Isabel Grape Research Articles

MANUFACTURING AND CHEMICAL CHARACTERIZATION OF ISABEL RED

Considering the potential consumption and economic importance that Isabel wine represents in the Brazilian consumer market, the aim of this research was to study the manufacturing and to determine the chemistry composition of red wine produced from Isabel grapes. The wine fermentation was achieved with 0.2 g/L of Saccharomyces cerevisiae yeast at 25ºC. After seven days of fermentation the correction of sugar was performed. After 40 days, the wine was separated from residues. The wine was clarified with commercial unflavored gelatin at the proportion of 0.2 g/L. The parameters total and volatile acidities, ethanol, dry extract, carotenoids, anthocyanins, total phenolic and reducing sugar were studied. Isabel grapes have the potential to be used to produce wine, hence its economic importance in Brazil. The chemical profile provided essential information about the Isabel red wine and the yeast used for inoculation result in good must fermentation, according to Brazilian legislation.

Development of microencapsulated grape juice powders using black 'Isabel' grape peel pectin and application in jelly formulation with enhanced in vitro bioaccessibility of anthocyanins.

In this study, pigmented pectin (grape pectin, GP) was extracted from the peels of black Isabel grapes. This highly methoxylated GP was composed mainly of galacturonic acid, arabinose, and other neutral monosaccharides. Its red color was ascribed to the anthocyanin content, and the main contribution was from malvidin-3-O-glucoside. To improve the yield and color properties of spray-dried Isabel grape juice powders, maltodextrin (MD) was substituted with this colored GP. When 25% of MD was substituted with GP, the powder yield increased from 46.0% to 60.4%, but it decreased to 21% when the substitution was 40%. GP inclusion increased the encapsulation efficiency of total anthocyanin in powders from 55.70% to 88.66%. When this spray-dried grape juice powder containing GP was utilized in a jelly recipe (4%-10%), a higher level of inclusion yielded stronger and more brittle jellies. When the jellies containing varying amounts of GP were subjected to in vitro digestion, the formulation with a higher amount of GP yielded a higher recovery of anthocyanins. In addition to being utilized as a carrier agent for spray-drying applications, this pigmented GP can also be tailored for a variety of applications, such as the development of pH-sensitive edible films and functional beverage formulations.

Ingredients from integral valorization of Isabel grape to formulate goat yogurt with stimulatory effects on probiotics and beneficial impacts on human colonic microbiota in vitro

Isabel grape (IG) products have high contents of phenolic compounds and fiber recognized for their positive impacts on microorganisms associated with health benefits to host. This study evaluated the effects of goat yogurts formulated with ingredients from IG integral valorization on the growth and metabolism of different probiotic strains, as well as on the population of selected bacterial groups and metabolic activity of human colonic microbiota in vitro. Goat yogurts with IG ingredients (IGI) stimulated the growth of tested Lactobacillus and Bifidobacterium probiotic strains during a 48-h cultivation, as well as decreased the pH values and enhanced the organic acid production. Goat yogurts with IGI increased the population of Lactobacillus spp. and Bifidobacterium spp. during a 24-h in vitro colonic fermentation. A stable Firmicutes:Bacteroidetes ratio close to 1 was found in media with goat yogurt formulations during the colonic fermentation, being similar to the effect caused by fructooligosaccharides. Goat yogurt formulations with IGI caused increased production of short-chain fatty acids and sugar consumption during colonic fermentation. Goat yogurts with IGI should be a valuable strategy for development of novel added-value foods with beneficial effects on gut microbiota and human health.

Valorization of grape by‐products as functional and nutritional ingredients for healthy pasta development

The objective of this study was the utilization of Isabel grape (Vitis labrusca) by-products for the development of grape pomace flour (GPF) as a new food ingredient to incorporate into a nutritional and functional pasta product adding different concentrations of GPF. The incorporation of GPF into the pasta formulation led to obtaining products with higher fiber content, lower firmness, and higher cooking loss of total solids. The antioxidant capacity of pasta samples was increased by incorporating polyphenols from GPF. The highest ORAC and FRAP results were observed in pasta containing GPF, comparing antioxidant activities. The pasta containing 50% GPF showed a good balance between high antioxidant activity and nutritional benefit with good consumer acceptability and potential to become a new functional food. Grape by-product represents a functional ingredient with low cost and a source of dietary fiber and natural antioxidants. Novelty impact statement Food agro-industrial by-products such as grape pomace flour (GPF) can be a source of functional ingredients. Fortification of pasta with GPF increased the antioxidant capacity of cooked pasta, and it was dose-dependent. The incorporation of GPF into the pasta formulation led to products with higher fiber content (up to 31%) and good consumer acceptability.

A fibre and phenolic-rich flour from Isabel grape by-products with stimulatory effects on distinct probiotics and beneficial impacts on human colonic microbiota invitro.

This study evaluated the effects of a fibre and phenolic-rich flour (IGF) prepared from Isabel grape by-products on the growth and metabolism of different probiotics and distinct bacterial populations part of the human intestinal microbiota during an invitro colonic fermentation. IGF was submitted to simulated gastrointestinal digestion before use in the experiments. IGF favoured the growth of the probiotics Lactobacillus acidophilus La-05, L. casei L-26 and Bifidobacterium lactis Bb-12, with viable counts of >7 log CFU per ml, as well as caused decreases in pH values and increases in organic acid production in the growth medium during 48 h of cultivation. IGF increased the population of beneficial micro-organisms forming the human intestinal microbiota, particularly Lactobacillus spp., decreased the pH values, and increased the lactic acid and short-chain fatty acid (acetic, butyric and propionic acids) production during 24 h of invitro colonic fermentation. These results indicate the potential prebiotic effects of IGF, which should represent a novel sustainable added-value ingredient with functional properties and gut-health benefits.

The effects of different drying methods on the in vitro bioaccessibility of phenolics, antioxidant capacity, minerals and morphology of black ‘Isabel’ grape

The black Isabel grapes were dehydrated by hot-air drying (HAD), vacuum-drying (VD), ultrasound-assisted vacuum-drying (US-VD), freeze-drying (FD), and their physical properties, phenolic compounds, antioxidant capacities, and mineral content were determined before and after simulated in vitro digestion. Among drying methods, FD provided the highest retention of the phenolic compounds, whereas US-VD caused the highest loss. The changes of phenolics of grapes differed among the digestion phases depending on the state of grapes (fresh or dried) and the drying method. The chlorogenic acid was the major phenolic compound identified, followed by protocatechuic acid and catechin. The malvidin-3-O-glucoside was the major anthocyanin followed by 3-glucosides of petunidin, delphinidin, cyanidin, and peonidin in the fresh and FD samples. At the end of digestion, a significant decrease in the levels of phenolics, minerals and no presence of anthocyanins was observed. VD raisins exhibited a higher bioaccessibility index for most of the phenolic compounds. Potassium was the most bioaccessible mineral from grape samples. Our results together with the morphology of the grapes revealed that different microstructures created by drying and the disruption of the natural matrix would influence the release, transformation, and subsequent absorption of phenolics and minerals in the simulated digestion model.

Incorporation of phenolic-rich ingredients from integral valorization of Isabel grape improves the nutritional, functional and sensory characteristics of probiotic goat milk yogurt

This study elaborated different probiotic goat milk yogurt formulations with addition of a low-calorie Isabel “Precoce” grape preparation and flour from derived solid by-products. Physicochemical characteristics, probiotic counts, phenolic and protein/peptide molecular weight profile, antioxidant capacity (AC) and sensory acceptance of different yogurt formulations were evaluated. Yogurts with Isabel grape ingredients (IGI) had high nutritional value, distinct phenolic profile and high AC. High counts of probiotic Lactobacillus acidophilus La-05 were found in yogurts during storage. AC of yogurts with IGI increased during a simulated gastrointestinal digestion with breakdown of high molecular weight proteins and release of protein-bound phenolics. AC of yogurts with IGI should be linked to goat milk peptides and Isabel grape phenolics. Yogurts with IGI had enhanced sensory acceptance. Incorporation of Isabel grape preparation and derived by-product flour into probiotic goat milk yogurt resulted in an added-value product with multifunctional characteristics and improved sensory characteristics.

Integral use of Isabel grapes to elaborate new products with nutritional value and functional potential

Abstract The benefits of grape consumption are widely recognized and mostly due to phenolic compounds. These beneficial effects will depend on the bioaccessibility of these compounds on grape and its derivatives. This study elaborated two formulations of Isabel grape preparation: PAX (with agave and xylitol) and PS (with sucrose); and two formulations of Isabel grape flour: FAX (from the PAX process residues) and the FS (from the PS process residues). The products were analyzed regarding their nutritional and antioxidant properties; their phenolic compounds’ bioaccessibility was also verified through a simulated digestion model. The preparation and flour exhibited relevant sugars levels (10.83-49.71 g 100 g-1). Those produced with natural sweeteners had a reduction in sugar concentration of 51% and 29% for preparation and flour, respectively, compared to formulations with sucrose, with the high fiber content in the flour is being further highlighted (20.14-21.95 g 100 g-1). The catechin (2.37-28.11 mg 100 g-1) was the most bioaccessible compound (22% to 168%), which together with the caftaric acid (2.31-69.43 mg 100 g-1) and malvidin 3-glucoside (8.65-16.47 mg 100 g-1) represent the compounds observed in greater quantity. The preparations showed higher bioaccessibility regarding grapes and flours for most of the phenolic compounds. Furthermore, the products elaborated presented higher values of anthocyanins and antioxidant activity than the in natura grape, highlighting the beneficial effect of grape processing.

He quantitative content of methanol in wines of isabel grape varieties and its impact on consumer health

He quantitative content of methanol in wines of isabel grape varieties and its impact on consumer health

Estimation of grape Isabel's quality in pre-harvest based on spectral signature

A non-destructive technique, that estimate the quality of the grape, was used in a vineyard, aiming to evaluate the logistics of use a portable infrared equipment [NIRs] (Brimrose Corp, USA) incorporated in a motor vehicle. The equipment estimate in the field quantifies phenolic compounds from the Isabel grape through spectral data. The spectra were taken in clusters of grapes, in the 2017 and 2018 harvests. The Near Infrared instrumentations were connected to a laptop and positioned in a micro-tractor (Gator-John Deere) to travel the vineyard. The phenolic compounds were estimates using predetermined calibration models. This methodology proved to be promising for estimating the grape quality.

Application of tamarind seed starch as edible coating in the post-harvest quality of grapes ‘Isabel’ (Vitis labrusca × Vitis vinifera L.)

The Isabel grape (Vitis labrusca × Vitis vinifera L.) is the most produced grape in Brazil, however, it has a short postharvest period due to rapid degradation during storage. The use of coating has been an alternative to prolong the shelf-life of fruits. The objective of this work was to evaluate the postharvest quality of 'Isabel' grapes coated with tamarind (Tamarindus indica L.) seed starch. The experimental design was completely randomized with five treatments with edible coating based on tamarind seed starch, at concentrations of 0, 0.5, 1, 1.5 and 2% and five replications. The grapes were immersed in the solutions with different concentrations and stored in B.O.D. at 12 ± 2 ° C and 85 ± 5% relative humidity for 12 days. Weight loss, color, pH, soluble solids, total titratable acidity, relationship between soluble solids and acidity, anthocyanins, flavonoids and vitamin C were evaluated. The 2% coating of tamarind seed starch was the most efficient, providing shelf life in 12-day grapes when stored at 12 ± 2 ° C and 85 ± 5% RH, and maintaining the main quality aspects, with higher SS / TA ratio and vitamin C.

Evaluation of antiproliferative and anti-inflammatory effects of non-pomace sediment of red grape juices (Vitis labrusca L.) in healthy and cancer cells after in vitro gastrointestinal simulation

Grape polyphenols are studied for their bioactive activities and health benefits. Grape juice clarification produces a colored non-pomace solid residue that is rich in polyphenols and may have potential for nutraceutical applications. This study therefore firstly investigated antiproliferative and anti-inflammatory properties of the non-pomace sediment of Bordo and Isabel grape juices before and after the gastrointestinal simulation, and evaluated the effects of the main individual phenolic compounds found in these sediments in regards to their antiproliferative action in healthy and cancer cells. The non-pomace sediments inhibited significantly the proliferation of colorectal adenocarcinoma cells (Caco-2) cells, whereas their digested fractions inhibited proliferation of hepatocellular carcinoma (HepG2) cells. However, the exposure to treatments caused no cell toxicity to healthy cells. When tested individually, the phenolic compounds quercetin and myricetin showed antiproliferative activity and led to cell viability of 56.47 and 51.07 % in Caco-2 cells and of 33.96 and 27.03 % in HepG2 cells, respectively. The non-pomace sediments and its digested fractions exhibited anti-inflammatory action by inhibiting the release of tumor necrosis factor alpha (TNF-α) in murine macrophages. These encouraging data suggests the potential use of this residue as dietary supplement or as a promising chemotherapy for antitumor therapies.

Study of the profile of bioactive compounds of the early Isabel grape cultivar (Vitis labrusca l) cultiated in the brazilian savanna

The objective of the present study was to evaluate the behavior of the bioactive compounds during the physiological development of the early Isabel grape cultivar (Vitis labrusca L), cultivated in the Brazilian savanna, with a view to future applications. This is a quantitative study carried out in the field and in the laboratory.The physical and chemical characterization was performed total phenolic compounds, antioxidant activity and the profile of the phenolic compounds by HPLC. The physical and chemical transformations of the berries were much more intense as from 60 DAA. The seeds presented high antioxidant potential in two analyzed methods. Three were phenolic compounds identified, chlorogenic acid being present in the berries, skins and pulps, catechin being present in the largest amounts, followed by epicatechin, present in the seeds. Such knowledge is important for future extractions and applications in foods and cosmetics.

Biofertilizantes na produção da videira Isabel

A videira “Isabel” é uma das culturas mais importantes tanto para o setor agrícola quanto para subsistência de pequenas famílias. O biofertilizante bovino surge como uma alternativa para substituir o uso excessivo de adubos químicos nas pequenas propriedades, em que pode ser utilizado em cultivos agrícolas proporcionando aspectos de qualidade e quantidade, agindo positivamente no sistema solo-água-planta. Nesta perspectiva, objetivou-se avaliar a produção de frutos de videira Isabel, adubadas com tipos e doses de biofertilizante bovino, durante o segundo ciclo produtivo. O experimento consistiu em delineamento em blocos casualisados, com fatorial 5 x 8, referente a cinco tipos de biofertilizante: (B1 = à base de esterco bovino, B2 = B1 + farinha de rocha MB4, B3 = B2 + leguminosa (Vigna unguiculata L. Walp.), B4 = B2 + cinza de madeira e B5 = B3 + cinza de madeira) e de 8 doses de biofertilizante (D1 = 0; D2 = 0,35; D3 = 0,7; D4 = 1,05; D5 = 1,4; D6 = 1,75; D7= 2,1; e D8 = 2,45 L/planta/vez), aplicadas a cada 2 meses. Os tipos de biofertilizante B1, B2, B4 e B5 exerceram valores significativos na produção, exceto para com a qualidade. O uso de biofertilizante aplicado 1,2 L/planta/vez proporciona maior eficiência produtiva de frutos de videira Isabel nos tipos B1, B2, B4 e B5, exceto para com ºBrix e acidez. A aplicação de diferentes tipos de biofertilizante bovino associado a dosagens ótimas acarreta em plantas com elevado potencial produtivo da videira Isabel.

Isabel red wines produced from grape pre-drying and submerged cap winemaking: A phenolic and sensory approach

The aim of this work was to determine the detailed phenolic composition and sensory profile of red wines produced from Isabel grape using two alternative winemaking: grape pre-drying (IPD) and submerged cap (ISC). IPD wines were produced by the grape drying using a tray dryer at 60 °C and 1.1 m/s of airflow and the ISC wines were produced using stainless steel screens inside the fermentation vessel aiming at avoiding the rise of the cap due to the carbon dioxide. As expected by the thermal degradation, IPD wines presented not quantifiable concentration of anthocyanins and were described as bitter, acid, herbaceous and astringent due to their higher content of galloylated (6.94 mg/L), monomeric flavan-3-ols (49.66 mg/L) and proanthocyanidins (6.28 mg/L), which were less affected by thermal degradation. Submerged cap wines were described as colorful, pungent and persistent in mouth probably due to the anthocyanin content (2.43 mg/L) and hydroxycinnamic acid derivatives (280.5 mg/L), respectively. Submerged cap is a promising procedure because these wines presented higher yield and anthocyanin content and color intensity similar to traditional wines; pre-drying winemaking can be considered less promising since it presented lower yield and sensory features that are not very appreciated by the consumers.

STABILITY OF ANTHOCYANINS FROM AGROINDUSTRIAL RESIDUE OF ISABEL GRAPE GROWN IN SÃO FRANCISCO VALLEY, BRAZIL

ABSTRACT Grape by-products are promising and sustainable sources of anthocyanins. Considering the factors related to degradation of those pigments, spectrophotometric and kinetic analyzes were carried out with the aim to evaluate the light and heat stability of anthocyanins from Isabel grape residue. We found that the exposure to luminosity (80W; 2500 lux) and high temperature (= 70ºC) significantly affected the absorption and content of those compounds (p <0.05), whose the most stable condition was obtained at 50°C (t1/2: 37.7h; k: 1.84 x 10-2 h-1) and protected from light (t1/2: 3,320.6h; k: 2.09 x 10-4 h-1). Therefore, the anthocyanins from the agroindustrial residue of Isabel grape are an alternative of natural colorants for food that can be packaged in opaque packaging and not subjected to severe heat treatment during processing.

The effect of Isabel grape addition on the physicochemical, microbiological and sensory characteristics of probiotic goat milk yogurt.

Goat milk is an attractive food because of its nutritional properties, easy digestibility and hypoallergenicity. Goat milk yogurt is an appropriate matrix for the inclusion of new ingredients such as probiotic cultures, fruit and its derivatives. Grapes are rich in polyphenols and recognized for their health benefits. The aim of this study was to improve the quality characteristics of probiotic goat milk yogurt by the addition of an Isabel grape (Vitis labrusca L.) preparation (IGP). For this, the influence of the addition of IGP on the physicochemical, microbiological and sensory characteristics of goat milk yogurt containing the probiotic Lactobacillus acidophilus LA-05 was evaluated during 28 days of refrigerated storage (5 ± 0.5 °C). Four yogurt formulations were prepared, each varying in the added IGP amount, as follows: Y0 (not containing IGP), YG15 (containing 15 g per 100 mL of IGP), YG20 (containing 20 g per 100 mL of IGP), and YG25 (containing 25 g per 100 mL of IGP). All formulations showed probiotic counts ranging from 7 to 8 log CFU mL-1 over the assessed storage period. The addition of 20 g per 100 mL of IGP affected positively the colour, viscosity, and sensory acceptance of the yogurt formulations. The production of goat milk yogurt containing L. acidophilus LA-05 and IGP is an option for developing a new goat dairy product with added value due to the inclusion of components with potential functional properties.

Grapevine yield components and composition of Isabel grape produced according to the organic and conventional systems

There is an increasing demand for organic grapes by the juice industry of Serra Gaucha, Brazil. This region presents a humid and hot summer, ideal climatic conditions for the development of a number of diseases. To control such diseases and problems brought about by other organisms, growers apply pesticides on the grapevines which may leave residues in grapes. However, in general, grapes produced by organic system have lower yield, but there is a lack of research data on this subject. Thus, an experiment was carried out over three years in order to compare the yield components and the physicochemical composition of the must of Isabel grapes conducted in both production systems. When the grapes were ripe, variables related to yield components were evaluated, such as the number of clusters/vine, yield/vine and weight/cluster. Then the grapes were sampled and taken to the laboratory where they were crushed and the musts were centrifuged and analyzed. The 3-year data mean were submitted to correlation analysis and Principal Component Analysis. The results show that conventional grapevines produced 2.18 times more than organic. However, the grapes from the organic system had higher density, Brix, pH, Brix/titratable acidity ratio, P and Mg but lower K, and Ca varied little between both production systems.

Optimization of the HS-SPME-GC/MS technique for determining volatile compounds in red wines made from Isabel grapes (Vitis labrusca)

Brazilian wine production is characterized by Vitis labrusca grape varieties, especially the economically important Isabel cultivar, with over 80% of its production destined for table wine production. The objective of this study was to optimize and validate the conditions for extracting volatile compounds from wine with the solid-phase microextraction technique, using the response surface method. Based on the response surface analysis, it can be concluded that the central point values maximize the process of extracting volatile compounds from wine, i.e., an equilibrium time of 15 minutes, an extraction time of 35 minutes, and an extraction temperature of 30 °C. Esters were the most numerous compounds found under these extraction conditions, indicating that wines made from Isabel cultivar grapes are characterized by compounds that confer a fruity aroma; this finding corroborates the scientific literature.

Application of abscisic acid (S-ABA) to cv. Isabel grapes (Vitis vinifera × Vitis labrusca) for color improvement: Effects on color, phenolic composition and antioxidant capacity of their grape juice

Hybrid grape Isabel (Vitis vinifera×Vitis labrusca) is the main cultivar used to produce grape juice in Brazil. However Isabel grape is deficient in anthocyanins. Application of abscisic acid (S-ABA), which is responsible for promoting the anthocyanin synthesis, offers a way for color improvement. This study evaluates the changes on the phenolic composition of Isabel grape juice produced from grapes treated with S-ABA, over two consecutive harvest seasons. Application of S-ABA to grapes increased the content of total anthocyanins in the corresponding juices and also the proportion of anthocyanins based on B-ring tri-substituted anthocyanidins. Regarding non-anthocyanin phenolic compounds, total flavonol content was only significantly higher in juices produced from grapes treated in the 2012 season, whereas the treatment did not significantly affect the content of hydroxycinnamic acid derivatives, flavan-3-ols, resveratrol and even the antioxidant capacity of juices. Juice from Isabel grapes treated with S-ABA provides an enhancement of total anthocyanin concentration, mainly when grapes are treated before or at the onset of véraison. As a consequence, the color intensity increased in all the juices obtained from treated grapes.