高直链玉米淀粉/羟丙基甲基纤维素可食性膜的制备及性能研究

以高直链玉米淀粉(HACS)和羟丙基甲基纤维素(HPMC)为主要成膜基材,采用溶液流延法制备了HACS/HPMC可食性膜。研究了不同配比的HACS与HPMC对可食性膜的结晶性能、力学性能、亲水性能和水蒸气阻隔性能等的影响。结果表明,随着HPMC比例的增大,HACS与HPMC之间的氢键作用减弱,复合膜的水溶性增大,连续相由HACS转变为HPMC,但HACS与HPMC的相容性变差。HPMC可有效降低可食性膜的结晶程度并抑制其在储藏过程中的老化。在复合膜中,当HACS与HPMC比例为8∶2时,可食性膜具有最大抗拉强度(7.5 MPa)、断裂伸长率(14.7%)、水接触角(84.33°)和最低水蒸气透过系数(2.17×10~(-10 )g·m·m~(-2)·s~(-1)·Pa~(-1))。纯HACS膜和纯HPMC膜的透光性能均优于HACS/HPMC复合膜。

Preparation and properties of edible films of high-amylose corn starch/hydroxypropyl methylcellulose

High-amylose corn starch (HACS) and hydroxypropyl methylcellulose (HPMC) were selected as the main film forming materials to prepare HACS/HPMC edible films by solution casting method. Effects of different proportions of HACS and HPMC on crystallization, mechanical, hydrophilic and water vapor barrier properties of edible films were studied. The results showed that with the increase of HPMC proportion, the hydrogen bond between HACS and HPMC weakened, the water-solubility of the composite film increased, the continuous phase transforming from HACS to HPMC, thereby their compatibility deteriorated. HPMC could effectively reduce the crystallization degree of edible films and inhibit their aging during storage. The HACS/HPMC (8:2) edible film had the largest tensile strength (7.5 MPa), elongation at break (14.7%), water contact angle (84.33°) and the lowest water vapor permeability (2.17×10-10 g?m?m-2?s-1?Pa-1). Both pure HACS film and pure HPMC film had better light transmittance than HACS/HPMC composite films.