Effect of carboxymethylcellulose on potassium bitartrate crystallization on model solution and white wine

Abstract

Instability in bottled wines refer to tartaric salts crystallization such as potassium bitartrate (KHT). It is not desirable as consumers see the settled salts as an evidence of a poor quality control. In some cases, it causes excessive gushing in sparkling wine. We investigate the effect of two oenological carboxymethylcellulose (CMC) for KHT inhibition in a model solution of white wine by studying the impact of some properties of CMC such as the degree of polymerization, the degree of substitution, and the apparent dissociation constant determined by potentiometric titration. Polyelectrolyte adsorption is used for determining the surface and total charge and for providing information about the availability of CMC charged groups for interacting with KHT crystal faces. The inhibitory efficiency of CMC on model solution is evaluated by measuring the induction time with the help of conductimetric methods. Crystals growth with and without CMC are studied by observation with MEB and by thermal analysis using DSC. The results confirm the effectiveness of CMC as an inhibitor of KHT crystallization in a model solution. The main hypothesis of the mechanism lies in the interaction of dissociated anionic carboxymethyl groups along the cellulose backbone with positively charged layers on KHT faces like the {0 1 0} face. Key factors such as pH, CMC chain length and total charge are discusses.

Study of the effect of organic acids on the crystal stability of wines

“…The loss of solubility of tartaric acid salts of potassium and calcium is the reason of precipitation of crystal sediment in wine [1][2][3]. Fresh grape must is oversaturated with potassium bitartrate and calcium tartrate.…”

“…It is known that the decrease in the content of calcium directly depends on pH and is based on the interaction of cation with tartrate form of tartaric acid. The content of this form increases with the growth of pH [3,4], contributing to more active formation of calcium tartrate and precipitation of generated crystals. The introduction of calcium tartrate seed crystals after de-acidification of wine with calcium carbonate enhances the precipitation of salts.…”

The influence of agricultural practices in vineyards on the predisposition of wines to crystalline turbidities

“…Various technological equipment and auxiliary materials can be used to combat crystalline turbidities [3][4][5][6][7][8][9][10][11], however, most of the methods for stabilizing wines to crystalline turbidities are extremely expensive and / or energy-intensive, as a result of which many enterprises, especially small farms, simply can not afford to use them.…”

Дестабилизация Вин. Кристаллообразование Калиевых Солей

“…Защитный эффект некоторых высокомолекулярных веществ положен в основу технологических методов борьбы с появлением кристаллического осадка в вине. Внесение препаратов на основе карбоксиметилцеллюлозы [41][42][43], полиаспартата [44], метавинной кислоты [42,45], искусственно выделенных маннопротеинов [42,46] продлевают срок кристаллической стабильности и служат дополнительной гарантией качества вина. однако данные вещества проявляют должный защитный эффект только при незначительной исходной склонности вин к кристаллообразованию, внесение их целесообразно после предварительной обработки виноматериалов с выведением из растворенного состояния битартрата калия.…”