【作者】 李敏；

【导师】 侯汉学； 景栋；

【作者基本信息】 山东农业大学 ， 食品加工与安全（专业学位）， 2023， 硕士

【摘要】 氧化是导致食品品质劣变的重要原因,抗氧化活性材料已被证明可以延缓食品的氧化变质,具有广阔的应用前景。然而,目前所开发的抗氧化活性包装多基于不可降解聚合物,其大量使用会造成严重的环境污染。因此,研发全降解抗氧化食品包装材料对延长食品保质期和保护环境具有重要意义。本文以聚己二酸-对苯二甲酸丁二醇酯（PBAT）和羟丙基二淀粉磷酸酯为成膜基材,采用挤出吹塑法制备了淀粉/PBAT（S/P）全降解抗氧化膜,探究了抗氧化剂种类、抗氧化剂添加量及淀粉和PBAT共混比例对薄膜理化性能和抗氧化活性的影响。主要研究结果如下:（1）抗氧化剂种类对淀粉/PBAT薄膜理化性能和抗氧化活性的影响。丁基羟基茴香醚（BHA）、丁基羟基甲苯（BHT）、叔丁基对苯二酚（TBHQ）和没食子酸丙酯（PG）的加入均使薄膜力学性能、氧气阻隔性能降低,表面疏水性和水蒸气阻隔性能增强。S/P-BHT薄膜的氧气渗透系数最高(8.82×10^-14 cm³·cm·cm^-2·s^-1·Pa^-1),S/P-PG薄膜的水蒸气渗透系数最低(2.48×10^-11 g·m·m^-2·s^-1·Pa^-1)。PG在薄膜中保留率最高（96.5%）,BHT保留率最低（59.3%）,S/P-PG薄膜的抗氧化活性最强。（2）优选PG为活性物质,探究PG添加量对薄膜理化性能和抗氧化活性的影响。随着PG添加量的增加,薄膜中出现的聚集体和异质结构增多,不透明度增加,力学性能降低,氧气阻隔性能、水蒸气阻隔性能和表面疏水性增强。S/P-3%PG薄膜具有最低的氧气渗透系数(4.14×10^-14 cm³·cm·cm^-2·s^-1·Pa^-1)和水蒸气渗透系数(1.82×10^-11g·m·m^-2·s^-1·Pa^-1)以及最高的表面疏水性（94.50°）,薄膜抗氧化活性与PG添加量呈正相关,S/P-3%PG薄膜的抗氧化活性最强。花生酱包装试验表明,制备的抗氧化膜能够有效延缓脂质氧化。（3）固定PG添加量为1%,探究淀粉/PBAT共混比例对薄膜理化性能和抗氧化活性的影响。随着淀粉比例的增加,薄膜中的异质结构增多,亮度和不透明度增加,力学性能、表面疏水性和水蒸气阻隔性能降低,氧气阻隔性能增强。随着薄膜中淀粉含量的增加,薄膜的溶胀度逐渐增加,薄膜中抗氧化剂的释放速度和释放程度增加,在相同作用时间内,具有更高淀粉含量的薄膜表现出更强的抗氧化活性。溶胀动力学与释放动力学试验表明可以通过改变薄膜中淀粉和PBAT共混比例来控制薄膜在不同极性食物模拟物中的溶胀行为,进而调控薄膜中抗氧化剂的释放行为。更多还原

【Abstract】 Oxidation is a well-known factor that induces food quality deterioration.To date,many antioxidant materials have been developed to delay the oxidative deterioration of food,showing broad application prospects.Nonetheless,the current antioxidant packaging is mostly based on non-biodegradable polymers,the massive use of which would cause serious environmental pollution and human health threats.Thus,the development of biodegradable antioxidant food packaging has gained great significance for extending food shelf life and protecting the environment.In this work,starch/poly（butylene adipate-co-terephthalate）（PBAT）biodegradable antioxidant film was prepared by extrusion blowing.The effects of antioxidant types and contents,and starch and PBAT blending ratios on physicochemical properties and antioxidant activity of the obtained films were investigated.The main results were listed as follows:（1）Effects of antioxidant types on physicochemical properties and antioxidant activity of starch/PBAT films.The addition of butylated hydroxy anisole（BHA）,butylated hydroxytoluene（BHT）,tertiary butylated hydroquinone（TBHQ）,and propyl gallate（PG）reduced the mechanical properties and oxygen barrier properties of the film,while enhanced the surface hydrophobicity and water vapor barrier.The oxygen permeability coefficient of S/P-BHT film was the highest(8.82×10^-14 cm³·cm·cm^-2·s^-1·Pa^-1),and the S/P-PG film had the minimum water vapor permeability coefficient(2.48×10^-11 g·m·m^-2·s^-1·Pa^-1).BHT has the minimum retention rate（59.3%）,and by contrast,PG showed the maximum retention rate（96.5%）in the film and exhibited the strongest antioxidant activity.（2）Selecting PG as the active substance and exploring the effect of PG addition on the physical and chemical properties and antioxidant activity of starch/PBAT films.With the increase of antioxidant contents,the number of aggregates and heterostructures appearing in the film increased.Higher antioxidant contents enhanced the opacity,oxygen/moisture barrier,and surface hydrophobicity,but reduced the mechanical properties.The S/P-3%PG film exhibited the lowest oxygen permeability coefficient(4.14×10^-14 cm³·cm·cm^-2·s^-1·Pa^-1),highest surface hydrophobicity（94.50°）,and lowest water vapor permeability coefficient(1.82×10^-11 g·m·m^-2·s^-1·Pa^-1).The antioxidant activity of the film was positively correlated with the amount of PG added,and the S/P-3%PG film had the strongest antioxidant activity.Packaging test for peanut butter indicated that the prepared antioxidation film effectively delayed lipid oxidation and extended the shelf life.（3）Effects of starch/PBAT blending ratios on the physicochemical properties and antioxidant activity of the film was investigated with a fixed PG addition of 1%.As the proportion of starch in the film increased,heterogeneous structures generated,resulting in an increase in brightness and opacity.Mechanical properties,surface hydrophobicity,and water vapor barrier properties were reduced,while oxygen barrier properties are enhanced.The increase in starch content caused higher swelling degree of the film,leading to an increase in the release rate and degree of antioxidants.The films with higher starch content exhibited stronger antioxidant activity at the same contact time.The swelling kinetics and release kinetics experiments indicated that the swelling behavior of the film in different polar food simulants could be controlled by changing the blending ratio of starch and PBAT in the film,thereby regulating the different antioxidant activities of the film.更多还原