TKF Science Writing

History and Origin

Gouda is a semi-soft cheese made primarily from cow’s milk and is named from the town of its origin in the South Holland region of the Netherlands.  In researching the origin of Gouda, some say that it dates back to 1697.  Farmers from the region would bring their cheese to the market and eventually, the cheese adopted the name from which it came.  

How Gouda is Made

The cow’s milk is cultured and heated until the curd is separated from the whey.  Curd is the part of milk that coagulates as seen when putting sour milk into a cup of coffee.  The whey or milk plasma is the liquid portion leftover after the curd has been strained.  The curd is then “washed” by adding hot water.  This separates out more whey from the curd.  The resulting mixture is pressed into circular moulds and soaked in a brine solution.  Eventually, a rind will form.  After soaking, the cheese is dried then coated to prevent dehydration and then allowed to ripen.

Taste

A very complex tasting cheese, Gouda meshes salty, sweet, sour, bitter, and umami (meaty or savory) flavors all in one tasty bite.  It also exhibits a fifth and not well-known flavor profile described as having mouthfullness, thickness, and a complex body.  This flabor profile is due to the presence of what are called Kokumi compounds.

Kokumi Sensation

Termed by the Japanese, Kokumi compounds generate the Kokumi sensation, which is a Japanese word used to describe deliciousness.  More succintly, it describes the continuity and roundness of a particular food.  Scientists in Munich, Germany, in a recent journal article from the Journal of Agricultural and Food Chemistry were seeking to unlock the flavor secrets of these compounds as it relates to Gouda cheese.

To start, the scientists chose two Gouda subjects of different ripeness; a 44-week and a 4-week cheese .  Their goal was to understand and apply biological principles that give rise to Gouda’s unique flavors by separating components and attempting to recombine them synthetically.  The results of the synthetically re-combined product was measured against the original components in natural Gouda.  They did this by focusing on the small-molecule metabolite profiles recognized by our taste sensors.

Senses

The four sensory tastes (bitterness, sweetness, sourness, and umami) were recognized previously in different studies of cheese.  Calcium and magnesium chloride were found to give rise to bitterness along with amino acids.  Lactic acid and hydrogen phosphate brought out a sour taste.  Sodium chloride and sodium phosphate were culpable for the salty sensation.  Lastly, Unami, the meaty or savory sensation was a result of monosodium L-glutamate and sodium lactate.

Results

The scientists found that tasters preferred and noticed a more pronounced mouthfullness, thickness, and a complex body in the natural 44-week subject more than the artificial re-combinant.  This lead scientists to believe that the Kokumi compounds and subsequent sensation are generated through the ripening process and that re-creating that taste may be a difficult endeavour.  In any event, to get the full Gouda flavor, for now, your best bet is to visit your local cheese shop.

I’ve always thought of eggs as a super food.  It is one of those foods that nutrition gurus across the world say we should eat.  In the past, due to their high cholesterol content, experts advised that eggs were best eaten sparingly.  Interestingly enough, many claim that there is no correlation between eggs and heart disease, the number one cause of death in North America.  Researchers now are saying that the egg can also help reduce high blood pressure.  Another benefit from our famed superhero, the egg.  The study was reported in the Journal of Agricultural Food Chemistry.

Eggs consist of 75% water, 12% proteins, 12% lipids (fats), and 1% vitamins, minerals, and carbohydrates.  Rich in bioactive proteins and peptides (short polymers formed from the linking of amino acids), eggs are a vehicle used to lower high blood pressure.  Scientists at the University of Alberta, Edmonton have found that the process of cooking eggs leads to more of these helpful proteins and peptides.

During digestion, the peptides are either absorbed through the intestine or locally through the gastrointestinal tract.  Antimicrobrial, anticancer, antihypertensive peptides and protease inhibitors all have been reported present in eggs.  One particular enzyme known as ACE (Angiotensin converting enzyme) was of particular interest to the researchers at the univeristy.

ACE is an enzyme responsible for regulating blood pressure.  It is part of the rennin-angiotensin system which which helps maintain stable cardiovascular functions.  ACE catalyzes the formation of angiotensin II (from angioetensin I), a potent vaso constrictor chemical which causes muscles to narrow blood vessels.  This results in the increasing of vascular resistance, decreasing blood flow, and ultimately to high blood pressure.  The compounds in the egg work to inhibit the formation of ACE.

Pharmaceutical companies have also guided efforts for antihypertensive drug development.  These drugs, aptly named ACE inhibitors, slow the activity of ACE.  Captopril, Benazepril, and Enapril are a few that belong to this category.  Often prescribed by doctors, these drugs are based on the same essential concept which is to inhibit ACE.  Side effects do occur for certain people and it is best to let a physician handle those issues.

Considering that table consumption accounts for 70% of total egg consumption in North America, differing cooking methods were addressed by the researchers.  The eggs were cooked two ways:

•  Boiling for 10 minutes, cooling for 5 under cold water, and then peeling.

•  Frying  after separating whites and yolk (each fried separately).

After cooking, they were frozen immediately and then subjected to varying scientific and metabolic processes such as changing pH and introducing pancreatic digestive enzymes.  This was done to mimic the metabolic actions in the gut.

The results showed that the fried egg had the strongest inhibitory factor.  Researchers hypothesized that this may be due to the fried egg having been cooked at a higher internal temperature (170 °C ) than the boiled egg (100 °C), which may have affected the release of bioactive peptides.

Be it fried eggs, egg salad, egg drop soup, or eggs Benedict, it seems that our superhero still belongs to the super food hall of fame.

Reference

J. Agric. Food Chem., 2009, 57 (2), pp 471–477

Other than keeping vampires away, I thought that the benefits of garlic were an urban myth.  Findings posted in the January 2009 issue of of the international chemistry journal Angewandte Chemie apparently have proven me wrong.  The study was conducted by researchers at the Queens University in Ontario.

The organic compound Allicin, which gives garlic its aroma and flavor is thought to be the prime mover.  The sulfenic acid formed  when Allicin decomposition starts reacts rapidly with free radicals which have been known to be responsible for the aging process.  Scientists produced synthetic allicin and the reaction between the acid and radicals resulted in a very potent anti-oxidant.

More specifically, it is peroxyl radicals that are the garlics main target.  Peroxyl radicals belong to to a group called free radicals which are highly  reactive oxygen molecules that have lost an electron.  This loss of an electron make these molecules unstable or in chemical terms, reactive.  To recover this lost electron, a free radical might steal an electron from a neighboring healthy cell.  As a result, vital cellular mechanisms could be compromised.  It is ironic that an essential element can have such a deleterious effect on the human body.  This constant attack on the body is known as oxidative stress and have been linked to diseases such as stroke, cancer, and heart disease. 

Free radicals are derived from basic metabolic processes as well as exposure to X-rays, smoking, air pollutants, ozone, and industrial chemicals.  The role of the anti-oxidant is to take away the harmful properties associated with free radicals.

There is a caveat to this study in that allicin is not found in fresh garlic and the reaction can only take place when the garlic is crushed.  Lots of recipes call for crushed garlic so this should not be a problem.  One technique to use is with the side of a chefs knife smash the garlic down.  This serves two purposes in that you have yourself some crushed garlic and the peeling of the outer skin becomes much easier.

Just like Tom Hanks said in the movie A League of  Their Own, “There’s no crying in baseball” so it may go with prepping and cooking onions.  I used to have a food service job in which I had to chop onions and fill a five gallon jug every Sunday.  If you want to talk about tears, you should have seen me ten minutes into that process.

Onions belong to the genus Allium.  Among the 500 or so species that belong to this genus, members also include garlic, shallots, leeks, and scallions. 

Researchers originally thought that the reason onions create tears is due to sulfuric acid in the eyes.  Huh?  That is correct, I did say sulfuric acid.  The process starts when an onion is first chopped or cut.  As the onions are cut, enzymes called allinases are released.  These enzymes convert amino acid sulfoxides into sulfenic acids.  These acids, being unstable, re-arrange to form gaseous syn-propanethial-S-oxide.  This gas was thought to stimulate the lachrymal glands in the eyes leading to the production of tears.  The water in the tears combine with the gas to form sulfuric acid resulting in stinging eyes.

In actuality, the real tear jerker is called lachrymatory-factor synthase.  This synthase is a second enzyme located in the onion which converts sulfoxides located in the onion into sulfenic acid.  If the enzyme can be blocked then a new product called a tearless onion could be born.  The problem is that the enzyme responsible for the tears is also the enzyme responsible for a good portion of an onions flavor.

Researchers have found that one way to tone down the tear factor is to have onions  grown in sulfur deficient soil thus inhibiting the uptake of sulfur.  This leads to less secondary sulfur compounds in the bulbs.  In doing so, however, the health benefits could be reduced and the onion could lose flavor.  Also, nature doesn’t really do things by accident so there must be some sort of grand design for an onion to have this tear inducing quality.  Strip that away and perhaps the onions natural defenses against fungal and bacterial infections could be compromised.

In the meantime, perhaps home cooks and chefs should just grin and bear it because “there’s no crying in cooking!”

Many people like to buy organic foods believing in the notion that it is a better product.  Unfortunately, this ”superior” product can cost three times as much as non-organically grown foods.  A study published in August of 2008 in the Journal of the Science of Food and Agriculture suggests that buying organically grown food for nutritional value could be a waste of money.

In the study, researchers at the University of Copenhagen have stated that there is no clear evidence to suggest that organically grown food is more nutritious than food grown with pesticides and other chemicals.  The study looked at the retention of minerals and trace elements in animals fed with a vegetable diet from three different cultivation techniques:

1.  low nutrient soil using animal manure and virtually no pesticides

2.  low nutrient soil using anmial manure and pesticides

3.  high nutrient soil using mineral fertilizers and pesticides

All crops experienced the same weather conditions and all were harvested at the same time.  The results showed that in all three cases, no differences in the percentage of trace minerals were seen in the crops.  The harvested produce (carrots, kale, peas, apples, and potatoes) was then fed to animals over a two year period and the uptake, if any, of these trace minerals in animal tissues was measured.  The results showed that no differences were seen in mineral retention based on the three cultivation techniques above.

The scientists go on to state that organic crops are more of a lifestyle choice for the people that can afford to purchase them.

I’m in the process of following a low carb diet called TNT (Targeted Nutrition Tactics), a high fat/high protein diet.  It really isn’t a diet but more of a long-term lifestyle choice.  The basic philosophy of this way of eating is to limit carbohydrate intake, which helps to retain and build lean muscle mass while losing fat.

In science terms, a carbohydrate includes sugars, starches, saccharides, polysaccharides, and cellulose.  These products are a result of the process called photosynthesis.  In chemistry terms, a carbohydrate is a molecule of carbon atoms surrounded by hydrogen (H) and hydroxyl groups (OH).  The general chemical formula for a carbohydrate is C(H2O).   The simplest carbohydrate is a monosaccharide.  Glucose, also known as a simple sugar and fructose, the sugar found in fruits, are common examples of a monosaccharide.  By combining two molecules of a monosaccharide (glucose and fructose), a disaccharide is formed.  Table sugar is the prime example in this category.  Polysaccharides are combinations of monosaccharides strung together.  These strings can be as long as 10,000 monosaccharides long.  These are plentiful in nature with starch and glycogen being two common examples.  Starches are found in stems, roots, and seeds of plants while glycogen is found primarily in the muscle and liver tissues of animals.  Our bodies are able to break down these long complex chains into glucose, which is used as an energy source.

Carbohydrates spike insulin, a hormone that causes our cells to take up glucose from the blood eventually storing it as the polysaccharide glycogen.  Glycogen is readily converted into glucose when the body needs it.  The strategy of a low carb lifestyle is to essentially force our bodies to use something else for energy.  That source is now fat.  One of the benefits of this type of high fat/high protein lifestyle is that it is now much easier to feel satiated without having to knock down a second plate of pasta.  You end up consuming fewer calories, which in turn can lead to weight loss.

This lifestyle also challenges the notion that all vegetables are good vegetables.  To examine this notion further, we should talk about a concept called the glycemic index.  This index was created to measure how readily our blood sugar is raised as it relates to the foods we eat.  For example, white rice, has a GI of anywhere from 50-70 (depending on origin).  On the other hand, carrots GI are 92.  Therefore, by eating carrots, you are raising your body’s blood sugar rather quickly signaling a rapid release of insulin which lowers your blood sugar rapidly.  Carrots and other high GI carbs (pasta, potatoes, bread) do not leave a feeling of satiation as compared to consuming a high fat food.  Often times, this can lead a  person to want to take eat more. 

Something that hasn’t been discussed yet is serving size.  A tool to measure this is called the Glycemic Load (GL).  The GL measures serving size and is the GI multiplied by the number of carbohydrate grams in a portion of food divided by 100.  The tenet behind this number is that a small portion of a high glycemic index food would give a similar result as a larger portion of a lower glycemic index food.  This should give a more accurate result of what kind of an effect a serving size of a particular food will have on actual glucose levels in the blood.

The beauty of this ”diet” is that there is no need to count calories or have to carry around a card with point systems on it.  The simplicity seems to work for me.  Eat high protein/fat foods with carbohydrates mixed in around workouts (carbohydrates help shuttle protein to muscles) and try not to combine carbohydrates and fats during the same meal.  I eat until I am satisfied but not stuffed and I have small meals throughout the day.  I have noticed that my jeans are a little bit baggier and that a need to tighten the belt a few more notches.  My energy levels are good and my latest blood work has my total cholesterol down and my triglycerides way down.  Who would have thought that this would be possible by eating bacon, eggs, and cheese every day.