Effect of Two Different Drying Methods on Molecular Structure, In Vitro Digestibility and Chemical Properties of Oca Tuber Flour

Abstract

Oca tuber flours (Oxalis tuberosa) are obtained by freeze‐drying (OFFD) and heat‐drying (OFHD), and their physicochemical, thermal, rheological, antioxidant, and structural properties are studied. Amylose content is 16.03% and 18.81% in OFFD and OFHD, respectively. Total starch, resistant starch, and integrated dietary fiber are higher in OFFD. The thermal properties, final viscosity, and pasting temperature of the flours are not affected by the drying process. The use of heat to obtain Oca tuber flour causes a considerable reduction in total phenolic compounds and antioxidant activity. However, the same process leads to higher digestion rate and glycemic index. Microscopy analysis shows better dispersion of the starch granules (less agglomeration) in OFFD with irregular granule shapes. These results could facilitate the selection of the best method to obtain Oca tuber flour, which could help to expand the use of this tuber as an ingredient in industrial food products.

Native and modified chayotextle flour effect on functional property and cooking quality of spaghetti

“…The particle size was higher in the CHFMD sample, as was also reported by Gonzalez‐Cervantes et al . (2020), in oca tuber flours obtained by heat‐drying. Leewatchararongjaroen & Anuntagool (2016) explained that the increase in particle size is a result of the effect of heat drying on the protein, which act as an adhesive, causing the agglomeration of starch granules.…”

Sweet potato color variety and flour production drying method determine bioactive compound content and functional properties of flour

“…Sweet potato flour may impart textural, nutritional, and antioxidant properties to processed foods as well as natural colors (Dereje et al, 2020). Various drying methods such as hot air drying, vacuum drying, microwave drying, freeze drying (FD), and infrared drying have been used in flour production (Ahmed et al, 2020; Gonzalez‐Cervantes et al, 2020; Wang et al, 2020). Conventional oven drying (OD) is an inexpensive process, but it can alter the functional and chemical characteristics of sweet potato flour.…”