Andrade Johana, González-Martínez Chelo, Chiralt Amparo
Instituto Universitario de Ingeniería de Alimentos para el Desarrollo, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.
Polymers (Basel). 2020 Feb 24;12(2):497. doi: 10.3390/polym12020497.
Lecithin-encapsulated carvacrol has been incorporated into poly (vinyl alcohol) (PVA) for the purpose of obtaining active films for food packaging application. The influence of molecular weight (Mw) and degree of hydrolysis (DH) of the polymer on its ability to retain carvacrol has been analysed, as well as the changes in the film microstructure, thermal behaviour, and functional properties as packaging material provoked by liposome incorporation into PVA matrices. The films were obtained by casting the PVA aqueous solutions where liposomes were incorporated until reaching 0 (non-loaded liposomes), 5 or 10 g carvacrol per 100 g polymer. The non-acetylated, high Mw polymer provided films with a better mechanical performance, but less CA retention and a more heterogeneous structure. In contrast, partially acetylated, low Mw PVA gave rise to more homogenous films with a higher carvacrol content. Lecithin enhanced the thermal stability of both kinds of PVA, but reduced the crystallinity degree of non-acetylated PVA films, although it did not affect this parameter in acetylated PVA when liposomes contained carvacrol. The mechanical and barrier properties of the films were modified by liposome incorporation in line with the induced changes in crystallinity and microstructure of the films.
为了获得用于食品包装的活性薄膜，已将卵磷脂包裹的香芹酚掺入聚（乙烯醇）（PVA）中。分析了聚合物的分子量（Mw）和水解度（DH）对其保留香芹酚能力的影响，以及将脂质体掺入PVA基质中作为包装材料所引起的薄膜微观结构、热行为和功能特性的变化。通过浇铸PVA水溶液来制备薄膜，在其中掺入脂质体，直到每100 g聚合物中达到0（未负载脂质体）、5或10 g香芹酚。未乙酰化的高Mw聚合物制成的薄膜具有更好的机械性能，但香芹酚保留量较少且结构更不均匀。相比之下，部分乙酰化的低Mw PVA产生了具有更高香芹酚含量的更均匀薄膜。卵磷脂提高了两种PVA的热稳定性，但降低了未乙酰化PVA薄膜的结晶度，不过当脂质体含有香芹酚时，它对乙酰化PVA的这一参数没有影响。脂质体的掺入改变了薄膜的机械性能和阻隔性能，这与薄膜结晶度和微观结构的诱导变化一致。
