Preparation and physicochemical properties of resistant starch III from green banana starch

• Main Authors: Hung,Chih-Chiao, 洪智僑
• Other Authors: Liao,Hung-Ju
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/69435465794010113865

碩士 === 國立嘉義大學 === 食品科學系研究所 === 103 === The objective of this study was to prepare RS III from green banana by using pullulanase followed by autoclaving-cooling cycle, and to investigate the physico-chemical properties, structural properties and in vitro digestibility of treated starch sample. Green banana was used as raw material and isolated to obtain green banana starch (GBS). RS III preparation was separated into two parts. First part was starch debranched by using enzymatic method and followed by autoclaving at 121°C for 30 min and annealed at 4°C for 24 h to obtain DGBS. Second part was obtaining ADGBS by treating DGBS with second autoclaving-cooling cycle. Amylose content of GBS increased significantly after debranching and annealing process. Moreover, resistant starch content of GBS 46.9% while DGBS and ADGBS were approximately 33.3%. Solubility of DGBS and ADGBS increased but swelling power showed an opposite result. For thermal properties, Tp values of RS III from DGBS and ADGBS were both higher than 130°C, showed a better thermal stability compared to GBS. Furthermore, higher content in total dietary fiber in ADGBS than DGBS and GBS had indicated increasing heat stable RS III. Moreover, due to the changes in gelatinization properties, pasting curves of DGBS and ADGBS were mostly approaching to zero, representing no change in viscosity. On the other hand, crystalline pattern of GBS was typically C type diffraction pattern while DGBS and ADGBS were representing a complex type of B type and V type diffraction pattern. Both ratios of peak infrared absorbance of DGBS and ADGBS were higher than GBS, representing higher tightness and intactness of the granules. Estimated Glycemic Index value of DGBS and ADGBS ranged between 61.1 and 64.4 showed that they belonged to medium GI food.In overall, the changes in physico-chemical properties of ADGBS and ADGBS prepared from GBS compared to native starch showed that they had insignificant pasting properties, higher crystallinity and better heat stability. Furthermore, higher heat stable RS III content in ADGBS led to greater heat stability among the samples. In conclusion, increasing RS III in green banana starch could lead to specific functions, and therefore, it can be applied in food processing industry in order to increase functional properties of processed food.