Feast and Phrase

Gastronomy in the world of words.

Tag: Aztec

Aquaponics

A for Aquaponics

This is the first piece in ‘A Food Education Alphabet’: an A to Z look at food and words to help spread the word about food issues like sustainability and healthy eating.

What is aquaponics?

Aquaponics combines ‘aquaculture’ (breeding aquatic creatures, mostly fish) with ‘hydroponics’ (growing plants without soil using a nutrient-rich solution).

Brought up in tanks, fish produce waste. The water containing this is fed past plants, which are grown in floating containers or gravel beds. They take up organic fertilizer compounds from the waste through their roots, cleaning the water in the process. This is then returned to the fish tanks.

Ammonia contained in the waste is converted to nitrates by worms and nitrifying microorganisms. Larger pieces can be removed using filters.

Aquaponics DiagramA simplified diagram of how aquaponics works. Feel free to use – please credit Feast and Phrase and provide a link to this piece. The featured image for this article is from Flickr user IMCBerea College and shows Finnley Hayes at work in the Aquaponics Facility.

What are the benefits of aquaponics?

Two products are gained from one efficient, self-cleaning system, with much higher yields.

Aquaponics calls for significantly less land – about a tenth of what would be needed for conventional agriculture. Aquaponics can therefore be easily adapted for urban locations.

Because aquaponics works in a cycle, it only requires around 5 to 10 percent of the water that would be used in soil-based farming. This makes it ideal for growing produce in areas with limited water, like deserts.

Aquaponics 3A triple-tiered aquaponics system with fish, watercress, and running water. From Flickr user Justin Leonard.

In hydroponics and aquaculture, water must be regularly replaced to avoid the respective build-up of fertilizers and fish waste. This is not the case with aquaponics: in addition to the water taken up by plants, small amounts are lost in transpiration.

Hydroponics uses artificial fertilizers, which can be costly. Those used in aquaponics are organic and produced in the same location.

The lack of soil means no weeds or soil-based insects. As the water is naturally filtered, fish are also provided with a healthier environment and are less prone to disease, reducing the need for antibiotics.

Aquaponics 2This photo nicely illustrates the different levels involved in aquaponics. From Flickr user charlie vinz.

What are the disadvantages of aquaponics?

People may be put off by the cost of setting up the system or by the thought of having to take care of the fish, though these are not difficult to arrange!

There will be electricity costs for the water pumps, and those living in colder areas will need to provide a greenhouse to ensure more stable growing climates – again, not particularly pressing issues.

Is aquaponics ethical?

This may be argued both ways. Those who avoid eating fish may well object to rearing them for food and using them to grow plants. Others may say that providing the fish with a clean, filtered system is perfectly ethical.

Aquaponics 1Another photo of an aquaponics system from Flickr user Justin Leonard.

How long has aquaponics been around?

While the discipline as we know it today began developing in the 1970s, early precursors to aquaponics include the chinampas or cultivation islands of the Aztecs, and Southeast Asian paddy fields.

What kind of aquatic life can you breed?

Varieties of fish which are bred in aquaponics include trout, tilapia, perch, and koi, to name a few. Shrimp and prawns can also be used, as can crayfish.

 

Maize

Nixtamalization: Aztecs and Ash

Maize brought life to Mesoamerica. Olmec, Maya, Toltec, Aztec – civilisations grew and declined in the region. Cultivated throughout, consumed by rulers and subjects, deified and revered, maize sustained them all. According to the Popol Vuh, the Mayan creation narrative, humankind was fashioned from the crop:

‘After that they began to talk about the creation and the making of our first mother and father; of yellow corn and of white corn they made their flesh; of corn-meal dough they made the arms and the legs of man. Only dough of corn meal went into the flesh of our first fathers, the four men, who were created.’

Popul Vuh: The Book of the People, translated into English by Delia Goetz and Sylvanus Griswold Morley from Adrián Recino’s translation from Quiché into Spanish.

Mayan Ruler in Maize God GuiseA Mayan image of a seated ruler in the guise of the Maize God, dated between 300 – 600 CE. From LACMA Collections Online.

In Book Eleven of the Aztec Florentine Codex, one line refers to the plant as ‘precious, our flesh, our bones’. It was to the goddess Chicomecóatl and her male partner Centéotl that the Aztecs paid tribute in festivals and artwork, honouring both as controllers of nature’s abundance.

Chicomecoatl Musée du Quai_BranlyA sculpture of Chicomecóatl from the Musée du Quai Branly, Paris. Located using Wikimedia Commons.

For all the divine rituals to bring about bountiful harvests, there was a more everyday practice which ensured that the various peoples of Mexico could benefit from their crop. With the goodness of its kernels locked away inside a tough casing, or ‘pericarp’, corn was as demanding as its deities, and needed work. How to sort out a tough and unyielding pile of maize? Water, ash, and a good soak – or nixtamalization, if you prefer.

Mesoamericans would leave corn in water with the addition of wood ash. This loosened up the pericarp, allowing the drained product to be readily ground for culinary use such as making dough, known in Spanish as masa. Quite why someone decided it would be a good idea to add ash to their maize and when they first did so has not been determined. The earliest evidence for this incredibly successful and much-adopted procedure, as Sophie D. Coe writes in America’s First Cuisines, comes in the form of equipment discovered in southern Guatemala, dating from between 1500 to 1200 BCE.

Codex_Borbonicus_(p._23) MaizeA depiction of maize in the Aztec Codex Borbonicus, now held in France. Located using Wikimedia Commons.

Communities may have followed different steps according to custom and tradition; with the process in wide use today, instructions can vary. A common suggestion is to cook the grains for some time in the liquid and then leave them to soak, using lime instead of ash – both sources of calcium oxide, which becomes calcium hydroxide on addition to water. This makes the soaking solution alkaline and breaks up the kernel skin.

Easy grinding aside, this has more significant results. In untreated maize, niacin (Vitamin B3) is held as niacinogen and niacytin, which cannot be used by the human body. Nixtamalization unbinds them, increasing the available niacin for the consumer. Deficiency of this nutrient can lead to pellagra, a disease with three debilitating consequences: dermatitis, diarrhoea, and dementia.

When Europeans took corn from Mexico back home they did not adopt nixtamalization, applying their wheat-milling technology to the grain. As a result, communities in Europe and colonised parts of Africa which came to extensively consume maize and were less economically capable of balancing their diets were afflicted by pellagra, a problem which continues to this day.

The Polenta, Pietro LonghiThe Polenta (circa 1740), by Italian painter Pietro Longhi: a testament to the European popularity of this corn-based porridge. Located using Wikimedia Commons.

Maize is also naturally low in tryptophan (used to make niacin) and lysine, two amino acids which cannot be produced by the body and must be acquired through the diet. Nixtamalization’s ability to improve the protein quality of corn is debatable; in any case, other foods can supply the missing amino acids. Beans performed this role for Mexican civilizations and were consumed with most meals. Treating the grain may also reduce mould toxins – this too, is subject to debate.

More immediately appreciable is the refined flavour of the maize, which New York-based restauranteur and food writer Zarela Martinez has described as ‘a taste and aroma like no other food on Earth — a delicately nutty quality combined with something almost chalky and mineral-like’. If that doesn’t inspire a craving for fresh tortillas…

Guatemalan TortillasThese will have to do for now. Guatemalan tortillas, taken by Flickr user Krista.

As for the word, it entered English from the Mexican Spanish nixtamal, describing the treated corn. That was taken from the Nahuatl nextamalli, a combination of the words nextli (‘ashes’ or ’cinders’) and tamal-li (‘bread made of steamed corn meal’). Tamal-li gives the name of the modern dish tamales.

Now spoken by around 1,500,000 people in the Central Mexican region, Nahuatl was the main language of the Aztec Empire in the 1400s, originally expressed with pictographs. Following the Spanish Conquest these were replaced with Latin characters, and a sizeable body of Nahuatl works was written down during the 16th and 17th centuries.

Codex_Mendoza_folio_52rA page from the Codex Mendoza, written in the 16th century to give Spanish Emperor Charles V an impression of Aztec life. This image shows some of the tribute items sent to Monteczuma II, last of the Aztec Emperors. Most of the writing is in Spanish; Nahuatl words can be seen under the pictures on the left. Located using Wikimedia Commons.

While English pronunciation renders ‘nixtamalization’ as ‘niks-tamalization’, the letter ‘x’ was used to represent a ‘sh’ sound in NahuatlNextli is therefore pronounced as ‘neshtli’, much in the same way that Méxica – a collective name which the Aztecs gave themselves – was pronounced not as ‘Meks-ee-ka’, but ‘Mé-shee-ka’By that logic, ‘Mexico’ should really be ‘Mé-shee-ko’.

(Both terms supposedly derive from Metzliapán (‘Moon Lake’), a name for Lake Texcoco; ‘Aztec’ from Aztecatl, meaning ‘Hailing from Aztlán’, the legendary ‘White Land’ from which they held themselves to have come. In 17th century Spanish, the letters ‘x’, ‘j’, and ‘g’ were used to denote ‘sh’ sounds, which eventually developed into the aspirated sound now largely represented by ‘j’ in Modern Spanish. The 18th century saw the letter ‘x’ increasingly used for ‘iks’. This past association of ‘x’ and ‘j’ explains the existence of modern alternatives like México and Méjico.)

Mexico City Plaza Large
Mexico City Plaza, or Zócalo. The city stands on what was once Lake Texcoco. Taken by Flickr user Eneas de Troya.

Modern research has produced varieties of corn with higher concentrations of lysine and tryptophan. The opposition to genetically modified foods considered, it is interesting to note the view put forward by Tom Standage, who argues in An Edible History of Humanity that maize is hardly a ‘natural’ plant due to intensive selective breeding which developed its wild ancestor teosinte into the crops known today.

Some new maize mutants are known to have smaller yields and be more susceptible to grain damage when mechanically harvested. That said, their nutritional benefits likely make nixtamalization less necessary. Whether or not the process falls in use, the word itself stands as a reminder of the rich cultural history behind the practice.

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