spice

#Advent Botany Day 23: Vanilla – nothing plain about this flavour!

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I’m not one for cream on my Christmas pudding, it just has to be custard or ice cream and so what I’m really admitting to is a love for vanilla. Vanilla is the quietest spice at Christmas but there is so much more to vanilla than merely two scoops of icecream.

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Natural vanilla is the fruit and seeds from a tropical, climbing orchid. There are other edible orchids (e.g. Dendrobium flowers and salep tubers), but it is certainly the most commonly used in food preparation.  Some orchids are harvested from the wild to eat (such as Orchis mascula and O. militaris for salep), but given the demand, luckily this isn’t true for vanilla. There are over 100 orchid species in the Vanilla genus, but the most commonly cultivated species is Vanilla planifolia (more commonly known as Madagascan or Bourbon vanilla).

V. planifolia is native to Central and South America, and was first domesticated by the Totonac people of east Mexico, who used it exclusively until Aztec conquerors demanded vanilla as a tribute. The Spanish conquistador Cortez brought vanilla to Europe, where initially it was only mixed with cocoa and drunk, but later was used in other deserts. Vanilla was very expensive during the 16th to 19th century, as Mexico had a monopoly on this luxurious spice. The reason for this was discovered by the French botanist Charles Morren who in 1836 observed Melipona bees pollinating the flowers, which have a range limited to Mexico. Therefore, the only way to cultivate vanilla elsewhere is by hand pollination. Morren experimented with hand pollination methods but the method still used today was devised by Edmond Albius, aged 12, in 1841. A twig or blade of grass is used to lift the rostellum, separating the stigma and anthers, and the thumb is used to transfer pollen to the stigma. The process is further complicated by each infloresence only lasting for 24 hours.

Vanilla is labour intensive to produce, so natural vanilla is still the second most expensive spice (after saffron). Albius’ method allowed vanilla to be grown in what is now Madagascar, Reunion and the Comoros Islands, which today account for 80% of the world’s vanilla pod production. You can find more about vanilla from the National Geographic website and an interesting site dedicated to vanilla.

For centuries vanilla has been used to flavour our foods, drinks and even pharmaceuticals but the main extract from the vanilla pod, vanillin, wasn’t isolated until 1858. Nicolas- Theordore Gobley obtained it by completely evaporating the vanilla extract and then recrystallizing it from hot water in order to separate it out from all of the several hundred other components found in the extract. Since the 1870’s companies have competed to produce synthetic vanillin from clove oil, lignin, guaiacol and glyoxylic acid. More recently, Rhodia has marketed a “natural” vanillin which is prepared using microorganisms. You can find out more about the structure of vanillin here.

Around 2% of the dry weight of the cured pods of Vanilla planifolia is vanillin. When the seed pods are first harvested, they are green and lack the vanilla flavour and aroma. Curing of the vanilla pods consists of just four steps. “Killing” often entails the pods being frozen or blanched in hot water to initiate reactions which develop the aroma. Sweating involves stacking pods within layers of wool for 7-10 days in a very hot (45–65 °C) and humid environment. Drying occurs to reduce the remaining moisture content to around 25%  in order to prevent rotting. Conditioning is the final step where the pods are left in the box for several months before being graded. It is after this curing process that vanillin develops the aroma and flavour that we have come to know and love.

To get into the Christmas spirit I’ve found some very Christmassy treats for you to make at home yourself:

A tropical Christmas pudding with a vanilla glaze and  beautiful danish cookies (vaniliekager) recipe.

 

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Advent Botany 2016 – Day 14 – Caraway — Culham Research Group

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By Emma (the unconventional gardener) Cooper Caraway, Carum carvi It’s possible to grow up in the UK and never consciously encounter caraway as a spice – I certainly did. And yet this versatile plant adds flavour to meat, fish, and vegetables details. But it’s claim to Christmas fame comes from its ability to make stand-out…

via Advent Botany 2016 – Day 14 – Caraway — Culham Research Group

Advent Botany 2016 – Day 7: The Clove — Culham Research Group

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To the microscopist, clove oil used to be one of the best smelling mounting and clearing agents when preparing samples for permanent mounting on a glass slide. However, cloves have a much wider range of uses including traditional use in herbal medicine to ease tooth-ache and to improve digestion. Cloves also make up part…

via Advent Botany 2016 – Day 7: The Clove — Culham Research Group

Saffron: the world’s most expensive spice (Part 2)

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by Jemma

This two-part blog post has looked at Crocus sativus, also known as saffron. Part 1 focused on the plant’s history in Europe (https://herbologymanchester.wordpress.com/2015/04/27/saffron-the-worlds-most-expensive-spice-part-1/). Part 2 will now focus on its genetics, harvest and uses.

 

Appearance

Saffron is a species of autumn-flowering plant that can grow up to 20-30 cm and produces around 4 flowers. These light- to dark-purple flowers each possess 3 bright crimson stigmas from which the spice saffron is obtained.

Saffron flowers.  Image taken from http://www.herbalencounter.com/2010/12/07/medicinal-spices-saffron-crocus-sativus/
Saffron flowers.
Image taken from http://www.herbalencounter.com/2010/12/07/medicinal-spices-saffron-crocus-sativus/

Genetics

Crocus sativus is a monomorphic clone, which means that almost every saffron plant is identical both physically and genetically. It is unknown in the wild and probably descends from Crocus cartwrightianus (also known as ‘wild saffron’), though Crocus thomasii and Crocus pallasii have also been suggested as saffron precursors. The species sativus probably arose through extensive selective breeding by growers after longer stigmas during Bronze Age Crete.

Crocus cartwrightianus - the plant from which the saffron crocus might be descended  Image taken from: http://commons.wikimedia.org/wiki/Category:Crocus_cartwrightianus
Crocus cartwrightianus – the plant from which the saffron crocus might be descended
Image taken from: http://commons.wikimedia.org/wiki/Category:Crocus_cartwrightianus

The saffron crocus is a triploid (possess 3 sets of each chromosome) that is male sterile and incapable of reproduction. Thus, the majority of propagation of Crocus sativus takes place by asexual reproduction.

 

Harvest

As mentioned previously, the plants crimson stigmas are the source of the popular spice. Due to the few produced per plant and the difficulty involved in manually extracting the minute stigmas, the saffron spice is the world’s most expensive spice by weight. Large quantities of flowers are required in order for marketable amount of saffron to be produced. Approximately 75,000 flowers, which give around 225,000 stigmas, are required to obtain a single pound (0.5 kg) of the spice. Each of these stigmas must be collected by hand and then immediately dried to prevent decomposition or mould from damaging them.

 

Medicinal uses

For as long as it has been cultivated by Homo sapiens, the saffron crocus has been used extensively for medicinal purposes. Even the paintwork by the Minoans hinted at the possibility of its use as a drug. Ancient Egyptian healers used Crocus sativus to treat a wide range of gastrointestinal problems; from stomach ache to internal bleeding. They also viewed it as an aphrodisiac, poison antidote and cure for measles. Alexander the Great was noted for having baths with saffron to help heal wounds after a battle. With its medieval revival, the medicinal uses of the crocus increased further. It was used to treat everything from coughs to smallpox, insomnia to heart diseases, and from stomach ache to gout. Saffron was even believed to be able to cure the Black Death.

Materia Medica jar containing saffron.
Materia Medica jar containing saffron.

Today, saffron is still used frequently in both alternative and modern medicine. Crocus sativus is included in the hematoxylin-phloxine-saffron (HPS) stain and Movat’s pentachrome stain, both of which are tissue stains used to make structures more visible under a microscope. This is because saffron stains collagen (most abundant protein and the main structural protein) yellow.

A tissue sample stained with HPS stain. Collagen is dyed yellow whilst muscle and cytoplasm are both pink. Image taken from http://en.wikipedia.org/wiki/HPS_stain
A tissue sample stained with HPS stain. Collagen is dyed yellow whilst muscle and cytoplasm are both pink. Image taken from http://en.wikipedia.org/wiki/HPS_stain

Use as a dye

For millennia saffron has been used to colour textiles and other items. It was traditionally reserved for nobles, political elites and important religious figures to emphasise their social standing. Even in small amounts, the sativus stamens produced a bright yellow-orange dye but with increasing amounts of saffron used, a richer shade of red was achieved. This led to these richer shades indicating those who were of particular importance. However, saffron is an unstable colouring agent over long periods of time, resulting in the vibrant colours to fade quickly. Over time there have been numerous attempts to replace saffron with a cheaper dye. Crocin, the main chemical in saffron that imparts the colour, has been discovered in other plants and is now extracted cheaper and easier from species in the Gardenia genus.

 

Culinary uses

Another use for saffron that dates back thousands of years is for cooking. A popular addition worldwide, saffron imparts a bright yellow-orange hue onto dishes and is included in everything from curies and soups to cheeses and baked goods. It is also sometimes added to liquors for flavour and colour. However, due to its high price, saffron is often substituted or combined with other spices in order to reduce the cost. Safflower (Carthamus tinctorius) and turmeric (Curcuma longa) are the most common replacements as they mimic the colour imparted by saffron. Though they can produce a similar colour to the pricey Crocus sativus spice neither safflower nor turmeric can replicate its distinctive taste (which is mainly due to the compound picrocrocin).

Safflower is sometimes used as a cheaper alternative to saffron
Safflower is sometimes used as a cheaper alternative to saffron

Other uses

In addition to the uses mentioned already, saffron was also a popular ingredient in perfumes in ancient Greece and Rome. They also included Crocus sativus in cosmetics, wine and potpourri. It was even considered a worthy offering for the gods. Queen Cleopatra of Egypt added saffron to her bathwater as she considered it an aphrodisiac.

Saffron: The world’s most expensive spice (part 1)

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by Jemma

 

This two-part blog post is going to focus on Crocus sativus, also known as saffron. Part 1 is going to focus on the plant’s history in Europe and part 2 (https://herbologymanchester.wordpress.com/2015/04/27/saffron-the-worlds-most-expensive-spice-part-2/) will focus on its genetics, harvest and uses.

 

Ancient Times

The cultivation and trade of the saffron crocus by humans has persisted for around 4 millennia; spanning cultures, continents and civilisations. The first recorded image of saffron appears in Minoan paintings. Though there is no written record of what they used the crocus for, suggestions have been made (mentioned in part 2) and it is clear that the plant held some significance for them. A powerful earthquake followed by a volcanic eruption resulted in the loss of this early settlement around 1,500 BCE. The Minoan herbal paintings survived over the next few millennia through being entombed by the volcanic ash, which preserved these early frescoes.

Minoan fresco depicting a saffron gatherer.  Image taken from: http://en.wikipedia.org/wiki/Wall_Paintings_of_Thera
Minoan fresco depicting a saffron gatherer.
Image taken from: http://en.wikipedia.org/wiki/Wall_Paintings_of_Thera

Saffron again became popular during the time of the ancient Greeks, when early documentation shows that they cultivated and harvested the plant for its spice. During this time, saffron began to be widely traded across the Mediterranean. The plant even had its own origin legend: the story of Crocus and Smilax. Crocus, a handsome young man, falls for the nymph (a female nature deity) Smilax. At first Smilax is flattered but she soon tires of his advances and turns Crocus into a saffron plant; the bright stigmas of the flower representing the glow of the undying and unrequited passion of Crocus. Possibly for this reason, saffron was widely associated with the class of professional courtesans and entertainers called the hetaerae. Though it remained a popular spice and medicine for many centuries, Crocus sativus cultivation in Europe went into decline following the fall of the Roman Empire.

 

It should be noted, however, that Crocus sativus cultivation was not limited to Europe. Whilst its popularity was still spreading, saffron began to be grown further and further from Greece. By the 3rd century AD, it had spread to China and was incorporated into their traditional medicinal practices.

 

Medieval Revival

For several centuries the cultivation of Crocus sativus was, for the most part, none-existent throughout Europe. This changed after the Moorish civilisation spread from North Africa around the 8th century and began reintroducing the spice. Saffron was rare, expensive and in high demand right up until the 14th century, when its use soared due to the medicinal applications of the plant in attempted treatments for the Black Death. However, many of the farmers that grew Crocus sativus had died from the disease and the demand far outstripped the supply. Thus large quantities of non-European saffron began to be heavily imported. The trade of saffron became of such significance that those found guilty of adulterating supplies were fined, imprisoned and even executed.

An image from La Francescina manuscript (1474) showing Black Death victims being treated. Image taken from http://commons.wikimedia.org/wiki/Category:Medieval_miniatures_of_plague?uselang=en-gb#/media/File:Plague-st-francis-la-francescina-jacopo-oddi-c1474.jpg
An image from La Francescina manuscript (1474) showing Black Death victims being treated. Image taken from http://commons.wikimedia.org/wiki/Category:Medieval_miniatures_of_plague?uselang=en-gb#/media/File:Plague-st-francis-la-francescina-jacopo-oddi-c1474.jpg

The Saffron War

As already mentioned, the Black Death during the 14th century drastically increased the demand for saffron in central and northern Europe to a level that local suppliers could not meet. The only other major producers at the time were Arab sources, who were unwilling to trade due to hostilities over the crusades. This left Greece as Europe’s primary supplier.

 

The sale of saffron quickly made merchants extremely wealthy and powerful, which disturbed the declining aristocracy. In an attempt to regain control, a group of nobles seized a large saffron shipment heading to Basel in Switzerland. The stolen cargo would be worth over £300,000 in today’s market. The theft triggered a 14 week long war, named the ‘Saffron War’ that lasted until the shipment was returned. Though the cargo was returned in this instance, the saffron trade was plagued with thieves for the majority of the 13th century. Pirates would target saffron bound for Europe, often ignoring ships loaded with gold in preference for this profitable spice.

 

Decline and Modern Revival

Trade of Crocus sativus began to dwindle for a second time during the 18th century. There have been a number of causes suggested for this decline, including fungal diseases destroying crops, cold winters and to traders offering steadily lower prices in an attempt to outcompete their rivals. By the middle of the 20th century, the crocus started to become primarily grown for ornamental purposes. The use of saffron as a spice fell out of fashion and the only areas in which it endured were southern France, Italy and Spain.

Materia Medica jar containing saffron.
Materia Medica jar containing saffron.

Since the turn of the millennia in 2000, saffron has been making a comeback. Today, rather than being predominantly grown in Greece and Europe, the majority of C. sativus is now grown in Iran and North America.