高透明度琼脂的制备工艺研究

琼脂是重要的海洋多糖产品,为了进一步完善我国琼脂产品加工体系和实现高透明度琼脂等深加工技术产品的国产化。对比国产琼脂和进口高透明度琼脂的品质差异,以透明度和凝胶强度为评价指标,对高透明度琼脂的配料工艺、氯乙酸添加量、反应温度、反应时间、清洗pH和原料种类对琼脂的品质影响进行了单因素实验。结果显示,进口高透明度琼脂的透明度、浊度、白度和凝胶强度分别为92.3%、21.1 NTU、65.61%、801.5 g/cm2左右,其透明度和白度高于国产琼脂,而浊度和凝胶强度低于国产琼脂。利用羧甲基化反应提高琼脂的透明度,优化得到工艺条件为:将Na₂SO₄溶解后加入原料琼脂,再将0.38 g/g氯乙酸分两次间隔10 min添加到反应体系中,50 ℃反应50 min,清洗后调节pH=5.0。该工艺条件稳定,采用三个不同批次琼脂进行高透明度琼脂制备,其透明度、凝胶强度和浊度分别为96.5%、1095.2 g/cm2、8.9 NTU,符合进口高透明度琼脂质量标准。本研究开发了高透明琼脂的生产工艺,为琼脂高值利用提供了参考。

Study on the Peparation of High Tansparent Agar

Agar is an important marine polysaccharide product. In order to further improve the domestic agar product processing system and the realization of localization of deep processing technology products such as high transparency agar. This paper aimed to explore the preparation of high transparency agar,based on comparing the qualities between domestic agar and imported high transparency agar. With transparency and gel strength as indicators of evaluation,a single factor experiment was performed on the effect of the high transparency agar batching process,the amount of chloroacetic acid added,the reaction temperature,the reaction time,the cleaning pH and the type of raw materials. The results showed that the transparency,turbidity,whiteness and gel strength of the high transparency agar were 92.3%,21.1 NTU,65.61%,801.5 g/cm2,respectively. In comparison,the high transparency agar had higher transparency and whiteness than those of domestic agar,while the turbidity and gel strength were lower than those of domestic agar. The transparency was improved by using the carboxymethylation modification. The optimized reaction conditions were as follows:the agar was added after Na₂SO₄ and other reagents dissolution,followed by addition of 0.38 g/g chloroacetic acid in two portions at intervals of 10 min. The reaction was carried out at 50 ℃ for 50 min. Adjust pH=5.0 after cleaning. The process conditions were stable,and for three different agars,the results showed the transparency,gel strength and turbidity of 96.5%,1095.2 g/cm2 and 8.9 NTU,respectively,which meet the counterparts of the high transparency agar. In short,this study develops a process for producing a high-transparency agar,which provides a reference for value-added utilization of agar.