Selective recovery of phenolic compounds and carbohydrates from carob kibbles using water-based extraction

Carob kibbles are an important renewable source of valuable compounds, such as fermentable sugars and phenolic compounds. However, the selective recovery of these compounds is not a trivial task. In this work, a strategy was developed to enable the recovery of both classes of compounds by means of a water-based extraction. One-step extraction recovered only approximately 20% of the phenolic compounds, corresponding to an extraction yield of 0.6g Gallic acid equivalents (GAE)/100g dry mass of carob kibbles. The obtained extract contained a significant amount of carbohydrates (110 g/L). The alternative two-step extraction developed enabled higher compound selectivity together with an increase in the yield of the phenolic compounds to about 70%, corresponding to 1.9 g(GAE)/100g carob dry matter. The two-step extraction was easily scaled-up and is an effective method to obtain significantly separated carbohydrates and polyphenol-rich streams that can be further processed, e.g., in biorefineries or food industries, respectively. (C) 2015 Elsevier B.V. All rights reserved.