolates to isothiocyanates for us. The amounts this produces are likely to be quite small, but release may be sustained, exposing our cells to compounds like sulforaphane for longer periods.
But the biggest barrier to people getting these beneficial molecules from rocket is the taste. This depends on when and where rocket crops are grown. In the summer, leaves can be extremely spicy and pungent, whereas in the winter they can be bland and tasteless.
There are many different varieties of rocketiStock)
Growth temperature likely plays a big role in determining the amounts of isothiocyanates released from leaves. Probably a stress response by the plants, it means hotter countries like Italy may produce more pungent leaves.
You can test this effect at home. Get two small pots and some rocket seeds from a local garden centre or supermarket. Plant two or three seeds in each. Keep one well-watered and relatively shaded, and the other in direct sunlight, watering infrequently. After a few weeks, taste the leaves from each pot one should taste much hotter.
The taste and flavour of rocket also varies because of the genetics of different varieties. Not only do leaves contain hot, pungent isothiocyanates, but also sugars (which create sweetness); pyrazines (which can smell earthy and pea-like); aldehydes (which smell like grass); alcohols (one in particular smells just like mushrooms); and many other types yet to be identified.
Recently, the worlds first rocket genome and transcriptome sequence was produced from the Eruca sativa species, allowing researchers to understand which genes may be responsible for making the compounds related to taste and flavour. Its genome contains up to 45,000 genes, which is more than the 42,611 genes humans are thought to have.
The research also found that different varieties produce more isothiocyanates and sugars than others. This explains why leaves can taste so different in the supermarket, even when bought from the same shop at the same time of the year. By knowing which genes are expressed in tissues and when, we can select rocket plants with improved taste and flavour profiles and breed new and improved cultivars.
To further complicate matters, our own genetics mean we dont all taste chemical compounds the same. We have many thousands of different odour receptors in our brains, and many different combinations of taste receptors on our tongues. These genetic differences are one of the reasons why coriander tastes different to different people. Those with a variant of the OR6A2 gene perceive the leaves as having a soapy flavour, which is thanks to the aldehyde compounds in coriander that activate this receptor variant.
Depending on whether you have a functioning or non-functioning copy of certain taste receptor genes, you may not be able to taste certain compounds at all. In the other extreme, if you have two working copies of a particular gene, some foods may taste unbearably bitter and unpleasant.
Another classic example is Brussels sprouts. Some people love them, while others loathe them. This is because of the gene TAS2R38 which gives us the ability to taste the bitter glucosinolate compounds in these vegetables as well as rocket.
Love or loathe? The superfood continues to divide (iStock)
Those people with two working copies of the gene are bitter supertasters. People with only one are medium tasters, while those with no working copies are blind to these compounds. So what is intense and inedible to one person might be pleasant and mild to another.
This partly explains peoples general food preferences and rocket leaves are an excellent example of these processes in action. A consumer study of rocket leaves showed that some people like them hot and pungent, others like them sweet and mild, and others just dont like them at all.
However, peoples culture and life experience probably also determine whether they like rocket and other foods. A previous study of rocket showed that peoples genetic differences are not necessarily an indicator of whether they will like something. Its perfectly possible to be a bitter supertaster and like rocket and Brussels sprouts depending on your upbringing and exposure to them.
Another study showed that preference for flavour and pungency of white radish is linked to differences in geography and culture. Japanese and Korean people liked pungency created by an isothiocyanate much more than Australians. Pickled radish is a common condiment in Asian countries: being regularly exposed to a food may predispose people to like it, irrespective of their taste sensitivity.
Very little is currently known about the interactions between plant and human genotypes. But ongoing research aims to find out which compounds people with different TAS2R38 genotypes are sensitive to. This will make it possible in the future to selectively breed in (or out) certain genes, and produce rocket types tailored to a persons preferences.
Luke Bell is a lecturer in temperate horticulture at the University of Reading. This article first appeared on The Conversation
- Mating Study Unlocks the Genetic Code of Attraction - Neuroscience News - March 18th, 2024
- Mindfulness in your DNA? Capacity to be present is partly a function of genetics, study finds - PsyPost - March 18th, 2024
- Genetic testing scam targets Medicare recipients, including those in Spokane - KXLY Spokane - March 18th, 2024
- Some people are genetically predisposed to gain weight. These 5 tips can help - CNN - March 18th, 2024
- SOPHiA GENETICS and The French Kidney Cancer Research Network (UroCCR) Publish Results from Multiyear ... - PR Newswire - March 18th, 2024
- Tissue samples show the deep genetic and cellular impacts of smoking - Medical Xpress - March 18th, 2024
- The regulatory landscape of chromatin accessibility - Nature.com - March 18th, 2024
- Genome assemblies of 11 bamboo species highlight diversification induced by dynamic subgenome dominance - Nature.com - March 18th, 2024
- Research reveals the genetic code behind non-identical twins - Medical Xpress - March 18th, 2024
- How genetic therapies transformed the lives of sickle cell patients - KPVI News 6 - March 18th, 2024
- The Next Wave of Privacy Litigation: The Illinois Genetic Information Privacy Act - Perkins Coie - March 18th, 2024
- State initiates study on genetic cancers, Lynch Syndrome - The Times of India - March 18th, 2024
- How genetic therapies transformed the lives of sickle cell patients - Citizentribune - March 18th, 2024
- Dr Plichta on Areas of Interest for Genetic Testing Research in Breast Cancer - OncLive - March 18th, 2024
- The Genetic History of the Jews Mosaic - Mosaic - March 18th, 2024
- New insights into genetic mechanisms could improve treatment of liver fibrosis - Medical Xpress - March 18th, 2024
- 5 Questions To Ask About The Ethics Of Genetic Data - Forbes - March 18th, 2024
- Couple raising money to fix sons club feet caused by rare genetic condition - 21 Alive News - February 18th, 2024
- What can bulls tell us about men? Genetic discovery could translate to human fertility research - Medical Xpress - February 18th, 2024
- Legislation seeks to bar life insurance companies from purchasing recreational genetic testing data - Delaware First Media - February 18th, 2024
- Family-based study identifies potential new genetic factors linked to Alzheimer's risk in people with African ancestry - National Institute on Aging - February 18th, 2024
- Genetic determinants of micronucleus formation in vivo - Nature.com - February 18th, 2024
- Near-gapless and haplotype-resolved apple genomes provide insights into the genetic basis of rootstock-induced ... - Nature.com - February 18th, 2024
- Accurate and sensitive mutational signature analysis with MuSiCal - Nature.com - February 18th, 2024
- CRISPR, the Genetic Revolution of the 21st Century | OpenMind - BBVA OpenMind - February 18th, 2024
- Genetic control of thermomorphogenesis in tomato inflorescences - Nature.com - February 18th, 2024
- Natural selection and genetic diversity maintenance in a parasitic wasp during continuous biological control application - Nature.com - February 18th, 2024
- Understanding how natural genetic variation contributes to adaptive responses to low oxygen - News-Medical.Net - February 18th, 2024
- Division of Epidemiology and Genetics - Epidemiology and Genetics - University of Southern California - February 18th, 2024
- Genetic study clarifies the link between birth weight and adult morbidity - Medical Xpress - February 18th, 2024
- AI and genetics underpin project to speed up CVD diagnosis and personalise treatment - Hospital Healthcare - February 18th, 2024
- Study Reveals Complex Interaction Between Genetics and Environment in Brain Functioning - Medriva - February 18th, 2024
- Unraveling the Impact of Genetics and Socioeconomic Status on Behavioral and Psychiatric Traits - Medriva - February 18th, 2024
- Genetic Investigation Reveals CETP Gene Variants Linked to Cardiovascular Resilience in Genome-Wide Association ... - Physician's Weekly - December 30th, 2023
- Raha Kapoor's blue eyes remind fans of her great-grandfather, Raj Kapoor; here's what genetics says - IndiaTimes - December 30th, 2023
- Genetic clue to pericarditis inflammation points to promising new treatments - News-Medical.Net - December 30th, 2023
- Certain genetic predispositions may increase risk of atrial fibrillation among those with high alcohol consumption - 2 Minute Medicine - December 30th, 2023
- Understanding the genetic basis of hereditary diffuse gastric cancer - News-Medical.Net - December 30th, 2023
- Genetic engineering was meant to save chestnut trees. Then there was a mistake. - The Washington Post - December 30th, 2023
- Unraveling the mystery of hereditary diffuse gastric cancer - EurekAlert - December 30th, 2023
- What is Genetics? | AMNH - American Museum of Natural History - December 22nd, 2023
- Who killed Shelley Connolly? Genetic genealogy leads authorities to a suspect and a conviction - Alaska's News Source - December 22nd, 2023
- C.S. Lewis, Atheism, and the Genetic Fallacy - Word on Fire - December 22nd, 2023
- FDA approves first genetic test to assess opioid addiction risk using DNA sample - Fox News - December 22nd, 2023
- Genetic blueprint of wild grapes could help breed better grapes - University of California, Davis - December 22nd, 2023
- Unlocking the genetic secrets of grape seedlessness - Phys.org - December 22nd, 2023
- Unlocking the genetic secrets of drought resilience in Persian walnuts - Phys.org - December 22nd, 2023
- FDA approves genetic test to assess patients risk of developing an opioid addiction - KXAN.com - December 22nd, 2023
- How researchers are CReATiNG synthetic chromosomes faster and cheaper - EurekAlert - December 22nd, 2023
- The promise of genetic therapies in sickle cell disease - The Lancet - December 22nd, 2023
- Assessment of genetic diversity, population structure and wolf-dog hybridisation in the Eastern Romanian Carpathian ... - Nature.com - December 22nd, 2023
- Genetics and Heart Disease: What you need to know - IndiaTimes - December 22nd, 2023
- How to become a geneticist - University of Sydney - December 22nd, 2023
- Study sheds light on the ancestry and genetics of Coast Salish woolly dogs | News | Vancouver Island University ... - Vancouver Island University News - December 22nd, 2023
- Human genetics | Description, Chromosomes, & Inheritance - December 13th, 2023
- BASIC GENETICS INFORMATION - Understanding Genetics - NCBI Bookshelf - December 13th, 2023
- Introduction to Genetics - Open Textbook Library - December 13th, 2023
- Clues to preventing Alzheimer's come from patient who, despite genetics, evaded disease Washington University ... - Washington University School of... - December 13th, 2023
- Environmental stress rather than genetics influenced height differences in early Neolithic people: Study - Phys.org - December 13th, 2023
- What is trisomy 18? Why the fatal genetic disorder is in the news and what it's like to get the diagnosis. - Yahoo Life - December 13th, 2023
- Spanish scientists identify the molecular mechanisms controlling the genes involved in proper formation of the heart ... - EurekAlert - December 13th, 2023
- GENEFIT, the First-Ever Fitness Technology to Integrate Personal Genetics with Wearable Tracker Data, Launches to ... - Fitt Insider - December 13th, 2023
- Genetic 'protection' against depression was no match for pandemic stress, finds study of first-year college students - Medical Xpress - December 13th, 2023
- Origin and evolution of the triploid cultivated banana genome - Nature.com - December 13th, 2023
- CellCharter reveals spatial cell niches associated with tissue remodeling and cell plasticity - Nature.com - December 13th, 2023
- How do we get our eye color? A genetics expert reveals the fascinating truth - Fox News - December 13th, 2023
- WVU Today | WVU scientists spice up genetic research through habanero peppers and AI - WVU Today - December 13th, 2023
- Genetic mutations that promote reproduction tend to shorten human lifespan, study shows - Phys.org - December 13th, 2023
- Stanford Scientists Discover Common Genetic Factor That Fends Off Alzheimer's and Parkinson's - SciTechDaily - December 13th, 2023
- Association of genetic risk and lifestyle with pancreatic cancer and their age dependency: a large prospective cohort ... - BMC Medicine - December 13th, 2023
- New bill would block American genetic data from access by companies tied to foreign adversaries - Homeland Preparedness News - December 13th, 2023
- Electric Eels Shocking Ability To Alter The Genetics Of Nearby Animals - Forbes - December 13th, 2023
- "When them genetics kick in its all over" - NBA fans send in rib-tickling reactions as LeBron James attends Zhuri James' volleyball game -... - October 16th, 2023
- David Liu, chemist: We now have the technology to correct misspellings in our DNA that cause known genetic diseases - EL PAS USA - April 7th, 2023
- World Health Day 2023: Understanding the science of Epi-genetics and how to apply it in our daily lives - Free Press Journal - April 7th, 2023
- Genetics - National Institute of General Medical Sciences (NIGMS) - March 29th, 2023
- GENETICS 101 - Understanding Genetics - NCBI Bookshelf - March 29th, 2023
- People always think Im skinny because of good genetics theyre shocked when they see what I used to lo... - The US Sun - March 29th, 2023
- Forensics expert explains 'genetic genealogy' process believed to be used in Kohberger's arrest - KTVB.com - January 6th, 2023
- Idaho student murders: What is genetic genealogy, a tool reportedly used to help capture the suspect? - FOX 10 News Phoenix - January 6th, 2023