de Carvalho Márcia Correa, Freitas Pedro A V, Jagus Rosa J, Agüero María V, Chiralt Amparo
Institute of Food Engineering Food UPV, Universitat Politècnica de València, 46022 Valencia, Spain.
Consejo Nacional de Investigaciones Científica y Técnicas (CONICET), C.A.B.A., Buenos Aires C1428EGA, Argentina.
Molecules. 2025 Apr 26;30(9):1928. doi: 10.3390/molecules30091928.
Obtaining active extracts from beet root leaves and stems (BLS) is an alternative for the valorization of this agricultural waste. Subcritical water extraction (SWE) at 150 °C and 170 °C has been used to obtain these extracts, which were incorporated (6% wt.) into polymer matrices to produce antioxidant films of thermoplastic starch (TPS) and polylactic acid (PLA) for the preservation of sunflower oil. A high extraction yield (67-60% solubilized solids) was achieved, and the extracts contained high levels of total phenols (51-73 mg GAE·g extract) and betalains and great radical scavenging capacity (EC: 30-22 mg mg DPPH). The highest temperature promoted the extract's phenolic richness and antioxidant capacity. The TPS and PLA films containing extracts exhibited color and UV-light blocking effects. The extracts reduced the oxygen permeability (OP) and water vapor permeability of PLA films while promoting those of the TPS films. The capacity of the films to preserve sunflower oil from oxidation was mainly controlled by the OP values of the films, which were very high in TPS films with low OP values. However, in the PLA films (which were more permeable to oxygen), the antioxidant extracts provided significant protection against sunflower oil oxidation.
从甜菜根叶和茎（BLS）中提取活性提取物是一种使这种农业废弃物增值的替代方法。已采用150℃和170℃的亚临界水萃取（SWE）来获取这些提取物，将其（6%重量）掺入聚合物基质中，以制备用于保存向日葵油的热塑性淀粉（TPS）和聚乳酸（PLA）抗氧化薄膜。获得了较高的提取率（67 - 60%的可溶固体），提取物含有高水平的总酚（51 - 73 mg GAE·g提取物）和甜菜色素，并且具有很强的自由基清除能力（EC：30 - 22 mg mg DPPH）。最高温度促进了提取物中酚类物质的丰富度和抗氧化能力。含有提取物的TPS和PLA薄膜表现出颜色和紫外线阻挡效果。提取物降低了PLA薄膜的氧气透过率（OP）和水蒸气透过率，同时提高了TPS薄膜的这些透过率。薄膜对向日葵油氧化的保存能力主要由薄膜的OP值控制，在OP值较低的TPS薄膜中OP值非常高。然而，在PLA薄膜中（其对氧气的渗透性更强），抗氧化提取物对向日葵油氧化提供了显著的保护作用。
