Optimization and enzymatic intensification of bioactive compound extraction from carob pulps with potential weight management applications

Abstract

Carob pulps (Ceratonia siliqua L.) are a rich source of bioactive compounds with potential benefits for weight management, particularly inositols, flavonoids and phenolic acids (e.g. gallic acid). This study aimed to develop and optimize a sustainable extraction method to maximize the recovery of these target compounds. A solid–liquid extraction (SLE) was first optimized using a Box–Behnken experimental design, evaluating different variables (temperature, time, sample concentration and ethanol content). A two-variable (2 V) model focused on the extraction of inositols and gallic acid was identified as the most efficient allowing high extraction yields (45 °C, 28 min, 100 mg/mL, pure water) compared to the three-variable (3 V) model (90 ºC, 42 min, 100 mg/mL, ethanol 50 %), which additionally prioritized the extraction of flavonoids. To further intensify the extraction, enzyme-assisted extraction (EAE) using two commercial cellulases were studied and significantly enhanced gallic acid release (up to 2.39 mg/g), confirming its selective extraction from the plant matrix. A two-step strategy combining EAE under 2 V conditions (inositols and gallic acid) with a second cycle of 3 V SLE (flavonoids) was selected as an ecofriendly alternative to maximize the content of bioactives and applied on different carob samples. Pinitol was the most abundant compound across all samples (16.7–73.0 mg/g) and gallic acid also achieved high values (1.9–8.4 mg/g). Regarding flavonoids, kaempferol and luteolin glucosides were the most abundant. This study provides a comprehensive framework for efficient and sustainable sample preparation of carob-derived bioactives intended for functional food or nutraceutical applications targeting weight management.