CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal.
Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
Int J Biol Macromol. 2024 Jun;271(Pt 1):132489. doi: 10.1016/j.ijbiomac.2024.132489. Epub 2024 May 20.
Rice husks are a low value byproduct, even though it possesses molecules with great potential, such as arabinoxylans, proteins, and silica. These molecules can be used to improve mechanical and physicochemical properties of materials for food packaging. In this work, hydrothermal treatment was used for a sustainable extraction of the valuable molecules present in rice husks. Various extraction temperatures (180, 200, and 220 °C) were performed targeting to extract fractions with distinct compositions. The water extract obtained at 220 °C demonstrated the highest extraction yield, 3 times superior to conventional hot water extraction. These extracts exhibited high content of proteins, phenolic compounds, and carbohydrates, particularly arabinoxylans. This extract was incorporated in chitosan-based films in different ratios, 1:0.1, 1:0.3, and 1:0.5 (chitosan:extract, w:v). The film with the lowest extract ratio presented the highest flexibility (higher elongation and lower Young's modulus) when compared to the pristine chitosan film. The antioxidant capacity was also increased, achieving an antioxidant capacity of >10-fold in comparison to control film. The results revealed that hydrothermal extraction emerges as an environmentally friendly and sustainable methodology for extracting valuable compounds from rice industry byproducts. This method exhibits significant potential to impart flexible and antioxidant properties to biobased materials.
稻壳是一种低附加值的副产物,尽管它含有具有巨大潜力的分子,如阿拉伯木聚糖、蛋白质和二氧化硅。这些分子可用于改善食品包装材料的机械和物理化学性质。在这项工作中,采用水热处理对稻壳中存在的有价值分子进行了可持续提取。进行了各种提取温度(180、200 和 220°C),以提取具有不同组成的馏分。在 220°C 下获得的水提取物表现出最高的提取产率,是常规热水提取的 3 倍。这些提取物含有丰富的蛋白质、酚类化合物和碳水化合物,特别是阿拉伯木聚糖。将该提取物以不同比例(壳聚糖:提取物,w:v)掺入壳聚糖基薄膜中,比例分别为 1:0.1、1:0.3 和 1:0.5。与原始壳聚糖膜相比,含有最低提取物比例的薄膜具有更高的柔韧性(更高的伸长率和更低的杨氏模量)。抗氧化能力也得到了提高,与对照膜相比,抗氧化能力提高了 10 倍以上。结果表明,水热提取是一种从稻壳工业副产品中提取有价值化合物的环保且可持续的方法。该方法具有为生物基材料赋予柔韧性和抗氧化性的巨大潜力。