Apple by-product is an extensive and inexpensive residue rich in dietary fibre, mainly insoluble fraction. Regarding soluble fibre, pectins are the predominant component responsible for specific physicochemical characteristics which are intimately related to its functional properties. To valorise apple by-product enhancing the solubility of pectins, high hydrostatic pressure (HHP) processing at 200–600 MPa during 15 and 30 min under controlled temperature was performed. Release of soluble carbohydrates was monitored using ion-exchange HPLC method with refractive index detection and dietary fibre composition was studied. A value of 200 MPa during 15 min was enough to enhance the solubilisation of cell wall components, mainly pectins, increasing significantly (p < 0.05) about threefold high/medium molecular weight soluble carbohydrates and maintaining total phenolic content. HHP preserved brightness, yellowish hue and slightly decreased pH. Furthermore, this valorisation procedure upgraded emulsion activity and stability improving the technological aptitude and enhanced swelling, oil-holding and cation-exchange capacities suggesting a potential lipid-lowering effect.

中文翻译：

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高静水压力处理可增强果胶对苹果副产物的增溶作用，从而改善技术功能特性

苹果副产品是一种广泛而廉价的残留物，富含膳食纤维，主要是不溶部分。关于可溶性纤维，果胶是负责特定理化特性的主要成分，这些特性与其功能特性密切相关。为了使苹果副产品增值以提高果胶的溶解度，在受控温度下于15和30分钟内在200–600 MPa下进行了高静水压（HHP）处理。使用离子交换HPLC方法通过折射率检测监测可溶性碳水化合物的释放，并研究膳食纤维的组成。15分钟内200 MPa的值足以增强细胞壁成分（主要是果胶）的增溶作用（p <0.05）约三倍的高/中分子量可溶性碳水化合物，并保持总酚含量。HHP保持亮度，淡黄色调和pH值略微降低。此外，这种增值程序提高了乳剂的活性和稳定性，从而改善了技术适应性，并增强了溶胀，持油和阳离子交换能力，表明潜在的降脂作用。