Mycotoxins are frequently found in fruits and fruit juices. However, data about occurrence and fate of mycotoxins along the fruit juice processing chain are currently insufficient. Herein, a liquid chromatographic/tandem mass spectrometric (LC–MS/MS) multi-mycotoxin method was developed and applied to investigate the effect of technological unit operations on the fate of three of the most relevant mycotoxins along the processing chain for cloudy and clear apple juice, namely patulin (PAT), ochratoxin A (OTA), and alternariol (AOH). Raw juice obtained directly after dejuicing was spiked with the aforementioned mycotoxins at pilot-plant scale prior to subjecting it to different technological unit operations. Regarding clear apple juice production treatment with a pectinolytic enzyme preparation, and pasteurization were insignificant for mycotoxin reduction, but fining with subsequent filtration was effective, although the mycotoxins showed different affinity towards the tested agents. The most effective fining agent was activated charcoal/bentonite in combination with ultrafiltration, which removed OTA (54 µg/L) and AOH (79 µg/L) to not quantifiable amounts (limit of quantification (LOQ) 1.4 and 4.6 µg/L, respectively), while PAT was reduced only by 20% (from 396 to 318 µg/L). Regarding cloudy apple juice production, all studied processing steps such as centrifugation and pasteurization were ineffective in reducing mycotoxin levels. In brief, none of the common steps of clear and cloudy apple juice production represented a fully effective safety step for minimizing or even eliminating common mycotoxins. Thus, ensuring the sole use of sound apples should be of utmost importance for processors, particularly for those manufacturing cloudy juices.

The current use and distribution of agricultural water resources is highly prone to effects of global climate change due to shifting precipitation patterns. The production of vegetable crops in open field cultivation often requires demanding water applications, being impaired in regions where climate change will increasingly evoke water scarcity. To date, increasingly occurring precipitation-free periods are already leading to moderate water deficits during plant growth, e.g., in southern Europe. Among all vegetable crops, leafy vegetables such as spinach (Spinacia oleracea L.) are particularly vulnerable to limited water supply, because leaf expansion is highly dependent on water availability. Besides biomass production, water limitation might also affect the valuable nutritional composition of the produce. Therefore, we investigated the impact of moderately reduced water supply on the chemical composition of spinach, cultivated in the open field in three consecutive years. Two different water supply treatments, full and reduced irrigation, were used in a randomized block design consisting of three sets of six plots each. In the reduced water supply treatment, the total amount of supplied water, including both irrigation and natural precipitation, amounted to 90%, 94% and 96% in 2015, 2016 and 2017, respectively, of the full, optimal water supply treatment. Spinach grown under limited water supply showed significantly higher fresh biomass-based contents of polyols (e.g., inositol, glycerol), ascorbic acid, potassium, nitrogen, phosphorous, zinc and manganese, as well as total flavonoids and carotenoids. Increased dry biomass-based levels were found for total inositol, zinc and manganese, as well as decreased levels for malic acid, fumaric acid, phosphate and chloride. Furthermore, we report a high seasonal variation of several minor phytochemicals, such as single flavonoids. Spinacetin derivatives, spinatoside-glucoside as well as a rather unusual hexuronylated methylenedioxy flavonoid showed highest amounts when grown under relatively low irradiation in autumn. Levels of patuletin derivatives tended to increase under high irradiation conditions during spring. In summary, the chemical composition of spinach was shown to be highly sensitive to moderately reduced water supply and seasonal variation, but the overall nutritional quality of fresh marketable spinach was only marginally affected when considering health-related constituents such as minerals, trace elements, flavonoids and carotenoids.

As climate change evokes changing precipitation patterns, the cultivation of vegetable crops in open fields might become more difficult in the future. Nowadays, many vegetable growers are already facing relatively long unprecedented precipitation-free periods. In many growing regions, irrigation is only available to a limited extent or not at all, and the cultivated plants will suffer from moderate water stress more often. Therefore, we examined the effects of moderately-reduced water supply on the chemical composition of pickling cucumber, cultivated in an open field and in a separate greenhouse trial. In the field trial, the reduced water supply treatment (RWS) provided 85–90% of the total water amount of the well-watered control treatment (CTR), applying a randomized block design with six replications comprising two consecutive weekly harvest periods. In fruits obtained by cultivation with reduced irrigation, levels of malic acid, calcium, and magnesium significantly increased, while those of phosphate, phosphorous, nitrogen, and iron decreased based on dry matter. Fresh matter-related results additionally revealed a decrease of myo-inositol and zinc, while sugars and total phenols remained unchanged. In the greenhouse experiment, the RWS obtained 60% of the irrigation amount of the CTR. Here, single cucumber compartments (exocarp, mesocarp, and endocarp) were examined. Chemical compositions changed in a similar, but more pronounced, manner as compared to the open field trial. The levels of individual, nutritionally relevant carotenoids in the peel of pickling cucumber, like lutein and β-carotene, were affected by RWS. Regarding the nutritional quality of fresh marketable cucumber fruits, malic acid, certain minerals and trace elements, as well as the carotenoids were shown to be sensitive to moderate water reduction.

This study reports a clear-cut relationship of the technological use of specific filter aids with highly variable vanadium levels in beer, wine, and fruit juices. First, the previously reported broad range of vanadium levels was confirmed in 68 commercial beverages by ICP-MS. Since cloudy apple juices exhibited significantly lower vanadium amounts than clear apple juices, filter aids used for clarification were analyzed and found to contain substantial and highly variable amounts of vanadium, particularly in all analyzed diatomite (38-368 mg vanadium per kg filter aid), but not in perlite products ( < 4 mg/kg). Subsequent pilot-scale precoat filtration experiments (170 L/batch) proved vanadium to be released from diatomite (Kieselguhr), increasing its levels from ca. 2.1-2.6 mu g/kg unfiltered to 27-201 mu g/kg filtered juice, depending on the use of diatomites high or low in vanadium. Thus, filter aid selection was shown to modulate the vanadium concentrations in clarified beverages.

Seasonal variations in water availability as increasingly provoked by climate change pose severe challenges for vegetable production, particularly for crops requiring reliable and high water supply for achieving satisfactory quality. In contrast to most previous studies applying severe water deficits, we examined the effects of moderate water deficits on the chemical composition of red radish tubers during three consecutive years with variable climatic conditions. Radish were cultivated in open field, applying two different water supply treatments and following a randomized block design comprising four sets of six plots each. The resulting water reductions of 3-20% led to a significant increase of dry matter-based myo-inositol levels, whereas those of selected minerals and trace elements, phenolics and glucosinolates decreased. Anthocyanin levels remained unchanged. Fresh-matter related levels of most analytes increased upon reduced water treatments due to higher dry matter contents. While pigment levels in radish remained unchanged, mild water deficit affected other quality-related parameters such as pungency-related glucosinolates.

The aim of this study was to determine the stability of various anthocyanins in red-coloured apple juice for the development of a new attractive beverage. Red-coloured apple juice was generated from red-fleshed apples of cultivar “Maggy” to analyse the composition of anthocyanins and the effect of storage at various temperatures. Cyanidin-3-galactoside (cy-3-gal) was identified as the main component of the anthocyanin profile, next to 5-carboxypyranocyanidin-3-hexoside, tentatively carboxypyranocyanidin-3-galactoside, and two cyanidin-3-pentosides. In addition, we found cyanidin-3-glucoside, another 5-carboxypyranocyanidin-3-hexoside, probably 5-carboxypyranocyanidin-3-glucoside, one 5-carboxypyranocyanidin-3-pentoside, two unknown anthocyanins, and another cyanidin-3-pentoside. The loss of anthocyanins during storage can be described as a first-order reaction as it is the case also for other red-coloured fruit juices. The T1/2 value of cyanidin-3-galactoside varied between 53 and 84 days after storage at 4 °C, and between 15 and 13 days at 20 °C. Storage at 37 °C reduced the T1/2 values from 7 to 6 days. A much longer half-life was observed for 5-carboxypyranocyanidin-3-galactoside. The T1/2 values at 4 °C were 250–315 days and 50–112 days at 20 °C. At 37 °C, T1/2 decreased from 23 to 25 days. The antioxidant capacity (TEAC) was constant during storage for at least 1 year. The colour of red apple juice, however, is less stable than in aronia, black currant and red grape juices, for example. Taken together, red apple juice, generated of the cultivar “Maggy”, is an attractive new fruit juice, but other cultivars of red-fleshed apples with higher anthocyanin concentrations would achieve a more colour-intense product.

Bentonite is the only fining agent which can stabilize wine and prevent protein haze formation after bottling. Currently many approaches are used to find an alternative because of bentonite's negative influence on color and aroma compounds. Nevertheless, the interaction of bentonite with wine proteins is not fully understood.Therefore, we analyzed the influence of a NaCa-combined bentonite on the protein content and composition of different wines showing a partial selectivity on protein adsorption. For example, glycosylated proteins were not removed by bentonite in notable amounts. Performing mass spectrometry we were able to demonstrate that 96% of class IV chitinase was adsorbed by bentonite, whereas varying adsorption behavior was observed for different thaumatin-like protein isoforms ranging from no removal to 98% of reduction. These differences may be explained by considering hydrophobicity surface of the proteins. Here, some differences are detected which might be an explanation for the better or worse adsorption.Our results demonstrate the importance to consider the isoforms of the potential haze-related proteins. Only the understanding of the interaction conditions of the wine component and their behavior with fining agents might result in the development of new strategies preventing protein haze formation.

Protein haze in white wines is a major technological and economic problem for the wine industry. In particular, an increased haze formation can be observed in wines from dry vintages. Therefore, field tests were carried out in steep slope vineyards planted with Riesling grapes over three dry growing seasons to study the effect of drought stress on the concentration of proteins in the resulting wines. Plots suffering from drought stress were compared with the surrounding drip-irrigated plots. Riesling grapes were processed into wines by conventional procedures. Protein amounts of the isolated wine colloids of the stressed samples (S) were always higher than those of the watered samples (W) (mean watered 13.8 ± 0.44, mean stressed 17.4 ± 0.40 g 100 g−1 isolated colloids). As a consequence, higher bentonite doses were needed to achieve protein haze stability of the drought-stressed treatments. Concerning the protein composition, there were no significant differences between stressed and watered treatments. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the molecular weights of proteins ranged from 12 to 75 kDa with an accumulation of chitinases and thaumatin-like proteins between 20 and 30 kDa. Concerning the protein composition, minor differences became obvious only between vintages but not between the stressed and watered samples. In-solution digest of proteins from Riesling grapes 2008 followed by LC-MSn and database research identified 15 proteins originating from grapes and 10 from the yeast Saccharomyces cerevisiae. In conclusion, our study demonstrates the importance to develop new strategies to prevent increased haze formation in wine under the predicted conditions of climate change. Prevention of drought stress by drip irrigation can be considered as one strategy to decrease protein amounts in wines.

The production of rhubarb juices, nectars, spritzers, and rhubarb wines is a growing market. The aim of this work was the chemical characterisation of nine monovarietal rhubarb juices from six different varieties and different vintages. The juice yields after pressing were consistently high between 80 and 90 % (kg juice/100 kg mash). The soluble solids were between 2.73 and 4.05 (o)Brix. Total sugar differed in a wide range (6.5-18.8 g/L); the sugar fraction was consisting of glucose (2.9-8.5 g/L), fructose (2.9-8.8 g/L) and minor amounts of sucrose (0.4-1.7 g/L). Main organic acids were malic acid (10.9-16.9 g/L), oxalic acid (3.0-7.6 g/L), and citric acid (0.7-2.2 g/L). Potassium was the mineral with the highest concentrations (2814-3895 mg/L). Also magnesium concentrations were comparably high and ranged from 53 to 136 mg/L. In contrast to other fruit and vegetable juices rhubarb juices contained no calcium, because exceeding oxalic acid precipitated rapidly with calcium to insoluble calcium oxalate. Particularly the natural sodium values are very high in comparison to other fruit and vegetable juices (5-202, mean 51 mg/L). Other striking parameters were chloride (139535 mg/L) and nitrate (341-1544 mg/L). Total polyphenols ranged from 219-459 mg/L, the antioxidant capacity from 2.6-5.5 mmol/L Trolox. Naturally occuring ascorbic acid was present in small amounts of 1067 mg/L. Flavanols (catechin, procyanidins B1, B2, C1) were present in concentrations from 17-63 mg/L, flavonols from 8-19 mg/L. Quercetin-3-rutinoside was the major flavonol. Special emphasis was given to the determination of anthocyanins in skins and flesh. Main anthocyanins were delphinidin-3-rutinoside, cyanidin-3-glucoside, and cyanidin-3-rutinoside; delphinidin-3-glucoside and carboxypyrano-cyanidin-3-rutinoside were only found in trace amounts. Highest concentrations were found in the skins (320-1286 mg/kg) whereas in the flesh the amounts were substantially lower (0-63 mg/kg). The pasteurised juices contained 11-40 mg/L anthocyanins.

Polysaccharides are the major high-molecular weight components of wines. In contrast, proteins occur only in small amounts in wine, but contribute to haze formation. The detailed mechanism of aggregation of these proteins, especially in combination with other wine components, remains unclear. This study demonstrates the different aggregation behavior between a buffer and a model wine system by dynamic light scattering. Arabinogalactan-protein, for example, shows an increased aggregation in the model wine system, while in the buffer system a reducing effect is observed. Thus, we could show the importance to examine the behavior of wine additives under conditions close to reality, instead of simpler buffer systems. Additional experiments on melting points of wine proteins reveal that only some isoforms of thaumatin-like proteins and chitinases are involved in haze formation. We can confirm interactions between polysaccharides and proteins, but none of these polysaccharides is able to prevent haze in wine.

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

Anthocyanins (ACN) can exert beneficial health effects not only through their antioxidative potential but also through modulation of inflammatory parameters that play a major role in CVD. A randomised cross-over study was carried out to investigate the effects of ACN-rich beverage ingestion on oxidation- and inflammation-related parameters in thirty healthy female volunteers. The participants consumed 330 ml of beverages (placebo, juice and smoothie with 8·9 (sd 0·3), 983·7 (sd 37) and 840·9 (sd 10) mg/l ACN, respectively) over 14 d. Before and after each intervention, blood and 24 h urine samples were collected. Plasma superoxide dismutase (SOD) and catalase activities increased significantly after ACN-rich beverage ingestion (P< 0·001), whereas after placebo juice ingestion no increase could be observed. Plasma glutathione peroxidase and erythrocyte SOD activities were not affected. An increase in Trolox equivalent antioxidant capacity could also be observed after juice (P< 0·001) and smoothie (P< 0·01) ingestion. The plasma and urinary concentrations of malondialdehyde decreased after ACN-rich beverage ingestion (P< 0·001), whereas those of 8-OH-2-deoxyguanosine as well as inflammation-related parameters (IL-2, -6, -8 and -10, C-reactive peptide, soluble cluster of differentiation 40 ligand, TNF-α, monocyte chemoattractant protein-1 and soluble cell adhesion molecules) were not affected. Thus, ingestion of ACN-rich beverages improves antioxidant enzyme activities and plasma antioxidant capacity, thus protecting the body against oxidative stress, a hallmark of ongoing atherosclerosis.

Gum Arabic (GA) is a popular wine additive. Due to its compositional and structural similarity to native grape cell wall arabinogalactans occurring in wine, the chemical proof of a GA addition is difficult. A method for its identification based on the colloid composition and multi-element (H, O and N, C) stable isotope analysis of the colloids was developed. For this purpose, the colloids from non-spiked, authentic (control) and spiked (300 mg l−1 GA) German white wines were isolated and analyzed for their monosaccharide composition. An addition of 300 mg l−1 GA changed the monomer sugar composition of the colloids. Particularly, l-arabinose, d-galactose, d-mannose and d-glucuronic acid were affected. Additionally, the oxygen stable isotope ratios of the isolated polysaccharides were shifted. Principle component analysis indicated the grouping of treated and untreated samples with 300 mg l−1 GA. The groupings were influenced by the content of l-arabinose and d-galactose, colloid content, monosaccharide content, monosaccharide composition and the δ18O values. It could also be concluded that a high content of l-arabinose and d-galactose was accompanied with a lower content of d-mannose. The control samples were only influenced by a significantly higher d-mannose content.

Protective properties of moderate wine consumption against cancers, cardiovascular, metabolic and degenerative diseases have been reported in various clinical studies. Here, we analysed the effect of red wine (RW) and white wine (WW) on myelination using an in vitro embryonic co-culture mouse model. The total amount of myelin was found to be significantly increased after RW and WW treatment, while only RW significantly increased the number of internodes. Both types of wine increased rat Schwann cell- (rSC) expression of the NAD+-dependent deacetylase sirtuin-two-homolog 2 (Sirt2), a protein known to be involved in myelination. Detailed chemical analysis of RW revealed a broad spectrum of anthocyanins, piceids, and phenolics, including resveratrol (RSV). In our assay system RSV in low concentrations induced myelination. Furthermore RSV raised intracellular glutathione concentrations in rSCs and in co-cultures and therefore augmented antioxidant capacity. We conclude that wine promotes myelination in a rodent in vitro model by controlling intracellular metabolism and SC plasticity. During this process, RSV exhibits protective properties; however, the fostering effect on myelinaton during exposure to wine appears to be a complex interaction of various compounds.

For more than a decade, Fourier-transform infrared (FTIR) spectroscopy combined with partial least squares (PLS) regression has been used as a fast and reliable method for simultaneous estimation of multiple parameters in wine. In this study, different FTIR instruments (single bounce attenuated total reflection, transmission with variable and defined pathlength) and different variable selection techniques (full spectrum PLS, genetic algorithm PLS, interval PLS, principal variable PLS) were compared on an identical sample set of international wines and ten wine parameters. Results suggest that the single bounce attenuated total reflection technique is well suited for the analysis of ethanol, relative density and sugars, but less accurate in the analysis of organic acid content. The transmission instrument with variable pathlength shows good validation results for the analysis of organic acids, but less accurate results for the analysis of ethanol and relative density as compared to the other instruments. The transmission instrument with defined pathlength was well suited for the analysis for all parameters investigated in this study. Variable selection improved model robustness and calibration results, with genetic algorithm PLS being the most effective technique.

A simple and effective processing method for rhubarb stalks including washing, comminution in a perforated disk mill followed by immediate dejuicing of the mash is presented. Rhubarb is an easy to process vegetable which does not necessarily need a special mash treatment like enzymation or heating to get high juice yields. The chemical composition of rhubarb juice is characterised by a low relative density and low Brix (4-4.8 degrees Brix), due to a low sugar content (about 12 g/l), whereas the total acidity is high (about 17 g/l). The major acid is malic acid, followed by oxalic acid and citric acid. The polyphenol content and the antioxidative capacity (TEAC) is relatively low; the same holds for anthocyanins (11.3-14.8 mg/l) which are consisting of cyanidin-3-rutinoside and small amounts of cyaniding-3-glucoside and delphinidin-3-rutinoside. Rhubarb juice contains a high amount of minerals, esp. potassium (up to 4000 mg/l), and magnesium (average 100 mg/l), whereas calcium is not present due to precipitation with oxalic acid. As is the case for some other vegetables juices, rhubarb juice contains high concentrations of nitrate (about 850 mg/l). (C) 2012 Elsevier Ltd. All rights reserved.