Flow properties and chemical composition of carob (Ceratonia siliqua L.) flours as related to particle size and seed presence

- Carob flours containing seeds had higher cohesion index and cake strength values.
- Extractability of polyphenols depended on cohesion index and cake strength.
- Flour without seeds had higher total sugar and soluble polysaccharides content.

Due to abundance in carbohydrates, dietary fibres and bioactive compounds, as well as for its outspread and low prices, carob (Ceratonia siliqua L.) flour has a great potential of use as a functional ingredient. The aim of this study was to analyse this potential by physical and chemical properties assessment of different particle sizes of carob flour with and without seeds. The influence of seed presence on physical and chemical properties of flour was also investigated. Seed presence in carob flour led to higher cohesivity and cake strength. It also affected the extraction efficiency of polyphenols, which was confirmed by the ranking of samples according to their procyanidin and tannins contents. With regard to the carbohydrate content, significant differences (P < 0.05) between the contents of fructose and glucose was established in samples differing by the presence of carob seeds. Spearman rank order correlations revealed a significant difference (P < 0.05) between physical and chemical properties of carob flours. These findings confirm the importance of understanding physical and chemical properties of carob flours in order to use them efficiently as a functional food ingredient.

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