BY-PRODUCTS OF PROCESSING CAROB MOLASSES AS SOURCES OF DIETARY FIBRE AND POLYPHENOLS

Abstract

Dietary fibre and polyphenols have been widely used to increase the functionality of some foods because of their potential effects on human health. In this study, extraction of dietary fibre and polyphenols from pomace obtained as a by-product of processing carob molasses has been studied. The dietary fibre and polyphenol extracts were prepared separately. The amount of dietary fibre in the carob molasses pomace was evaluated with two assays: the Association of Official Analytical Chemists’ enzymatic-gravimetric method and the enzymatic-chemical method. The methods were compared, each having been preceded by conventional extraction and ultrasound-assisted extraction of carob molasses pomace. It has been found that when the enzymatic-gravimetric method and the ultrasound-assisted extraction method were used, the total dietary fibre contents were significantly higher than after using the enzymatic-chemical method and the conventional extraction method. Conventional extraction of polyphenols from carob molasses pomace has shown a relatively higher polyphenol content and antioxidant activity than ultrasound-assisted extraction. Ultrasound-assisted extraction took less time than conventional extraction did. The polyphenol profile was characterised by means of a high-performance liquid-chromatography diode array detector using 10 phenolic standards. Six compounds, i.e. caffeic, syringic, -epicatechin, trans-cinnamic acid, myricetin, and naringin were determined with the high-performance liquid chromatography-diode array detector using both conventional extraction and the ultrasound-assisted extraction. Our results suggest that carob molasses pomace can be used to prepare low-calorie, high-fibre, and antioxidant-rich foods, nutraceuticals, and pharmaceuticals.

Keywords

• antioxidant activity
• enzymatic-gravimetric method
• enzymatic-chemical method
• dietary fibre
• polyphenols
• carob by-product