Search

Potassium polyaspartate (KPA), a colloidal additive for tartaric stabilization, has recently been approved for use in wine (OIV/OENO 543-2016) and has been adopted by many wineries in Europe. Previous research has highlighted its efficacy for tartrate stabilization, which is similar to that of other additives such as metatartaric acid (MT) and carboxymethylcellulose (CMC). However, unlike CMC and MT, KPA has been reported to not affect color or cause haze formation, and to maintain its effect over time. In the present study, we evaluated for the first time the efficacy of KPA in wines treated with different KPA concentrations at high temperatures. A full factorial experimental design was used to investigate the effects and interactions of temperature, storage time, and the dose of KPA on tartaric stability in red and white wines, as evaluated by a conductivity test. The results of this study showed that storage temperature is the variable with the greatest influence on the efficacy of KPA. However, KPA was still able to maintain its efficiency for at least 45 days at temperatures ~40°C, conditions that can sometimes occur during commercial shipment. The results obtained from the conductivity test were consistent with those from a cold test used as a control for measuring tartaric stability.

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.

The Panel on Food Additives and Flavourings (FAF) provided a scientific opinion re‐evaluating the safety of metatartaric acid (E 353) when used as a food additive. Metatartaric acid (E 353) had been previously evaluated by the Scientific Committee on Food (SCF) and Joint FAO/WHO Expert Committee on Food Additives (JECFA). Based on the presumption that metatartaric acid is fully hydrolysed pre‐systemically to l(+)‐tartaric acid, the Panel concluded that metatartaric acid (E 353) should be included in the group acceptable daily intake (ADI) of 240 mg/kg body weight (bw) per day, expressed as tartaric acid, for l(+)‐tartaric acid‐tartrates (E 334–337, 354) which was established by the EFSA FAF Panel in 2020. Exposure estimates were calculated for metatartaric acid (E 353) using a maximum level and refined exposure assessment scenario. The Panel also concluded that there is no safety concern for the use of metatartaric acid (E 353) at the reported use and use level. The Panel made a number of recommendations., This publication is linked to the following EFSA Journal article: http://onlinelibrary.wiley.com/doi/10.2903/j.efsa.2020.6030/full

The research was aimed at verifying the efficacy of potassium polyaspartate (KPA), added at bottling, for prevention of the precipitation of potassium bitartrate (KHT). The stability of KHT was determined with the mini-contact test and the cold test. The effect of KPA on the colloidal stability of white and red wines was also studied. Turbidity, color, and total anthocyanins and flavonoids (red wines only) were monitored. In the first experiment, the stabilizing effect of KPA added at bottling, with or without Arabic gum, tannins, and filtration (0.45 µm cut-off), was studied in comparison with metatartaric acid (MTA). KPA proved to have good stabilizing efficacy for prevention of KHT precipitation and maintained its effect in all trials after 1 year of bottle aging. On the contrary, all the trials with MTA became unstable after 6 months. Moreover, KPA did not modify wine turbidity and color. The filtration (0.45 µm cut-off) did not reduce its stabilizing efficacy. In the second experiment, the effect of KPA added to a white and a red wine, respectively clarified with casein and gelatin or vegetal protein and/or bentonite, was studied. KPA did not cause any increase in turbidity or appreciable changes in the color of the white wines of the different trials. A preliminary treatment with bentonite can prevent the possible formation of haze in red wines after the addition of KPA. PRACTICAL APPLICATION: KPA prevented the precipitation of KHT in unstable white and red wines. The stabilizing effect persisted after 1 year of bottle aging. The oenologist does not need to adopt special prescriptions when using KPA in combination with Arabic gum or tannins in prebottling operations. A treatment with bentonite prevented the appearance of turbidity in red wines after the addition of KPA.

Dissertação de mestrado em Tecnologia e Ciência Alimentar, O presente trabalho foi elaborado no âmbito da dissertação de Mestrado em Tecnologia e Ciência Alimentar nas Caves Campelo S.A., e teve como principal objetivo acompanhar o processo completo de vinificação em vinhos verdes, nomeadamente das castas Alvarinho, Loureiro e Arinto. Pretendeu-se avaliar diferentes métodos de filtração e diferentes estabilizantes tartáricos de modo a obter os resultados mais benéficos para a empresa, efetuando-se ensaios de filtração e de estabilização tartárica. No primeiro caso, analisaram-se os parâmetros físico-químicos e por consequente a medição da turbidez no vinho não filtrado, procedendo-se em análise comparativa dos valores de turbidez e dos parâmetros FQ com os outros dois métodos em estudo, filtração por placas e por terras. Sendo a presença de cristais um dos fatores de rejeição do vinho por parte do consumidor, os ensaios de estabilização tartárica centraram-se na adição de ácido metatartárico e de carboximetilcelulose (CMC), analisando o efeito de cada um deles e o impacto nos parâmetros físico-químicos e sensoriais. Paralelamente à medição da condutividade elétrica (teste minicontacto) da CMC e do ácido metatartárico realizou-se um teste frio, no qual se monitorizaram os resultados durante trinta dias. A análise sensorial é um dos pontos cruciais quer na produção quer na sua aceitação do vinho. Para o efeito, as amostras foram provadas por um painel de cinco provadores. Os resultados obtidos permitiram concluir que os métodos de filtração testados conferem resultados satisfatórios surgindo, porém, alterações em determinados parâmetros físico-químicos. É possível inferir que a CMC e o ácido metatartárico previnem a precipitação tartárica, no entanto, o ácido metatartárico apresenta resultados mais vantajosos nas três castas. A adição dos estabilizantes tartáricos não evidenciou diferenças significativas nos parâmetros físico-químicos. A nível sensorial é possível verificar que cada casta apresenta um comportamento distinto face aos diferentes métodos de filtração/adição dos estabilizantes tartáricos., The present work was carried out in the form of a curricular internship at Caves Campelo S.A. and its main objective was to follow the complete vinification process of vinhos verdes, namely Alvarinho, Loureiro and Arinto. The goal was to evaluate diferente filtration methods and different tartaric stabilizers in order to ascertain which one would yield the most beneficial results for the company. Accordingly, triplicate filtration and tartaric stabilization tests were performed. In the first case, the physicochemical parameters were analyzed, turbidity was measured in unfiltered wine and a comparative analysis of turbidity and CF parameters was conducted through plate filtration and Diatomaceous earth. Considering the presence of crystals is one of the factors of wine rejection by the consumer, the tartaric stabilization tests focused on the addition of metatartaric acid and carboxymethylcellulose (CMC), analyzing their effect and impact on the physical and chemical and sensory parameters. In parallel with the electrical conductivity (mini-contact test) measurement of CMC and metatartaric acid, a cold test was performed and the results were monitored for a period of thirty days. Sensory analysis of wines is one of the crucial points in both wine production and acceptance. To this purpose, the samples were tested by a panel of five tasters and the descriptive characteristics were evaluated on a radar diagram and the final evaluations on a bar graph. The results allow to conclude that plate filtration provides better wine clarification, although some alterations in certain physicochemical parameters may occur. It could also be inferred that CMC and metatartaric acid prevent tartaric precipitation. However, metatartaric acid shows more advantageous results in the three varieties tested. The addition of tartaric stabilizers revealed no significant differences in physicochemical parameters. At the sensory level, it can be concluded that each wine variety reacts differently to the filtration/addition methods of tartaric stabilize.

All additives used to stabilize wines against the precipitations of potassium bitartrate have some limits: metatartaric acid (MTA) is effective but very unstable, carboxymethylcellulose is stable and effective in white wines but affects color stability in red wines, mannoproteins have a variable effectiveness depending on wine composition. This work was aimed at testing the effect of new stabilizing products on tartaric precipitations, focusing on the use of Na and K polyaspartate salts (PASPs). The effectiveness of 4 different PASPs and 1 MTA added to red and white wines was compared using the mini-contact test and cold test. The dose effect and the stability of the products over time were also studied. The PASPs showed a similar stabilizing effect and a longer stability over time compared to MTA. PASPs can be considered interesting as additives for wine tartaric stabilization. Further work is in progress to better characterize their enological properties.

Seven commercial metatartaric acid (MTA) products used for tartaric stabilization of wines were investigated regarding molecular masses and composition. Combined size-exclusion chromatography with MALS detection showed that the products had medium molecular masses in a range of 2–9 kDa. All samples were highly polydisperse products with a broad molecular weight distribution. Beside oligomeric or polymeric contents, the products contained on average 13 g/100 g monomeric tartaric acid, thus reducing the effectiveness of MTA in respect of achieving tartaric stability. An analytical method to determine MTA in wines and grape juices based on an anion-exchange cleanup step, HPLC separation, and MS detection was developed. The method shows a sufficient robustness to evaluate important enological or food legal aspects in connection with MTA.

Carboxylmethylcellulose (CMC) is authorised to prevent wine tartaric instability. The effect of CMC structural characteristics on their effectiveness is not well understood. The main purpose of this study was to compare the impact of CMC's with different degrees of substitution and molecular weight, on tartaric stability, tartaric acid, mineral concentration, phenolic compounds, chromatic and sensory characteristics in white wines, and compare its effectiveness with other oenological additives. Mini-contact test showed that all CMC's and metatartaric acid stabilized the wines; however, some arabic gums and mannoproteins do not stabilized the wines. CMC's had no significant effect on tartaric acid, potassium, calcium and sensory attributes. Tartaric stabilization effectiveness depends on CMC's degree of substitution, but also on wine matrix, probably its initial potassium content. Results suggest that CMC is a good alternative to white wine tartaric stabilization; nevertheless deeper structure knowledge is necessary in order to choose the appropriate CMC for a given tartaric instability.

The aim of this work was to test the tartaric stabilising effect of potassium polyaspartate (KPA) in comparison to metatartaric acid and carboxymethylcellulose (CMC). Wines of the varieties Chardonnay and Rheinriesling (vintage 2017) were used, furthermore their instability was increased by addition of potassium and tartaric acid. The samples were stored at 2 ∘C and 20 ∘C and analyzed after 70, 120 and 175 days. Results showed that the non-stabilized wines exhibited significant precipitations of potassiumhydrogentartrate at both temperatures. The stabilizer CMC could not prevent precipitation in the base wines at 20 ∘C. For the enriched wines the stabilising effect of CMC was inadequate. Although metatartaric acid gave sufficient stabilization in most variants, in enriched Rheinriesling the stabilising effect lessened after prolonged storage at 2 ∘C and a tartaric precipitate was detected. Only the wines stabilized with potassium polyaspartate remained blank at all dates and variants and showed no loss of potassiumhydrogentartrate. Control of the residual levels of tartaric acid and potassium after storage confirmed these results. Therefore it can be stated that of the three stabilizers tested, only potassium polyaspartate, even at half the recommended application rate, prevented the precipitation of Weinstein in all variants and thus had the best tartaric stabilising effect.

Sediments of potassium bitartrate, and in a lesser extent calcium tartrate, are some of the most common causes of instability in bottled wines. The most traditional stabilization method is cold stabilization whose effectiveness depends on wine composition and it's time and energy consuming. In this review, besides the aforementioned method, ion exchange, electrodialysis and the use of authorised additives as metatartaric acid, mannoproteins or carboxymethylcellulose are discussed. Finally, a cost assessment reveals that ion exchange is the cheapest technology and mannoproteins the higher-priced additive.

The performance of polystyrene anion exchangers in purifying wastewaters containing metatartaric acid and heavy metal ions (especially those from electroless plating processes) was investigated. The following anion exchangers were selected: Lewatit MonoPlus M 500, Lewatit MonoPlus MP 64, Lewatit MP 62 and Amberlite IRA 402. A batch method was used to study the influence of: phase contact time (1-120 min); solution pH (2-9); concentration of initial heavy metal Cu(II), Zn(II), Co(II) and Ni(II) complexes (1.25 x 10(-4) M to 8.0 x 10(-3) M); temperature (303-333K); and interfering ions (Cl-, NO3-, SO4(2-), Ca2+, Mg2+). The amounts of Cu(II), Zn(II), Co(II) and Ni(II) complexes with metatartaric acid sorbed at equilibrium using the strongly basic anion exchanger Lewatit MonoPlus M 500 were equal to 7.25 mg/g, 3.21 mg/g, 3.78 mg/g and 3.98 mg/g, respectively. The equilibrium sorption capacity increased slightly with increasing temperature. The optimal pH sorption was found to be 6.5. The experimental data were analysed using the Langmuir and Freundlich models. The maximum adsorption capacities q(0) determined from the Langmuir adsorption equation equal to 7.53 mg/g, 3.75 mg/g, 3.55 mg/g and 4.60 mg/g were in good agreement with the experimental values for Lewatit MonoPlus M 500. The kinetic data obtained at different concentrations were modelled using pseudo first order, pseudo second order and intraparticle diffusion equations. The experimental data were well described by the pseudo second order kinetic model.

A instabilidade do vinho em relação ao ácido tartárico e seus sais é ainda um problema para os produtores de vinhos, sendo a estabilização tartárica dos mesmos, uma prática corrente em enologia. A eliminação de uma fração do ácido tartárico é geralmente conseguida pela sua precipitação pelo frio, com intervenção de catiões presentes no vinho, nomeadamente potássio (K) e cálcio (Ca). Existem no entanto outras alternativas, como por exemplo resinas de troca iónica que removem os catiões K e Ca, evitando a precipitação do ácido tartárico. Este estudo pretende contribuir para a compreensão do fenómeno de precipitação deste ácido nas formas de tartarato de cálcio e de hidrogenotartarato de potássio, avaliando a estabilidade tartárica em diferentes vinhos brancos e tintos, de seis ensaios feitos à escala industrial com recurso a um equipamento de troca iónica de permutadores catiónicos, comparativamente a outras técnicas tradicionais de estabilização tartárica, como sejam o tratamento pelo frio e o tratamento com a adição de ácido metatartárico. O estudo efetuado permitiu concluir que a utilização do equipamento de troca iónica conduz a vinhos estáveis do ponto de vista tartárico, sendo que as principais alterações nas características dos vinhos se verificam nos valores de pH e da acidez total, com consequências na cor dos vinhos, especialmente no caso dos vinhos tintos; Tartrate Stabilization of Wine Abstract: Wine instability concerning tartaric acid and its salts is still a difficult problem for wine producers, as tartaric stabilization is a normal practice in winemaking. The elimination of some tartaric acid occurs normally through its precipitation at low temperatures, with intervention of cations present in wine, mainly potassium (K) and calcium (Ca). Nowadays ion exchange resins can be used to remove K and Ca cations, avoiding tartaric acid precipitation. This study aims to gain insight of tartaric acid precipitation phenomena, either in the form of calcium tartrate or potassium hydrogen tartrate, evaluating the tartaric stability of white and red wines using an equipment of ion exchange and comparing it with the traditional tartaric stabilization methods, cold stabilization and metatartaric acid. Tartaric acid content by HPLC and cations by flame atomic absorption spectrometry were determined. Tartaric stability was evaluated by mini contact and saturation temperature methods. With the use of the ion exchange resins, stable wines were obtained. Differences in pH and total acidity were also observed with consequences in color, especially regarding red wines.

Mestrado Vinifera EuroMaster - Instituto Superior de Agronomia The sensitivity of metatartaric acid (MA) to high temperatures is the main limit for its actual use in enology. For this reason MA is generally used only for ready-to-drink wines that are stored for few months in bottle. The objective of this work was to obtain more information about the use of MA in order to prevent tartaric salts precipitation in wine by monitoring its effectiveness along the time. Tartaric stability was followed in a white wine during a ten-week experiment. 10 g/Hl of MA was added to wines with different five pH values, namely 3.0, 3.2, 3.5, 3.7 and 3.9 at room temperature (20°C), and to wines at original pH of 3.2 under three different temperatures commonly found in real storage conditions, precisely 12°C, 20°C and 35°C. To monitor tartaric stability we used a test based on the electrical conductivity developed by Boulton (1983). At the end of the experiment we found both a pH and a temperature effect. It was found a polynomial relation (R2 = 0,85) between tartaric stability and pH. The highest the pH, the highest the instability and the shortest the protection against tartrates precipitation. Furthermore, over 20°C we observed a rapid general decrease of MA effectiveness and that there was a linear relation (R2 = 0,99) between temperature and tartaric stability, so that we can affirm that the highest the temperature, the higher the wine instability; this is probably due to a faster MA hydrolysis. Metatartaric acid is surely able to prevent tartrates precipitation, but since in our experimental conditions it could not protect the wine for longer than one month, we would suggest extreme prudence about its use especially during long storage periods

The paper presents experimental results and their evaluation for the sorption of copper(II), zinc(II), cobalt(II) and nickel(II) complexes with metatartaric acid on chelating ion exchangers with different functional groups. The literature lacks the data concerning sorption of heavy metal ions in the presence of metatartaric acid on ion exchangers. The effect of important parameters such as the value of pH, the metal(II) ion and ligand concentration as well as their molar ratio and the type of functional group of the ion exchanger used was studied. It was found that the time of 60 min was sufficient for sorption to attain equilibrium. The equilibrium sorption capacities for copper(II), zinc(II), cobalt(II) and nickel(II) complexes with metatartaric acid were 37.35 mg/g, 32.02 mg/g, 32.78 mg/g and 28.31 mg/g on Lewatit TP 207 and 42.15 mg/g, 34.32 mg/g, 27.76 mg/g and 21.70 mg/g on Lewatit TP 260, respectively. The sorption optimum pH was 7. Temperature does not affect the sorption process significantly. The sorption data were well fitted by the Langmuir adsorption model whereas kinetics of the sorption process was well described by the pseudo second order kinetics equation.

5.1 Traditional White Wine Fining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 5.1.1 Bentonite Fining of White Juices and Wines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 5.1.2 Use of Gelatin in White Wine Fining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 5.1.3 Fining with Plant Proteins: A Solution for the Future . . . . . . . . . . . . . . . . . . . . . . . . 136 5.1.4 Must Clarification Using the Flotation Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 5.1.5 Other Fining Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 5.1.6 Equipment for the Addition of Fining Agents to Wine . . . . . . . . . . . . . . . . . . . . . . . 146 5.1.7 Wine Fining: General Conclusion and Practical Recommendations . . . . . . . . . . . . 147 5.2 Use of Adjuvants for Stabilizing Wine with Respect to Tartrate Salt Crystallization . . . . 147 5.2.1 Use of Metatartaric Acid for Stabilization of Tartrate Salt Precipitation . . . . . . . . . 148 5.2.2 Use of Yeast Mannoproteins for Stabilization of Tartrate Salt Precipitation . . . . . . 149 5.2.3 Use of Carboxymethylcelluloses for Stabilization of Tartrate Salt Precipitation . . 150 5.3 Use of Mannoproteins to Stabilize Wines as Regard to Protein Haze . . . . . . . . . . . . . . . . . 151 5.4 Use of Mannoprotein Fractions to Improve the Foaming Properties of Sparkling Wines . 153 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

Groups of rats were given metatartaric acid in the drinking-water in concentrations of 0 (control), 0.1, 0.5 or 3.0% for 18 wk. No effects associated with treatment were seen in the results of the haematological examinations and serum analyses. The treated animals consumed less water and food than the controls, probably because of the unpalatability of the test material. Administration of the 3% solution was associated in males with a reduced growth rate, some impairment of urine-concentrating ability during prolonged water deprivation (also seen in males on 0.5%) and histopathological changes in the stomach indicative of an inflammatory response in the submucosal layer. Both sexes of the 3% group showed an increase in relative kidney weight, without accompanying histopathological change. The no-untoward-effect level in this study was 0.1% metatartaric acid in the drinking-water, equivalent to a mean daily intake of 80 mg/kg body weight in the males and 130 mg/kg in the females.

Aims: Inhibition of potassium hydrogen tartrate (KHT) crystallization by carboxymethylcellulose (CMC) is tested in a model solution and in wines. Tartaric acid salt crystallization risk is assessed by computing the supersaturation, saturation temperature and excess KHT with respect to the saturation equilibrium using MEXTAR® (Mesure de l’EXces de TARtre) software.Materials and results: Firstly, the time for crystals to appear was recorded by monitoring the conductivity in a model solution and in a wine, and the inhibition ratio was computed. At 11,5 °C, 0,5 mg.L-1 CMC inhibited KHT crystallization. The inhibitory effect increased exponentially with increasing CMC concentration and was several times greater than that of polysaccharides and polyphenols, the protective colloids in wine (Gerbaud et al., 1997). At 2 °C, 30 mg.L-1 CMC had the same inhibitory effect than 10 mg.L-1 at 11.5°C.Secondly, 20 red and white wines were refrigerated for 3 weeks at -4 °C with CMC or metatartaric acid. Results show that the addition of 20 mg.L-1 CMC has an inhibitory effect at least equivalent to 100 mg.L-1 metatartaric acid. Furthermore, for 10 wines preheated for 8 days at 30 °C and then refrigerated for 2 months at 0 °C, 5 and 20 mg. L-1 CMC maintains its inhibitory efficiency, unlike metatartaric acid which is hydrolysedSignificance and impact of the study: The OIV-OENO 366-2009 and OIV-OENO 02/2008 resolutions recently authorized the use of CMC to prevent tartaric acid salt precipitation. With no impact on health, and stable under heating and in acid solution, CMC is an efficient candidate for tartaric stabilization. The optimal concentration of 20 mg.L-1 (2 g.hL-1) should however be adapted to local wine storage conditions and KHT crystallization risk.