Baking Soda Vs. Baking Powder

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When I think of Christmas, I am reminded of the snow, turkey and gift exchanges. One of my favourite gifts to give friends are baked goods I make from scratch. This year, I baked around 200 cookies and instead of the usual chocolate chip, I decided to spice it up a bit and try different recipes. My favourite recipe one was the one for matcha cookies (see picture) that my friends and family absolutely loved.

While scrolling through different cookie recipes, I noticed some of them only had baking powder while others only had baking soda. There were even ones with both! I wondered what made baking powder and baking soda different and how to know which one to use.

Well, the only ingredient in baking soda is sodium bicarbonate. It is a base that when an acid like acetic (vinegar) is added causes a neutralization reaction in which carbon dioxide gas is produced (bubbles). In the context of baking, the gas gets trapped in the batter causing cakes and cookies to rise.

The problem with just using baking soda is that the reaction occurs immediately during mixing and the batter doesn’t rise in the oven. To overcome this, baking powder can be used. Baking powder consists of baking soda as well as two acids: monocalcium phosphate and sodium acid pyrophosphate. What is important about these acids is that they react a bit when the wet ingredients meet the dry but the majority of the carbon dioxide is produced in the presence of heat (e.g. when you place the batter into the oven). As a result, more bubbles are formed while your goodies are baking, creating a fluffier texture.

So when do you use baking soda, baking powder or both? Well, if there is an acidic component in a recipe (e.g. lemon juice) and you can quickly get it into the oven, using only baking soda would be a good choice. If not, baking powder is the way to go. With that said, baking powder is not as fast reacting as baking soda, so when additional fluffiness is needed, both are used.

Always remember to check whether a recipe calls for baking soda or baking powder. You cannot substitute one for the other. I learned a few years back that if you accidently use baking soda instead of baking powder, you end up with waffles that have a distinctive metallic tasting.

Happy baking!

Sources:

  1. https://news.ncsu.edu/2014/05/baking-soda-powder/
  2. http://bakerbettie.com/baking-101/baking-powder-and-baking-soda/
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Micronutrients: Vitamin A

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This post is dedicated to my good friend since high school Angela Mak who wanted to learn more about the different types of vitamins and their various functions.

For starters, let’s learn about the differences between macro and micronutrients. Generally speaking, nutrients are substances needed by the body for proper growth and development. Our bodies can’t produce nutrients ourselves so we need to eat in order to meet our nutrient requirements.  You can probably tell from the prefixes that “macro” is on a larger scale than “micro”. Similarly, macronutrients such as carbohydrates and proteins are needed in larger quantities compared to micronutrients. For example, adults should have at least 200-300 grams of carbohydrates a day versus the 700-900 micrograms of vitamin A    (285, 000 times less!).

Wait…700 micrograms is not a lot so why is vitamin A important?

First, some background information about vitamin A. There are multiple sources of vitamin A. You can get vitamin A from meat (in the form of retinal esters) or from plants (as beta carotene). The best plant sources come from orange and red plants like carrots. Vegetarians have a harder time meeting vitamin A requirements because beta carotene from plants has to be converted before the body can use it. This conversion is not 100% efficient and you need 12 times more beta carotene than retinal esters.

Vitamin A’s primary role is for eyesight and immune protection. Vitamin A works with a protein in the eye called “rhodopsin” to detect light and send signals to the brain. Therefore people deficient in vitamin A can suffer from a condition known as “night time blindness”. Vitamin A also keeps the membranes around your nose, lungs and skin healthy, helping to form mucus. Lacking vitamin A will cause the membrane to dry and crack leading to infections. An extreme case of vitamin A deficiency is “Xerophthalmia” when the eye gets too dry and fails to make tears.

Does this mean I should eat a lot of meat to get perfect vision?

Unfortunately that’s not quite how it works. Too much vitamin A is toxic because vitamin A is fat soluble. It can be stored in the body as opposed to water soluble vitamins that can be excreted in urine. Vitamin A is kept in the liver and liver cells can only hold a certain amount of vitamin A. Continually consuming high amounts of vitamin A causes liver failure and eventual death. In 1597, Dutch officers became severely ill from eating polar bear liver. They experienced vitamin A toxicity, recalling that animal foods are generally higher in vitamin A and because they were eating liver which is the polar bear’s primary storage site of vitamin A. If you are curious, adults should take no more than 2000-3000 micrograms of vitamin A (the kind found in meat).

Vegetarians on the other hand don’t have to worry about vitamin A toxicity. The only thing that happens is that as more and more beta carotene is stored (beta carotene is an red-orange pigment which gives carrots their colour), the orange becomes more visible in the skin. In other words, you turn orange. Guess the people that told you that eating too many carrots turns you orange weren’t lying after all!

Sources:

https://umm.edu/health/medical/altmed/supplement/vitamin-a-retinol

Picture Sources:

http://vitahound.com/dog-health-library/dog-nutrition/vitamin-b-deficiencies-in-dogs-diet-is-bases-for-poor-health/

Caramel: Candy or Burnt Sugar?

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What do you think of when you hear the word “caramel”? Do you think of the Salted Caramel Mocha from Starbucks or the chocolate bar Caramilk? It’s incredible how many variations of caramel there are available to us. I remember when I was a kid, caramel only meant one thing: Werther’s Original. I loved unwrapping the yellow foil and sucking on the caramel until my mouth was numb.

But what exactly is caramel and where does it get it’s distinct colour and flavour from?

Turns out caramel is made from sugar that has undergone a process known as “caramelization”. Caramelization uses heat to remove water and breakdown sugar to give caramel it’s nutty flavour and brown appearance. The type of caramel depends on the sugar used. When we think of sugar we usually refer to table sugar which is made of sucrose however there are other types of sugar caramel can be made from like honey that consists of mostly fructose. The type of sugar is important because different sugars have different caramelization temperatures. For instance, fructose’s caramelization temperature is 110 degree Celsius while sucrose is 160 degree Celsius. Therefore honey will create a darker looking caramel than table sugar.

To keep things simple, let’s explore the caramelization reaction of table sugar. As the sugar is heated, it begins to boil and decompose. But how can sugar decompose? Well, sucrose is actually a type of “disaccharide” which is a fancy word scientists use to call two “monosaccharides” or 2 simple sugars joined together. The 3 simple sugars are “fructose”, “glucose” and “galactose”. So when we say sucrose “decomposes”, the two sugars units that were previously joined together separate, creating fructose and glucose. Afterwards, a condensation reaction occurs. This means the sugar units combine and form a larger molecule losing water in the process. Other reactions like isomerisation (rearrangement of atoms in a molecule) and dehydration (loss of a water molecule) follow. The ones we are more concerned with are the fragmentation (when a molecule is broken into smaller parts) and polymerization (adding more sugar units to a molecule) reactions because fragmentation produces the flavour and polymerization produces the colour of caramel.

So wait… caramel is just sugar and heat? Not so fast. There are stages of caramelization and depending on how you want to use the caramel will determine the time and temperature you heat the sugar at. For example, stage 5 is called “large ball”. It is table sugar heated at 119 degrees which is suitable for making soft caramels. On the other hand, stage 7 is called “hard crack” which is sugar heated at 165 degrees to make hard candies like Werther’s Original”. If you are not careful enough and you heat the sugar too long to “Black Jack”, the sugar breaks down into pure carbon giving you a burnt flavour.

If candies don’t appeal to you, the same concepts we’ve discussed can be applied to vegetables. Most of you have probably tried caramelized onions or carrots and personally I love caramelized onions on my burgers. Caramelization is possible because carrots and onions have a high sugar content.

Sources:

http://www.food-info.net/uk/colour/caramel.htm

Photo Credit:

http://tastykitchen.com/blog/2011/01/step-by-step-honey-caramel-sauce/

Spherification

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The first time I went to Menchies, a self-serve frozen yogurt chain, the topping called “popping boba” amazed me the most. It looked like caviar but when I bit it, a burst of juice exploded in my mouth. It was very light, refreshing and fun to eat. Turns out, we have food science to thank for these spherical balls of fruit juice. 

Making “popping boba” relies on a technique called spherification that is the reaction between calcium chloride, water and sodium alginate. Calcium chloride is a white powder and sodium alginate is a yellow one. Sodium alginate is a salt, a product of neutralization. It is derived from the reaction between alginic acid and a base like sodium hydroxide. Alginic acid is found in the cell walls of brown algae and is extracted by drying and processing seaweed. To start spherification, sodium alginate is added to the desired juice. A good tip is to use a blender to incorporate alginate to ensure it is evenly distributed. The juice should also be cold. If it is hot, the alginate will solidify before adding it to the calcium and you get jelly instead of juice inside the boba. Not only that, the juice must also have a pH greater than 3.6 which is hard considering the pH of orange juice is about 3.5. Too much acidity converts sodium alginate back into alginic acid which thickens it. A solution to this problem is to add “alkaline” that neutralizes acids giving it the ability to raise the pH of a substance. An example of an alkaline is sodium citrate.

Another name for alginate is “hydrocolloid” which is defined as a substance that forms a gel when added to water. This explains the next step in spherification. A syringe is used to add the juice one drop at a time into a calcium chloride water mixture. In water, calcium chloride dissociates into ions and according to the reactivity series, calcium is more reactive than sodium resulting in the formation of calcium alginate. On top of that, the Na has a 1+ charge while calcium has a 2+ charge. This means twice the bonds are required in calcium alginate. An increase in the number of bonds form a more ridged molecule creating a thin gel layer on the outside of the boba while keeping the desired juices on the inside. One final tip is to to store the boba in the same juice as its interior. The gel layer is very thin and permeable to small molecules. If it is stored in water, diffusion will occur giving you a very dilute inside.

This is just the very basic type of spherification. The reason why it comes out as a sphere is because the syringe creates droplets in the calcium chloride. With other tools, the shape can be manipulated to create ravioli, gnocchi etc. The possibilities are just endless!

Sources:

http://www.chefsteps.com/activities/the-science-of-spherification

https://itschemicallydelicious.wordpress.com/2013/02/07/the-science-behind-spherification/

http://www.modernistcookingmadeeasy.com/define/molecular-gastronomy-glossary/what-is/sodium-alginate

http://science.howstuffworks.com/innovation/edible-innovations/molecular-gastronomy3.htm

Photo Credit:

http://imgarcade.com/1/popping-boba-frozen-yogurt/

Making an Introduction: Molecular Gastronomy

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Have you ever used a recipe and it didn’t turn out exactly how you imagined it? This happens to me especially in baking. I expect to make 2 dozen “gooey, soft chocolate chip cookies” but I actually end up with 15 rock solid ones! Some recipes are also hard to duplicate. You have to have exactly 612g of flour, 11g of baking powder and what the heck does “a pinch of salt” even mean? If amateur chefs like me end up having to eyeball everything, what’s the point of looking for a recipe in the first place?

This dilemma haunted chefs for a long time and scientists began wondering if they could use the science behind food to create the perfect dish every single time. A new branch called “molecular gastronomy” was born and people began coming up with new recipes and methods of cooking. Molecular gastronomy aims to understand the physical and chemical processes that occur in cooking. For example, the reason why an egg goes from transparent to translucent is because heat “denatures” or changes the structure of the proteins in eggs. Understanding these proteins and what temperature denaturation occurs determines how long one should cook an egg for while keeping it “sunny side up”. Some people despise molecular gastronomy because they think it takes away from the art of cooking. Previously it would take years for a chef to perfect the simplest cooking techniques but now anyone who is literate can produce the same results.

I see the perspective both sides are coming from. I respect the work and creativity of chefs but I am also interested in the research done in molecular gastronomy. The best option would be having molecular gastronomical techniques serve as a tool for experienced chefs. 

In my upcoming articles, I will be exploring the fascinating world of molecular gastronomy from debunking cooking myths to looking at the types of equipment or ingredients used. Maybe one day I’ll even develop a foolproof chocolate chip cookie recipe!

Source:
http://science.howstuffworks.com/innovation/edible-innovations/molecular-gastronomy3.htm

Photo Credit:

http://science.howstuffworks.com/innovation/edible-innovations/molecular-gastronomy3.htm

Super(man)foods Pt. 3

3. Green Tea (Ice cream)

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When I went to Hong Kong during Christmas, I had the chance to try green tea soft serve ice cream that tasted phenomenal. The most surprising part was that it came from McDonald’s! In comparison to Canada, there are a lot more green tea flavoured foods in Hong Kong. Oreos, Kit Kats…you name it! Green tea is thought to have originated from China and when outsiders started realizing it’s beneficial properties, they began demanding it. With supply following demand, companies had to follow suit and most restaurants today offer green tea on their drinks menu. For example, Starbucks’ “Green Tea Frappuccino” used to be a hidden jewel but over the years it has made its way onto the regular menu. But seriously, why are people so hyped up about green tea?

Well, similar to our chocolate discussion, green tea is full of an antioxidant called catechin. High levels of catechin are maintained due to minimal processing of green tea. Not only that, research has shown that green tea lowers blood cholesterol. Wait, what is cholesterol? It is a substance similar to fat that is produced by the liver and found in (yummy) foods like hamburgers and fries. Having small amounts of cholesterol is important because it is involved in bodily processes like forming cell walls and synthesizing vitamin D. Problems arise when we have too much of. It hardens the walls of our arteries, reducing the flow of blood. In the case of a heart attack, there is so much cholesterol built into the walls that it completely blocks off the blood supply to the heart. This is why green tea is said to prevent heart attacks and improve blood flow.

Your body is interconnected, so it’s no surprise a healthy heart also means a healthy brain. The brain has its own blood vessels to supply it with sufficient levels of oxygen/nutrients. Good blood flow from drinking green tea ensures the brain is properly fed. In addition, when scientists did an MRI scan to study the brain activity of individuals who drank green tea, they noticed more activity in the areas responsible for memory. In other instances, green tea has also been found to prevent Alzheimer’s by preventing plaque from forming in the brain.

The next time you head to a tea shop looking for green tea, go for the matcha. Even less processed, matcha has been found to have 7x the amount of antioxidants compared to dark chocolate and 137x more catechin than what is found in regular green tea. It is said that drinking 1 cup of matcha green tea is equivalent to drinking 10 cups of regular green tea. How is this possible? Matcha green tea is ground up tea leaves so essentially you are consuming the whole leaf as opposed to drinking the water flavoured by tea leaves. The problem is that good matcha powder can get pricey and you have to be careful especially when buying it online. Trustable sources are David’s Tea and Teavana.

Now that you know about 3 different types of superfoods, it’s time for you to make a chocolate, matcha incorporated salmon soup. Just kidding! I hope you enjoyed learning about superfoods and have gained a new appreciation towards them – I certainly have! But just keep in mind moderation is key regardless of how “healthy” or “unhealthy” something is considered to be. 

matcha

Sources:

http://kidshealth.org/teen/food_fitness/nutrition/cholesterol.html

http://www.nhlbi.nih.gov/health/resources/heart/heart-cholesterol-hbc-what-html

http://www.onegreenplanet.org/vegan-food/matcha-green-tea-a-superfood-to-supercharge-you/

http://www.webmd.com/food-recipes/health-benefits-of-green-tea?page=2

Photo Credits:

http://ohjoy.blogs.com/my_weblog/japan/

http://splash.suntimes.com/2014/03/21/trending-now-on-the-mark/matcha

Super(man)foods Pt. 2

2. Cocoa (Chocolate)

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Did you know that white chocolate’s not actually chocolate? Yes, my jaw dropped too. But in other news, for all of you chocolate lovers out there, a new study done by Hershey (surprise, surprise) shows that dark chocolate and cocoa powder (a.k.a. hot chocolate) have higher levels of antioxidants compared to their “super fruit” counterparts like blueberries, cranberries and pomegranates. 

But wait, what are antioxidants and why are they important? As the name suggests, antioxidants prevent the body from undergoing oxidation. Oxidation is a normal process and is required by the body to function properly. Problems arise when factors like stress, smoking, or alcohol accelerates the natural rate of oxidation increasing the chances of producing “free radicals”. Free radicals are formed when the bond in an oxygen molecule improperly splits during respiration, leaving the atoms with unpaired valence electrons. In this state, they are unstable and in order to regain stability, they steal electrons from their neighbours. This creates another free radical and the cycle continues. Regardless of how “rad” these free radicals sound, they are dangerous when they react with cell membranes. The structures of cells change, leading to cancer, aging and all sorts of diseases. Thank goodness we have antioxidants because they act as a shield, reacting with free radicals before they can reach the cells in our bodies.

Now back to chocolate, to be more specific, the antioxidants present are polyphenols and flavonols. Any food with polyphenol or flavonol is considered a “superfood” due to their ability to defend against cardiovascular disease and to keep the arteries in check.

If you have to get the “healthier” version of chocolate, opt for a bar of dark chocolate and try to skip the hot chocolate. In the study, the chocolate used was dark and the cocoa power was “non-alkalized”. Cocoa normally has a bitter taste but the process of alkalization gives it the smooth, rich, chocolaty flavour we get from hot chocolate mixes. Alkalization unfortunately destroys most of the polyphenols leaving little to no antioxidants. 

Obviously, we shouldn’t eat chocolate like there’s no tomorrow, but once in a while treat yourself! There’s antioxidants in there you know? 

Sources:

http://www.aging-no-more.com/free_radicals.html

http://www.healthchecksystems.com/antioxid.htm

http://www.mydr.com.au/nutrition-weight/antioxidants-their-role-in-health

http://www.rice.edu/~jenky/sports/antiox.html

http://www.theatlantic.com/health/archive/2011/10/antioxidants-explained-why-these-compounds-are-so-important/247311/

http://www.webmd.com/food-recipes/20110207/is-chocolate-the-next-super-food?page=2

Photo Credit:

http://www.loopjamaica.com/2015/01/06/latest-jamaica-news-community-loop-food-is-dark-chocolate-good-for-you/

Ever wonder what's in your food? As a food science student, I certainly do. I'll be exploring the ingredients found in common food items and explaining the science behind them. I’ll also be blogging about interesting news articles about food ranging from new products to scientific discoveries. Enjoy!