In the present study, in order to assess the influences of drying methods on the chemical structures, in vitro digestibility and prebiotic potential of polysaccharides extracted from Chimonobambusa quadrangularis shoot (CPSs), four drying methods, including hot air-, vacuum-, freeze-, and spray-drying, were utilized to dry CPSs. Results revealed that the physicochemical characteristics and prebiotic activity of CPSs varied by different drying methods. In comparison with the other drying methods, freeze-dried CPSs had higher uronic acid content (9.58%), lower medium-high molecular weight (117.63 kDa), smaller particle size (115.97 nm) and better solubility. All four CPSs fractions exhibited low degree of digestibility to pretended human gastric juice (< 2%) and α-amylase (< 5%). The freeze-dried CPSs showed the greatest prebiotic activity as this polysaccharide induced the strongest proliferation effect of probiotic bacteria and the highest production of total short chain fatty acids. Our results collectively provided substantial evidence that the freeze-drying method proposed in this study could be an effective technique in improving the prebiotic potentiality of CPSs.

中文翻译：

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不同干燥方法对竹笋残渣多糖的结构特征和益生元活性的影响。

在本研究中，为了评估干燥方法对从四角奇异果枝（CPSs）提取的多糖的化学结构，体外消化率和益生元潜力的影响，共有四种干燥方法，包括热风，真空，冷冻和喷雾干燥被用来干燥CPS。结果表明，不同干燥方法对CPS的理化特性和益生元活性的影响不同。与其他干燥方法相比，冷冻干燥的CPS具有较高的糖醛酸含量（9.58％），较低的中高分子量（117.63 kDa），较小的粒径（115.97 nm）和较好的溶解度。所有四个CPS馏分均对假装的人胃液（<2％）和α-淀粉酶（<5％）具有较低的消化率。冷冻干燥的CPS显示出最大的益生元活性，因为这种多糖诱导了益生菌的最强增殖作用和最高的总短链脂肪酸产量。我们的研究结果共同提供了充分的证据，表明本研究中提出的冷冻干燥方法可能是提高CPS益生元潜力的有效技术。