Gaseous ozone treatment of chickpea grains: Effect on functional groups, thermal behavior, pasting properties, morphological features, and phytochemicals.

ABSTRACT

The applicability of ozone has been increased to include pulse grains because of their increased production and significance as plant-based protein source. In many developed countries, there is a growing demand for products made from chickpeas grains. Whole chickpea grains were treated with ozone gas (500-1000 ppm) for 20-30 min. The structural, thermal, pasting properties, and phytochemicals of the ozone-treated, as well as control samples, were evaluated. Minor structural changes in the functional groups in the protein and starch molecules were observed in the treated sample. Ozonation caused significant changes in the pasting properties such as peak viscosity, trough viscosity, breakdown viscosity, final viscosity, setback viscosity, and peak temperature values. Microstructure revealed a reduction in the particle sizes of chickpea powders with the severity of ozone treatment. The total flavonoids (41.35-48.94 mg QE), alkaloids (1120.24-1453.57µg/g), and xanthoprotein (0.995-1.387 µg/g) increased significantly (p < 0.05) with ozone treatment. Commercially, chickpea grains can be ozone treated for achieving desired functional characteristics in a target product. PRACTICAL APPLICATION Before consuming grain that has been treated with gaseous ozone, it is vitally important for all consumers to have a solid understanding of the facts presented here regarding variations in the chickpea nutritional profile. The impact of ozone treatment on functional groups, thermal behavior, pasting properties, and morphological features in chickpeas reveals vital information regarding changes occurred on macromolecules such as starch, proteins, and bioactive compounds. Since ozonation aids in extraction of health-beneficial bioactive compounds and brings about change in the starch and protein morphology, making them more digestible, it can be highly useful in preparation of health foods.