Summary: | 博士 === 國立中興大學 === 食品暨應用生物科技學系所 === 105 === Musa Pei Chiao is the main cultivated variety of banana in Taiwan. The objective of this study was to investigate the different substitution ratios of banana starch in wheat flour. The changes in the pasting properties of flour, rheological properties of dough, glycemic index, and sensory of white bread quality in terms of processing were investigated.
The results showed that banana starch incorporation in the making of bread could affect its taste and texture. The rheological properties of the dough were significantly changed by different substitution ratios of banana starch. The highest peak viscosity and final viscosity were observed in the sample with a high ratio of banana starch. The addition of banana starch increased flavor diversity and consumers’ preferences of the bread. As a consequence of the compositional changes, a slow and low rate of enzymatic hydrolysis of carbohydrate was observed. Therefore, banana starch was found to be playing a key role in reducing glycemic index after meal. However, the hardness of the bread was significantly increased by the use of banana starch at a higher ratio. The retrogradation of starch molecules during storage led to an increase of hardness of toast.
Corona electrical discharge (CED) belongs to an atmospheric pressure cold plasma. In this study, raw banana starch (indigenous to Taiwan), which contained resistant starch and amylose at a level of 58.4 g/100 g and 14.5 g/100 g, respectively, was treated by CED at 30 kV/cm, 40 kV/cm, and 50 kV/cm for 3 minutes. After the CED treatment, starch analyses showed that there were no apparent changes in the resistant starch and amylose contents. Only surface and non-penetrative damage caused by plasma etching at different voltage strengths were observed on the starch granules.
The CED treatments reduced the total area of diffraction peak, gelatinization enthalpy (by -21% to -38%), and different pasting behaviors including peak viscosity, breakdown, final viscosity, and setback. The CED treatments were capable of increasing relative crystallinity and gelatinization temperature. This study revealed the potential of CED plasma technology as a tool to modify the characteristics of banana starch.
All these results would provide more theoretical basis for the utilization of banana starch. The application of the novel CED plasma technology might have the potential to increase the use and economical value of banana. Our results suggested that the CED treated banana starch could also be applied in in various food products (e.g., frozen foods, sauces, baked goods) as well as other starch-based products to promote their health potential.
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