種植在台灣香蕉品種的穀粉和澱粉的特徵及抗酶澱粉改良

Characterization of Flours and Starches from Banana Cultivars Grown in Taiwan and the Enzyme-Resistant Starch Improvement

歐意堤(Aoitip Samanros)

指導教授 ： 林貞信

國立屏東科技大學/農學院/食品科學系所/博士(2021年)

https://doi.org/10.6346/NPUST202100417

摘要

許多香蕉在成熟期間被丟棄，因此非常有必要的去研究綠色香蕉的潛在工業應用。在本研究中，先從四個香蕉品種（Musa AAA Cavendish; Pei Chiao, Tai Chiao No.5, Tai Chiao No.7 和 Musa ABB; Kluai Namwa）中分離出粉和澱粉，然後再表徵。所有被評估的香蕉粉，其組成相似，含有大量碳水化合物（大於 85.72%, d.b.），大部分碳水化合物含量為澱粉（大於 73.95%, d.b.）。直鏈澱粉含量從 19.05% 到 23.95% 不等。在香蕉澱粉中，Kluai Namwa 的直鏈澱粉含量和總澱粉含量高於其他品種。香蕉澱粉顆粒不規則形狀，呈現表面光滑的細長形和球形兩種。所有香蕉澱粉都顯示出 B 型態，相對結晶度在 23.9-25.9% 之間。從示差掃描熱分析法獲得的糊化溫度範圍，分別為香蕉粉的 73.4-81.7°C 和香蕉澱粉 的70.3-77.4°C。在香蕉品種中，北蕉、台蕉5號和台蕉7號有顯著最高的尖峰黏度值，在香蕉粉（426-445 RVU）和在分離澱粉（446-478 RVU）。此外，香蕉粉和澱粉的體外澱粉消化率測試顯示，抗性澱粉 (RS) 的含量分別高達 81.1% 和 85.9%。 Kluai Namwa 的 RS 含量最高。蒸煮後，RS 轉化為快速消化澱粉 (RDS) 和緩慢消化澱粉 (SDS)。保留在煮熟香蕉中的RS和SDS，觀察到最低和最高組合值分別是煮熟的台蕉 5 號和 Kluai Namwa 澱粉。四種研究香蕉品種的粉和澱粉的 SDS 和 RS 組合為 18% 至 47%。 PCA 評估的各種特性間的關係顯示，前兩個分量描述了總方差的 88.2%。通過用支鏈澱粉酶處理香蕉澱粉去分支，使用中心複合旋轉設計 (CCD)探討澱粉固體濃度 (5-10%, w/v)、培養時間 (8-24 小時) 和酶濃度（15-50 支鏈澱粉酶 U/g 澱粉），來優化第III 型抗性澱粉 (RS3) 的產量。該研究的反應是水解的程度。統計分析實驗結果指出，只有酶濃度和培養時間會影響水解程度，而澱粉濃度沒有顯著影響。 RS3的產率隨著水解的增加而穩步增加，達到42.8%的峰值。發現香蕉澱粉完全去分支的最佳條件是酶濃度為 45 支鏈澱粉酶 U/g 澱粉、培養時間為 16 小時。此外，程序步驟包括酶去分支和溫度回凝-反覆結晶（4/25 °C 和 4/35 °C，8 天），RS 含量增加可以高到 66%。

關鍵字

香蕉 ； 粉 ； 去分支澱粉 ； 體外消化率 ； 理化性質 ； 支鏈澱粉酶 ； 第三型抗性澱粉

並列摘要

Lots of bananas were discarded during maturation period. Therefore, it is necessary to study potential industrial applications of green banana. In this study, flours and starches were firstly seperated from four banana varieties (Musa AAA Cavendish; Pei Chiao, Tai Chiao No.5, Tai Chiao No.7 and Musa ABB; Kluai Namwa), and then characterized. All banana flours evaluated were similar in their composition with high amounts of carbohydrates (greater than 85.72 % on a dry basis), with most of the carbohydrate content being starch (greater than 73.95% on a dry basis). The amylose content varied from 19.05% to 23.95%. In banana starches, the Kluai Namwa showed higher amylose content and total starch content than the other varieties. Banana starch granules were irregularly shaped, showing both elongated and spheroid forms with a smooth surface. All banana starches revealed a B-type pattern with relative crystallinity ranging between 23.9-25.9%. The gelatinization temperature ranges obtained from differential scanning calorimetry were 73.4-81.7°C and 70.3-77.4°C for flours and starches, respectively. In banana varieties, Pei Chiao, Tai Chiao No.5 and Tai Chiao No.7 had significantly highest peak viscosity in both banana flour (426-445 RVU) and isolated starch (446-478 RVU). Additionally, in vitro starch digestibility tests in banana flours and starches showed fractions as high as 81.1% and 85.9% the resistant starch (RS), respectively. Kluai Namwa had the highest RS content. After cooking, RS converted to rapidly digestible starch (RDS) and slowly digestible starch (SDS). RS and SDS remained in cooked bananas with lowest and highest of combined values being observed for cooked Tai Chiao No. 5 and Kluai Namwa starch, respectively. Combined SDS and RS of flours and starches of the four studied banana varieties at 18 to 47%. Relationships of various properties evaluated by PCA showed that the first two components described 88.2% of the total variance. Banana starch was debranched by treatment with pullulanase and the yield of resistant starch type III (RS3) optimized with respect to starch solid concentration (5-10%, w/v), incubation time (8-24 h) and enzyme concentration (15-50 pullulanase U/g starch) using central composite rotatable design (CCD). The response of the study was a degree of hydrolysis. Statistical analyses of experimental results indicated that only enzyme concentration and the incubation time influenced the degree of hydrolysis, whereas the starch concentration did not present a significant effect. The yield of RS3 was increased steadily with increasing of hydrolysis to peak at 42.8%. The optimum for complete debranching of banana starch was found to occur at 45 pullulanase U/g starch for the enzyme concentration and 16 h for incubation time. Additionally, the process steps included enzymatic debranching and retrogradation with temperature – cycle crystallization (4/25 °C and 4/35 °C, 8 days), the RS content increased up to 66%.

並列關鍵字

banana ； flour ； debranched starch ； in vitro digestibility ； physicochemical properties ； pullulanase ； resistant starch type III

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