改性方法对柠檬皮渣粉结构及功能特性的影响

张巧; 何雨婕; 李贤; 雷激

doi:10.13386/j.issn1002-0306.2023030143

改性方法对柠檬皮渣粉结构及功能特性的影响

Effects of Modification Methods on the Structural and Functional Properties of Lemon Peel Residue Powders

摘要

摘要: 为提高柠檬皮渣粉的品质及柠檬加工副产物综合利用率，本研究采用微波、高速剪切、超微粉碎三种方式对柠檬皮渣粉进行改性，通过扫描电镜、傅里叶红外光谱、热重分析对改性前后的形态结构、热稳定性进行分析，并对理化、功能特性进行测定以评价不同改性柠檬皮渣粉的综合品质。结果表明，三种改性使柠檬皮渣粉结构变得疏松；改性后主要官能团未发生明显变化；微波、高速剪切处理显著提高了柠檬皮渣粉的热稳定性（P<0.05）。整体而言，经高速剪切改性的柠檬皮渣粉各项理化、功能特性均为最佳，其总膳食纤维含量（Total dietary fiber，TDF）、可溶性膳食纤维（Soluble dietary fiber，SDF）含量、持水力、持油力、膨胀力分别为81.88%、33.07%、20.05 g/g、2.00 g/g、34.99 mL/g，并具有最佳的阳离子交换能力、延迟葡萄糖透析的能力、吸附葡萄糖能力、吸附胆固醇能力，因此具有与膳食纤维（Dietary fiber，DF）类似的理化和功能特性。相关性分析提示，柠檬皮渣粉中SDF含量与各理化、功能指标之间呈极显著正相关（P<0.01）。综上，提高SDF含量可作为改善柠檬皮渣粉品质的一个参考指标，经高速剪切改性后的柠檬皮渣粉具有作为优质DF来源的潜力，这可为提高柠檬皮渣粉的品质及其作为潜在的功能性食品配料提供一定理论参考。

Abstract: In this study, lemon peel residue powders were modified by microwave, high-speed shear and ultra-fine grinding, respectively, to improve its quality and the comprehensive utilization rate of lemon processing by-products. The morphological structure and thermal stability before and after modification were characterized by scanning electron microscopy, Fourier infrared spectroscopy and thermogravimetric analysis. The physicochemical and functional properties were measured to evaluate the overall quality of the lemon peel residue powders after different modifications. The results showed that the structure of lemon peel residue powders was loosened after these three modifications and the main functional groups were not significantly changed after the modification. The thermal stability of lemon peel residue powders was significantly improved after microwave and high-speed shear modification (P<0.05). Overall, the physicochemical and functional properties of the lemon peel residue powders modified by high-speed shearing were the best. Its total dietary fiber (TDF), soluble dietary fiber (SDF), water holding capacity, oil holding capacity and swelling capacity were 81.88%, 33.07%, 20.05 g/g, 2.00 g/g and 34.99 mL/g, respectively, as well as had the best cation exchange capacity, ability to delay glucose dialysis, glucose adsorption capacity, and cholesterol adsorption capacity, and therefore had similar physicochemical and functional properties to dietary fiber (DF). Correlation analysis suggested a highly significant positive correlation between the SDF content in lemon peel residue powders and each physicochemical and functional index (P<0.01). In conclusion, increasing the SDF content could be used as a reference indicator to improve the quality of lemon peel residue powders, and the lemon peel residue powders modified by high-speed shear had the potential to be a high quality source of DF, which could provide some theoretical reference to improve the quality of lemon peel residue powder and its potential as functional food ingredient.