Abstract
The effects of soaking and cooking on soluble sugars, alpha-galacto-oligosaccharides (α-GOS) and soluble dietary fibres (SDF) and insoluble dietary fibres (IDF) were assessed in five legumes (lentil, chickpea, fenugreek, faba bean and Egyptian faba bean). In raw seeds, total α-GOS content ranged from 2500 mg/100 g (chickpea) to over 4000 mg/100 g (fenugreek). Stachyose was predominant in fenugreek, lentil and chickpea, whereas verbascose was the main α-GOS in faba bean and Egyptian faba bean. IDF represented 69–87% of the total dietary fibres in all studied legumes, while SDF content varied noticeably. During soaking, total α-GOS content decreased between 10% (lentil and faba bean) and 40% (chickpea). In fenugreek, soaking reduced IDF and increased SDF concentration, possibly due to partial IDF solubilisation from the cell wall. Cooking further decreased α-GOS and increased total dietary fibre content. The different behaviours of these five legumes during processing illustrate the high biodiversity within legume species.
Disclosure statement
All authors have no conflicts of interest.