Introduction. Any waste can become a raw material for new products. Therefore, waste should be considered as secondary material resources. Grape pomace is the basic waste of wine industry, and research in its chemical composition may allow for a more effective recycling of food industry waste. Study objects and methods. The research featured sweet and fermented pomace of white and red grapes, namely “Chardonnay”, “Sauvignon Blanc”, “Riesling”, “Pinot Blanc”, “Traminer Pink”, “Viognier”, “Morava” “Pinot Noir”, “Roesler”, “Cabernet Sauvignon”, “Merlot”, “Saperavi”, and “Rebo”. They were obtained in the production of wines at wineries in the Krasnodar region. Mass concentrations of organic acids and cations of alkaline and alkaline-earth elements were determined in extracts by capillary electrophoresis. The data was converted to dry matter. Moisture content was calculated as a percentage of the change in the mass of grape pomace. Results and discussion. The moisture content of sweet pomace varied from 49.33 ± 2.04 to 70.35 ± 0.60%, and in fermented pomace – from 47.49 ± 0.02 to 64.24 ± 0.60%. The varieties were studied for mass concentrations of tartaric, malic, succinic, citric, and lactic acids. Tartaric and malic acids proved to be the most abundant ones. The pomace of Riesling grapes had the greatest amount of tartaric acid (104.47 ± 4.16 g/kg). The “Chardonnay” variety proved rich in malic acid (19.40 ± 2.67 g/kg), while the “Morava” pomace had the biggest amount of citric acid (12.61 ± 1.12) and succinic acid (11.72 ± 1.23). The research also defined concentrations of alkaline and alkaline-earth elements. Their content ranged from 41.04 to 3.29 g/kg. Potassium appeared to be the main cation in the pomace samples. The share of potassium in the total mineralization of pomace was up to 94%. The “Riesling” variety grown near Novorossiysk had the largest amount of potassium (36.46 ± 4.65 g/kg). The samples demonstrated a significant correlation between the content of tartaric acid and potassium. Conclusion. The research revealed a significant variation in the concentration of the organic acids and cations of alkaline and alkalineearth metals, depending on the grape variety, the place of its growth, and processing. The grape pomace samples differed moisture content. It depended on the volume of the liquid fraction, i.e. wort or wine material selected during pressing.
The article is devoted to the research of the makeup of phenolic compounds and fatty acids of grape pomace. The phenolic compounds were identified in skin and seed extracts and in extracts of skin-and-seed mixtures; the fatty acids – in grape oil generated by direct pressing. It was established that anthocyanins were present mainly in the skins. Low concentrations of ten components of the anthocyanin complex were identified in the Saperavi seeds. Maximum amounts of anthocyanins were found in the Saperavi skins. The concentration of quercetin distinguished by a PP-vitamin activity was by 1.5 to 2.0 times higher in the skin-andseed mixtures, especially of Roesler grapes, than in the skin itself. Maximum amounts of flavan-3-ols, hydroxy-cinnamic and hydroxybenzoic acids and oligomeric procyanidins, as well as the highest antioxidant activity were observed in the skin-and-seed mixture. The highest value of the correlation factor was observed in cases of interaction of antioxidant activity and concentration of procyanidins (r = 0.83), antioxidant activity and concentration of anthocyanins (r = 0.78), and antioxidant activity and concentration of flavan-3-ols (r = 0.75). Among the flavan-3-ols, it was (+)-D-Catechin that prevailed in grape seeds, with its concentration in the Pinot Noir extract (OAO APF Fanagoria) reaching 468 mg/dm3. Maximum concentration of Epigallocatechin-gallate was observed in the Saperavi and Pinot Noir seeds. As regards the concentration of hydroxy-cinnamic acids in the seeds, n-coumaric acid (Ancellotta, Saperavi) stood apart among the others; gallic acid (Saperavi, Ancellotta) came forward among the hydroxy-benzoic acids. In the reviewed samples of grape seeds, procyanidins of groups В1 , В2 and В3 distinguished by high antioxidant activity prevailed. Prevalence of linoleic and oleic acids was established for grape oil extracted from the seeds of such red grape varieties as Cabernet Sauvignon, Pinot Noir and Saperavi. Maximum concentrations of oleic acid were found in the Pinot Noir and Riesling seeds. Palmitic and stearic acids were also available in rather high concentrations in the grape oil.
Experimental data on the content of biologically valuable components in grape pomace are presented. The presence of organic acids was revealed in an amount from 33.35 g/kg (Saperavi) to 108.2 g/kg (Rebo). The main acid is tartaric. Phenolic compounds have been identified: anthocyanins, flavones, flavan-3-ols, oxycinnamic and hydroxybenzoic acids, procyanidins. The main anthocyanins found in grape pomace are the 3-O-glycosides of malvidin, petunidin, cyanidin, peonidin and delphinidin. The highest total content of hydroxybenzoic acids was in the pomace of Pinot Noir grapes – 720 mg/kg, further in descending order of concentration followed by pomace from Saperavi grapes (708 mg/kg), Cabernet Sauvignon (681 mg/kg), Merlot (575 mg/kg) and Rebo (545 mg/kg). The highest total content of vitamins was found in the pomace of Rebo grapes – 639 mg/kg, the lowest – Merlot (471 mg/kg). In all samples, vitamin B1 prevails, then in decreasing order – ascorbic acid, vitamins B2, B3, B5, B7. Moreover, their concentrations vary significantly depending on the grape variety from which the pomace is obtained. The influence of the grape variety on the content of these biologically valuable components in the pomace has been established, which must be taken into account in the production of biologically active substances that increase the nutritional status of a person.
Introduction. Grape pomace is the most important by-product of winemaking that can be used as an additional raw material. There is a need for an optimal storage technology so that pomace can be further processed to obtain new types of products. We aimed to study the effect of grape pomace treatment on its microflora. Study objects and methods. We identified and quantified microflora on the fresh and one-month-stored pomace samples from white and red grape varieties. The samples were exposed to conventional drying at 60–65°C, infrared drying at 60–65°C, as well as sulfitation with sulfur dioxide and sodium metabisulfite. Results and discussion. The pomace microflora can be considered a microbial community. Almost all the samples stored for one month in an open area contained Saccharomyces cerevisiae yeasts, higher concentrations of filmy yeasts of the Candida, Pichia, Hansenula, Hanseniaspora/Kloeckera, and Torulaspora genera, as well as conidia of Mucor, Aspergillus niger, and Penicillium molds. Prevalent bacteria included acetic acid (mainly Acetobacter aceti) and lactic acid (Lactobacillus plantarum, Pediococcus, Leuconostoc) bacteria. These microorganisms significantly changed concentrations of volatile and non-volatile components, decreasing total polysaccharides, phenolic compounds, and anthocyanins 1.7–1.9, 3.7–4.0, and 4.0–4.5 times, respectively. The contents of micromycetes and bacteria in the one-month-stored samples were significantly higher than in the fresh pomace. Predrying and sulfitation decreased bacterial contamination, but to a lesser extent compared to micromycetes. Conclusion. Long-term storage spoiled pomace, leading to significant changes in its chemical composition. Sulfitation reduced microorganism growth during storage, but did not provide long-term preservation (over a month), while pre-drying at 60–65°C promoted longer storage.
Foreign food industries know a variety of products derived from wine yeast cells. These products are used to improve the sensory properties of wine. This article describes the effect of a new yeast biosorbent on the sensory and physicochemical properties of white and red wine, e.g., their sorption capacity for heavy metals. The research featured red and white wines treated with the novel biosorbent. Glutarom (France) served as control. The study relied on various physicochemical, organoleptic, biochemical, and microbiological methods. The biosorbent affected neither the volume fraction of ethyl alcohol nor the mass concentration of sugars and titrated acids. However, the biosorbent reduced the mass concentration of volatile acids in terms of acetic acid: it decreased by 20% in the white wines and by 50% in the red wine samples. The mass concentration of the reduced extract decreased by 0.2–0.7 g/dm3 as the amount of sorbent increased. In the white wine samples, the protein concentration decreased by 1.5–1.8 times, while the concentration of polysaccharides decreased by 110–115 mg/dm3. The content of phenolic compounds decreased by 13–37%, depending on the amount of the sorbent, due to their condensed forms. The biosorbent reduced the value of the redox potential. The yeast sorbents effectively adsorbed metal cations, including those of heavy metals. A set of experiments also revealed the difference in sorption time for different metal cations. The effectiveness of the biosorbent was dose-dependent. The wines treated with the biosorbent had better sensory assessment results, especially the red wine samples. They had a soft, round, and harmonious flavor and a bright aroma with pronounced varietal tones. The novel biosorbent proved to have a good sorption capacity for phenolic compounds, as well as cations of toxic metals. It improved the sensory profile of the red and white wines. This biosorbent can substitute their imported analogs in the Russian wine industry.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.