| 摘要: |
| 目的 提高聚(L-乳酸)(PLLA)薄膜的氧气(O2)、水蒸气(H2O)阻隔性，解决延展性差等问题。方法 采用熔融共混法分别将聚(对苯二甲酸己二酸丁二醇酯)(PBAT)、聚(L-乳酸-衣康酸丁二醇酯)(P(LA-BI))与PLLA共混制备薄膜。在此基础上，加入具有阻O2、阻H2O双功能的抗水解剂(Z)进行进一步改性。结果 Z的添加(质量分数为6%)在保持PLLA/PBAT和PLLA/P(LA-BI)薄膜力学强度的基础上，将2种薄膜的断裂伸长率大幅提高至387%和316%，薄膜展现出优异的柔韧性;PLLA/P(LA-BI)/Z6膜的氧气透过率(OTR)和水蒸气透过率(WVTR)分别为6.4 cm3/(m2.d)和43.1 g/(m2.d)，较添加Z6前分别降低了54.6%和61.9%，薄膜获得了优异的O2、H2O阻隔性能。在酸奶的贮藏过程中，PLLA/PBAT/Z6组和PLLA/P(LA-BI)/Z6组酸奶的可滴定酸度在第21天时仍保持在合理范围内，达到了延缓酸奶贮藏过程中后酸化的效果。在后续的感官评定中相较于PLLA/PBAT组和PLLA/P(LA-BI)组，添加Z6组包装的酸奶获得了更高的评分。结论 将具有阻O2、阻H2O双功能的Z6抗水解剂添加到PLLA基薄膜中改善了薄膜的延展性，提高了O2、H2O阻隔性能，同时在酸奶贮藏过程中起到良好的保质保鲜效果。因此，PLLA/PBAT/Z6和PLLA/P(LA-BI)/Z6薄膜可以代替市面上不可降解的酸奶包装材料进行推广使用。 |
| 关键词: 生物可降解材料 聚乳酸 阻隔性 柔韧性 酸奶包装 |
| DOI：10.19554/j.cnki.1001-3563.2024.15.014 |
| 分类号: |
| 基金项目:食品科学与工程学院第九届大学生科技创新与创业基金项目(2023) |
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| Preparation of Poly(L-lactic Acid)-based Blended Film with High Oxygen and Moisture Barrier Properties and Its Effect on Preservation of Yogurt |
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AN Da, SUN Jiamao, GE Chen, YUN Xueyan
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(College of Food Science and Engineering, Inner Mongolia Agricultural University, Hohhot 010018, China)
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| Abstract: |
| The work aims to improve the oxygen (O2) and water (H2O) barrier properties of poly(L-lactic acid) (PLLA) films and to solve the problems of poor ductility. The melt blending method was used to prepare films by blending poly(butylene adipate terephthalate) (PBAT) and poly(L-lactic acid-itaconic acid butylene diol ester) (P(LA-BI)) with PLLA, respectively. On this basis, an anti-hydrolyzing agent (Z) with dual function of O2 and H2O barrier property was added for further modification. The addition of Z (6 wt%) significantly increased the elongation at break of PLLA/PBAT and PLLA/P(LA-BI) films to 387% and 316%, while maintaining the mechanical strength of the films, and the films exhibited excellent softness and toughness; The oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) of PLLA/P(LA-BI)/Z6 films were 6.4 cm3/(m2.d) and 43.1 g/(m2.d), respectively, which were 54.6% and 61.9% lower than those before the addition of Z6, and the films obtained excellent O2 and H2O barrier properties. The titratable acidity of yogurt in the PLLA/PBAT/Z6 and PLLA/P(LA-BI)/Z6 groups remained within a reasonable range at the 21st day, which achieved the effect of delaying post-acidification during yogurt storage. In the subsequent sensory evaluation, the yogurt with the addition of Z6 packaging received higher scores compared with the PLLA/PBAT and PLLA/ P(LA-BI) groups. The addition of Z6 anti-hydrolyzing agent, which has the dual functions of O2 and H2O barrier properties, to PLLA-based films improves the ductility of the films, enhances the O2 and H2O barrier properties, and at the same time plays a good quality and preservation effect in the yogurt storage process. Thus, PLLA/PBAT/Z6 and PLLA/P(LA-BI)/Z6 films can be promoted for use in place of commercially available non-biodegradable yogurt packaging materials. |
| Key words: biodegradable materials poly(L-lactic acid) barrier properties softness and toughness yogurt packaging |
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