Okra (Abelmoschus esculentus) Powder Production and Application in Gluten-Free Bread: Effect of Particle Size

Okra (Abelmoschus esculentus) has interesting nutritional and technological properties and is naturally gluten-free (GF). This study investigated the physicochemical properties of okra powder obtained by a low-temperature drying process and its impact on GF bread. Its potential synergy with other hydrocolloids (i.e., hydroxypropylmethylcellulose (HPMC) and Psyllium fibre (Psy)) was also studied. As the importance of powder particle size in food design is well known, whole okra powder (WOP; ≤ 1000 µm) and fine okra powder (FOP; ≤ 250 µm) were produced. Compared to the standard formulation, WOP and FOP doughs required less water to reach the desired dough consistency (200 ± 20 Brabender unit) and generally showed higher stability during mixing. Dough development was affected by HPMC more than okra powder particle size. Breads containing WOP or FOP in combination with HPMC exhibited high specific volume and soft texture, while the combination with Psy resulted in a less-developed, harder and darker bread. The combination with HPMC also guaranteed a longer shelf-life, regardless of okra powder particle size. These results may prove useful for the agri-food industry, as they demonstrate that okra can be used as an innovative natural hydrocolloid.