Introduction and description
Courgette also called Zucchini is a summer squash.
When small and only about 6 inches long it is referred to as a courgette, once it has grown to sizeable proportions it is known as a marrow.
My father used to grow massive marrows.
My Mum used to stuff them and bake them in the oven, but there are only so many stuffed marrows one can take in the autumn, when you are a child. Nowadays, with all the ingredients we have available there are a lot more things one can do when your courgettes get out of control [as they inevitably do] and you find you are the proud possessor of several marrows.
Along with other squashes and pumpkins, it belongs to the species Cucurbita pepo. Zucchini can be dark or light green, although the golden zucchini, is a deep yellow or orange color.
In a culinary context, zucchini is treated as a vegetable; it is usually cooked and presented as a savory dish or accompaniment. Botanically, zucchini are fruit, a type of botanical berry, being the swollen ovary of the zucchini flower. Zucchini, like all squash, has its ancestry in the Americas. However, the varieties of squash typically called "zucchini" were developed in Italy, many generations after their introduction from the Americas.
The marrow is an easy vegetable to grow – with care you can have a very large crop in a relatively short time. Marrow, courgette, squash and pumpkin are all closely related and are grown in basically the same way. They need a sunny position, a moisture-retentive soil and somewhere out of cold winds.
Marrows are easy to grow from seed and can be sown outdoors in the spot where they are to grow, or you can start them off indoors in pots. Two weeks before planting or sowing seed outdoors, make planting pockets 4ft apart for marrows. Do this by making a hole about a spade’s depth, width and height and fill with a mixture of compost or well-rotted manure and soil. Sprinkle a general fertiliser over the soil. Plant one plant on top of each planting pocket. You can also grow marrows in growbags or containers. Plant one or two per growbag, or one per container.
Keep the soil constantly moist by watering around the plants not over them. As they need plenty of water, sink a 15cm (6in) pot alongside the plants when planting out. Water into this and it will help ensure that the water goes right down to the roots and does not sit around the neck of the plant, which can lead to rotting. Marrows should be supported off the soil, a net string bag can be used for this. Common problems include
- Powdery Mildew which appears as a white powdery deposit over the leaf surface and leaves become stunted and shrivel. Remedy: Keep the soil moist and grow in cooler locations.
- Grey mould: A usually grey, fuzzy fungal growth which can begin as pale or discoloured patches. Remedy: Remove damaged plant parts before they can become infected. Cut out infected areas into healthy tissue and clear up infected debris. In greenhouses, reduce humidity by ventilating and avoid overcrowding of young plants and seedlings.
The following brief analysis is based on the observation from Dr Duke and simply summarises his findings. Mrs Grieve has no entry for Courgettes or Marrows and groups them with cucumbers and melons. Even then very little activity is described. But the marrow in particular does have nutritional value and more is being found out about the benefits of the chemicals in the plant.
Alpha-Linolenic-Acid and Linoleic-Acid can be found in fruit, flowers and the seed. Ferulic-Acid is also to be found in the entire plant and has very extensive activity – for example it is Analgesic; Anti-allergic; Antiarrhythmic; Antibacterial, Anticancer; Anti-herpetic; Anti-inflammatory, Antispasmodic; Anti-thrombic; Antitumor, Antiviral, Candidicide, ; Metal-Chelator and so on – see Dr Duke’s analysis.
Courgettes are the immature fruit, and plants generally encourage consumption of only the mature fruit so that their seeds can be dispersed. As such the immature fruit is not especially rich in minerals [it does contain Boron, Sodium, Potassium, Magnesium, Phosphorus and Calcium ] or vitamins. Immature courgettes are mostly water. The more mature fruit does have one extremely useful constituent and that is Fibre [11,000 - 130,952 ppm ] meaning it helps bowel movements and constipation. Mannitol in the marrow is a Diuretic; Flatugenic and Laxative.
The vitamins it has are
- α-Tocopherol - a type of vitamin E.
- Beta-Carotene – β-Carotene is a strongly coloured red-orange pigment, and a precursor to vitamin A. It is also found in the flower
- Thiamine, also known as vitamin B1 is also found in the flower
- Riboflavin, also known as vitamin B2, also found in the flower
- Niacin, also known as vitamin B3, also found in the flower
- Ascorbic acid also known as Vitamin C, also found in the flower
The fruit [and also the seed] does have almost all the amino acids
It is clear however that the plant tries to discourage consumption of the immature fruit by giving it a bitter taste, if it is struggling to produce enough mature fruits to ensure its seeds survive:
Brighton and Hove Allotment association - Poisonous courgette warning - A cautionary tale! By Melanie Matthews
I had been baffled by several of my meals being ruined by an awful, bitter taste – so bitter that a tiny bit left an awful taste in my mouth for quite some time afterwards. I wondered if the oil was rancid, I wondered what ingredient could possibly taste so awful. Then finally, the culprit was revealed – the last ingredient was grated courgettes, and the dish went from lovely to appallingly bitter.
Loathe to throw out a big pan of food, I tried to eat around the courgettes and pick out the broad beans, but I had to admit, it tasted bitter beyond anything I wanted to eat, and eventually gave up. My partner refused to touch it.
I woke up around 3am with stomach cramps, diarrhoea, the same bitter taste in my mouth, and a pounding heart. I was quite worried, and my partner said I should look at the research he had done on bitter courgettes – it turns out they can contain a poison called Cucurbitacin E, which can develop if the plant is hybridised and/or water-stressed. What the research did not reveal though was how serious this was and what the consequences were.
I rang NHS Direct and told her I had poisoned myself with a courgette; she quite clearly thought I was barking, and asked if it was mouldy. I gave up, and rang the out-of-hours doctor and told him my symptoms matched everything for Cucurbitacin E poisoning, and was I going to die from this? He said he’d never heard of it and I’d better go to A and E.
I waited in A and E for several hours, feeling terrible, and eventually saw a doctor who thankfully took me seriously and went to look up this poison. He said I should be fine but should get some tests run in a week or so. I felt pretty ropey for the next few days but the tests were fine and I’m still here to tell the tale. There is a story of someone who died from this poison, though.
If we look at Dr Duke’s analysis of the Courgette, it will be clear that the flower is a much more active part of the plant medically than the courgette itself.
- Zeaxanthin in the flower, for example, is the pigment that gives corn, saffron, and many other plants, their characteristic colour. Dr Duke’s analysis indicates it has anti-cancer and anti-tumour activity, but several observational studies have provided preliminary evidence that zeaxanthin is associated with lower incidence of age-related macular degeneration (AMD),
- PUFA - Polyunsaturated fatty acids in the flower help those with skin conditions being Antiacne and Antieczemic, although as Wikipedia says “The biological effects of the ω-3 and ω-6 fatty acids are largely mediated by their mutual interactions”
- Adenosine is an antiviral and has considerable heart related activity having Diuretic, Vasodilatory, anti-Heart arrhythmia, Hypotensive [blood pressure lowering] and Blood thinning properties.
- Lupeol is AntiEBV; Antiflu; Antimalarial; Antiviral and Hypotensive
But plants do not normally encourage the consumption or removal of a flower unless they use bulbs to reproduce. And we find that indeed the plant has chemicals such as Anthophyll in the flower, which is a Bruchifuge [Strictly, a substance intended to kill plant pests], as well as being an Insectifuge and Pesticide. A MUFA [monounsaturated fatty acid] is also found in the flower and it is Allergenic , Dermatitigenic [An agent that causes inflammation of the skin (dermatitis)] and an Insectifuge [a substance or preparation for driving off insects. ] and Irritant. One of the fascinating aspects about the amounts of these chemicals is there is just enough to act as a repellent to insects, but not to seriously hurt and some chemicals even come with their own after effect pain relief. Alpha-Spinasterol in the flower, for example is an Anti-inflammatory.
This aside, the flower is a storehouse of nutrients – intended of course for the baby marrow, but also available to us.
The seed contains a number of minerals - Zinc, Silicon, Calcium, Chromium, Cobalt, Copper, Iron, Magnesium, Manganese, Phosphorus, Potassium, Selenium, Sodium, Tin, as well as Salicylic-Acid. They also contain sucrose, rather indicating that we were meant to consume the seeds as well. The chemicals, although having antibacterial properties also serve to protect the seeds by being a Pesticide. Some of the minerals are also Taenicides - a medicine that destroys tapeworms.
On the whole people rarely use marrow seeds in the way pumpkin seeds are used [roasted etc], but this quote from an allotment association indicates they are edible:
“yes, the seeds are edible but …. I do hope you are not so desperate for food that you have to resort to eating your seed supply for next year”
Lecithin in the seed is indicated as being Antialzheimeran; Antidementia; Antieczemic; Antimanic , Antipsoriac; Antisclerodermic [Scleroderma is a chronic disease, which causes your body to make too much of the protein collagen]; Antiseborrheic [preventing or relieving the symptoms of seborrheic dermatitis ]; and AntiTourette's . The seed also contains natural GABA. So maybe the seed is worth a bit more study.
Courgettes can be sliced or cut into batons; or they can be trimmed, cut in half lengthways, then into 2mm-wide slices. They can be boiled, fried or roasted in the oven. Roasting has the advantage that it intensifies the flavours. We have provided a recipe for Dukkah, but other spice mixtures also work well, for example, - ½ tsp dried oregano, 1 tsp coriander seeds, crushed , 1 tbsp caster sugar and Salt & pepper. Courgettes can be simply rolled in the spice mixture and roasted in butter, or used with egg wash and flour.
Marrow can be very successfully curried using various combinations of coconut cream, cumin seeds, mustard seeds, onion, garlic , tomatoes, fresh ginger, green chillies, turmeric and fresh coriander.
When young, courgettes can be eaten raw in salads [they go well with apple and toasted pine nuts] or in salsas with yoghurt salt and mint. It is also possible to slice yellow and green courgettes into long, thin strips using a mandoline or potato peeler. These can be marinated; griddled; added to salads; served with an oil, lemon juice and rind dressing and feta cheese cubes, basil salt and pepper; or added to pasta.
Stuffed courgette or marrow
Most of the recipes you will find in cookbooks or on the Internet provide various ways of stuffing the courgette or marrow. Courgettes, because of their size tend to be halved lengthwise and their centres spooned out to take the filling. A marrow on the other hand can be halved lengthwise or cut width-wise into 2-3 inch rounds. In both cases the marrow may have to hollowed out with a knife, as the flesh becomes more fibrous and full of seeds as the marrow becomes older. If it is very fibrous with a hard skin it is not worth eating. Marrow skin can be left on but is best not eaten.
- Red rice and spices - Cooked red rice; parmesan cheese, grated; tomatoes peeled and diced; diced prosciutto fried, (optional); carrot, peeled and julienned; garlic and onion, chopped and fried; ground spices – coriander, cumin, salt, pepper; chopped fresh herbs - basil, tarragon, parsley.
- Cheese and chipolata - Onion and garlic, finely chopped and fried, breadcrumbs; mature cheddar, grated; finely chopped flat-leaf parsley; Cumberland pork chipolata, squeezed from their skins
- Sun-dried tomatoes and chestnuts - red onion and garlic chopped and fried; fresh sage, chopped; sun-dried tomatoes chopped; vac-packed chestnuts, chopped; cooked basmati rice; dried cranberries; pinch of ground allspice
- Persian rice stuffed - Salt and black pepper; jasmine rice, cooked; cardamom; cinnamon; ground cumin, paprika; dried apricots, coarsely chopped ; grated orange rind; fresh lemon juice; fresh orange juice; shelled dry-roasted, unsalted pistachios ; chopped fresh dill ; chopped fresh flat-leaf parsley; goat cheese, crumbled; can cooked no-salt-added chickpeas, rinsed and drained
Courgette and apple hummus
20g dried apple rings, chopped
1 large courgette
2 tbsp lemon juice
7 tbsp extra virgin olive oil
1 medium garlic clove
1 large pinch sea salt
1 small pinch black pepper
3 tbsp tahini
½ tsp ground cumin or ¼ tsp smoked paprika
A small handful of fresh parsley or coriander
1 Roughly chop the apple and courgette, add to the blender with the other ingredients and pulse a few times.
2 Use a spatula to scrape down the sides and then blend the mixture until smooth. Taste for seasoning.
3 Serve with a Crudites of cucumber, carrots, red peppers, fennel or courgette batons and pink radishes to serve
The spice mixture Dukkah can be used to coat strips of courgette or marrow. Roll the strips in flour [gram flour, rice flour etc], then dust off. Dip each fry into an egg wash, then coat generously with dukkah. Place on to a greased baking tray, and sprinkle more dukkah over the top if necessary. Spray with olive oil, then cook for 30 minutes or until sizzling and golden.
110g (2/3 cup) hazelnuts,skins removed or pistachios
80g (1/2 cup) sesame seeds
2 tablespoons coriander seeds
2 tablespoons cumin seeds
2 teaspoons freshly ground black pepper
1 teaspoon flaked sea salt (like Maldon brand)
1 tsp of fennel seeds [optional]
½ tsp cinnamon [optional]
2 tsp dried oregano[optional]
Spread the hazelnuts over a baking tray and cook in preheated oven until toasted.
Place in a food processor and process until coarsely chopped. Transfer to a large bowl.
Toast the sesame seeds. Add to the bowl with the hazelnuts.
Toast the coriander seeds until aromatic and seeds begin to pop. Transfer seeds to a mortar and pestle. Pound until finely crushed. Add the crushed spices, pepper and salt to the hazelnut mixture and mix well.
Vietnamese marinated steak and pappardelle courgettes
Adapted from The Vietnamese Market Cookbook by Van Tran and Anh Vu
For the dressing
1 Cut the courgettes in half lengthways and use a vegetable peeler to shave off thin slices.
2 To make the dressing, put the sugar and water in a pan over a medium heat. When the sugar has completely dissolved, add the soy sauce followed by the grated ginger and the sesame oil. Cut the clementine in half and squeeze the juice into the pan.
3 Soak the courgette slices in the dressing for 3-5 minutes then set to one side. Cut the sirloin steak into thin slices and marinate in the dressing for 5 minutes, then lightly sear the sirloin in a frying pan or on a griddle.
4 Divide the sirloin between 2 serving plates. Arrange the courgette strips alongside the seared sirloin.
5 Sprinkle the chopped coriander, white sesame seeds and shallot over the beef.
Crispy courgettes fritters
The tea towel needs to be very clean for this and you need to gather the towel and squeezeover the sink to get the shards as dry as possible, a wet mixture does not produce the lovely crisp fritters you want. Don't be alarmed by the straggly lumpiness of this batter; it's meant to be this way. Chop up the limes and tumble them about the edges of the plates. Sprinkle over a little more chopped mint and eat them just as they are, spritzed with lime juice as you go. Makes: about 25 fritters
4 courgettes (approx. 750g / 1¾lb)
6 spring onions (finely chopped)
250 grams feta cheese
1 small bunch fresh parsley (chopped)
1 small bunch fresh mint (chopped (plus extra to sprinkle over at the end))
1 tablespoon dried mint
1 teaspoon paprika
140 grams plain flour, rice flour or gram flour
3 large eggs (beaten)
olive oil (for frying)
Coarsely grate the courgettes.
Spread the little shards out on a tea towel and leave for about 20 minutes. Squeeze to remove water
Put the chopped spring onions in a bowl and crumble in the feta. Stir in the chopped parsley and mint, along with the dried mint and paprika. Add the flour and season well with salt and pepper. Gradually add the beaten egg and mix thoroughly before stirring in the drained, grated courgettes.
Heat a few tablespoons of oil in a large frying pan and drop heaped dessertspoons of the mixture into the hot oil, flattening the little cakes down with the back of the spoon as you go. Cook these little patties for about 2 minutes each side until golden, and then transfer to a couple of waiting plates.
Marrow and potato gratin
Serve this with crusty bread for mopping up the juices. Recipe adapted from one by Olia Hercules; therecipekit.co.uk
6 tbsp sunflower oil
800g marrow, cubed and without the skin
30g rice flour
3 banana shallots, sliced
2 tbsp tomato puree
4 garlic cloves, sliced
400g cooked potatoes, thinly sliced
300ml crème fraiche
Salt and black pepper
1 small bunch of dill, chopped
1 Heat 2 tbsp of sunflower oil in a heavy-based pan. Dip marrow in flour, and fry until caramelised. Do this in batches, adding some extra oil each time. Remove each marrow piece to a paper towel.
2 Fry the shallots and the tomato paste in the oil, stirring all the time, until the shallots start to soften. Then add the garlic and cook for another minute.
3 Mix the potatoes, sour cream and 300ml of water and put into a casserole dish, season with sea salt and pepper.
4 Place the browned marrow on top and cook in the oven for 50 minutes or until the liquid is reduced. Sprinkle with dill and serve.
Courgette praline cake
Moist and dense with a hint of cinnamon, this courgette cake with maple icing and salted almonds is an indulgent way to use up a courgette garden-glut. Let the frosting set for at least 30 minutes before cutting. This cake will store well for a few days at room temperature, wrapped tightly
For the icing
1 In a bowl, stir together the eggs, oil, courgette, sugar and vanilla extract.
2 In a separate bowl, combine the flour, bicarbonate of soda, baking powder, salt and cinnamon. Add the dry ingredients to the courgette mixture and stir.
3 Divide the batter evenly into three 23cm cake tins (well greased or nonstick). If you don't have three pans, bake the cake in batches. Bake until the cake is light brown and set in the middle, about 22-25 minutes. Turn the cakes out on to a rack to cool.
4 In a saucepan, combine the brown sugar and butter. Cook on a medium heat, stirring constantly, until the butter melts and the sugar has dissolved.
5 Pour in the milk. Continue to stir and bring to a boil. Remove the pan from heat and stir in the maple syrup. Set aside to cool slightly.
6 Place the icing sugar in a bowl. Pour the butter mixture over the icing sugar and mix with a spoon until the icing is smooth.
7 Place one layer of the cake on a plate and pour icing in the centre. Spread the icing out to the edges, then set the next cake on top. Repeat. Set the third cake on top and pour the remaining glaze over the cake, let it naturally drip down the sides. Sprinkle the top with the nuts.
Gluten free Marrow cake
150g coconut oil
175g coconut sugar
3 medium eggs
200g ground almonds
30g gluten free plain flour
1 tsp baking powder
300g marrow peeled, cored, & grated
70g pine nuts
1 lemon, zest
Preheat oven to 200°C/180°C fan/gas 6. Grease a 20cm springform tin (that’s also 5cm deep) with coconut oil, and line the base.
Cream the coconut oil and coconut sugar together until fluffy – this should take 3 mins. Then stir in the eggs one at a time.
Fold in the ground almonds, flour and baking powder, followed by the sultanas, courgettes, 50g pine nuts and lemon zest.
Spoon the batter into the tin, scatter over the remaining pine nuts and cook for 50 mins. When the time is up, use a skewer to check it’s cooked – it should come out clean.
Allow to cool completely before removing from the tin. Serve with coconut yogurt and extra lemon zest.
- Dr Duke’s list of Chemicals and their Biological Activities in: Cucurbita pepo L. (Cucurbitaceae) -- Zucchini 027494
- Exposure of Cucurbita pepo to DDE-contamination alters the endophytic community: A cultivation dependent vs a cultivation independent approach 027496
- Role of Zucchini and Its Distinctive Components in the Modulation of Degenerative Processes: Genotoxicity, Anti-Genotoxicity, Cytotoxicity and Apoptotic Effects 027500