Esfandiari Ahmadreza, Rownaghi Marzieh, Niakousari Mehrdad
Department of Food Science & Technology, College of Agriculture, Shiraz University, Shiraz, Iran.
Department of Food Science & Technology, College of Agriculture, Shiraz University, Shiraz, Iran.
Ultrason Sonochem. 2025 Jun 20;120:107440. doi: 10.1016/j.ultsonch.2025.107440.
Gum Arabic is a multifunctional natural polysaccharide that is widely used in the food and pharmaceutical industries, but its powdered form often exhibits poor structural and functional properties. Recent advances in spray freeze-drying (SFD) and ultrasound-assisted spray freeze-drying (US-SFD) present promising strategies for improving powder quality. While prior studies have explored basic SFD applications, limited attention has been paid to the impact of ultrasound during freezing on gum Arabic's structure and functionality. This study aimed to evaluate how US-SFD affects the physicochemical and structural characteristics of gum Arabic cryogels at 1 and 3 % concentrations. Feed solutions were atomized into liquid nitrogen and freeze-dried, with ultrasound applied during freezing for selected samples. Bulk and tapped density, porosity, thermal behavior, morphology, crystallinity, color, and solubility were evaluated. US-SFD-1 % and US-SFD-3 % exhibited the lowest bulk densities (0.003 ± 0.000 and 0.006 ± 0.002 g/cm) and highest porosities (up to 99.660 ± 0.086 %), indicating the formation of highly porous, lightweight powders. FTIR revealed reduced O-H stretching intensities in US-SFD samples, suggesting alterations in hydrogen bonding, while XRD confirmed their amorphous nature. Color analysis showed SFD-1 % had the highest ΔE (25.260 ± 2.936), though SFD-3 % appeared more yellow. However, the study was limited by the absence of ultrasound intensity optimization and the evaluation of only a narrow concentration range. Future investigations should focus on a more comprehensive exploration of processing parameters and assess the functional applications of these cryogels in food, pharmaceutical, and biomedical industries.
阿拉伯胶是一种多功能天然多糖，广泛应用于食品和制药行业，但其粉末形式的结构和功能特性往往较差。喷雾冷冻干燥（SFD）和超声辅助喷雾冷冻干燥（US-SFD）的最新进展为提高粉末质量提供了有前景的策略。虽然先前的研究探索了基本的SFD应用，但冷冻过程中超声对阿拉伯胶结构和功能的影响却很少受到关注。本研究旨在评估US-SFD如何影响1%和3%浓度的阿拉伯胶冷冻凝胶的物理化学和结构特征。将进料溶液雾化到液氮中并进行冷冻干燥，对选定的样品在冷冻过程中施加超声。评估了堆积密度、振实密度、孔隙率、热行为、形态、结晶度、颜色和溶解度。US-SFD-1%和US-SFD-3%表现出最低的堆积密度（0.003±0.000和0.006±0.002 g/cm）和最高的孔隙率（高达99.660±0.086%），表明形成了高度多孔的轻质粉末。傅里叶变换红外光谱（FTIR）显示US-SFD样品中O-H伸缩强度降低，表明氢键发生了改变，而X射线衍射（XRD）证实了它们的非晶态性质。颜色分析表明，SFD-1%的ΔE最高（25.260±2.936），不过SFD-3%看起来更黄。然而，该研究受到缺乏超声强度优化以及仅评估狭窄浓度范围的限制。未来的研究应集中在对加工参数进行更全面的探索，并评估这些冷冻凝胶在食品、制药和生物医学行业中的功能应用。
