Carob (Ceratonia siliqua L.) fruit’s main industrial use is locust bean gum production, while pods and other by-products have a less valuable use. Previously reported health-related properties of carob fruit suggest the presence of valuable bioactive compounds that could be valorized into food ingredients. The objective of this work was to evaluate antioxidant and anti-hypertensive properties of carob¿s by products, i.e. pod, seed coat and germ. Methanol:water (1:1) extracts were evaluated for total phenolics (TP) through the Folin-Ciocalteu assay, hydrophilic antioxidant activity by oxygen radical absorbance capacity (ORAC),2,2-diphenyl-1-picrylhydrazyl radical inhibition (DPPH) and Trolox equivalent antioxidant capacity (TEAC-ABTS), and angiotensin converting enzyme (ACE) inhibitory activity. Direct antioxidant assays were alsoused to evaluate samples without extraction (DPPH-QUENCHER and TEAC-ABTS-QUENCHER). Germ and seed extracts showed the highest content in TP, roughly 2-fold as compared to pod. Seed peel extracts showed similar or higher antioxidant properties than germ and pod. Although the three tested carob by-product extracts showed anti-hypertensive activity, seed peel extract¿s activity was highest.On the other hand, seed peel showed significantly lower activity than pod and germ when direct methods were used (on the solid sample, without extraction). This may indicate better extractability of seed peel antioxidants, as compared to those of pod and germ, which might contain higher proportions of phenolic compounds. These results report bioactivity levels of carob fruit processing by-products, indicating the potential for valorization of these, especially seed peel extract, as observed from its antioxidant and anti-hypertensive properties.

Póster presentado a la 31st EFFoST International Conference titulada: Food Science and Technology Challenges for the 21st Century - Research to Progress Society, celebrada en Sitges (España) del 13 al 16 de noviembre de 2017.

This study has been supported by the National Institute for Agricultural and Food Research and Technology of Spain (INIA: RTA2014-0037-C02).

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