Abstract: Using water extraction method,an Astragalus polysaccharide (abbreviated APS) was extracted and purified from Astragalus membranaceus,and its carboxymethylated product was prepared.Using the carboxymethylated degree of substitution (DS) as an indicator,the carboxymethyl conditions of APS were optimized by orthogonal experiment.Using the moisture content (d.b.) of tobacco shred as an indicator,the physical moisture retention properties of APS,APS-C, propylene glycol (PG) and glycerol were measured.The effect of these compounds on sensory comfort of cigarette was investigated.The results showed that:1) the optimal carboxymethylation condition was 60 ℃ of reaction temperature,4 h of reaction time,350 mL dosage of 20% NaOH solution and 65 g of chloroacetic acid,and the DS under these conditions was higher than 1.5;2) the physical moisture retention property of APS-C and APS was significantly superior to PG and glycerol,but the physical moisture retention property of APS was inferior to APS-C,but superior to PG and glycerol;3) APS-C can make mainstream cigarette smoke mellow and full,reduce irritation and miscellaneous odor,and have a role to enhance on cigarette sensory comfort.

Key words: Astragalus membranaceus, Astragalus polysaccharide, carboxymethylation, cigarettes, moisture retention property