Effects of Gelatinization and Gel Storage Conditions on the Formation of Canna Resistant Starch

• Published in: Food and bioprocess technology 2012-10, Vol.5 (7), p.2665-2673
• Main Authors: Wandee, Yuree, Puttanlek, Chureerat, Rungsardthong, Vilai, Puncha-arnon, Santhanee, Uttapap, Dudsadee
• Format: Article
• Language: English
• Subjects: Agriculture; Autoclaving; Biotechnology; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Cooking; Crystals; Food Science; Gels; Melt temperature; Original Paper; Slurries; Starch; Storage conditions; Thermal stability
• ISSN: 1935-5130; 1935-5149
• DOI: 10.1007/s11947-011-0629-0

The effects of gelatinization and gel storage conditions on the formation of canna resistant starch (RS) were investigated. Starch slurries (10%, dwb) were autoclaved at 121 °C for 30, 60, and 120 min. The gels obtained were subsequently stored at different temperatures (4 °C, 30 °C, and 100 °C) and times (0, 1, 3, 5, and 7 days). Analyses of the RS content in gelatinized starch samples in comparison with that in granular starch showed that the RS fraction in granular starch was very high (97.3% w / w ); however, nearly all of the RS was thermally unstable, as indicated by a great reduction in RS content (to 1.9% w / w ) after cooking at 100 °C for 20 min. The RS contents in gelatinized starch samples were 12.0–15.9% w / w , which were reduced to 7.9–10.8% w / w after cooking. Storage of gels resulted in a significant increase in the amount of the thermally stable RS fraction, e.g., a thermally stable RS content of 16.8% w / w was found in the gel sample gelatinized for 120 min and stored at 4 °C for 3 days. This indicated that the ordered structures of the RS portion were tightened under the storage conditions. The gelatinization temperature of canna starch was 72.2 °C, whereas the RS products exhibited two melting temperature ranges, 51.1–76.3 °C and 163.1–165.1 °C, indicating that the newly formed crystals were very strong.