Effect of pullulanase debranching on the yield of retrograded pearl millet starch and its intrinsic qualities

• Published in: Journal of food measurement & characterization Vol. 17; no. 3; pp. 2566 - 2575
• Main Authors: Manimegalai, P., Parimalavalli, R.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2023; Springer Nature B.V
• Subjects: Amylopectin; Amylose; Cereals; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Crystallinity; Diffraction patterns; Engineering; Food; Food Science; Glucose; Granular materials; Helices; Millet; Original Paper; Pennisetum glaucum; Pullulanase; Scanning electron microscopy; Starch; X-ray diffraction; Debranching; Pearl millet starch; Crystallinity; Intrinsic quality; Morphology; Retrogradation
• ISSN: 2193-4126; 2193-4134
• DOI: 10.1007/s11694-022-01779-3

The present study evaluated the effect of debranching process on the production of retrograded starch from pearl millet starch. Starch was debranched with pullulanase for 12 h and stored at 4 °C for 24, 48, and 72 h; intrinsic qualities were determined for both retrograded starch and debranched retrograded starch. Native starch granules had round and smooth surfaces. The granular appearance has been lost and has led to a more compact microstructure due to the retrogradation process. The X- ray diffraction pattern of the native starch granules revealed an A- type with 22.40% crystallinity. After retrogradation and debranching, the crystalline type changed from A-type to B-V type. Consequently the percentage of crystallinity was increased in retrograded starch (55.69%) and debranched retrograded starch (61.53%) stored for 72 h. Amylose content was increased from 29.39 to 49.31% retrograded starch and 35.35 to 47.31% debranched retrograded starch in different storage hours at 24, 48 and 72 h. The X-ray diffraction pattern and scanning electron microscopy analyses showed that pearl millet starch debranched with pullulanase advantages for amylopectin to be debranched by pullulanase and short amylose chains released from amylopectin can form double helices, so the increased percentage of crystallinity and a large, more compact, laminiplantation structure. Debranched retrograded starch significantly (p < 0.05) improved the resistant starch content (52.24%) compared to retrograded starch stored for 72 h (43.67%). The study concluded that debranching and subsequent storage at 48 h best technique to produce a higher amount of resistant starch yield from pearl millet starch.