Bread has a short shelf-life, which leads to staling and disposal. This study aims to incorporate starch from stale bread into a bio-composite with sodium alginate, gellan gum and glycerol. The response surface methodology was used to optimize the concentrations of sodium alginate (0–4%), gellan gum (0–1%) and glycerol (0–1%) as fillers in starch bio-composites based on the resulting tensile strength, hardness and water absorption ability. The responses were the water absorption ability, hardness and tensile strength of the bio-composite. Well-fitting models were generated for water absorption ability (R ² = 0.8938), hardness (R ² = 0.8607) and tensile strength (R ² = 0.9742) with a probability value of less than 0.001, which demonstrates the high significance of the models. The optimum parameters were 3.83% sodium alginate, 0.62% gellan gum and 0.69% glycerol. Meanwhile, the water absorption ability, hardness and tensile strength were 0.44%, 49.55 mJ and 41.00 N/m², respectively. The effects of electron beam irradiation on the contact angle of the bio-composite were also studied. Electron beam irradiation increased the contact angle up to 77.56° and reduced fractures in the microstructure of the bio-composites compared with those in the non-irradiated sample. These are important properties of the bio-composite to be used in utensils.

中文翻译：

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来自不新鲜面包的可生物降解淀粉复合物：电子束辐照的影响

面包的保质期很短，这会导致变质和处置。本研究旨在将不新鲜面包中的淀粉与海藻酸钠、结冷胶和甘油结合到生物复合材料中。响应面法用于优化海藻酸钠 (0-4%)、结冷胶 (0-1%) 和甘油 (0-1%) 作为淀粉生物复合材料中填料的浓度，基于所得拉伸强度，硬度和吸水能力。响应是生物复合材料的吸水能力、硬度和拉伸强度。为吸水能力（R ² = 0.8938 ）、硬度（R ² = 0.8607）和抗拉强度（R ^{2 ）生成了拟合良好的模型}= 0.9742)，概率值小于 0.001，这表明模型的显着性很高。最佳参数为 3.83% 海藻酸钠、0.62% 结冷胶和 0.69% 甘油。同时，吸水能力、硬度和抗拉强度分别为0.44%、49.55 mJ和41.00 N/m ²。还研究了电子束辐照对生物复合材料接触角的影响。与未辐照样品相比，电子束辐照将接触角提高到 77.56°，并减少了生物复合材料微观结构的断裂。这些是用于器具的生物复合材料的重要特性。