The Effect of Inulin as a Fat Replacer in a Regular Homemade Chocolate Pudding
Individual Project: Written Report Olga Suchshinskaya & Maggie McKay Lab Section 003 November 24, 2008
I. Title: The Effect of Inulin as a Fat Replacer in a Regular Homemade Chocolate Pudding.
II. Abstract: Inulin is a functional ingredient usually extracted from the chicory root that has become
increasingly popular in the food industry due to its potential health benefits as well as its
functional properties in foods. Both an indigestible fiber and a prebiotic food, it is most known
for promoting digestive health. When added to food products, it is mainly used to replace fat
because it has been shown to simulate the creamy texture that fat contributes to food products.
The type of inulin used in this experiment was HP inulin, which is especially designed for
replacing fat. It has a high degree of polymerization, and is therefore only slightly soluble in
water. It forms a gel when mixed in aqueous solution, works well with other gelling agents,
retains water, and stabilizes gels. It also has been show to contribute little viscosity to a product.
In this experiment, the effects of different inulin concentrations on a cornstarch-based
homemade chocolate pudding were compared to the effects of butter in the original recipe. The
control was the original recipe that used 5.57 g butter per 100g pudding. The three variables
were 10g inulin/100g pudding, 20g inulin/100g pudding, and 30 g inulin/100g pudding. Results
revealed no significant difference (p > 0.05) in viscosity between the control and the 10 g and 20
g inulin samples. However, there was a significant increase (p < 0.05) in viscosity between the
aforementioned samples and the 30 g inulin sample. There was no significant difference (p >
0.05) between the activities of water of the four samples. For each of the three trials, 6-7
volunteers completed a subjective sensory panel to evaluate the color, sweetness, texture, and
palatability of the four variables. Overall, the 30g inulin was ranked as having the most preferred
color. On the other hand, the control was ranked as having the best sweetness, texture, and
palatability. The 10 g inulin sample was ranked as having the second-best sweetness, texture,
and palatability. Based on these results, using 10 g of inulin or less per 100 g of chocolate
pudding seems to best simulate the properties of the full-fat version of the pudding while also
providing similar texture, sweetness, and palatability. In addition, adding inulin allows for the
aforementioned health benefits.
A) Background Information: The Effects of HP Inulin, Butter, Cornstarch, and Milk Proteins on Homemade Chocolate Pudding
Inulin is a functional ingredient that has become increasingly popular in the food industry. It
is a natural fructan used by plants for carbohydrate storage (Niness 1999). Plants containing inulin
include wheat, onion, bananas, garlic, and chicory (Niness 1999). Typically, food industries extract
the fructan from the chicory root (Niness 1999).
Inulin is proving to be a successful functional ingredient in foods due to its research-
supported health benefits as well as favorable effects on the properties of some food products.
According to an article by Kathy Niness published in the Journal of Nutrition, inulin is used as a fat
and/or sugar replacement in foods, thus helping to reduce the total kcal of a product (Niness 1999).
Not only that, but as it is an indigestible fiber, it enhances ones daily fiber intake, and can thus help
people meet the American Heart Association recommendations of 14 g fiber per 1000 kcal (AHA
2008). An increase in ones intake of inulin would improve digestive health, promoting the
regulation of bowel movements (Roberfroid 2005). Similarly, inulin is a prebiotic food, meaning that
it promotes the growth of beneficial micro flora in the colon. More specifically, it is fermented by
bifidobacteria. As a result, inulin helps to increase the proportion of beneficial bacteria in the colon,
and decrease the proportion of potentially harmful bacteria (Roberfroid 2005).
Stemming from its role as an indigestible fiber, inulin has also been shown to decrease
serum triglyceride and blood cholesterol levels in patients with hypertriglyceridemia or
hypercholesterolemia (Niness 1999 and Roberfroid 2005). Hence, inulin may help reduce ones risk
for cardiovascular disease. Moreover, as research shows it does not have great influence on serum
glucose levels, it can be safely used by diabetics (Niness 1999).
Finally, inulin may also improve calcium storage in bones. According to Niness, over ten
research studies have shown that inulin enhances calcium absorption and deposition in the bones of
rats and humans (Niness 1999).
Questions that still remain unanswered regard the daily amount of inulin needed to achieve
the different health benefits inulin provides: bowel regulation, prebiotic effects, increased calcium
absorption, a decrease in serum cholesterol and triglyceride levels, etc. There seems to be much
debate on this issue of how much inulin will cause an increase in its different health benefits. Cargill
Health and Food Technologies claim that consuming 5 g of inulin a day will provide one with the
prebiotic effects of inulin, and that consuming 8 g a day will increase calcium absorption (Cargill
Inc. 2005). However, in a study published in Nutrition, the author Dahl stated that it is acceptable to
consume as much as 40 g of inulin per day. Furthermore, in Dahls study, which observed the effects
of inulin on patients in wheelchairs, the 12.6 g/day of inulin given to subjects throughout a three-
week period did not cause an increase in calcium absorption. Dahl further cited another study in
which subjects receiving 17 g/day of inulin had no increase in calcium absorption. On the other
hand, Dahl also stated other studies in which acute calcium absorption was noted in patients who
were suffering from a health condition that required greater calcium absorption (Dahl 2005). In terms
of bowel regulation, the 12.6g/day administered to subjects in Dahls study was enough to provide
bowel regularity (Dahl 2005). But is that the minimum amount needed to provide regularity? The
same question can be proposed in terms of inulins effects on serum cholesterol and triglyceride
levels: Just how much is enough? One thing that is certain, however, is inulins ability to lower the
total kcal and fat content of foods.
Besides its potential to provide health benefits, inulin also has a positive effect on the
properties of food products. In fact, it is used to replace fat and/or sugar in baked goods, table
spreads, fillings, dairy products, frozen desserts, and dressings (Niness 1999). As stated by Hunter in
Consumers Research Magazine, inulin lowers the caloric value of food while enhancing the texture
and thickness of the food, producing a creamy mouth-feel (Hunter 2003). Inulin is also known to
raise the viscosity of sauces, increase air and thus volume of nonfat icings and whipped toppings,
and add a sweet taste to the productall the while not affecting the color of the food (Hunter 2003).
A study published in the International Dairy Journal by Tarrega confirmed some of these food-
enhancing effects of inulin. In this study, the researchers compared fat-free, starch-based dairy
desserts that contained different inulin concentrations, with a full-fat version of the dessert. The fat-
free samples containing inulin increased in sweetness, thickness, and creaminess as the inulin content
increased. Moreover, the inulin-containing samples that had a low starch concentration were rated as
having the same thickness as the full-fat version of the dessert (Tarrega 2006).
A study by El-Nagar produced similar results when comparing an inulin-containing low-fat
yogurt ice cream with a high fat version of the ice cream. El-Nagar explained that inulin is
hygroscopic, meaning that it binds tightly to water, forming a gel-like network and thus contributing
to the viscosity and thickness of a product (Nagar 2002). Since it binds water so tightly, it also is a
strong stabilizer of molecules, thus improving the consistency of the ice cream. As a result, the
inulin-containing sample was rated by participants as being similar in quality to the high-fat version,
and also as having a soft and smooth texture. In this experiment, increasing the inulin content from
10g to 14g to 18g did not have an increasing effect on texture (Nagar 2002). Thus, the effects of
inulin may reach a maximum value at a certain inulin concentration.
It is important to note that there are different types of manufactured inulin products. Though
all types of inulin share some general characteristics in terms of their effects on food properties, they
also affect food properties in unique ways due to differences in their structures. In this experiment,
Raftiline HP gel was the type of inulin used in all three trials. Standard inulin is made up of 92%
inulin and 8% sugars. HP inulin, on the other hand, does not contain sugars (Foodnavigator.com
2003). Unlike other types of inulin, HP inulin is known as high perfo