Exploring composites of alternative flour sources and marine biomass residues for sustainable degradable food packaging films [DATASET]

This study proposes an innovative strategy to valorise agricultural and marine by-products by developing sustainable films based on different pigmented popcorn and sorghum flours, rich in bioactive polyphenols and starch, combined with holocellulosic residue from Gelidium corneum (marine biomass), a by-product of industrial agar extraction, as a possible alternative to conventional plastics. Films were produced by melt-compounding and compression-moulding with a 40:60 w/w ratio of popcorn or sorghum flour to algae residue and were compared to control films without marine biomass. The effect of incorporating and storing marine biomass was investigated. Results showed that the addition led to a more heterogeneous film morphology and modified the optical properties of the marine biomass films, decreasing luminosity, whiteness index, and internal transmittance, while enhancing yellow and green hues due to pigment interactions, with significant changes occurring during storage. In general, incorporating marine biomass increased tensile strength and stiffness, reduced elongation at break, and, upon storage, further enhanced rigidity through starch retrogradation. Additionally, the presence of biomass modulated water vapor permeability, water uptake, and hydrophobicity. These findings demonstrate the potential of combining pigmented popcorn and sorghum flours with Gelidium corneum residue as sustainable composite films, representing a promising strategy for environmentally friendly packaging.

本研究提出了一种创新性策略，通过开发可持续包装膜来实现农业与海洋副产物的资源化利用：以富含生物活性多酚与淀粉的不同有色爆米花粉、高粱粉为基底，结合工业琼脂提取过程产生的副产物——石花菜（Gelidium corneum，海洋生物质）的全纤维素残渣，以此作为传统塑料的潜在替代方案。本研究采用熔融共混与压制成型工艺，按照爆米花粉/高粱粉与藻类残渣40:60的质量比制备复合膜，并以不含海洋生物质的空白对照膜作为参照。研究考察了添加与储存海洋生物质对复合膜的影响。结果表明，添加海洋生物质会使膜的微观形貌更不均一，并改变其光学性能：降低了膜的明度、白度指数与内部透光率，同时因色素间的相互作用加深了黄、绿色调，且储存过程中上述变化更为显著。总体而言，添加海洋生物质可提升复合膜的拉伸强度与刚度，降低其断裂伸长率；储存过程中还可通过淀粉回生进一步提升膜的刚性。此外，藻类残渣的存在可调控复合膜的水蒸气透过率、吸水率与疏水性。上述研究结果证实，将有色爆米花粉、高粱粉与石花菜残渣结合制备可持续复合膜具备应用潜力，可为环保包装提供一条极具前景的路径。