Quinoline Yellow

picture of a yellow-green splash - quinoline yellow

Quinoline yellow


Quinoline yellow is a food additive with an E number of 104. Additives with E numbers between 100 and 199 are generally used as food dyes.

Other names for Quinoline yellow include:

  • Food Yellow 13
  • D&C Yellow No. 10
  • Acid Yellow 3
  • Quinidine Yellow KT
  • Japan Yellow 203
  • Lemon Yellow ZN 3
  • C.I. 47005
picture of a yellow-green splash - quinoline yellow

Quinoline Yellow Provides a Yellow-Green Colour


Quinoline yellow is used to give food a greenish-yellow/lemon-lime colour. The name quinoline comes from a chemical derived from coal tar. It may be found in products like juices or sorbet. However, it is not currently approved for food use in the U.S.1 or Canada2.

The molecular formula of the water soluble form is: C18H13NO5/8/11S1/2/3Na1/2/3.

Health Effects

Like other artificial food colours, Quinoline yellow may result in increased hyperactivity in children. It may also cause allergy symptoms in people who are allergic to aspirin. However, one report indicates that there is no conclusive evidence for either of these claims3.


Sometimes, the history behind a scientific discovery can be fascinating, and to me, the story of Quinoline is falls into this category.

It starts with an analytical chemist, named Friedlieb Ferdinand Runge (born ear Hamburg, Germany, in 1795). Friedlieb, who was a medical student, was working with extracts from the deadly nightshade plant. He discovered that he could dilate a cat’s eyes using one of these extracts.

The famous German poet and philosopher, Johann Wolfgang von Goethe, heard about Friedlieb’s experiments, and asked for demonstration. Goethe was impressed, and suggested Friedlieb study coffee. In 1819, Friedlieb discovered caffeine

Friedlieb Ferdinand Runge completed his medical studies, and then earned a Doctorate in chemistry at the University of Berlin in 1822. He became a chemistry professor at the the University of Breslau, but by 1831 he had become tired of academic life. So, he moved into a chemical factory in Oranienburg to work on synthetic dyes. During this time, his work also included the discovery of coal tar products and a large number of substances derived from coal tar, including Quinoline.

Unfortunately, in 1856 he got into a dispute over the rights to a process he had developed for the manufacture of synthetic fertilizer. The widow of the factory owner evicted him, and in 1867, he died in obscurity and poverty.


  1. Summary of Colour Additives for Use in the United States
  2. Canadian Food Additive Dictionary
  3. Scientific Opinion on the re-evaluation of Quinoline Yellow (E 104) as a food additive

Further Reading




Posted in Colour, Food Additives, Ingredients


Cochineal, Carmine and Carminic Acid

Let’s talk about British soldiers, the ancient Inca and Aztec civilizations, the Cardinals of the Catholic Church, and what any of that has to do with food.

It turns out that there is an insect called the Cochineal that lives on cactus in the Southern U.S. down through Mexico and Central America. The ancients discovered that when they squashed these bugs, their fingers would be stained bright red. They like the effect so much that eventually, they started harvesting the insects just so they could dye things.
In Europe, red dyes existed, but they were no where near as vibrant as the dye produced from Cochineal. After the new world was discovered, the cochineal dye became one of the most valuable imports to Europe. It was used to colour everything from the trim on a Cardinals cassock to the coats of British Soldiers who of course become known as the red coats.

Today, as you have already guessed, the dye has now become widely used in foods as well as in cosmetics.  It has largely been replaced by synthetic dyes in the textile industry.  In 1995 the estimated total demand for Cochineal was 300 tonnes.1  The largest producers are Peru and the Canary Islands.


Cochineal or carmine or carminic acid on a food label refers to a natural bright red food dye with an E number of 120. Additives with E numbers between 100 and 199 are generally used as food dyes.


The Cochineal is an insect. Carmine is the crimson red pigment produced by the insect, and carminic acid is the actual chemical that gives the pigment its colour.

To produce carmine, the dried cochineal insects are boiled in water. This produces carminic acid which is then combined with alumn. Other chemicals such as cream of tartar, stannous chloride, or potassium hydrogen oxalate, can be added to help extract a solid (powder) from the liquid.

Common Uses:

Carmine is commonly used in yogurt, candy, beverages, applesauce, baked goods, and red-colored beverages.

Unfortunately, Canadian rules allow manufacturers to list only the word “colour” on the ingredient label. As a result, I haven’t found any specific examples of products containing carmine.

If you happen to know of any products that use carmine, please leave a comment.

Health Issues / Side Effects:

Some people have had allergic reactions and even anaphylactic shock after eating foods coloured with carmine.2 Industrial workers exposed to carmine may develop asthma.3


Many people are not comfortable consuming food products made from insects. These foods are not suitable for vegetarians and vegans. Insects are not considered kosher, so they are not suitable for Jews and Muslims who follow kosher or halal diets.  As a result, there has been some pressure for companies to stop using it.  Last year, Starbucks announced that they would be replacing carmine with the tomatoe based dye, lycopene.4


  1. United Nations Food and Agriculture Organization
  2. World Health Organization – International Programme on Chemical Safety
  3. U.S. National Library of Medicine
  4. Starbucks Blog



Posted in Colour, Food Additives, Ingredients

Calcium Chloride

Picture of Canned Tomatoes Containing Calcium Chloride

Calcium chloride

Blizzards, Swimming Pools, Glass and Stewed Tomatoes

Picture of Canned Tomatoes Containing Calcium Chloride

Canned Tomatoes Containing Calcium Chloride

So what do snow storms, swimming pools, glass and canned tomatoes have in common?  Since you can see the title of this post, you’ve probably already guessed that the answer is calcium chloride.

Calcium chloride is a very widely used chemical. North American consumption in 2002 was 1,687,000 tons1. It can be used for:

Why is Calcium Chloride in My Food?

Calcium chloride is commonly used in a wide range of food products.  Everything from cheese and tofu to beer, canned fruits and vegetables and sports drinks.

Calcium chloride is a food additive with an E number of 509. It often added to food as a firming agent. It reacts with the natural pectin found in fruits to prevent softening that may occur during processing.

Here is a list of some common products that contain calcium chloride:

Cheese Making

When making cheese, calcium chloride helps create a firmer setting curd.   Store bought (pasturized) milk or goats milk may have a lower calcium content.  The amount of calcium in the milk will affect coagulation and coagulation time of the cheese.  Adding the calcium chloride allows cheese makers to better control the coagulation process.  The amount of calcium chloride added will depend on:

  • the acidity (pH) and calcium concentration of the milk;
  • processing conditions, such as temperature;
  • desired coagulating time.


To get the correct mineral levels and acidity in the brewing water used for beer, calcium chloride is just one of the “brewing salts” that may be added.

Molecular Gastronomy – Spherification

One of the most interesting uses is in a process called spherification where it is combined with sodium alginate.  This Molecular gastronomy technique is used to make fake (faux) caviar, often using fruit or vegetable juices.


Calcium chloride is a simple molecule composed of one calcium atom and two Chlorine atoms.  The chemical formula is CaCl2

Where does Calcium Chloride Come From?

It does occur naturally in some minerals, but it is very rare.

This is where the glass fits into the puzzle. In 1861, a Belgian chemist named Ernest Solvay, invented a process for producing sodium carbonate (sometimes called soda ash). Sodium carbonate was coming into high demand at the time because it is used in glass making. Glass is made by melting silica sand, calcium carbonate and sodium carbonate together.

Solvay’s process basically takes limestone (CaCO3) and salt Brine (2 NaCl) to produce sodium carbonate (Na2CO3).  And, you won’t be surprised to find out that the main by-product of the Solvay process is calcium chloride.  Of course the actual Solvay process is quite a bit more complicated than I can explain here.  For anybody whose interested, the chemical formula is:

2 NaCl +  CaCO3 → Na2CO3 + CaCl2

Health Issues / Side Effects:

I have not found any reports of health issues or side effects of calcium chloride when used at levels normally found in food.  The U.S. Food and Drug administration classified it as “Generally Regarded as Safe” (GRAS) in 1975.2

If anybody has any reports to the contrary, please leave a comment, and I will update this post.  Thanks.


  1. Calcium Chloride – Wikipedia
  2. Food and Drug Administration GRAS Report for Calcium Chloride

Further Reading

  1. CSK Food Enrichment – Calcium Chloride in Cheese
  2. Using Salts for Brewing Water Adjustment



Posted in Firming Agent, Food Additives

Sunset Yellow FCF

Picture of a Sunset
Picture of a Sunset

Sunset Yellow

Sunset Yellow FCF

Sunset yellow FCF, also known as yellow dye #6, is used to give foods an orange-yellow colour.


Sunset yellow is looks like an orange-red powder.1 It is another azo dye, similar to tartrazine, and allura red. An azo dye is a chemical compound where two hydrocarbon groups are joined by two nitrogen atoms. The letters azo are derived from the french word for nitrogen, azote.

Azo dyes account for roughly 60 to 70% of all dyes used in the food and textile industries.2 The reason they are so popular is that azo dyes are cheap to produce and are more stable than most natural food dyes.

If you’re interested in the scientific chemical name, it is Disodium 6-hydroxy-5-(4-sulfonatophenylazo)-2-naphthalene-sulfonate.  (Sunset yellow is much easier to pronounce).

The chemical formula is C16H10N2Na2O7S2

Common Uses:

Sunset Yellow FCF is used in many different types of products, ranging from soft drinks to candies and snack foods. Specific products include:

If you have other examples of products that contain tartrazine, let me know by leaving a comment.

Health Issues / Side Effects:

There have been reports that Sunset Yellow may cause allergic or intolerance reactions in certain people, particularly those with a pre-existing sensitivity to aspirin.  Other reports have linked it to increases in tumours, however, a review by the World Health Organization found no evidence of this (in either short or long term studies).3
If you have had personal experience with a tartrazine allergy, please leave us a comment.

E Number:

The E number for Sunset Yellow is 110. Other yellow dyes include tumeric/curcumin (E 100), riboflavin (E 101), tartrazine (E 102), and quinoline yellow (E 104).


So what does FCF stand for?

I’ve puzzled over that for a while. None of my sources seemed to provide an answer. Instead, there were just references to “Sunset Yellow FCF”.
It turns out that the answer might be very simple:
FCF = For Colouring Food


  1. Food and Agriculture Organization of the United Nations
  2. Azo Dyes – www.food-info.net
  3. University of Guelph Food Safety Network

Further Reading

Canadian Food Additive Dictionary

FDA Food Additive Status List

UK Foods Standards Agency, Approved Food Additives

Food Standards – Australia and New Zealand



Posted in Colour, Food Additives, Ingredients

How to Store Herbs

Picture of Potted Sage
Picture of Sage Leaves (How to Store Herbs)

How to Store Herbs

How to Store Herbs

Herbs are a great way to add flavour to your cooking. Of course, they taste the best when they are used moments after harvesting. I know this isn’t always practical, and this post will give provide some tips on how to store herbs so that you always get the best flavour.

Short Term Storage

If you are not lucky enough to have your own herb garden, then you are going to want to store herbs when you bring them home from the grocery store or market. How you store them really depends on the type of herbs you have.

Storing Herbs in the Refrigerator

Many herbs can be easily stored in the refrigerator by following a few easy steps:

  1. Poke some holes in a zippered plastic bag.
  2. Put a dry paper towel in the bag.
  3. Fill the bag loosely with dry leaves or stems.
  4. Zip the bag 3/4 of the way shut.
  5. Keep the bag in the refrigerator crisper drawer for 3 to 5 days.
  6. When you are ready to use the herbs, wash and spin dry the leaves.

This method works particularly well for chervil, chives, cilantro, dill, fennel leaves, marjoram, mint, oregano, parsley, rosemary, sage, and thyme.

Other Methods


Never store basil in the refrigerator.  Refrigeration ruins basil.  The leaves will lose their flavour when stored at temperatures below 50°F.  The leaves will turn black at temperatures below 45°F.

The best way to keep basil is to place the freshly picked stems in a glass of water out of direct sunlight. The water needs to be changed everyday. If left in the water long enough, the stems will start to form roots. You can then plant these cuttings to grow a whole new basil plant.

Long Term Storage

If you need to store herbs long term, you generally have two options: drying or freezing.

Drying Herbs

Picture of Potted Sage

Potted Sage on My Balcony

Dried herbs can be kept and used for up to 12 months. Following these instructions will provide the best results:

  1. Gather small bunches of the herb so that the group of stems is about 2 cm (a little less than 1 inch) across.
  2. Strip the leaves from the bottom quarter of the stems.
  3. Tie a piece of string or twine tightly about 2 cm from the end of the stems.
  4. Hang the herbs upside down in a warm, dark, dry, dust free location.
  5. When the leaves become dry and crumbly, strip the off the stems and put them in glass jars.

Note that not all herbs are suitable for drying. Basil, dill, parsley, cilantro, fennel and chervil are not suitable for drying.

Herbs that dry well include:

  • rosemary
  • sage
  • oregano
  • marjoram
  • thyme
  • winter savory
  • tarragon
  • chamomile
  • mint

Freezing Herbs

Sometimes (especially when you have a lot), freezing herbs is the only option. Basil, dill, parsley, cilantro, fennel and chervil can be frozen using the following method:

  1. Place 2 cups of clean leaves (stems removed) into a blender or food processor.
  2. Add 1/2 cup olive oil.
  3. Process until a loose purée is formed. You may need to add an extra tbsp or two of olive oil.
  4. Pour the purée into ice cube trays and freeze.
  5. Once they are frozen, pop the cubes out of the tray and wrap them in plastic. Then store them back in the freezer in an airtight container.

Do you store herbs or do you always use them fresh? What methods do you use? It’d be great if you let us know in a comment.


Posted in Food Storage, Fresh Food

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