Bilateral Moisturizing Effect Of Sucrose Esterpolygonatum Sibiricum Polysaccharide Hydrolysate And Its Application

The moisture content of tobacco directly affects the processing characteristics of tobacco and the sensory quality of cigarette products.However,as a porous hygroscopic material,tobacco is easy to lose water under dry condition,and adsorb water under damp condition,leading to quality deterioration.Therefore,it is of great importance to develop a humectant with bilateral moisturizing properties which can achieve moisture retention and moisture resistance effects simultaneously.In this paper,the bilateral humectants were prepared by combination of sucrose esters?SEs?and natural polysaccharides as well as their hydrolysates to enhance the bilateral moisturizing properties of cigarettes.Meanwhile,mechanisms of the humectants for improving the bilateral moisturizing capacities were discussed.Firstly,influence of SEs with various hydrophilic–lipophilic balance?HLB?values on adsorption and desorption properties of tobacco was investigated using moisture proof index?MPI?and moisture retention index?MRI?as evaluation indicators.Results showed that P-15and S-5?HLB values of 15 and 5,respectively?were capable of improving the moisture resistance of tobacco effectively.MPI of P-15 and S-5 were 2.1440 and 2.0820 respectively,which were higher than control?1.9472?and propylene glycol?1.8268?.However,MRI values decreased,indicating that the moisture holding capacity of tobacco was weakened.Analysis of the pyrolysis products of S-5 and P-15 via pyrolysis-gas chromatography-mass spectrometry showed that the main pyrolysis products of SEs were higher fatty acids and their methyl esters,aldehydes,ketones and esters,which contributed to better sensory quality of cigarettes.In order to enhance moisture holding ability of tobacco,the moisture adsorption and desorption abilities of different natural polysaccharides were evaluated,of which Polygonatum sibiricum polysaccharide?H0?was the one with the best moisturizing effect.MRI of tobacco sample added with H0 increased from 1.9205 to 2.0412,suggesting that H0 exhibited better moisture retention performance than propylene glycol;however,the hygroscopicity of tobacco increased after adding H0.H0 was then enzymatically hydrolyzed by complex cellulase to prepare two hydrolysates?H1 and H2?.Compared with H0,H1 and H2 showed further improved moisture retention and absorption capacities in tobacco.Then,P-15 and S-5 were mixed with H1,H2 and H0 respectively to prepare the bilateral humectant?SPMs?,which were evaluated for their effect on desorption and adsorption characteristics of tobacco.Results revealed that SPMs improved both of the moisture retention and proof abilities of tobacco simultaneously,of which S-5-H1 had better bilateral moisturizing property than propylene glycol.MPI of S-5-H1 samples at addition amount of 1%/0.4%and2%/0.4%?SEs/Polygonatum sibiricum polysaccharide?were 1.9929 and 2.0070 respectively,and MRI were 2.1612 and 2.1380 respectively,all higher than those of propylene glycol.The former improved the sensory quality of cigarettes,while the latter decreased the sensory quality slightly.Thereafter,the mechanisms of moisture resistance and retention effect of the humectants were discussed using moisture adsorption isotherms,low field nuclear magnetic resonance?LF-NMR?and environmental scanning electron microscope?ESEM?.Modeling of the isotherms suggested that SEs decreased the monolayer moisture content?M₀?of tobacco,showing weaker moisture holding capacity at low RH,while S-5-H1 increased the M₀,contributing to a stronger moisture retention.LF-NMR was utilized to analyze the water distribution in tobacco.Results revealed that during adsorption,S-5-H1 and S-5 reduced the interaction strength of tobacco with water and the chemically bound water content through hydrophobicity of the long carbon chain in SEs,thereby achieving moisture resistance effect.Additionally,during desorption,the hydrophilic groups contained in S-5-H1 induced stronger interaction between water and tobacco and more chemically bound water content,thus improving the moisturizing effect.Moreover,ESEM was used to observe the surface structure of tobacco.It was found that tobacco with S-5-H1 expanded less at high RH;the tobacco surface was smoother and the shrinkage degree of structure was smaller at low RH.S-5-H1 could maintain the relatively stable morphology of the tobacco surface in both high and low RH environments,thus slowing down the rate of moisture change.Finally,S-5-H1 was applied to the cigarettes,and results showed that the bilateral moisturizing capacity of finished cigarettes could also be promoted by S-5-H1,verifying the effectiveness of SPMs.Through analysis of the particulate phase components in mainstream smoke of cigarettes,it was found that adding SPMs increased the content of palmitic acids,stearic acids,their esters and furans in the mainstream smoke,thereby improving the sensory comfort.