Inactive Dry Yeast Research Articles

Effect of selected Saccharomyces cerevisiae yeast strains and different aging techniques on the polysaccharide and polyphenolic composition and sensorial characteristics of Cabernet Sauvignon red wines.

The objective of this work was to study the effect of two Saccharomyces cerevisiae yeast strains with different capabilities of polysaccharide liberation during alcoholic fermentation in addition to subsequent aging on lees with or without oak wood chips as well as aging with commercial inactive dry yeast on the physical, chemical and sensorial characteristics of Cabernet Sauvignon red wines. The HPS (high levels of polysaccharides) yeast strain released higher amounts of polysaccharides (429 g L(-1)) than EC1118 (390 g L(-1)) during alcoholic fermentation, but the concentration equalized during the aging period (424 and 417 g L(-1) respectively). All aging techniques increased the polysaccharide concentration, but the increase was dependent on the technique applied. A higher liberation of polysaccharides reduced the concentration of most of the phenolic families analyzed. Moreover, no clear effect of the different aging techniques used in this study on color stabilization was found. The HPS wines were better valued than the EC1118 wines by the panel of tasters after alcoholic fermentation. In general, the HPS wines showed better physicochemical and sensorial characteristics than the EC1118 wines. According to the results obtained during the aging period, all aging techniques contributed to improve wine quality, but it was difficult to establish the technique that allowed the best wine to be obtained, because it depended on the aging technique used and the period of aging.

<b>The impact of dietary dry yeast on lactation curves of primiparous and multiparous Saanen goats

Twenty-four Saanen goats (fifteen multiparous and nine primiparous) during their lactation period were used, from the kidding until the 200th day of lactation; and were distributed in a completely randomized design and in a factorial arrangement (3 diets x 2 parity orders). The diets were composed of either soybean meal (SBM), soybean meal plus inactive dry yeast (SMDY) or inactive dry yeast (DY) used as the protein source. The analyses of milk yield, body weight and dry matter intake (DMI) were made through the Bayesian methodology. For construct the lactation curves were used the Wood’s nonlinear model. The inclusion of inactive dry yeast in the diets reduced the rate of yield increase until the lactation peak for primiparous goats, but for multiparous goats the reverse was noted. The SMDY diet reduced the rate of yield decline after peak for primiparous goats, whereas for multiparous goats the inclusion of inactive dry yeast in the diet increased the decline of the rate of yield during this period. It was observed that inactive dry yeast can be used to replace soybean meal in diets used for multiparous Saanen goats.

Red wine and oenological extracts display antimicrobial effects in an oral bacteria biofilm model.

The antimicrobial effects of red wine and its inherent components on oral microbiota were studied by using a 5-species biofilm model of the supragingival plaque that includes Actinomyces oris, Fusobacterium nucleatum, Streptococcus oralis, Streptococcus mutans and Veillonella dispar. Microbiological analysis (CFU counting and confocal laser scanning microscopy) of the biofilms after the application of red wine, dealcoholized red wine, and red wine extract solutions spiked or not with grape seed and inactive dry yeast extracts showed that the solutions spiked with seed extract were effective against F. nucleatum, S. oralis and A. oris. Also, red wine and dealcoholized wine had an antimicrobial effect against F. nucleatum and S. oralis. Additional experiments showed almost complete and early degradation of flavan-3-ol precursors [(+)-catechin and procyanidin B2] when incubating biofilms with the red wine extract. To our knowledge, this is the first study of antimicrobial properties of wine in an oral biofilm model.

Impact of Glutathione-Enriched Inactive Dry Yeast Preparations on the Stability of Terpenes during Model Wine Aging

The impact of the addition of glutathione-enriched Inactive dry yeast preparations (g-IDYs) on the stability of some typical wine terpenes (linalool, α-terpineol, β-citronellol, and nerol) stored under accelerated oxidative conditions was evaluated in model wines. Additionally, the effects of a second type of IDY preparation with a different claim (fermentative nutrient) and the sole addition of commercial glutathione into the model wines were also assessed. Model wines were spiked with the low molecular weight fraction (<3 kDa permeate) isolated from the IDYs, avoiding the interaction of aroma compounds with other yeast components. An exhaustive chemical characterization of both IDY permeates was carried out by using targeted and nontargeted metabolomics approaches using CE-MS and FT-ICR-MS analytical platforms. The findings suggest that the addition of <3 kDa permeate isolated from any of the IDYs employed decreases the loss of typical wine terpenes in model wines submitted to accelerated aging conditions. The g-IDY preparation did indeed release reduced GSH into the model wines, although this compound did not seem exclusively related to the protective effect on some aroma compounds determined in both model wines. The presence of other sulfur-containing compounds from yeast origin in g-IDY, and also the presence of small yeast peptides, such as methionine/tryptophan/tyrosine-containing tripeptide in both types of IDYs, seemed to be related to the antioxidant activity determined in the two permeates and to the minor loss of some terpenes in the model wines spiked with them.

Impact of Using New Commercial Glutathione Enriched Inactive Dry Yeast Oenological Preparations on the Aroma and Sensory Properties of Wines

The effect of the addition of a commercial enriched glutathione inactive dry yeast oenological preparation in the volatile and sensory properties of industrially manufactured rosé Grenache wines was evaluated during their shelf-life. In addition, triangle tests were performed at different times during wine aging (among 1 and 9 months) to determine the sensory differences between wines with and without glutathione inactive dry yeast preparations. Descriptive sensory analysis with a trained panel was carried out when sensory differences in the triangle test were noticed. In addition, consumer tests were performed in order to investigate consumers’ acceptability of wines. Results revealed significant sensory differences between control and glutathione inactive dry yeast wines after 9 months of aging. At that time, glutathione inactive dry yeast wines were more intense in fruity aromas (strawberry, banana) and less intense in yeast notes than control wine. The impact of the glutathione inactive dry yeast in the aroma might be the consequence of different effects that these preparations could induce in wine composition: modification of yeast byproducts during fermentation, release of volatile compounds from inactive dry yeast, interaction of wine volatile compounds with yeast macromolecules from inactive dry yeast and a possible antioxidant effect of the glutathione released by the inactive dry yeast preparation on some specific volatile compounds.

Impact of replacing soybean meal in beef cattle diets with inactive dry yeast, a sugarcane by-product of ethanol distilleries and sugar mills

This study assessed the intake, total and partial apparent digestibility of nutrients, pH, ruminal ammonia concentration, nitrogen efficiency usage, and productive performance of beef cattle fed with different soybean meal replacement levels with inactive dry yeast (IDY 0, 250, 500, 750, and 1000g/kg). The forage:concentrate ratio was 60:40 and the forage source was corn silage. Concentrates were formulated to comprise 220.0g/kg CP independent of treatments. In the first experiment (EXP 1), 35 Nelore bulls with an initial average weight of 370±42kg were distributed across a completely randomized design, with five treatments and seven replicates to assess nutrient intake and performance. EXP 1 lasted 98 days and was divided into a 14-day adaptation period and three experimental periods of 28 days each. In the second experiment (EXP 2), five castrated Nelore steers with an initial average weight of 320±39kg were fistulated in the rumen and abomasum and distributed in a 5×5 Latin square design, balanced for residual effect. The purpose of this experiment was to assess the total and partial digestibility of nutrients, pH, ruminal ammonia nitrogen, and nitrogen efficiency of usage. EXP 2 lasted 90 days, divided into five experimental periods. Each period lasted 18 days and was divided into 10 days for adaptation to the diets and 8 days to collect samples. The intake of dry matter (DMI) decreased linearly (P=0.03) with increased dietary IDY levels. Conversely, the intake of neutral detergent fiber assayed with a heat-stable amylase and corrected for ash and nitrogenous compounds [aNDFom(n)] in g/day (P=0.043), and the g/kg body weight (P=0.011) increased linearly as IDY was added to the concentrate. The experimental diets showed no effect (P>0.05) on the total and partial apparent nutrient digestibility. IDY had no effect (P>0.05) on ruminal pH, ruminal ammonia nitrogen, or dietary nitrogen efficiency. Additionally, IDY had no effect on productive performance variables, with the exception of average daily gain (ADG), which decreased linearly (P=0.028) as IDY was added to the concentrate. IDY addition resulted in decreases in DMI and ADG for beef cattle in feedlots (EXP 2). However, the apparent digestibility of nutrients and microbial efficiency were not affected. In addition, IDY did not reduce feed conversion or carcass gain. The high market price of soybean meal might make feasible its total replacement by IDY, even considering the possibility of a small reduction in ADG.

Nutritive value of diets containing inactive dry yeast for lactating Saanen goats

Twenty-four Saanen goats, 15 multiparous and nine primiparous, were distributed in a completely randomised design in a factorial arrangement (3 diets × 2 parities). The treatments were soybean meal (SB), soybean + dry yeast (SBDY), or dry yeast (DY) as a protein source in the diet, and ground corn, mineral supplement, and corn silage (400 g/kg). The study was conducted to evaluate the nutritive value of diets containing inactive dry yeast as a protein source postpartum, postpeak, and during late lactation in dairy goats. To estimate the faecal excretion of indigestible material, neutral detergent fibre was used as an internal marker. The diets did not affect dry matter intake (DMI). However, DMI and nutrient intake were higher for multiparous goats compared with primiparous goats. The digestibility of dry matter and total digestible nutrients (TDN) were higher for primiparous goats in the postpartum period. In the postpeak and late lactation periods, there were no differences in digestibility of DM and nutrient between parities. The TDN was similar in the diets in the postpeak period and at lactation end. The goats fed the DY diet had lower urea nitrogen in blood. The use of inactive dry yeast to substitute soybean meal in diets for primiparous and multiparous lactating Saanen goats is a good alternative for maintaining the nutritional value of diets.

Effect of additives on the rehydration ofSaccharomyces cerevisiaewine strains in active dry form: influence on viability and performance in the early fermentation phase

The effect of five additives on the rehydration process of three commercial Saccharomyces cerevisiae wine strains, in the form of active dry yeast, was tested using the approach of design of experiments. The response to additives was monitored by observing the viability, measured using fluorescence methodology at the end of the rehydration experiments, and fermentative performance, focusing attention on the first phase of fermentation, assessed based on ethanol production and the total number of cells after 48 h from the time of inoculation in synthetic must. The results showed a correlation between viability and the presence of magnesium in the rehydration medium. However, improvement in viability was not associated with better fermentation performance, which was not affected or in some cases significantly reduced. Among the additives examined, only rehydration with inactive dry yeast and ammonium showed a positive effect on the subsequent fermentations, but not for all of the strains tested. In general, considering all of the additives tested, no relationship was found between viability at the end of rehydration and fermentation performance. These findings suggest that the viability of the rehydrated yeast cells may not be a good index of fitness in the subsequent fermentation. Copyright © 2014 The Institute of Brewing & Distilling

Effect of substitution of soybean meal for inactive dry yeast on diet digestibility, lamb's growth and meat quality

The present study was divided into two main experiments: (i) experiment 1 included the evaluation of apparent nutrient digestibility, pH and ruminal ammonia concentration, and (ii) experiment 2 investigated the nutrient intake, growth performance and meat quality of lambs fed diets containing replacement levels (0, 33, 67 and 100% in dry matter basis) of soybean meal by inactive dry yeast (IDY). experiment 1 used four rumen-fistulated entire male Santa Ines lambs distributed in a 4×4 Latin square. experiment 2 used 36 entire male Santa Ines lambs in a randomized block design with four treatments and nine replicates. A quadratic effect (P<0.05) of IDY was observed on the apparent digestibility of dry matter, organic matter, crude protein, ether extract and neutral detergent fiber corrected for ash and protein. A quadratic effect of the diet and sampling time was observed (P<0.05) on the concentration of ammonia nitrogen in the rumen. The sampling time (P<0.05) affected the ruminal pH with the data adjusted to a quadratic model. Growth performance was not affected by IDY in the diets. The subcutaneous fat thickness decreased linearly (P<0.05) with increased levels of IDY in the diet. The meat crude protein and ash concentration increased linearly (P<0.05), and the intramuscular fat concentration decreased linearly (P<0.05) with increased levels of IDY in the diet. IDY can replace up to 100% of the soybean meal in lambs diets, with the use of this by-product depending on economic factors and market availability.

Assessment of glutathione levels in model solution and grape ferments supplemented with glutathione-enriched inactive dry yeast preparations using a novel UPLC-MS/MS method

A novel, robust and fast ultra-high performance liquid chromatography-MS method has been developed for the simultaneous quantification of reduced glutathione (GSH) and oxidised glutathione (GSSG) in grape juice, wine and model wine solution. Sample preparation is minimal and does not require derivatisation. The method has very good performance in terms of sensitivity and selectivity. The limit of detection was 0.002 and 0.001 mg L−1 for GSH and GSSG, respectively. The amount of GSH and GSSG released by commercial glutathione-enriched inactivated dry yeast preparations (GSH-IDYs) into a model solution was assessed. Significant differences in the amount of GSH and/or GSSG released into a model wine by different GSH-IDYs were observed, with ethanol influencing this release under certain conditions. The GSH and GSSG levels in grape juice fermentations supplemented with GSH-IDY were also assessed in relation to different addition times during fermentation. GSH-IDY addition can lead to elevated wine GSH levels, provided the supplementation is done early during alcoholic fermentation.

Performance of lactating goats fed diets containing inactive dry yeast

Twenty-four Saanen goats (15 multiparous and 9 primiparous) from 21 days prepartum to 200 days in lactation were used to evaluate milk yield and composition. Animals were randomly distributed in a 3 × 2 factorial arrangement (3 diets × 2 parity orders) and fed a 40:60 forage:concentrate diet composed of soybean meal, soybean meal + dry yeast or dry yeast as protein source, plus ground corn, mineral supplement and corn silage. The protein source did not influence the body weight of pre and postpartum goats. Prepartum, postpartum and postpeak dry matter intake (DMI) were not altered by diets. However, goats fed the diet containing dry yeast as protein source had lower DMI in late lactation. Milk yield and feed efficiency were not affected by diets. Milk components, acidity and somatic cell count were not influenced by diets during all lactation phases. However, fat and total solid contents postpartum were higher for primiparous goats and somatic cell count postpeak was lower for multiparous goats. Dry yeast can be used to replace soybean meal in diets for lactating Saanen goats.

Effect of using glutathione-enriched inactive dry yeast preparations on the phenolic composition of rosé Grenache wines during winemaking

&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Aim&lt;/strong&gt;: To know the effect of the addition of a commercial glutathioneenriched Inactive Dry Yeast (G-IDY) oenological preparation on the &lt;strong&gt;phenolic profile and colour parameters of rosé Grenache wines.&lt;/strong&gt;&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Methods and results&lt;/strong&gt;: A Control wine (Cont-W) and a wine with the GIDY preparation (G-IDY-W) were industrially manufactured. The evolution of the phenolic composition (anthocyanins and non-anthocyanins) and colour of both types of wines was evaluated during winemaking and their shelf-life (after 1, 2, 3 and 9 months of bottle aging). Results revealed that wines manufactured with the G-IDY preparation showed differences in both their phenolic composition and colour characteristics with respect to the control wines, particularly after 9 months of aging. These differences were more evident in the anthocyanin than in the non-anthocyanin compounds.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Conclusions&lt;/strong&gt;: The G-IDY wines showed a greater decrease of the anthocyanins from grape origin, probably due to the formation of anthocyanin-polysaccharide complexes, and a higher concentration of some anthocyanin-derived pigments. These changes can be related to the slower colour evolution determined in wines produced using G-IDY preparations.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Significance and impact of the study&lt;/strong&gt;: The addition of the G-IDY preparation during winemaking modifies the anthocyanin composition of the resulting wines, which seems to provoke a slower colour evolution during their shelf-life.&lt;/p&gt;

Effect of inactive dry yeast from sugar cane as protein source on rumen fermentation in Saanen goats

Five castrated and ruminally cannulated Saanen goats (±48.19kg) were used to evaluate intake, digestibility and rumen fermentation parameters of diets with inactive dry yeast as a soybean meal substitute (0, 25, 50, 75 and 100%). Goats were randomly assigned to a 5×5 (five levels of dry yeast x five periods) Latin square design. Diets were composed of corn silage (40%), ground corn, soybean meal and/or dry yeast and mineral supplement. The intake and digestibility of DM, OM, CP, NDF and TC were not influenced by the treatments. However, EE intake showed negative linear effect. The TDN content did not change with the inclusion of dry yeast in the diets. The pH, N-NH3 concentration and rumen short-chain fatty acids content did not differ among diets. Rumen content scanning electron microscopy observations did not suggest microbial colonization and degradation changes. Dry yeast from sugar cane can replace soybean meal in diets for Saanen goats without changing the rumen fermentation pattern, intake and digestibility.

Performance of dairy goats fed diets with dry yeast from sugar cane as protein source

The effects of inactive dry yeast (Saccharomyces cerevisiae) from sugar cane were studied in 18 primiparus Saanen dairy goats (51.07±1.43) on dry matter intake and digestibility, milk production and quality. Animals were distributed in a completely randomized design during 90 days (from day 60 of milking). Diets were composed of soybean meal; soybean meal + dry yeast; or dry yeast, as protein sources, and ground corn, mineral supplement and corn silage (40%). Animals fed the dry yeast diet showed lower intake of dry matter (DM), organic matter (OM), crude protein, ether extract and neutral detergent fiber. Diets did not influence milk yield; however the milk production efficiency (kg of milk produced/kg of crude protein ingested) was better in goats fed the dry yeast diet. Acidity, somatic cell counts and milk urea nitrogen values were not affected by treatments. Animals fed the soybean + dry yeast diet had higher fat and total solids than those fed the dry yeast diet. The digestibility of DM, OM and total carbohydrate was lower for soybean only and soybean + dry yeast diets. Total digestible nutrients were higher for dry yeast and soy bean diets than soybean + dry yeast diet. Dry yeast from sugar cane is a good alternative protein source for feeding lactating dairy goats and can be recommended because it maintains the production performance.

Reversed-Phase High-Performance Liquid Chromatography–Fluorescence Detection for the Analysis of Glutathione and Its Precursor γ-Glutamyl Cysteine in Wines and Model Wines Supplemented with Oenological Inactive Dry Yeast Preparations

A reversed-phase high-performance liquid chromatography–fluorescence detection methodology involving a pre-column derivatization procedure using 2,3-naphtalenedialdehyde in the presence of 5 and 0.5 mM of dithiothreitol to determine total and reduced glutathione (GSH) and γ-glutamyl-cysteine (γ-glu-cys) in musts and wines has been set up and validated. The proposed method showed good linearity (R 2 >99% for reduced and total GSH, and R 2 >98% for γ-glu-cys) in synthetic wines, over a wide range of concentration (0–10 mg L−1). The limits of detection for reduced GSH in synthetic and real wines were almost the same (0.13 and 0.15 mg L−1, respectively) and slightly higher for γ-glu-cys (0.24 mg L−1). The application of the method allowed knowing, for the first time, the amount of total and reduced GSH and γ-glu-cys released into synthetic wines by oenological preparations of commercial inactive dry yeast (IDY). In addition, the evolution of these three compounds during the winemaking and shelf life (0–9 months) of an industrially manufactured rosé wine supplemented with a GSH-enriched IDY showed that although GSH is effectively released from IDY, it is rapidly oxidized during alcoholic fermentation, contributing to the higher total GSH content determined in wines supplemented with GSH-enriched IDYs compared to control wines.

Role of Specific Components from Commercial Inactive Dry Yeast Winemaking Preparations on the Growth of Wine Lactic Acid Bacteria

The role of specific components from inactive dry yeast preparations widely used in winemaking on the growth of three representative wine lactic acid bacteria (Oenococcus oeni, Lactobacillus hilgardii and Pediococcus pentosaceus) has been studied. A pressure liquid extraction technique using solvents of different polarity was employed to obtain extracts with different chemical composition from the inactive dry yeast preparations. Each of the extracts was assayed against the three lactic acid bacteria. Important differences in the effect of the extracts on the growth of the bacteria were observed, which depended on the solvent employed during the extraction, on the type of commercial preparations and on the lactic acid bacteria species. The extracts that exhibited the most different activity were chemically characterized in amino acids, free monosaccharides, monosaccharides from polysaccharides, fatty acids and volatile compounds. In general, specific amino acids and monosaccharides were related to a stimulating effect whereas fatty acid composition and likely some volatile compounds seemed to show an inhibitory effect on the growth of the lactic acid bacteria. These results may provide novel and useful information in trying to obtain better and more specific formulations of winemaking inactive dry yeast preparations.

Application of Supercritical CO2 Extraction for the Elimination of Odorant Volatile Compounds from Winemaking Inactive Dry Yeast Preparation

A procedure based on the application of supercritical CO(2) extraction to reduce and/or to remove odorant volatile compounds from a winemaking inactive dry yeast (IDY) preparation has been set up. By applying a factorial design, a screening of different temperatures and pressure conditions was assayed in order to determine the optimal deodorization conditions, and afterward the effect of several sample pretreatments was investigated. The best extraction conditions were achieved at 200 atm and 60 degrees C, applying the cryogenic grinding of the sample and using 40% (w/w) ethanol as cosolvent. By using these conditions, it was possible to reduce to approximately 70% of the volatile compounds present in the samples that may be released into the wines and therefore affecting their sensory characteristics. Odorant volatile compounds such as 2-methylhydroxypyrrole, 2-ethyl-6-methylpyrazine, and 2,3,5-trimethylpyrazine completely disappeared from the deodorized sample as verified by GC-O analysis. Additional experiments in model wines confirmed the low release of volatile compounds from the deodorized samples, without provoking any change to their nonvolatile composition (nitrogen compounds and neutral polysaccharides) that is related to the technological properties of these preparations.

Characterization of Commercial Inactive Dry Yeast Preparations for Enological Use Based on Their Ability To Release Soluble Compounds and Their Behavior toward Aroma Compounds in Model Wines

The characterization of commercial enological inactive dry yeast (IDY) with different applications in wine production has been carried out. This study was based on the yeast's ability to release soluble compounds (high molecular weight nitrogen, free amino nitrogen, peptidic nitrogen, free amino acids, and polysaccharides) into model wines and on its behavior toward the volatility of seven wine aroma compounds. Important differences in soluble compounds released into the model wines supplemented with commercial IDY were found, with the free amino acids being among the most released. The volatility of most of the aroma compounds was affected by the addition of IDY preparations at a concentration usually employed during winemaking. The extent of this effect was dependent on the physicochemical characteristics of the aroma compound and on the length of time the IDY preparations remained in contact with the model wines. Whereas shorter contact times (2, 4, and 6 days) mainly promoted a "salting-out" effect, longer exposure (9 and 13 days) provoked a retention effect, with the consequent reduction of aroma compounds in the headspace. The use of different commercial preparations also promoted different effects toward the aroma compounds that may be at least in part due to differences in their ability to release soluble compounds of yeast origin into the wines.

Volatile profile and potential of inactive dry yeast‐based winemaking additives to modify the volatile composition of wines

AbstractBACKGROUND: With the objective of determining the potential of winemaking additives based on inactive dry yeast (IDY) to modify the volatile composition of wines, gas chromatography coupled to mass spectrometry was employed to characterize the volatile profile of a widely used IDY preparation. To have the most accurate picture of the volatile compounds, pressurized liquid extraction technique (PLE) was used with different solvents and extraction temperatures. Complementary headspace solid‐phase microextraction was applied to gain insight into the volatile composition. In addition, the ability of some target volatile (pyrazines) to be released into model wines was investigated.RESULTS: The PLE technique was mainly suitable for the extraction of volatile compounds with a low to medium molecular weight and the best extraction yields were obtained by using apolar solvents (hexane) and high temperatures (150 °C). PLE in combination with solid‐phase microextraction allowed the identification of 35 volatile compounds, most of them heterocyclic‐containing nitrogen compounds formed during the processing of IDY that could be released into the wines: the signal of four target masses corresponding to 2,5‐dimethylpyrazine, trimethylpyrazine, methylbutylpyrazine and 2‐ethyl‐3,5‐dimethylpyrazine increased in the synthetic wines after 13 days when IDY was left in the model wines.CONCLUSION: The study confirmed that some volatile compounds identified in IDY which were formed during processing could be released into the wines which might modify wine aroma composition. Copyright © 2009 Society of Chemical Industry

Scientific evidences beyond the application of inactive dry yeast preparations in winemaking

In recent years the use of inactive dry yeast (IDY) preparations such as inactive yeast, yeast autolysates, yeast extracts and yeast hulls or walls have been widely used within the oenological industry to improve either technological processes or the sensory characteristics of wines. Some of these preparations have very specific applications and there are currently many of these products in the market under different brands that promise different ways of improving wine characteristics. Nevertheless, scientific information about the chemistry beyond their use and their action mode is still scarce. The objective of this review is to revise the different applications of specific IDY preparations in winemaking, on the basis of their action mechanisms taking into consideration the scientific information available, underlining the necessity of more scientific work in order to better characterize their chemical composition, their action mechanisms, and the establishment of better criteria for their oenological use.