Isn’t it amazing that a tiny seed can germinate and grow into a whole plant, which may have juicy fruit, spectacular flowers or enough energy to sustain a herbivorous animal? It’s frustrating that we have become so removed from our farms and food sources. I was horrified that it took me 23 years to find out peanuts are legumes that grow underground. What else am I missing out on? Lets explore some more plant food origins.
What is a fruit?
The question seems simple, yet funnily enough it took our whole class of nutrition and dietetic students to come up with a reasonable answer off the top of our heads. After a lot of stumbling and er.. ah.. fruits, like, have seeds and taste sweet, but not always.. come from plants.. bananas and apples and berries and stuff… Uh oh. We had some reading to do!
Fruits develop from the flower of a plant.Brown, A., Understanding Food Principles and Preparation. Fifth ed. 2015, Stamford, CT: Cengage Learning. Technically speaking, fruits are ripened ovaries. Mmm yum, right?
- Simple fruits develop from one flower
- Examples are apricots, cherries, peaches, apples, pears, citrus fruits, cucumber and pumpkin
- Aggregate fruits develop from several ovaries on one flower
- Examples are strawberries, raspberries and blackberries
- Multiple fruits develop from a cluster of several flowers
- Examples are figs and pineapples
A little more on pineapples because they are commonly thought to grow on trees. The pineapple plant is about one metre tall and produces one fruit at a time (you can watch a short video on harvesting pineapples here). Pineapples originate from South America and they are special because of their rich source of bromelain, an enzyme with therapeutic benefits including relief of osteoarthritis, diarrhoea and cardiovascular disorders, anti-cancerous properties, enhanced drug absorption and treatment of surgical trauma, bronchitis and sinusitis. Pineapples are so special they wear a crown!
Fruits of the sea
Have you ever thought of how the nori (seaweed) of your sushi is grown? Nori is the Japanese name for a genus of red algae, Pyropia. The majority of the worlds nori is grown in Japan, where production is a multi-billion dollar enterprise. Many challenges are involved in growing nori; too much swell can damage the seaweed and low salinity of the water increases the risk of disease, of which there are about ten different types. Other types of algae can overtake the growth of the nori and also be troublesome for production. To say the least – there is an art to the science of growing nori and a lot more effort has gone into your sushi than you may have previously thought!
Nori is probably the most well known seaweed in Australia, but did you realise seaweed is a common additive in a whole heap of food products? Agars, carrageenans and alginates are polysaccharides (carbohydrates) used for gelling, thickening and stabilising food products. They are typically not broken down in the human digestive tract, meaning they don’t provide our bodies with energy. Next time you’re in the supermarket have a look for these ingredients and think of the journey they have taken from the ocean, through processing and into the food product. Apart from gelling and thickening food products, many seaweeds taste great and have a range of health benefits! You might like to see some tips for integrating more seaweed into your diet.
We have explored some underwater edibles, but what about underground foods? The roots of a plant structurally support the plant and absorb the water and nutrients required for the plant to live and grow. Beetroot, carrot and sweet potato are roots which store nutrients for the rest of the plant. Potato and ginger are tubers, which are underground food reserves for the plant, but not necessarily roots. Bulbs are buds with overlapping leaves, which may be membranous or fleshy. The leaves are nutrient reserves, which allow the plant to lie dormant through periods of unfavourable conditions (winter or drought). Onions, garlic, chives, leeks and shallots are bulbs.
I mentioned my late discovery of peanuts (aka “ground nuts” or “goobers“) growing underground. The troublesome little treasures like to grow in sandy soil and need a minimum soil temperature of 18˚C before they germinate. Peanut crops are special because they are considered both legume and oil crops. If you’re a nutcase like me, you’d be interested to see a video of a peanut harvest.
So if a peanut is a legume, what is a nut?
Sorry to be confusing, but it depends if we are talking in the botanical sense or culinary sense. Botanically speaking, nuts are actually fruits! They are simple fruits with typically one seed and a hardened ovary wall. In the culinary sense, a nut could be anything from a seed (almond, brazil nut, cashew) to a legume (peanut), but they are certainly not in the “fruit” food group. Complicated. According to the Australian Dietary Guidelines, culinary nuts are rich in kilojoules, protein, fibre, unsaturated fatty acids and micronutrients such as folate, vitamin E, selenium, magnesium and other minerals.
Shoot, there’s a lot to know.
Fruits are ovaries, pineapples have therapeutic properties, seaweed is worth billions, nuts are fruits, peanuts are legumes and brazil nuts are seeds. Like a lot of things in nutrition science, there is not a straight answer and it seems the more you learn, the more you know you don’t know. The origins of plant foods is a complex and endless topic I know I will always be curious about and I hope you are too.
References [ + ]
|1.||⇪||Brown, A., Understanding Food Principles and Preparation. Fifth ed. 2015, Stamford, CT: Cengage Learning.|