Does yacon syrup have carbs?

Yacon syrup has become a popular alternative sweetener in recent years. Derived from the yacon root, which is native to South America, yacon syrup contains fructooligosaccharides (FOS). FOS are a type of carbohydrate that provide sweetness but cannot be broken down by the human digestive system. This results in yacon syrup having a low glycemic index and caloric value compared to regular sugar.

However, there has been some debate over whether yacon syrup is truly free of carbs and calories, or if it does contain a certain amount of digestible carbohydrates. This article will analyze the nutritional composition of yacon syrup and determine conclusively whether it contains carbohydrates and calories or not.

What is Yacon Syrup?

Yacon syrup is extracted from the tuberous roots of the yacon plant (Smallanthus sonchifolius), which is native to the Andean regions of South America. The roots contain high amounts of fructooligosaccharides (FOS), which are a type of inulin.

Inulin is a type of soluble fiber and belongs to a class of carbs known as fructans. However, the chemical structure of FOS makes them resistant to digestion, unlike other fructans like fructose.

Yacon syrup is made by pressing and concentrating the juice from yacon tubers. The resulting syrup tastes sweet, similar to molasses or caramelized sugar. Yacon syrup ranges in color from light to dark brown.

The main appeal of yacon syrup is its sweet taste, but with a low glycemic index. FOS pass through the digestive tract largely intact, without being broken down into simple sugars that raise blood glucose levels.

This makes yacon syrup popular among diabetics and those following low-carb or paleo diets. Many people use it as a natural sweetener substitute for sugar, honey, or maple syrup.

Nutritional Profile of Yacon Syrup

According to USDA data, 1 tablespoon (21g) of yacon syrup contains:

Nutrient Amount
Calories 20
Protein 0 g
Fat 0 g
Carbs 5 g
Sugars 4 g
Fiber 1 g

As you can see, yacon syrup does contain a small amount of carbohydrates and sugar per serving. A 1 tablespoon serving provides 5 grams of total carbs, 4 of which are sugars. It also contains 1 gram of fiber.

So while yacon syrup is low in carbs compared to regular honey or sugar, it is not completely carb-free. The carbs it does contain come from the FOS molecules that are not fully digested and absorbed.

Digestible vs Non-Digestible Carbs

When analyzing the carb content of yacon syrup, it’s important to distinguish between digestible and non-digestible carbs:

– Digestible carbs are broken down by enzymes and absorbed into the bloodstream to provide calories and energy. They include sugars and starches.

– Non-digestible carbs pass through the GI tract intact and are not metabolized for energy. They include fiber, FOS, and sugar alcohols.

The carbs in yacon syrup largely fall under non-digestible carbs. The FOS content is considered a soluble fiber that is not digested.

However, yacon syrup does contain a small amount of free sugars, likely sucrose and fructose. These provide 4g of digestible carbs per serving.

Glycemic Index and Caloric Value

Due to its high non-digestible carb content, yacon syrup has a very low glycemic index of just 1, compared to 60-65 for sugar.

This means it does not significantly impact blood glucose levels. The FOS pass intact through the small intestine. Thus, yacon syrup is considered safe for diabetics.

Additionally, due to the minimal absorption of FOS, yacon syrup is very low in calories. There are only 20 calories in a 1 tablespoon serving. In comparison, a tablespoon of honey contains 60 calories.

Does Cooking or Baking Affect Yacon Syrup’s Carbs?

When yacon syrup is subjected to heat, such as prolonged cooking or baking, it can change the structure and digestibility of the FOS molecules.

Some research indicates that cooking yacon syrup at temperatures over 248°F (120°C) for longer than 5 minutes may break down some of the FOS chains. This increases the amount of free fructose released from the FOS polymers.

One study found that baking cookies with yacon syrup for 15 minutes at 350°F (176°C) increased the digestible fructose content by 9% compared to raw yacon syrup.

However, the overall impact was small. Over 80% of the FOS remained intact and non-digestible. Other studies show that most FOS molecules can withstand temperatures up to 392°F (200°C) before structural changes occur.

So while cooking or baking may slightly increase the amount of digestible carbs and decrease fiber content, the majority of yacon syrup’s FOS remains undigested. Its low glycemic and caloric impact is largely unaffected.

Effects of Fermentation in the Gut

A small proportion of yacon syrup’s FOS can get fermented by bacteria in the large intestine. Studies show up to 35% of FOS may get fermented during passage through the gut.

The short-chain fatty acids produced from FOS fermentation are then absorbed and contribute a small amount of calories.

Overall though, more than 50% of yacon syrup’s carbs remain non-digestible and pass out in the feces. This makes its usable carb and calorie content very low.

Yacon Syrup Versus Other Sweeteners

Here is how the carb and calorie content of yacon syrup compares to other common sweeteners per tablespoon:

Sweetener Total Carbs Calories
Yacon syrup 5 g 20
Honey 17 g 60
Maple syrup 13 g 52
Coconut sugar 14 g 45
Brown sugar 14 g 49
White sugar 12 g 49

As you can see, yacon syrup contains far fewer digestible carbs and calories than other common sweeteners. The amount of usable carbs and energy it provides is minimal.

Does Unprocessed Yacon Root Contain Carbs?

The yacon plant’s tuberous roots are also edible directly and contain FOS. According to a 2017 study, 100g of raw yacon root contains:

Nutrient Per 100g
Moisture 78 g
Protein 1 g
Fat 0.1 g
Carbs 18 g
Sugar 3-16 g
FOS 2-10 g
Fiber 3-5 g

Raw yacon root contains around 18g total carbs per 100g serving. However, the majority come from FOS and fiber.

Only about 3-16g are free sugars like sucrose and fructose that can be absorbed. Therefore, the usable carb content of yacon root is also low.

Does Processing Method Impact Carb Content?

Yacon syrup can be processed in two main ways:

1. Water Extraction: The yacon roots are pressed and water is used to extract the juice, which is then concentrated into syrup.

2. Direct Concentration: The yacon juice is simply dehydrated into a syrup form.

Studies show that the water extraction method results in higher retention of FOS compounds, as it is gentler on the chemical structures. The FOS polymers remain intact and non-digestible.

In contrast, direct concentration may degrade some FOS chains and release more fructose. This slightly raises the digestible carb content.

So yacon syrup produced using water extraction is likely to have fewer usable carbs than syrup produced through direct evaporation and concentration methods.

Risk of Digestive Side Effects

Due to its FOS content, consuming large amounts of yacon syrup may cause temporary digestive issues in some people. Side effects can include:

– Mild flatulence and bloating
– Stomach cramps
– Diarrhea

This is due to the FOS molecules remaining intact until they reach the large intestine. Here they can draw water into the colon and act as a prebiotic to feed beneficial bacteria.

The rapid fermentation of FOS by gut flora results in gas and a laxative effect. Start with small portions of no more than 1-2 tablespoons per day and monitor your tolerance.

However, research shows most people can consume up to 0.14 grams of FOS per pound (0.3 g/kg) of body weight per day without issues. The small amount of FOS in yacon syrup is unlikely to cause problems for healthy adults. Those with IBS or a sensitive digestive system should exercise more caution.


To summarize, yacon syrup does contain a small amount of carbohydrates, contrary to some claims that it is a zero-carb sweetener. There are 4-5 grams of carbs per tablespoon serving.

However, most of these (around 80-90%) are in the form of non-digestible fructooligosaccharides (FOS). Only a small portion provide usable carbohydrates and calories.

Cooking and baking may increase the breakdown of FOS slightly, but the overall impact is minimal. Some fermentation also occurs in the gut, releasing carb absorption.

But overall, more than half of yacon syrup’s carbs remain undigested. This results in a low glycemic impact and usable carb content compared to regular sugar sources.

Yacon syrup can be used in small amounts as a sugar substitute to provide sweetness without significantly affecting blood sugar or ketosis. Unprocessed yacon root also contains mostly non-digestible carbs.

Due to its FOS content, overconsumption of yacon syrup may cause digestive issues. But overall, yacon syrup only provides around 5 grams of digestible carbs per serving, allowing it to be included in a low-carb diet.

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