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Ship Biscuit and Salted Beef

Let’s get this Bread (and other sources of Carbohydrates)

By Alyssa Shewmaker

Did you know that 5 out of 7 of our foods tested contain carbohydrates? Carbohydrates are made up of three components: fiber, starch, and sugar. Fiber and starch are complex carbs and sugar is a simple carb. Some examples of these carbs are pasta, bread, and veggies. In our case, this includes the oatmeal, biscuits, peas, wine, and beer that are tested in the SBSB research project! Carbohydrates also include fiber. Fiber is a type of carbohydrate the human body can not digest. There are two types of fiber, soluble and insoluble fiber. Soluble fiber dissolves in water and forms a gel consistency (think of the coating around chia seeds when immersed in water) while insoluble fiber does not dissolve in water.

Carbohydrates are broken down into glucose (blood sugar), and then are used for energy to power your body. Carbohydrates are the body’s main source of energy, but the amount of energy depends on if they are broken down from a simple or complex carbohydrate. Although a large part of the sailor’s diet comes from carbohydrates, these foods have varying energy densities. The energy from a simple carb (think beer) gets used much faster than a complex carb. The issue with consuming a majority of simple carbohydrates, is the energy supplied is not efficient enough to keep a busy body working. When a complex carb is eaten (think oatmeal), the structure of the food is much sturdier, therefore it takes a longer time to breakdown causing energy to be released slowly over time. A complex carb is an ideal source of energy for sailors.

“You do not want to miss these results, I’ve been told I have a complex breakdown!”

Fiber is needed in a daily diet to help with satiety (feeling of satisfaction) and keeping the bowels moving. Fiber can help improve cholesterol and blood sugar levels, and assist in preventing diseases such as diabetes, heart disease and rectal cancer. Fiber is like the super hero of carbs, always willing to help out his buddies in the body. But just like all things, too much or too little fiber can cause some health problems in the body. 

Our first step in analyzing carbohydrates in our food is to find the nitrogen-free extract (NFE); better known as simple carbohydrates. Sugars and starches are highly digestible forms of carbohydrates, while fibers are generally less digestible and pooped out. Fiber is not included in the nitrogen-free extract equation. NFE is calculated as the percentage of feed that is not moisture, protein, fiber, fat, or inorganic residue.

NFE = % DM – (% EE + % CP + % ash + % CF)

Dry matter (DM)

Ether extract (EE)

Crude protein (CP)

Ash is the inorganic residue

Crude fiber (CF)

Our amazing team has already performed the dry matter test! (For the results and information on the insanely cool dry matter test, please visit our blog post: To sum up the results, the wet goods (especially meats) all decreased in water content, whereas the dried goods mostly remained the same. The difference in moisture was mainly caused by the change in osmolality between the meat and the salty brine. This helped preserve the meat! Below is a picture of the ground up food items in the dessicator ready to undergo drying! 

Moisture assay showing the ground food items in crucibles for drying.

Once NFE is calculated, we will get started on finding the amount of fiber in our food! Total digestible nutrients (TDN) is the sum of digestible fiber, protein, lipid, and carbohydrate components of the feed. This is sometimes used to describe energy available in feeds. Below is the formula to calculate TDN. This formula will be used to identify crude fiber, or the total fiber content. 

TDN = digestible NFE + digestible CF + digestible CP + (digestible EE x 2.25) 


Nitrogen-free extract (NFE)

Crude fiber (CF)

Ether extract (EE)

Crude protein (CP)

Once we have crude fiber we are able to get down and dirty with our soluble and insoluble fiber. We found two tools to help up mirror soluble and insoluble fiber well. Neutral detergent fiber (NDF) is the structural components of the plant, specifically cell wall. NDF is a predictor of voluntary intake because it provides bulk or fill. This measures the digestible and indigestible parts found in the cell wall. We will also be using Acid Detergent Fiber (ADF) to help identify the amounts of each fiber. ADF is the least digestible plant component found in the alkaline sections of the cell wall. We can measure the soluble fiber by taking the difference in NDF and crude fiber to get the soluble fiber content of the food!


Stay tuned for our next post!