Structural and functional characterization of legume seed ferritin concentrates

Abstract

The aim of this work was to produce legume seed ferritin concentrates, which were then evaluated for structural properties and susceptibility to gastrointestinal proteases. Five legume seeds, namely red lentil (RL), chickpea (CP), green lentil whole (GLW), moon dal washed (MDW), and yellow split peas (YSP) were subjected to aqueous extraction followed by MgCl2 + sodium citrate-induced precipitation of iron-binding proteins. Ferritin concentrate gross yield was highest for CP (19.1 ± 2.6%) followed by RL (17.6 ± 1.4%), YSP (14.8 ± 1.4%), and GLW (12.9 ± 4.3%), while MDW (9.7 ± 3.3%) was lowest. Iron content of the ferritins ranged from 30–45 mg/100 g in comparison to 5–17 mg/100 g in the seed flour. During simulated gastrointestinal digestion, most of the iron was released by pepsin digestion. We conclude that these iron-enriched protein concentrates are potential ingredients to formulate functional foods and nutraceuticals against iron deficiency anemia. Practical applications Iron deficiency anemia (IDA) continues to be a global problem that can inflict severe damages to human health. The current and most common therapeutic approach to IDA treatment involves the use of inorganic iron supplements. However, the low level of inorganic iron absorption creates serious side-effects such as constipation and high oxidative stress that could lead to degenerative diseases. Organic iron in the form of plant ferritins provides a more absorbable alternative to inorganic iron. However, phytoferritins are present in very small quantities, which make the use of pure forms mostly impracticable. In this work, the preparation of crude phytoferritin concentrates was achieved in addition to their structural and functional characterization that demonstrates potential utility in IDA treatment. The crude ferritin concentrates can be used to formulate functional foods and nutraceuticals as therapies for IDA management.