College of Chmistry&Chemical Engineering, Yantai University , Yantai, China.
Yantai DongJie Environment Protection Machinery & Engineering Co., Ltd ., Yantai, China.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2020 Jul;37(7):1099-1109. doi: 10.1080/19440049.2020.1755062. Epub 2020 Apr 29.
The aim of this study was to investigate the effects of carboxymethyl celluloses (CMC) with different structures (viscosity and degree of substitution) on the stability of tartrates as well as the growth mechanism of potassium bitartrate (KHT) crystals. Six CMC samples with different viscosity and degree of substitution were investigated by GPC, XRD and SEM to establish their molecular weight, crystal structure, particle size and molecular morphology. As oenological additives, they were studied in model solution and in Cabernet Sauvignon wine. The tartaric stability and inhibitory efficiency were evaluated by conductivity via mini-contact test and compared with metatartaric acid and mannoproteins commercial additives. The results suggest that under the same degree of substitution (DS), with an increase of viscosity, CMC molecular chains agglomerate and fold, the solubility in the wine decreases, thus the effect of stabilising tartrate deteriorates. Whilst at the same viscosity, with an increase of DS, the charge density of CMC molecules increases and the binding ability of ions increases and thus the stabilising tartrate has an obvious effect. The negative charge on the -COO- groups extended from CMC polymer tends to repulse the HT group in solution while attracting K ions to produce a concentration gradient at the crystal surface. In addition, CMC complexes with K ions in solution, reducing the number of K ions able to diffuse to the adsorption layer. Generally, CMC-6 with a higher the degree of substitution and lower viscosity had best application effect on tartrate stabilisation, and from the price and application performance, CMC was found to be superior to commercial additives like metatartaric acid and mannoproteins.
本研究旨在探究不同结构（黏度和取代度）的羧甲基纤维素（CMC）对酒石酸盐稳定性的影响，以及酒石酸氢钾（KHT）晶体生长机制。通过凝胶渗透色谱（GPC）、X 射线衍射（XRD）和扫描电子显微镜（SEM）研究了 6 种具有不同黏度和取代度的 CMC 样品，以确定其分子量、晶体结构、粒径和分子形态。作为酿造添加剂，在模型溶液和赤霞珠葡萄酒中对其进行了研究。通过微型接触试验通过电导率评估了酒石酸的稳定性和抑制效率，并与偏酒石酸和商品化的甘露聚糖进行了比较。结果表明，在相同取代度（DS）下，随着黏度的增加，CMC 分子链聚集和折叠，在葡萄酒中的溶解度降低，因此稳定酒石酸盐的效果恶化。而在相同黏度下，随着 DS 的增加，CMC 分子的电荷量增加，离子结合能力增强，因此稳定酒石酸盐的效果明显。CMC 聚合物上的-COO-基团的负电荷会在溶液中排斥 HT 基团，同时吸引 K 离子在晶体表面产生浓度梯度。此外，CMC 在溶液中与 K 离子形成复合物，减少了能够扩散到吸附层的 K 离子数量。通常，取代度较高、黏度较低的 CMC-6 对酒石酸盐的稳定化具有最佳的应用效果，而且从价格和应用性能来看，CMC 优于偏酒石酸和甘露聚糖等商品化添加剂。
