Carob Antioxidant Properties
Carob; It is a fruit rich in polyphenolic compounds such as gallic acid, gallotanins, condensed tannins and flavonoids. In laboratory studies, carob extracts and powders show significant antioxidant activity.
However, antioxidant capacity measured in a test tube does not mean that the same effect will occur in the human body. In this article, we discuss what antioxidant compounds are present in carob, how they are measured, how processing affects these compounds, and how the results should be interpreted.
What is an Antioxidant and How is it Measured?
Antioxidants are compounds that can slow down or prevent oxidation reactions caused by reactive molecules such as free radicals. The most discussed group of antioxidants in plant foods is polyphenols.
Antioxidant properties in foods are usually evaluated in the laboratory by methods such as:
| Total phenolic substance (Folin-Ciocalteu method) | It approximates the total amount of phenolic compounds in the sample; the result is usually given as the equivalent of gallic acid. |
| Radical scavenging tests (DPPH, ABTS) | For example, it measures the extent to which it neutralizes an artificially created radical. |
| Lipid oxidation tests | For example, it evaluates the extent to which it retards the oxidation of fats. |
| Metal chelation tests | It measures the capacity to bind metal ions, which accelerates oxidation. |
Each method measures a different aspect of antioxidant behavior; therefore, the results obtained by different methods cannot be directly compared. In addition, all of these tests are performed in a laboratory (in vitro) environment.
What antioxidant compounds are in carob?
The polyphenol profile of carob fruit has been examined in many studies. According to review studies, mature carob pods may contain 16–20 percent condensed tannins by dry weight (Goulas et al., 2016).
In a detailed analysis of carob fiber in Germany, 24 polyphenol compounds were identified and the total yield was found to be 3.94 g/kg in dry weight. The distribution of these polyphenols is as follows (Owen et al., 2003):
| Compound group | Share in total polyphenols |
|---|---|
| Free gallic acid | Approx. 42% |
| Gallotanins | About 29% |
| Flavonoids (mainly myricetin- and quercetin-rhamnosides) | About 26% |
| Simple phenols (mainly cinnamic acid) | About 2% |
| Methyl gallate | About 1% |
Similar compounds have been detected in carob products in different studies. Gallic acid, catechin, quercetin, myricetin, and kempferol have been identified in the Imera variety in Greece (Amerikanou et al., 2025). In studies on carob powder, quercitrine and cinnamic acid have been reported to be among the most abundant phenolics (Frühbauerová et al., 2022).
We consider the chemical structure of carob tannins and polyphenols in more detail in a separate article.
What Do Laboratory Studies Show?
In a pioneering study conducted in Japan, crude polyphenol fraction was obtained from carob pods. The total polyphenol content of this fraction was measured as 19.2 percent. The crude polyphenol fraction showed a stronger protective effect than pure polyphenols such as catechins and procyanidins in the beta-carotene bleaching test. In DPPH radical scavenging and lipid peroxidation tests, it showed weaker activity than pure compounds at the same concentration; however, when corrected for polyphenol concentration, its activity was found to be comparable to pure compounds (Kumazawa et al., 2002).
Antioxidant activity has also been studied in food products such as carob powder and molasses:
- In the Czech Republic, the total phenolic substance in carob powder prepared by cryogenic grinding was measured as 6.46 mg gallic acid equivalent/g, and the antioxidant capacity of this powder was found to be higher than that of powders prepared by vibrating grinding (Frühbauerová et al., 2022).
- Syrups prepared in Lebanon from 19 different carob accessories generally contained more phenolic acids, flavonoids, and total phenols and showed higher antioxidant capacity than date and maple syrups (Toufeili et al., 2022).
- The total phenolic substance in carob molasses purchased from the market in Turkey was found to be in the range of 5.80–18.00 mg gallic acid equivalent/g (Yavuz Küçük & Duraklı Velioğlu, 2022).
- Another study examining commercial carob molasses in Turkey observed significant differences between the antioxidant potential and gallic acid content of the samples (Deliorman Orhan et al., 2025).
These results show that the antioxidant properties of carob products vary widely according to the type, variety and production method of the product.
How Does Processing Affect Antioxidant Compounds?
Carob is usually not direct; It is consumed dried, roasted, ground or extracted. These processes can affect polyphenols in different directions.
Roasting. In a study conducted in Lebanon, roasting carob powder increased the total phenolic substance and total antioxidant activity values in the powder (Srour et al., 2016). It should be taken into account that the Maillard reaction products formed during roasting may also contribute to the results of some antioxidant tests.
Grinding. Extending the grinding time in the vibrating mill increased the extractability of phenolic compounds in carob powder; however, the bioaccessibility of these compounds decreased in digestion simulation (Červenka et al., 2022). A study conducted in Portugal also reported that the fine fraction of 100 μm and below showed a different phenolic and antioxidant profile than the coarse fractions (Vilas-Boas et al., 2022).
Heat treatment and condensation. Long heat treatments in molasses and syrup production can alter the polyphenol profile and lead to the formation of undesirable compounds like HMF. Researchers therefore recommend more moderate heating regimes in syrup production (Toufeili et al., 2022).
Bioaccessibility: How Much of the Compounds Can Be Used?
The amount of antioxidant compounds in a food is not the same as how much these compounds can be used in the body. Bioaccessibility refers to the proportion of compounds that are released from food during digestion and become ready for absorption.
Digestion simulation studies with carob powder provide remarkable findings in this regard. In the Portuguese study, the total phenolic content measured during the gastric digestion stage increased compared to the undigested sample (Vilas-Boas et al., 2022). In the Czech studies, the bioaccessibility of some phenolics increased compared to the grinding method, while others decreased (Frühbauerová et al., 2022; Červenka et al., 2022).
These findings show that the knowledge of "there are so many antioxidants in this product" alone is not enough; the behavior of the compounds during digestion is also important. In addition, a significant portion of carob polyphenols are bound to fiber, and some of these compounds can reach the large intestine and interact with the microbiota there.
Interpreting Antioxidant Results Correctly
When talking about the antioxidant properties of carob, it is necessary to make the following distinctions:
| Health impact ≠ laboratory activity | Radical scavenging of an extract in a test tube does not indicate that the same effect will occur in the body. |
| Extract ≠ food | The concentrated extracts used in the studies and the carob powder consumed daily do not have the same composition and dosage. |
| Human studies are limited | In a study conducted in Turkey, although bread containing carob molasses pulp flour had a higher antioxidant content than control bread, it did not make a significant difference in total antioxidant and total oxidant status values in the blood in healthy participants (Tuşat et al., 2025). |
| The methods are different | The results obtained with different tests cannot be converted to each other and cannot be directly compared. |
Therefore, the most accurate expression for carob is this: Carob is a fruit rich in polyphenols and shows significant antioxidant activity in laboratory studies; the possible contributions of these properties to human health are still being investigated.
Frequently Asked Questions
Does carob contain antioxidants? Yes. Carob contains polyphenolic compounds such as gallic acid, gallotanins, condensed tannins, and flavonoids, which show antioxidant activity in laboratory tests.
Which is the most important antioxidant compound of carob? In an analysis of carob fiber, it was reported that about 42 percent of the polyphenols were free gallic acid. This is followed by gallotanins and flavonoids (Owen et al., 2003).
Does the antioxidant value of roasted carob decrease? In one study, it was reported that roasting increased the total phenolic substance and antioxidant activity values of carob powder (Srour et al., 2016). However, the result may vary depending on the roasting conditions and measurement method.
Is carob molasses a source of antioxidants? Molasses contains phenolic compounds; however, the content varies widely depending on the product. It should not be forgotten that molasses is also a dense source of sugar.
Carob Products with Carob Türkiye
Carob is a fruit that attracts attention in scientific studies with its polyphenol-rich structure. The preservation of these properties depends on the quality of the raw material and processing conditions.
At Carob Türkiye, we supply carob fruit, crumbs, flour/powder, kernels, and extracts. For information about our extract products Carob Extract page and What is Carob Extract? You can review our article, for your wholesale and export requests. You can contact us.
This content is for informational purposes only; it is not a substitute for medical advice.
Domestic resources
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