Study On The Effect Of Sodium Carboxymethyl Cellulose (CMC) On The Tartrate Stabilization Of Wines

The tartrazine?mainly potassium hydrogen tartrate and calcium tartrate?in red wine will appear as precipitates in bottled fermented wine,affecting the perception,while sodium carboxymethyl cellulose?CMC?can be used to prevent tartrate in wine brewing.The main purpose of this paper is to study the effects of CMC with different structures?degree of substitution and viscosity?on the stability of tartar.Major research has been done in the following aspects:?1?The molecular weight,crystal structure and molecular morphology of CMC samples were characterized by Ush viscometer,X-ray diffraction?XRD?and scanning electron microscopy?SEM?.The results show that with the same degree of substitution,the diffraction intensity increases slightly with the increase of viscosity,the strong diffraction peak does not shift,the crystal structure changes little,the intermolecular entanglement occurs,and the binding ability with ions decreases.With the increase of substitution degree,the diffraction intensity and crystallinity of CMC with the same viscosity decrease.The substitution degree mainly affects the linear charge density of polymer chain,but has little effect on the molecular weight of main chain and increases the binding ability with ions.?2?In the process of tartar stabilization,CMC as a stabilizer depends on many factors,such as the concentration of CMC,the pH value of the system,the type and strength of ions,etc.This chapter mainly studies the effects of these factors on the apparent viscosity of CMC solution.The results show that CMC aqueous solution exhibits near Newtonian fluid behavior at low concentration,pseudoplastic behavior at high concentration,and the viscosity of solution increases with increasing concentration without exception.With the decrease of pH value,the apparent viscosity first decreases and then increases.With the addition of K⁺the viscosity of CMC aqueous solution decreases,but the difference is not obvious;with the introduction of Ca²⁺the viscosity of CMC aqueous solution decreases.?3?The changes of DS and viscosity of CMC have significantly changed its physical and chemical properties,thus affecting their application performance.Atomic absorption spectrometry was used to determine K⁺,Ca²⁺in solution and micro-contact test was used to determine the change rate of electrical conductivity of wine samples after adding additives.The inhibitory effect of additives on tartar was evaluated and compared with two other commonly used additives?metatartaric acid and yeast mannose glycoprotein?.The results showed that different types of CMC had different stabilizing effects on tartar in wine.With regard to the type of CMC,the higher the viscosity of CMC sample is,the greater the change rate of conductivity is,and the stability of CMC tartrate decreases with the same degree of substitution.With the increase of substitution degree of CMC,the change rate of conductivity decreases and the stability of wine tartar increases.In terms of the effect and cost of tartar stabilization,sodium carboxymethyl cellulose is the most cost-effective additive.?4?In order to eliminate the interference of other factors,simulated wine was used instead of wine.Atomic absorption spectrometry was used to determine K⁺in solution and micro-contact test was used to determine the change rate of electrical conductivity of added wine sample,and to evaluate the inhibitory effect of additives on simulated tartar KHT.The crystal morphology of potassium hydrogen tartrate?KHT?was characterized by scanning electron microscopy?SEM?.The results showed that the effect of CMC on stabilizing potassium hydrogen tartrate in simulated wine was the same as that in Cabernet Sauvignon red wine.