The Effect of Carob Extract on Antioxidant, Antimicrobial and Sensory Properties of Bread

Abstract

To improve the nutritional value of bread, as well as to satisfy consumers whose awareness of the importance of nutrition to preserve health is growing significantly, it is desirable to enrich bread and bakery products with functional components. Carob (Ceratonia siliqua L.) is an evergreen tree that is widely distributed in the Mediterranean region and belongs to the legumes group. As carob pulp contains a unique combination of polyphenolic compounds and dietary fibre, it can be a useful raw material for the production of enriched bakery products. In this work, the possibility of applying carob extract as a potential natural preservative and functional additive in the production of bread was investigated. With this aim, 0.5, 1.5, 2.5 and 3.5% of powdered carob extract (CP) were added to bread dough and the quality characteristics of the bread were examined. The microbiological quality of bread was significantly better in samples with the addition of CP, which was confirmed by the lower values of the total number of bacteria and the absence of the Bacillus cereus. The addition of up to 3.5% carob extract had no negative effect on the sensory quality of the bread. The brightness of the bread samples decreased (L*), while the proportion of the red tone (a*) increased, and the intensity of the yellow tone (b*) decreased with an increase in the proportion of CP. The amount of total phenols (0.27 mg GAE/g) for the sample with 3.5% CP in bread was significantly higher compared to the control sample (0.12 mg GAE/g). The total antioxidant activity also increased significantly with the increase in the proportion of CP. Therefore, the present study proves that powdered carob extract can be successfully included in the production of a healthy functional food.

Keywords

• bread quality
• carob flour
• antioxidant activity
• antimicrobial activity
• sensory characteristics