What is Carob Fiber and Where is it Used?
In addition to sugar, the pulp of the carob fruit contains a significant amount of dietary fiber and polyphenols. After the sugars are removed with water, the remaining, insoluble fiber-rich part can be processed into a functional food ingredient called "carob fiber". What distinguishes this fiber from many other fiber sources is that it carries a high amount of polyphenols due to its structure.
In this article, we discuss what carob fiber is, how it is obtained, its polyphenol composition, its technological effects in bread, pasta and snacks, and what studies in humans show, along with their limitations.
What is Carob Fiber?
The term "carob fiber" generally refers to a preparation rich in insoluble dietary fiber obtained from carob pulp in the literature. In the 2003 clinical study of Zunft et al., this product was defined as "carob pulp preparation with high insoluble fiber content"; Gruendel et al. also called the same type of product "insoluble dietary fiber preparation rich in polyphenols".
These definitions point to an important distinction. Carob flour (powder) is obtained by drying and grinding the fleshy part of the fruit and preserves its natural sugars to a large extent. Carob fiber, on the other hand, is a product in which a significant part of the sugars are removed and concentrated in fiber and polyphenols. Therefore, although the two products come from the same raw material, they are different in terms of composition and intended use.
Another source of carob fiber is the pulp left over from molasses production. In molasses production, after the sugars are extracted with water, a fiber-rich solid remains. In a clinical study conducted in Turkey, this pulp was dried and turned into flour and used in bread formulation as a "by-product with high nutritional value with high insoluble fiber and antioxidant content".
Soluble and Insoluble Fiber Difference
Dietary fibers are generally divided into two groups as water-soluble and insoluble fibers. While soluble fibers can form viscous solutions or gels with water, insoluble fibers are more volumizing and water-retaining properties.
Carob is an interesting example in this respect; since different parts of the same fruit offer different types of fiber:
| Pulp (fleshy part) | Rich in insoluble fiber and polyphenols; It is a source of carob fiber products. |
| Nucleus endosperm | It contains galactomannan, a soluble fiber, i.e. carob gum (E410). |
For this reason, when "carob fiber" is mentioned, insoluble fiber originating from pulp is mostly meant; carob gum is considered as a separate product. In the background of their study, Zunft et al. stated that in the background of their study, it was observed that insoluble fiber obtained from carob pulp could affect blood lipids in a similar way to soluble fibers in animal studies; this indicates that this fiber, although insoluble, may behave unusually.
Polyphenol Composition: What Sets Fiber Apart
The most distinctive aspect of carob fiber is its polyphenol content. In the 2003 study of Owen et al., the main polyphenols in carob fiber were isolated and their structures were elucidated. A total of 24 polyphenolic compounds were identified in the study and a yield of 3.94 g/kg was obtained in dry weight.
| Polyphenol group | Share in total polyphenols (Owen et al., 2003) |
|---|---|
| Free gallic acid | %42 |
| Gallotanens | %29 |
| Flavonoids | %26 |
| Simple phenols (mainly cinnamic acid) | about 2% |
| Methyl gallate | %1 |
Among flavonoids, myricetin-3-O-rhamnoside and quercetin-3-O-rhamnoside stood out with shares of about 9 percent and 10 percent, respectively. The authors concluded that carob fiber is rich in phenolic antioxidants, both in quantity and variety.
Carob pulp also contains condensed tannins. In a 2017 study by Macho-González et al., the effects of fiber-purified extract from carob fruit on carbohydrate digestion and absorption due to its condensed tannin content were examined in laboratory and animal models. These findings are at the experimental level and should not be generalized directly to human health.
Use in Bread and Dough Products
One of the most common uses of carob fiber in the food industry is in baked goods. The addition of fiber changes the water absorption capacity and rheological behavior of the dough.
In the 2012 study by Miś et al., 1–5 percent carob fiber was added to wheat flour; it has been reported that this addition increases the water absorption capacity of the dough from approximately 56 percent to 59 percent and makes the dough more rheologically stable during kneading. Such data indicate that the amount of water and kneading time in fiber bread formulations need to be readjusted.
In a clinical study conducted in Turkey (Tuşat et al., 2025), white bread enriched with molasses pulp flour and wheat germ was developed. During the formulation phase, breads containing 0-20 percent molasses pulp flour were prepared, and the final test bread was determined to contain 20 percent pulp flour and 20 percent wheat germ. The fiber, polyphenol, antioxidant, and resistant starch content of the test bread was found to be significantly higher than the control bread. No significant difference was observed in blood glucose and oxidative markers during the intervention phase with 16 healthy volunteers; on the other hand, it was reported that the test bread increased the feeling of satiety, especially in the first measurement times.
Use in Pasta and Snacks
Pasta is a frequently preferred product for fiber enrichment. In the 2017 study by Biernacka et al., pastas in which wheat flour was substituted with 0-5 percent carob fiber were examined. The findings can be summarized as follows:
- As the fiber content increased, the color of the pasta became noticeably darker.
- The optimum cooking time is shortened, the cutting force is linearly reduced.
- Up to 4 percent carob fiber had little impact on overall acceptability.
- Total phenolic substance content and antioxidant activity increased significantly.
In the snack industry, mixtures containing carob flour and fiber are also being tried. In Arribas et al.'s study on extruded gluten-free snacks, high nutritional value products were developed from rice, pea and carob flour mixtures; it has been reported that extrusion reduces total dietary fiber by approximately 30 percent and the insoluble fraction is more affected by this process than the soluble fraction. This result is a reminder that the expected benefit from fiber may vary depending on the process conditions.
What Do Human Studies Show?
Carob fiber has also been investigated in humans for its effects on blood lipids. While these studies are promising, they are limited in number and the participant groups are small.
Zunft et al. (2003): In this randomized, double-blind, placebo-controlled study with 58 volunteers with hypercholesterolemia, participants consumed a bread and fruit bar containing a total of 15 g of carob fiber per day for 6 weeks. It was reported that LDL cholesterol decreased by 10.5 percent in the carob fiber group; The decrease in the LDL/HDL ratio remained at the borderline level of significance. A decrease in triglycerides was also observed in women.
Ruiz-Roso et al. (2010): In a double-blind, randomized, placebo-controlled study with 88 volunteers with hypercholesterolemia, a fiber very rich in insoluble polyphenols was consumed for 4 weeks, 4 g twice a day. At the end of the study, a 17.8 percent decrease in total cholesterol and a 22.5 percent decrease in LDL cholesterol were reported compared to baseline; no significant change was observed in the placebo group.
Gruendel et al. (2007): In a cross-design study conducted with 19 healthy volunteers, it was observed that triglyceride and free fatty acid responses decreased but glucose response increased the day after consuming foods containing 50 g of carob fiber. In another study of the same team, it was reported that carob fiber increased plasma glucose and serum insulin responses when taken together with glucose loading. The authors emphasized that these findings related to glucose should be investigated in the future.
When these studies are evaluated together, it can be said that the possible effects of carob fiber on the lipid profile are worth investigating, but the effects on glucose metabolism are not consistent and more studies are needed. These findings do not mean that carob fiber cures any disease.
This content is for informational purposes only; it is not a substitute for medical advice.
Formulation Considerations
For manufacturers looking to add carob fiber to a product, some practical points stand out:
| Color | Carob fiber darkens the product; this may be a limitation in light-colored products. |
| Water balance | Fiber binds water; the amount of water in dough and mixtures should be readjusted. |
| Taste and astringency | Its polyphenol and tannin content can create a slightly astringent taste at high rates. |
| Process effect | Processes involving high temperatures and pressures, such as extrusion, can alter fiber fractions. |
| Labeling | Statements regarding fiber content must be verified by analysis and comply with applicable legislation. |
Frequently Asked Questions
What is the difference between carob fiber and carob flour? Carob flour is obtained by drying and grinding the fleshy part of the fruit and preserves its natural sugars. Carob fiber, on the other hand, is a product that has removed most of the sugars and is concentrated in fiber and polyphenols.
Is carob fiber soluble or insoluble? Pulp-derived carob fiber is predominantly insoluble fiber. The soluble fiber source of carob is carob gum obtained from the kernel.
Can molasses pulp be utilized? Yes. In research, the pulp left over from molasses production was dried and turned into flour and used as a fiber source in products such as bread.
Does carob fiber lower cholesterol? Reductions in LDL cholesterol have been reported in some small-scale clinical trials; however, these findings do not imply a cure and need to be confirmed by larger studies.
Carob Raw Materials with Carob Türkiye
Carob fiber is one of the products obtained by passing the fleshy part of the fruit through different processing steps. The quality of these products is largely related to the cleanliness, moisture and processing of the starting raw material.
At Carob Türkiye, we supply carob fruit, crumb, flour/powder, kernel and extract. For related products Carob Kibble (Granular) and Carob Flour / Powder Our pages for the properties of flour What is Carob Flour Powder? You can review our article. For your wholesale and export requests Contact Now You can contact us on our page.
Foreign sources
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org/ 10. 1007/ S00394- 003- 0438- y Ruiz-Roso, B., Quintela, J. C., de la Fuente, E., Haya, J., Pérez-Olleros, L., "Insoluble carob fiber rich in polyphenols lowers total and LDL cholesterol in hypercholesterolemic subjects", Plant Foods for Human Nutrition, 2010, 65(1), 50–56. doi.
org/ 10. 1007/ S11130- 009- 0153- 9 Owen, R. W., Haubner, R., Hull, W. E., Erben, G., Spiegelhalder, B., Bartsch, H., Haber, B., "Isolation and structure elucidation of the major individual polyphenols in carob fibre", Food and Chemical Toxicology, 2003, 41(12), 1727–1738. doi.
org/ 10. 1016/ S0278- 6915(03)00200- X Gruendel, S., Garcia, A. L., Otto, B. et al., "Increased acylated plasma ghrelin, but improved lipid profiles 24-h after consumption of carob pulp preparation rich in dietary fibre and polyphenols", British Journal of Nutrition, 2007, 98(6), 1170–1177. doi.
org/ 10. 1017/ S0007114507777127 Gruendel, S., Otto, B., Garcia, A. L. et al., "Carob pulp preparation rich in insoluble dietary fibre and polyphenols increases plasma glucose and serum insulin responses in combination with a glucose load in humans", British Journal of Nutrition, 2007, 98(1), 101–105. doi.
org/ 10. 1017/ S0007114507701642 Tuşat, E., Parlak, E., Yıldırım, G., Öztop, K., Gülşen, B., Özdemir, Y., Uysal, Y., "Impact of White Bread Fortified With Carob Molasses Pulp Flour and Wheat Germ on Glycemic Response and Antioxidant Capacity in Healthy Subjects", Food Science & Nutrition, 2025, 13(12), e71046. doi.
org/ 10. 1002/ FSN3. 71046 Biernacka, B., Dziki, D., Siastała, M., Różyło, R., Gawlik-Dziki, U., "Physical, sensorial, and antioxidant properties of common wheat pasta enriched with carob fiber", LWT – Food Science and Technology, 2017, 77, 186–192. doi.
org/ 10. 1016/ j. lwt. 2016. 11. 042 Miś, A., Grundas, S., Dziki, D., Laskowski, J., "Use of farinograph measurements for predicting extensograph traits of bread dough enriched with carob fibre and oat wholemeal", Journal of Food Engineering, 2012, 108(1), 1–12. doi.
org/ 10. 1016/ j. jfoodeng. 2011. 08. 007 Macho-González, A., Garcimartín, A., López-Oliva, M. E. et al., "Fiber purified extracts of carob fruit decrease carbohydrate absorption", Food & Function, 2017, 8(6), 2258–2265. doi.
org/ 10. 1039/ C7FO00166E Arribas, C., Cabellos, B., Sánchez, C., Cuadrado, C., Guillamón, E., Pedrosa, M. M., "The impact of extrusion on the nutritional composition, dietary fiber and in vitro digestibility of gluten-free snacks based on rice, pea and carob flour blends", Food & Function, 2017, 8(10), 3654–3663. doi.
Scientific Resourcesorg/ 10. 1039/ C7FO00910K
