Sheng Zhicun, Guo Ainan, Wang Jing, Chen Xiaolan
Jiangsu Agri-animal Husbandry Vocational College, Taizhou, Jiangsu, 225300, China.
Tianjin University of Science and Technology, Tianjin, 300457, China.
Heliyon. 2022 Oct 19;8(10):e11168. doi: 10.1016/j.heliyon.2022.e11168. eCollection 2022 Oct.
As an alternative chitosan source, edible insects have been proposed as an unconventional but viable option. Taking fly pupae as an example, this work performed chitosan extraction through a traditional chemical method with some modifications, and investigated its physicochemical properties and antimicrobial activity. The results showed that adding 0.5% sodium sulfite (NaSO, w/w, NaSO/fly pupae) synergized with sodium hydroxide (NaOH) for deproteinization was more effective than lye alone. Acid leaching was applied for desalination, and the optimal concentration of hydrochloric acid (HCl) was determined as 2 mol/L by ash content. For decoloration, the optimal decolorization oxidant was sodium hypochlorite (NaClO) with a concentration of 1.0%. For the deacetylation of chitin to chitosan, both the yield and degree of deacetylation (DD) using segmented treatment with alkali-NaOH were higher than those of traditional one-time deacetylation. The established physicochemical properties corresponded with the typical characteristics of chitosan. The determination of antimicrobial activity of chitosan by the turbidimetric method showed that chitosan exhibited notable activity in the order of > > , and this effect decreased with the increase in viscosity-average molecular weight (Mη). These results proved the viability of our improved method for the preparation of chitosan, a valuable antimicrobial agent, using an alternative natural source.
作为一种替代壳聚糖来源，食用昆虫已被提议作为一种非常规但可行的选择。以蝇蛹为例，本研究通过传统化学方法并进行一些改进来提取壳聚糖，并研究了其理化性质和抗菌活性。结果表明，添加0.5%亚硫酸钠（NaSO，w/w，NaSO/蝇蛹）与氢氧化钠（NaOH）协同进行脱蛋白比单独使用碱液更有效。采用酸浸法进行脱盐，通过灰分含量确定盐酸（HCl）的最佳浓度为2 mol/L。对于脱色，最佳脱色氧化剂是浓度为1.0%的次氯酸钠（NaClO）。对于几丁质脱乙酰化为壳聚糖，采用碱-NaOH分段处理的产率和脱乙酰度（DD）均高于传统的一次性脱乙酰化。所确定的理化性质与壳聚糖的典型特征相符。通过比浊法测定壳聚糖的抗菌活性表明，壳聚糖表现出显著的活性顺序为> > ，且这种效果随着粘均分子量（Mη）的增加而降低。这些结果证明了我们使用替代天然来源制备壳聚糖（一种有价值的抗菌剂）的改进方法的可行性。
