Waste valorization of apple seeds for protein extraction is a sustainable approach to the management of apple seed waste in the apple processing industry. The purpose of the research is to study the modification of apple seed protein isolates under different doses of irradiation on functional, structural, thermal, and morphological characteristics. Different irradiation doses of 8, 15, 20 25, and 50 kGy showed significant variations in protein content (88.70%–86.45%), total phenolic content (774.13–285.42 mg GAE/100g), and color profile of the apple seed protein. Irradiation altered the apple seed protein isolates' functional properties with increased foaming properties and emulsifying properties and decreased water and oil absorption properties. Irradiation induces denaturation and cross-linking in the apple seed protein structures, which increase surface hydrophobicity (708.66–1740.66), decreased zeta potential (−18.60 to −39.39 mV), and alteration in protein secondary structures with decreased α-helix (11.52–10.43 %), β-sheet content (60.82–60.13%), and random coils (16.82–16.19%), and increased β turns (10.79–13.22 %). DSC and TGA analysis revealed improved thermal properties using irradiation doses of 8–20 kGy whereas reduction for 25–50 kGy in irradiated apple seed proteins. Scanning electronic microscopy showed pores and aggregated structures of irradiated apple seed protein isolates. The study revealed the potential of irradiation as one of the non-thermal techniques for modifying apple seed protein isolates for protein valorization in various food applications.

中文翻译：

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苹果种子分离蛋白的辐照诱导修饰：探索技术功能、结构、热和形态特征


用于蛋白质提取的苹果种子废物增值是苹果加工业中苹果种子废物管理的可持续方法。本研究的目的是研究不同剂量辐照下苹果籽分离蛋白对功能、结构、热学和形态特征的修饰。 8、15、20、25和50 kGy的不同辐照剂量显示苹果籽蛋白的蛋白质含量（88.70%–86.45%）、总酚含量（774.13–285.42 mg GAE/100g）和颜色分布存在显着差异。辐照改变了苹果籽分离蛋白的功能特性，增加了发泡特性和乳化特性，降低了吸水和吸油特性。辐照会引起苹果种子蛋白质结构的变性和交联，从而增加表面疏水性 (708.66–1740.66)，降低 zeta 电位（−18.60 至 -39.39 mV），并改变蛋白质二级结构，减少 α 螺旋 (11.52– 10.43%）、β-折叠含量（60.82-60.13%）和无规卷曲（16.82-16.19%），以及增加的β转数（10.79-13.22%）。 DSC 和 TGA 分析表明，使用 8-20 kGy 的辐照剂量可改善热性能，而辐照的苹果种子蛋白则可减少 25-50 kGy。扫描电子显微镜显示了经过辐照的苹果种子分离蛋白的孔和聚集结构。该研究揭示了辐照作为一种非热技术的潜力，可用于修饰苹果种子分离蛋白，从而在各种食品应用中实现蛋白质增值。