探討馬鈴薯皮澱粉之特性及其作為可食膜之影響

Characterization of Potato Peel Starch and Its Effects on Edible Film Properties

毛若漫(Motsa Nomalungelo)

指導教授 ： 邱亞伯

國立屏東科技大學/國際學院/食品科學國際碩士學位學程/碩士(2021年)

https://doi.org/10.6346/NPUST202100239

摘要

糧食減少與浪費是全球普遍存在的問題，此問題已納入聯合國永續發展目標之其中具體目標12.3。傳統上，不可生物降解的食品包裝材料，已被用於最大程度地減少食品損失和浪費。然而，它們的廣泛使用，卻已成為環境污染的主要來源。因此，主要來自澱粉類食品材料之可生物降解的薄膜，已被開發作為替代食品包裝材料。然而，對於利用土地生產非糧食用途之農作物的相關辯論，並不利於可食用薄膜原料的持續生產，並取代為食品工業中的合成聚合物。因此，研究指出利用食品加工與農業廢棄物，被認為是開發可食用膜的潛在原料替代品，尤以澱粉作為基質之廢棄物。由於目前對於馬鈴薯皮澱粉（PPS）在可食性薄膜生產的相關研究較少，本研究主旨在開發PPS與評估其成膜特性。評估以不同PPS濃度 (2.48％、4.48％和6.48％ (w/v) 製成之可食用膜，並分別評估其外觀、厚度、物化性質、阻隔性、光學、熱度、結晶度及微結構特性，並與對照組-羧甲基纖維素 (CMC) 薄膜的性能進行比較。結果顯示，PPS為高澱粉收率 (11.2 ％) 、高直鏈澱粉 (29.49％) 及低水分含量 (18.81％) 。此外，在60 oC時PPS之澱粉吸水率與溶解度皆有所增加。PPS澱粉顆粒外觀橢圓完整、表面光滑及無裂縫，且大澱粉顆粒較小澱粉顆粒分布廣。熱重分析結果顯示，約有40％的質量損失，其與澱粉大分子在285至300°C之間發生的解聚合有關，而X射線衍射分析顯示其為 “B” 型結晶度，具有56.2 %結晶度。以PPS製成之可食用膜，其外觀、理化特性、阻隔性及不透明性皆比CMC更好。然而，兩種可食用薄膜樣品都表現出相似的熱穩定性、無定形 X 射線衍射圖及標準的海洋與土壤生物降解性（~90%：分別為 6 個月與 2 年）和厚度（≤ 0.25 毫米）特性。此外，PPS濃度的增加使PPS可食膜的厚度、不透明性、表面特異性、橫截面積及生物降解期增加，且可食用膜能表現出較佳的理化阻隔性能與熱特性 (熱重分析與差示掃描量熱法分析之結果)。然而，馬鈴薯皮澱粉的增加對於PPS可食用膜的視覺外觀與結晶度 (X射線衍射圖) 並無影響。該研究證實，在最佳之澱粉濃度 (4.48 % (w/v)) 、甘油 (26.52 % (v/w)) 及乾燥溫度 (51.9 ºC) 的條件下，PPS是一種具有前景的澱粉來源，可用於生產可加速生物降解之可食用薄膜。

關鍵字

馬鈴薯澱粉 ； 羧甲基纖維素 ； 生物降解之可食用膜 ； 熱性能 ； X射線結晶度

並列摘要

Food loss and wastage is a prevalent global issue and their reduction is listed in the United Nations Sustainable Development Goals, target 12.3. Traditionally, non-biodegradable food packaging materials have been used to minimize food losses and wastes; however, their widespread use has become a major source of environmental pollution. Consequently, biodegradable films have been developed as alternative food packaging material, mostly from starchy food materials. Nevertheless, the debate over the relative merits of using land to produce crops for non-food use threatens the sustainable production of edible films to replace synthetic polymers in the food industry. Therefore, food processing and agricultural waste materials are reported as potential raw material substitutes in the development of edible films, particularly starch-based edible films. Hence, based on the scarcity of research findings of potato peel starch (PPS) in edible film production, this study aimed to develop and evaluate the film-forming characteristics of PPS. Edible films composed of different PPS concentrations (2.48 %, 4.48 %, and 6.48 % (w/v)) were developed and their visual, thickness, physicochemical, barrier, optical, thermal, crystallinity, and microstructural properties, respectively, were evaluated and compared against the properties of carboxymethyl cellulose (CMC)-based film, used as the control. The results revealed that high starch yields (11.2 %), high amylose content (29.49 %), and low moisture content (18.81 %) were determined for PPS. Moreover, there was an increase in water absorption and solubility of starch granule at 60 ºC. The PPS granules were round to oval shape, complete, with smooth surface, and higher distribution of large particles than smaller particles. Thermogravimetric results displayed 64 % mass loss was related to depolymerization of starch macromolecules that occurred between 285 to 300 °C, whilst the differential canning calorimeter exhibited a single endothermic peak with a narrow temperature range. Furthermore, the X-ray diffraction analysis revealed a ‘B’ type crystalline with 56.2 % crystallinity. Edible films were successfully developed from PPS and presented better visual, physicochemical, barrier, and opacity properties than CMC. However, both edible film samples exhibited similar thermal stability, amorphous X-ray diffraction patterns, and standard sea and soil biodegradability (~90%: 6 months and 2 years, respectively) and thickness (≤ 0.25 mm) properties. Moreover, increases in PPS concentrations resulted in increased PPS-based edible films’ thickness, opacity, heterogeneity of surface and cross-sectional area, and biodegradability period. Furthermore, the edible films exhibited improved physicochemical barrier with increase in PPS concentration. Nonetheless, the increase in potato peel starch failed to affect visual appearance, thermal properties and crystallinity (X-ray diffraction patterns) of the PPS-based edible films. This study confirmed that at optimum starch concentration of 4.48 % (w/v), glycerol (26.52 % (v/w)), and drying temperature (51.9 ºC). PPS is a promising source of starch for the production of accelerated biodegradable edible films.

並列關鍵字

potato peel starch ； carboxymethyl cellulose ； , biodegradable edible film ； thermal property ； X-ray crystallinity

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