摘要
以柑橘皮为原料,分析、比较新鲜柑橘皮果胶(fresh citrus pectin,FCP)与干制柑橘皮果胶(dried citrus pectin,DCP)的物化特性差异。采用传统酸法结合金属螯合剂(六偏磷酸钠)分别从新鲜、干制柑橘皮中提取得到果胶FCP、DCP,测定FCP和DCP的物化特性参数,包括水分、灰分、酸不溶灰分和蛋白含量等基本理化指标,以及半乳糖醛酸含量、酯化度、胶凝度、分子质量和表观黏度等果胶品质评价指标。结果表明:FCP与DCP的基本理化性质相差不大,FCP半乳糖醛酸含量、酯化度、胶凝度和分子质量分别为77.29%、67.5%、179.8和158.8 kD,而DCP对应的值依次为74.98%、66.7%、153和109.1 kD,FCP表观黏度值高于DCP。新鲜和干制柑橘皮果胶品质存在一定差异,特别是作为果胶品质重要参考指标的胶凝度,FCP要高于DCP,而这可能与FCP的分子质量较高有关,但两者的半乳糖醛酸含量和酯化度均符合果胶品质的国家标准GB25533—2010《食品安全国家标准食品添加剂》要求。
In this study, the physico-chemical properties of fresh citrus pectin(FCP) and dried citrus pectin(DCP) were analyzed and compared. FCP and DCP were prepared from fresh and dried citrus peel by traditional acid method with metal chelators(sodium hexametaphosphate). Then, their physico-chemical properties parameters were determined including moisture, ash content, acid insoluble ash content, protein content, and pectin quality evaluation indexes such as galacturonic acid content, esterifi cation degree, gelation degree, relative average molecular weight and apparent viscosity. The results showed that both pectins had no significant difference in physico-chemical properties. Galacturonic acids content, esterifi cation degree, gelation degree and relative average molecular weight of FCP were 77.29%, 67.5%, 179.8 and 158.8 kD, respectively, and those of DCP were 74.98%, 66.7%, 153 and 109.1 kD, respectively. Apparent viscosity of FCP was higher than that of DCP. An obvious difference between both in quality was observed. Especially, FCP had a higher gelation degree as an important indicator of pectin quality than DCP. This was probably due to the higher molecular weight of FCP. However, the esterifi cation degree and galacturonic acid content of both pectins met the requirements of the national standard for pectin quality. Therefore, dried citrus peel is more suitable for commercial pectin production for storage and season reasons.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2014年第13期66-69,共4页
Food Science
基金
"十二五"国家科技支撑计划项目(2012BAD33B06)
关键词
新鲜柑橘皮
干制柑橘皮
果胶
物化特性
fresh citrus peel
dried citrus peel
pectin
physico-chemical properties
