Apple pomace, a by-product of juice production, is a high-fibre, high-polyphenol functional food ingredient. Extrusion (barrel moisture 15%, 20% or 30%) of apple pomace, followed by drying, allows it to be supplied in a convenient form. Extrusion caused degradation of the apple pomace cell wall structure. Water solubility was significantly increased by extrusion but oil holding capacity was reduced. Total extractable polyphenols, measured as gallic acid equivalents, were reduced by extrusion (barrel moisture 30%) but were not affected by extrusion at lower barrel moisture contents (15% or 20%). However, individual sub-groups of extractable flavanols, flavonols, phenolic acids and dihydrochalcones were increased by extrusion. There was little effect of extrusion on the release of total polyphenols from the matrix into the supernatant, as measured by total extractable polyphenols (measured as gallic acid equivalents) released during in vitro digestion. There was a marked increase in total flavanols, phenolic acids and dihydrochalones released into the supernatant during the gastric phase but changes in flavonoids were less obvious. The changes in the bioaccessibility of individual polyphenols released during intestinal digestion were dependent on the type of polyphenol and extrusion conditions. The antioxidant activity, as measured using oxygen radical absorbance capacity (ORAC) of the bioaccessible nutrients released upon in vitro intestinal digestion, was significantly enhanced by extrusion (from 78.2 to 400–500 μmol Trolox equivalents per mL at the ileal phase). The increased ORAC may be attributed in part to the increased release of individual polyphenols.

中文翻译：

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苹果渣挤出后在体外消化时可提高抗氧化活性†

苹果渣是果汁生产的副产品，是一种高纤维，高多酚功能性食品成分。将苹果渣挤出（桶装水分为15％，20％或30％），然后干燥，以方便的形式提供。挤压引起苹果果渣细胞壁结构的降解。通过挤出显着增加了水溶性，但是降低了持油量。以没食子酸当量计的总可萃取多酚含量通过挤压（每桶水分为30％）而减少，但在较低的桶中水分含量（15％或20％）下不受挤压的影响。然而，通过挤压增加了可提取的黄烷醇，黄酮醇，酚酸和二氢查耳酮的各个亚组。挤出对总多酚从基质向上清液的释放几乎没有影响，体外消化。在胃阶段释放到上清液中的总黄烷醇，酚酸和二氢ch子的总含量显着增加，但黄酮类化合物的变化不太明显。肠道消化过程中释放的单个多酚的生物可及性变化取决于多酚的类型和挤压条件。抗氧化活性，通过使用体外消化后释放的生物可利用营养素的氧自由基吸收能力（ORAC）来衡量，通过挤压得到显着提高（回肠期从78.2到400-500μmolTrolox当量/ mL）。增加的ORAC可能部分归因于单个多酚释放的增加。