Grape Juice Concentrate Research Articles

Rapid quantification of the adulteration of pomegranate juices by Raman spectroscopy and chemometrics

The juice drink industry has repeatedly been exposed to adulteration. Unscrupulous producers, for example, use cheap juice for substitution in the pursuit of more significant economic benefits, which presents a tremendous challenge for the control of the quality of drinks. The objective of this study was to apply Raman spectroscopy combined with chemometrics to rapidly quantify the adulteration concentration of apple juice or grape juice in pomegranate juice. Two supervised learning algorithms: partial least squares regression (PLSR) and support vector machine regression (SVR) were used to analyze the Raman spectra of 114 samples. The coefficient of determination (R2), root mean square error (RMSE), and residual prediction deviation (RPD) of the prediction set when using PLSR and SVR to predict the adulterated concentration of apple juice in pomegranate juice were 0.9357 and 0.9465, 6.446% and 5.974%, 3.945 and 4.322, respectively. The R2, RMSE, and RPD of the prediction set when using PLSR and SVR to predict the adulteration concentration of grape juice in pomegranate juice were 0.9501 and 0.9502, 6.334% and 5.571%, and 4.475 and 4.481, respectively. It was concluded that Raman spectroscopy combined with chemometrics has excellent potential for application as a rapid quantitative method to detect adulterated concentrations of pomegranate juice.

Aromatic and chemical differences between Msalais wines produced at traditional craft workshops and modern plants

The making of Msalais, a traditional wine fermented in the A′wati production region in Southern Xinjiang (China), currently undergoes a shift from traditional craft workshop (TCW) fermentation to modern plant (MP) production. Major differences in the practices, technology, and microbes used in TCWs and MPs caused the quality of MP wines somewhat deviates from high quality of TCWs wine. Exploring the sensory and chemical differences between TCW wines and MP wines will facilitate a successful shift of Msalais-making from TCWs to MPs. Here, the sensory and chemical characters of 25 TCW and MP Msalais wines were qualitatively and quantitatively analyzed. Laboratory-scale Msalais-making experiments were performed to compare the effect of winemaking conditions on the sensory characters of wine. MP wines had a stronger caramel odor, but a relatively weaker floral and fruity odors than TCW wines, while TCW wines had a significantly stronger fruity odor but a weaker caramel odor than MP wines(p < 0.05). These differences could be ascribed to the higher content of higher alcohols, furans, and methionol in MP wines, and a higher concentration of esters, fatty acids, volatile phenols, terpenes, lactones, and norisoprenoids in TCW wines. Differences in grape residue treatment, grape juice concentration, native microbial community, dissolved oxygen levels, and fermentation temperature resulted in the sensory differences between Msalais wines. These findings will help to improve the quality of MP Msalais to retain the typical sensory features of traditional TCWs wines, and allowing an objective control of the TCW and MP technologies.

Effect of Metschnikowia pulcherrima on Saccharomyces cerevisiae PDH By-Pass in MixedFermentation with Varied Sugar Concentrations of Synthetic Grape Juice and Inoculation Ratios

The effects of Metschnikowia pulcherrima and high glucose osmolality on S. cerevisiae pyruvate dehydrogenase pathway (PDH) by-pass were examined by varying the starting sugar concentration of synthetic grape juice and the inoculation ratio of S. cerevisiae to M. pulcherrima. The findings revealed that M. pulcherrima and osmolarity impacted S. cerevisiae’s PDH by-pass. The inoculation concentration of M. pulcherrima significantly affected pyruvate decarboxylase (PDC) activity and acs2 expression when the initial sugar concentration was 200 g L−1 and 290 g L−1. The osmolarity caused by the initial sugar (380 g L−1) significantly influenced the enzymatic activity of S. cerevisiae, which decreased PDC and acetaldehyde dehydrogenase (ALD) activities while increasing Acetyl-CoA synthetase (ACS) activity. The reduction in acetic acid in the wine was caused by M. pulcherrima altering the initial sugar concentration faced by S. cerevisiae, which in turn affected enzymatic activity. The alteration of enzyme activity and accumulation of primary metabolites revealed why mixed fermentation could reduce the acetic acid content in wine by altering the enzymatic activity and affecting the expression of several key genes. The M. pulcherrima inoculation levels had no significant effect on the acetic acid and glycerol concentration in the same fermentation medium.

Vacuum impregnation on apples with grape juice concentrate: Effects of pressure, processing time, and juice concentration

Apple cubes were subjected to vacuum impregnation using grape juice concentrate. The effect of pressure reduction (VP = 100–500 mmHg), immersion time (t = 10–30 min), and concentration of grape juice (C = 40–60°Brix) on impregnation parameters were evaluated using response surface methodology. Second-order polynomial equations were developed (R2 > 0.895) to describe the behavior of water loss, total soluble solids, L*, a*, Hue, total color difference, the color of impregnated/treated areas (AU/AOP), antioxidant activity, total monomeric anthocyanin, and dimensionless volume (V/Vo) in the impregnated product. VP had a significant (p ≤ 0.05) effect on mass transfer parameters, color parameters, AU/AOP, and bioactive compounds. However, at 60°Brix and 500 mmHg, the lower V/Vo values were reached due to cell disruption. Therefore, it is recommended to use a VP = 500 mmHg and t less than 20 min to significantly impregnate compounds and obtain a product without considerable morphometric modification.

Concentration of grape juice: Combined forward osmosis/evaporation versus conventional evaporation

The present study aimed to evaluate the process of forward osmosis (FO) for the concentration of grape juice using NaCl as the osmotic solution facing the thermal evaporation process, commonly used in industry. A combined experiment (FO + evaporation) was also performed to evaluate the potential of FO as a pre-concentration process. FO experiments were performed according to the Box-Behnken design. Some degree of concentration of the grape juice was obtained in all FO experimental runs, and it was observed a strong influence of the parameters studied on the fluxes. In the evaporation experiments, the quality of the final product was affected concerning the content of phenolic compounds, which have undergone significant degradation by heat. In the combined process, grape juice concentration to up to 65.7°Brix could be achieved showing greater retention of quality factors and bioactive compounds, highlighting the advantage of FO and its potential as a pre-concentration step.

The High Content of Quercetin and Catechin in Airen Grape Juice Supports Its Application in Functional Food Production.

Ensuring healthy lives and well-being constitutes one of the Sustainable Development Goals of the UN 2030 agenda. Consequently, research into how natural products may promote health is essential for the new generation of nutraceuticals and functional foods that are in high demand today. Grape juice is a natural foodstuff composed of water, sugars, minerals, vitamins and a wide array of polyphenols. Polyphenols are bioactive compounds of great interest due to their antioxidant properties and benefits to health, supporting antimicrobial, anti-aging, and anticarcinogenic activity. The majority of grape juice produced in the world is used for the production of wine, although a small part is used in the food industry, mainly in baby food and sports drinks. The aim of this work is to determine the polyphenol content in the natural and concentrated juice of Airen grapes, the main white grape variety produced in Spain. For this, fresh juices from five grape varietals (Airen, Sauvignon Blanc, Gewürztraminer, Verdejo and Tempranillo) and concentrated Airen juice were analyzed and compared. Results showed similar contents of phenolic acids and stilbenes in all grape varietals studied, although the Airen variety demonstrated a higher concentration of two flavonoids: quercetin and catechin. It can be concluded that the grape juice concentration process negatively affects the stability of these compounds, causing a reduction in the polyphenol content that ranges between 54–71%, with the exception of quercetin and catechin.

A study on electrical conductivity and performance evaluation of ohmic evaporation process of grape juice

Examination of the Ohmic evaporation process in terms of electrical conductivity value and laws of thermodynamics is limited in the literature. In this study, the moisture content of the grape juice sample was concentrated from 5.75 kg water/kg Dry-Matter (DM) to approximately 2 ± 0.3 kg water/kg DM by an ohmic evaporator. Evaporation process was applied in three different voltage gradients (16–24 V/cm) by Ohmic evaporator. The electrical conductivity value was found to be between 0.21 and 0.77 S/m during the heating process while it was between 0.77 and 1.01 S/m during the evaporation process. In addition, when evaluating this process concerning thermodynamic laws, it was stated that increasing voltage gradient had a positive effect on energy efficiency, exergy efficiency, and improvement potential values. To conclude, it was achieved that the ohmic heating-assisted evaporation process could be used in the concentration of grape juice and an effective system with an average of 80% energy efficiency. Practical applications As the ohmic heating process is known as a homogeneous, rapid, and efficient heating technique, its use in food applications is gradually increasing in recent years. Evaporation process is one of the preservation methods used especially in the fruit juice industry. An alternative evaporation method has been obtained by integrating the ohmic heating process into the evaporation process. It was determined that the voltage gradient used and foam formation were an effect on the electrical conductivity and performance analyses. It was determined that as the voltage gradient increased, the amount of water removed from the grape juice increased (kg/s) and the total processing time shortened. It is considered that this study may be a data source in the literature related to pilot and industrial-scale production lines by determining electrical conductivity value during the evaporation of grape juice and investigating energy efficiencies.

Whole, concentrated and reconstituted grape juice: Impact of processes on phenolic composition, “foxy” aromas, organic acids, sugars and antioxidant capacity

The concentration and reconstitution processes of grape juices can result in losing compounds associated with beverage quality. In this context, three tanks containing 50,000 L of grape juice were individually concentrated up to 68 °Brix using a triple vacuum concentrator. The concentrated juice was reconstituted up to the original °Brix of the whole juice (18.4). Phenolic compounds, sugars and organic acids were quantified by high-performance-liquid-chromatography. “Foxy” aromatic compounds were also quantified by gas-chromatography/mass-spectrometry. The concentration and reconstitution process resulted in significant losses (Tukey test, p < 0.01) of trans-caftaric acid, decreasing from 397.08 to 159.14 mg/L, chlorogenic-acid from 34.97 to 8.44 mg/L, aromatic furaneol compound from 9.06 to 1.93 mg/L, as well as total losses for gallic-acid, caffeic-acid, p-coumaric-acid, syringic-acid, hesperidin, pelargonidin-3-glucoside and epicatechin compounds. The concentration and reconstitution of grape juice preserved the antioxidant capacity and most of the quantified compounds, with the reconstituted juice having good nutritional quality.

Effect of high hydrostatic pressure processing on phytochemicals, antioxidant activity, and behavior ofBotrytis cinereain white grape juice concentrate

High hydrostatic pressure (HHP) was applied on a white grape juice concentrate (GJC) to evaluate its effectiveness and possible application as an alternative to thermal pasteurization. GJC was processed at pressure levels of 200, 300, and 400 MPa for 2 and 4 min at room temperature (20 ± 2°C) and changes in various quality parameters after HHP processing and after subsequent storage at 4°C for 35 days were examined. The effect of the HHP treatments on the conidial fungi Botrytis cinerea was determined after inoculating the GJC with a conidial suspension. The results shown a significant reduction of B. cinerea (ufc/ml) at 400 MPa/4 min, in day 0 and after 35 days of storage sample. The physicochemical analysis of GJC showed that the sugar contents increased after treatments but decreased during storage. The total antioxidant activity and total flavonoid content in HHP-treated samples were significant decreased. Practical applications HHP processing of concentrated grape juice has proved to be efficient to retain content of antioxidant compounds and activity as well as characteristic quality of the GJC that is widely used in blending of fruit juices or as a natural sweetener in various food products. The experimental results have shown that HHP process could be a valid alternative to thermal pasteurization of GJC.

Production and Characterization of Flavored Dairy Dessert Containing Grape Juice Concentrate

Grape juice concentrate (GJC) contain high amounts of natural sugars, vitamins and polyphenols so it can be used as a natural sweetener and functional ingredient. The novelty of the present study was to produce flavored dairy dessert, as well as evaluating effect of GJC, gelatin and cream on its physicochemical, mechanical and sensorial properties. In this study, optimization of breakfast flavored dairy dessert formulation containing GJC was done using design expert and response surface methodology. The effects of cream (75-90 %), gelatin (0 - 0.5 %) and GJC (10-25 %) on properties of flavoured flavored dairy dessert were evaluated. The samples were subjected to fat, acidity, pH, total solids content, sugar content, hardiness, colour, antioxidant activity and sensory attributes. At first, modelling of responses was done using data regression analysis, and then 3D charts were drawn for each response. The results showed that, the samples became firmer, and darker in colour as the level of GJC increased. The antioxidant activity of the desserts was increased mostly by GJC level. Maximum hardness and radical inhibitory activity of samples was 1380 g and 73.5%, respectively. The general acceptability of the desserts was affected by the amount of GJC. Based on the standard range of responses and the most desirability, the optimal point was obtained. At the optimal point the amount of cream, GJC and gelatin were 75.05, 20.59 and 4.36% respectively. Flavored dairy dessert could be considered to be a suitable source of vitamins, soluble fibre, antioxidants, amino acids, and a good source of natural sweets.

Colorimetric detection of cadmium ions using modified silver nanoparticles

Metal ion sensors are a significant and challenging area in the analytical sciences. In this study, the use of grape juice for bio-synthesizing of silver nanoparticles (AgNPs) and using it for simple and rapid colorimetric detection of Cd2+ ions is described. The as-prepared AgNPs were characterized by standard analytical techniques including UV–visible and FTIR spectroscopic methods and transmission electron microscopy (TEM). The plasmon resonance band of the silver nanoparticles was observed at 410 nm and it was found that its intensity is related to the grape juice concentration and pH. The TEM image showed the average size of 5–10 nm for AgNPs. The detection of Cd2+ ions was based on the changes of absorbance due to complex formation of the metal ion. The colorimetric detection of Cd2+ was led to a linear dynamic range from 0 to 150 µmol/L (r2 = 0.9993) and a low detection limit of 4.95 µmol/L for cadmium in aqueous solution. These results are close to or better than the previous reports. This bio-synthesized AgNPs can be used as simple alternative design for colorimetric sensing of Cd2+ in water samples.

Optimization and Production of Flavored Dairy Dessert Containing Grape Juice Concentrate, Gelatin and Cream Using Response Surface Methodology

Optimization and Production of Flavored Dairy Dessert Containing Grape Juice Concentrate, Gelatin and Cream Using Response Surface Methodology

Effect of Carrot Pomace Powder and Dushab (Traditional Grape Juice Concentrate) on the Physical and Sensory Properties of Cakes: A Combined Mixtures Design Approach

Background:Carrot pomace powder (CPP), a valuable by-product of carrot processing, and Dushab, a traditional grape juice concentrate, can be utilized for enrichment of products.Methods:Combined mixtures methodology using D-optimal design was found to be an effective technique to investigate the effects of replacing wheat flour and sucrose with CPP and Dushab on water activity, moisture content, specific volume, crumb color and textural properties of cakes and their sensory evaluation.Results:Moisture content, color difference and browning index of cakes increased with an increase in the amount of CPP and Dushab substitution. The specific volume of the cakes reduced in the supplemented CPP and Dushab cakes. By increasing the level of CPP and Dushab, the firmness of the cakes increased whereas cohesiveness decreased. Chewiness and gumminess were not affected by Dushab substitution but increased by the increment of CPP. Dushab substitution led to the decline of cake springiness compared to the control one. The least sensory accepted product, with a mean score of 0.7 in a scale from 0 to 1, had the maximum substitution of CPP (24% wheat flour) and Dushab (100% sucrose).Conclusion:The optimization tool indicated that a functional cake with high desirability can be achieved with the substitution of 10% wheat flour by CPP and 65% sucrose by Dushab.

Levels of Furaneol in Msalais Wines: A Comprehensive Overview of Multiple Stages and Pathways of Its Formation during Msalais Winemaking.

4-Hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol) is present in food. It has a caramel-like flavor, which affects the quality of food, and is formed via multiple pathways. Msalais is a traditional wine fermented from boiled local grape juice in Xinjiang (China). It has a strong caramel odor, which suggests high furaneol content. Furaneol formation during Msalais-making had not been investigated to date. Here, high-performance liquid chromatography and different fermentation models of Msalais-making were used to investigate the furaneol content and formation during Msalais-making. The furaneol content of Msalais is high, between 27.59 ± 0.493 mg/L and 117.6 ± 0.235 mg/L. It is formed throughout the entire Msalais-making process. The formation pathways include the Maillard reaction and chemical hydrolysis of bound furaneol during grape juice concentration; enzymatic release and/or chemical acidic hydrolysis of furaneol glucosides, and biosynthesis from Maillard products and d-fructose-1,6-diphosphate during fermentation; chemical transformation of Maillard products at room temperature (16–25 °C) and hydrolysis of furaneol glucosides during storage. Importantly, furaneol is formed by an efficient biotransformation of Maillard products. These findings suggest that furaneol content can be used as an important indicator of wine quality, and could be controlled by controlling the grape quality, grape juice concentration, fermentation, and wine storage.

Application of digital images and multivariate calibration for the quantification of anthocyanin and antioxidant activity in grape juice

Background and Aims The current methods for measuring the anthocyanin concentration (AC) and antioxidant activity (AA) of grape juice have limitations. The objective of this work was therefore to evaluate the application of digital imaging as a simple, fast and low‐cost method for determining AC and AA in juice. Methods and Results The AC and AA of 75 grape juice samples were measured using reference methods and then correlated against digital images of 200 dpi resolution obtained with a scanner, using partial least squares regression. The samples were separated with the Kennard–Stone algorithm into calibration sets (50 samples) and external validation sets (25 samples). The models used for the quantification of AC and AA presented a root mean square error of calibration of 8.8 mg/L and 9.8 μmol and a root mean square error of prediction of 7.5 mg/L and 8.0 μmol, respectively. The correlation coefficients for the adjustment were 0.8479 and 0.9258 for the models in the determination of AC and AA, respectively. Conclusions Digital imaging and multivariate calibration can be used to measure efficiently selected parameters of grape juice composition. Significance of the Study Analytical methods based on digital imaging offer promising alternatives to conventional methods, since they are fast, simple, non‐destructive and employ little or no chemical reagents, thereby reducing analysis costs and facilitating in situ analysis.

Evolution of the aromatic profile of traditional Msalais wine during industrial production

ABSTRACT Msalais is a traditional Chinese wine. The strong caramel odor makes Msalais monotonous and inharmonious, with more imbalances in industrially produced Msalais. In this study, the aromatic evolution of Msalais during industrial production was analyzed by sensory testing and gas chromatography-mass spectrometry. The analysis revealed that dynamic changes of corresponding aromatic compounds were consistent with the change of odors. The concentration of grape juice caused strong caramel odor and weak floral and herbaceous odors in industrial Msalais. Further, controlled fermentation ameliorated the imbalance. These findings revealed the traditional aromatic characteristics that should be improved during the industrial production of Msalais.

Effect of water deficits and season on berry development and composition of Cabernet Sauvignon (Vitis viniferaL.) grown in a hot climate

Background and Aims The effect of season and deficit irrigation treatments was monitored on berry development and composition, yield and wine composition of Vitis vinifera L. cv. Cabernet Sauvignon grown in a hot climate during 2003–2005. Methods and Results The treatments were regulated deficit irrigation (RDI) and prolonged deficit irrigation (PD), compared with a standard industry irrigation (Control) treatment. Compared to the Control, RDI berries were smaller from a reduction in mesocarp (flesh) rather than in exocarp (skin) or seed mass but insufficient to significantly impact on yield. The PD treatment reduced berry size driven by mesocarp reduction resulting in a lower yield. Season 2005 had a significantly larger yield, mainly as a result of increased berry fresh mass, exocarp and seed mass compared to that of either 2003 or 2004. Grape juice TSS and pH were not significantly affected by water deficit, but each varied between seasons. The malic acid concentration of grape juice was reduced by the RDI and PD treatments, resulting in enhancement of the tartaric : malic acid ratio. Grape anthocyanin at harvest was unaffected by irrigation treatment but significantly impacted by season. Wine colour density, anthocyanin, ionised anthocyanin and phenolic substances were increased by RDI and PD and impacted by season. Conclusions Wine attributes were improved further by PD relative to RDI. Seasonal effects were shown to have an impact greater than the within-season water deficit treatments on most aspects of berry development and composition. Significance of the Study The study has demonstrated the utility of the PD treatment as an irrigation tool, where water availability is significantly limited and/or where improved spectral properties are required for wines.

Grape juice concentrate alleviates epididymis and sperm damage in cadmium-intoxicated rats.

The possibility of long-term grape juice concentrate (GJC) consumption conferring a protective effect against cadmium (Cd)-induced damage to the epididymis, completely preserving sperm profile, was evaluated here for the first time in the scientific literature. Male Wistar rats (n=6/per group) received an intraperitoneal Cd injection (1.2mg/Kg) at age 80days and GJC (2g/Kg) by gavage from 50days until 136days old. Groups receiving either Cd or GJC were added. An intraperitoneal injection of saline (0.9%) and water by gavage was administered in the absence of treatment with Cd or GJC. Animals were anaesthetized and exsanguinated at 136days; the vas deferens, left testis and epididymis were removed; and perfusion continued with fixative. The right epididymis was collected for morphological analysis. Cd had a devastating effect demonstrated by reduced sperm count in testes and epididymis, sperm production and normal sperm count, besides increased epididymis sperm transit time and completely disorganized morphology. These alterations were attributed to higher Cd levels in the testes and a lipid peroxidation (LP) process. Consumption of GJC plus Cd intoxication was effective, reducing metal accumulation and LP. Consequently, we could identify a preserved sperm profile, with improvement in testis and epididymis sperm count, normal sperm structure and sperm transit time. Moreover, GJC extends its protective effect to the epididymis, allowing complete re-establishment of its morphology, ensuring successful sperm maturation process. In conclusion, our study indicates long-term GJC as a promising therapy against reproductive chemical intoxication injury damage, preserving sperm prior to ejaculation.

EFEK ANTIBAKTERI SUPERNATAN JUS ANGGUR MERAH YANG DIISOLASI DENGAN KECEPATAN SENTRIFUGASI 12.000 rpm TERHADAP PERTUMBUHAN S. MUTANS

Background: Streptococcus mutans (S.mutans) is a gram-positive bacteria in oral cavity which produced acid as the common cause of dental caries. In order to prevent the growth or kill Streptococcus mutans, antibacterial is required. Red grape (Vitis vinifera) is suspected to contain antibacterial.Method: An experimental study using the post test only control group design is carried out to Streptococcus mutans with tube dilution method and streaking on the Brain Heart Infusion. A range of concentration from 40%, 50%, 60%, 70%, 80%, 90%, 98%. The control group are group of bacteria and red grape juice control.Result: The analysis of Minimum Inhibitor Bactericidal (MIC) is show a difference absorbent value as the given concentration (Anova, p&lt;0,05). The correlation test show is strong reciprocal association between concentration of res grape juice and absorbent value (r=-0,978; p&lt; 0,05). The analysis of Minimum Bactericidal Concentration (MBC) is shows difference of the number of colonies as given concentration (Anova, p&lt;0,05). The correlation reveals a very strong reciprocal association between concentration of red grape juice and the number of Streptococcus mutans colonies growth (r=-0,925; p&lt; 0,05).Conclusion: The conclusion is supernatant of red grape juice has effect the growth as antibacterial agent on Streptococcus mutans in vitro, with MIC at concentration 60% and MBC at concentration 80%

Grape Juice Concentration by Progressive Freeze Concentrator Sequence System

Concentration is a complex process that could change the physical and chemical conditions of a substance and significantly affects the quality of fruit juice. Thus, this study aimed to evaluate the effect of different operating parameters on the bioactive compounds retention and the concentration effectiveness of grape juice by using progressive freeze concentration (PFC). The concentration process performance was assessed through total phenolic content (TPC) increment and effective partition constant (K). This research was carried out by using progressive freeze concentrator sequence system (PFCSS), which has been proven to be able to operate efficiently. It was found that the most optimum operating condition occurred with a coolant temperature of −8C, circulation flowrate of 3000 mL/min operation time of 20 minutes and solution concentration of 8%Brix. The results suggest that PFC may contribute a great potential in concentrating grape juice, therefore could contribute to the economy of the juice industry. Practical Applications Nowadays, there is a growing interest on progressive freeze concentration (PFC) in juice concentration due to its several advantages. In this study, a process sequence of PFC is develop to acquire high performance system in terms of operation time, no intervention of human operator and most importantly production of high quality product, which is grape juice concentrate. Red globe grape is among the most cultivated, most commercially important and studied cultivars, including processing method in order to produce high quality juice. This study is focused on the preservation and concentration of grape juice by using progressive freeze concentrator sequence system (PFCSS). The results can be a guide in the determination of processing method that can be used in producing red globe grape juice with good quality and highest concentration of TPC and other bioactive compound.