Abstract Aim of the present work was to evaluate the physiochemical and rheological properties of hot water extracted pectin from the kinnow (Citrus nobilis + Citrus deliciosa) peel. Hot aqueous extraction of peel at 90 °C for 30 min at pH 5 followed by ethanol precipitation and lyophilisation yielded 6.13% of pectin whereas e-factor was 15.313. Physicochemical characteristics of extracted pectins (EP) were calculated and compared with the HMP (high methoxyl pectin) and PP (pure pectin). Steady state shear and oscillatory dynamic rheological tests were carried out to evaluate material’s mechanical properties. Frequency sweep and temperature sweep experiments were done and found that in all the experiments, elastic modulus (G′) was greater than viscous modulus (G″) and both increase with increase of frequency. Power law model was computed to study the adequacy of fitting of the rheological data of pectin at different concentrations. SEM, FTIR tests were used for examining the structures of extracted pectin and commercial pectin. It was found that extracted pectin from kinnow peel is low methoxyl pectin. From physicochemical and rheological study it is confirmed that extracted pectin can be used successfully to make low calorie jams, jellies and as thickener in food products.

中文翻译：

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金诺果果胶的分离及其表征

摘要 本工作的目的是评价从金诺（Citrus nobilis + Citrus deliciosa）果皮热水提取果胶的理化和流变学特性。在 90 °C 下在 pH 5 下对果皮进行热水提取 30 分钟，然后进行乙醇沉淀和冻干，得到 6.13% 的果胶，而 e-因子为 15.313。计算提取果胶 (EP) 的理化特性，并与 HMP（高甲氧基果胶）和 PP（纯果胶）进行比较。进行稳态剪切和振荡动态流变测试以评估材料的机械性能。进行了频率扫描和温度扫描实验，发现在所有实验中，弹性模量（G'）大于粘性模量（G''），并且都随着频率的增加而增加。计算幂律模型，研究不同浓度果胶流变学数据拟合的充分性。SEM、FTIR 测试用于检查提取果胶和商业果胶的结构。发现从kinnow果皮中提取的果胶是低甲氧基果胶。理化和流变学研究证实，提取的果胶可成功用于制作低热量的果酱、果冻和食品中的增稠剂。