Antioxidant activity, total phenolics content, anthocyanin, and color stability of isotonic model beverages colored with Andes berry (Rubus glaucus Benth) anthocyanin powder

The stability of anthocyanin (ACN) freeze-dried powders from Andes berry (Rubus glaucus Benth) as affected by storage, addition of maltodextrin as a carrier agent, and illumination was evaluated in isotonic model beverages. The ethanolic ACN extract was freeze dried with and without maltodextrin DE 20. Isotonic model beverages were colored with freeze-dried ACN powder (FDA), freeze-dried ACN powder with maltodextrin (MFDA), and red nr 40. Beverages were stored in the dark and under the effect of illumination. Half life of the ACNs, changes in color, total phenolics content (TPC), and antioxidant activity were analyzed for 71 d. Addition of maltodextrin and absence of light stabilized the color of beverages and improved ACN and TPC stability during storage. The antioxidant activity of the beverages was higher when they were colored with MFDA and highly correlated with ACN content. There was no correlation between antioxidant activity and TPC. It is concluded that addition of maltodextrin DE 20 as a carrier agent during freeze-drying improves the color and stability of nutraceutical antioxidants present in Andes berry extract. This suggests a protective enclosing of ACNs within a maltodextrin matrix with a resulting powder that could serve as a supplement or additive to naturally color and to enhance the antioxidant capacity of isotonic beverages.     

Mechanical α-relaxations and stickiness of milk solids/maltodextrin systems around glass transition

BACKGROUND: Stickiness correlates with changes in mechanical α‐relaxation properties and often results from glass transition and plasticisation of amorphous food components. In this study, milk solids with maltodextrins with different dextrose equivalents (DE9 and DE17) were analysed for glass transition (T_g), α‐relaxation (T_α) and sticky point (SPT) temperatures using differential scanning calorimetry, dynamic mechanical analysis and a sticky point test respectively. RESULTS: At the same maltodextrin contents, T_g and T_α were lower for milk solids with the higher‐DE maltodextrin. Increasing maltodextrin contents gave T_g, T_α and SPT at higher temperatures, and the magnitudes of α‐relaxations with high maltodextrin (DE9 and DE17) contents were less pronounced. CONCLUSION: Stickiness was governed by glass transition and affected by skim milk/maltodextrin composition. Stickiness was reduced with increasing maltodextrin content as a result of maltodextrin miscibility with skim milk solids, particularly lactose, which changed the relaxation behaviour above the glass transition. The mixes of milk solids with low‐DE maltodextrin may show improved dehydration characteristics and powder stability resulting from increased T_g, T_α and SPT. Copyright © 2011 Society of Chemical Industry     

Quantitation of the odour-active compounds in Andes berry (Rubus glaucus Benth) fruit using the molecular sensory approach

The odour-active volatiles of Andes berry fruit (Rubus glacus Benth) were isolated by solvent-assisted flavour evaporation. Subsequent gas chromatography–olfactometry and gas chromatography coupled to mass spectrometry analyses and application of stable isotopic dilution analyses allow identifying 2-heptanol and ethyl butanoate as key aroma compounds in this fruit. Other relevant odorants were 4-hydroxy-2,5-dimethyl-3(2H)-furanone and ethyl benzoate, because of their contribution to the overall Andes berry aroma (high OAVs).     

Parameter optimization for spray-drying microencapsulation of jaboticaba (Myrciaria jaboticaba) peel extracts using simultaneous analysis of responses

The present study aimed to conduct a simultaneous optimization of different carrier agents and temperatures for the production of jaboticaba extracts by spray-drying microencapsulation. The 30% maltodextrin (control), 25% arabic gum + 5% maltodextrin and 25% Capsul™ + 5% maltodextrin carriers were used at air-drying inlet temperatures of 140, 160 and 180 °C. The following responses were evaluated: anthocyanin retention (AR), moisture content (MC), total solids (TS), hygroscopicity (H), overall color difference and antioxidant activity. Scanning electron microscopy (SEM) analysis was also performed. The AR, MC, H and overall color difference parameters were selected for simultaneous optimization by the desirability approach. The results showed that the highest desirability (0.7–0.8) was achieved when 30% maltodextrin was used at 180 °C. According to the SEM analysis, the use of maltodextrin and gum arabic allowed for the formation of more homogeneous particles, which is recommended in spray-drying microencapsulation.     

Glass transition temperatures and some physical and sensory changes in stored spray-dried encapsulated flavors

Commercial spray-dried powder flavors (strawberry and orange) encapsulated in different amorphous matrices (maltodextrin and maltodextrin-sucrose) were stored for 20 days under constant relative humidities of 32%, 43%, 58% and 75%. Glass transition temperatures (T_g) of the different powders and maltodextrin DE 12 were measured using differential scanning calorimetry (DSC). Caking/collapse visual observations and aroma strength (measured by a trained sensory panel) were recorded and correlated with the glass transition temperature of the different spary-dried flavors. Glass transition data explained collapse occurrence and loss of aroma strength in encapsulated strawberry and orange flavors after storage at various relative humidities.The presence of sucrose in the carrier formulation negatively affects storage stability of the encapsulated flavor.     

New Insights in the Use of Trehalose and Modified Starches for the Encapsulation of Orange Essential Oil

During the encapsulation of aromas by spray-drying, some volatile components may be lost; consequently, the sensory profile could be modified in the final product. Therefore, the selection of the carrier matrix for the encapsulation is crucial to obtain high aroma retention and long shelf-life stability, reduce aroma oxidation and increase physical stability of the powder. With the aim of studying the use of trehalose for the encapsulation of orange essential oil, emulsions were prepared containing mixtures of trehalose–maltodextrin (TMD) and sucrose–maltodextrin (SMD). Two modified starches were used as emulsifiers. The emulsions were spray-dried and stored at 25 and 37 °C. The aroma retention was evaluated using head space–solid phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC-MS) and by sensory evaluation. In addition, some physical properties of orange essential oil powders, such as water sorption and glass transition temperature (T _g), were determined. The sensory profiles obtained for TMD and SMD were different: TMD formulations retained mainly limonene, while SMD retained mostly α-pinene and myrcene. The modified starches (Capsul and Hi Cap) used as emulsifiers also affected the retention of certain volatiles. Therefore, the selection of components in the carrier matrix is relevant to the retention of aromas in orange oil powders. Regarding the physical properties, TMD formulations presented better characteristics in comparison to SMD, particularly due to the higher T _g values. The high aroma retention levels and the good physical characteristics are promising results in relation to the inclusion of the developed formulations in dehydrated citric juices.     

Effect of grape pre-drying and static pomace contact on physicochemical properties and sensory acceptance of Brazilian (Bordô and Isabel) red wines

Wine quality is evaluated by sensory attributes and physicochemical properties whose relationship is intensely investigated. This work aimed to analyze the physicochemical properties and sensory attributes of wines from Bordô and Isabel American grapes elaborated by a traditional and two novel winemaking processes: pre-drying and submerged static pomace. It was possible to observe significant differences between the samples in all physicochemical properties (P < 0.001), except in volatile acidity. Bordô and Isabel pre-drying wines presented the highest values of dry extract (43.00 and 33.66 g L^?1) in comparison with the other wines which presented dry extract below 30 g L^?1. Furthermore, pre-drying wines showed the highest phenolic content (1340.80 and 908.80 mg L^?1) in comparison with static pomace (998.02 and 433.46 mg L^?1) and traditional treatments (983.96 and 560.26 mg L^?1). Sensory analysis showed significant differences between the samples in all attributes, except in appearance acceptance. Cluster analysis and multidimensional scaling was successfully applied and allowed to observe the relationship between physicochemical properties and sensory attributes. Total phenolic content and color indexes were associated with the appearance of wines, as well as alcohol content and acidity on aroma. The results also revealed the connection between dry extract and total and reducing sugars with the body of wines from innovative vinification. The flavor was associated with several physicochemical properties and also influenced the global acceptance of the samples. The innovative wines showed great acceptance in all sensory attributes, and the employment of these treatments on an industrial scale should be considered once providing wines with unique characteristics.     

Stable Isotope Ratios and Aroma Profile Changes Induced Due to Innovative Wine Dealcoholisation Approaches

The high ethanol level in wine has become an important issue for all the main wine producing countries. Several techniques are available to the wine industry to reduce the ethanol content; among them, the membrane contactors are certainly one of the newest. Very few studies on the effect of this practice on the wine quality and aroma profile and on the stable isotopes composition are available. A pilot and industrial plant equipped with the membrane contactor system were used in the study in the dealcoholisation on several white and red wines. Significant changes for several classes of aroma compounds in both pilot- and industrial-scale experiments were observed, even though these changes were not always in perfect agreement with the sensory evaluation carried out. Finally, modifications on the δ¹⁸O of up to 1?‰ for 2 %?v/v and of up to 4?‰ for 8 %?v/v ethanol removal were encountered. An increase of δ¹³C of ethanol of up to 1.1?‰ for 2 % and of up to 2.3?‰ for 4 % of dealcoholisation rate was also observed. Dealcoholisation via membrane contactor seemed to affect the overall wine composition (aroma and flavour), even though the main concern resided on the alteration of the isotopic composition which could be linked to product authenticity issues.     

Water Adsorption and Glass Transition of Spray-Dried Soy Sauce Powders Using Maltodextrins as Carrier

Moisture adsorption isotherm and glass transition temperature of various spray-dried soy sauce powders containing different types and concentrations of maltodextrins were studied and compared. Maltodextrins of dextrose equivalent (DE)?=?5, DE?=?10 and DE?=?15, respectively, with concentrations of 20 or 40 % (w/v) were used as carrier agents. The equilibrium moisture content was reduced with increased maltodextrin concentration, whereas it was not apparently influenced by the value of maltodextrin DE. Both the Brunauer–Emmett–Teller (BET) and Guggenheim–Anderson–de Boer (GAB) models could be applied to simulate the moisture adsorption behaviour of the soy sauce powders. The monolayer moisture content of the powders was determined by fitting experimental data to the BET/GAB models with a _w up to 0.53, although both models could fit satisfactorily with the experimental data to a higher water activity level_. The glass transition temperatures (T _g) of the powders equilibrated under various water activities were determined using a differential scanning calorimeter. Increasing moisture adsorption of the soy sauce powders resulted in a T _g reduction, and the experimental T _g values fitted the Gordon–Taylor model well. The BET and Gordon–Taylor models were applied together to predict the critical moisture contents (i.e. 0.0464–0.0777 g water/g dry matter) and water activities (i.e. 0.032–0.241), above which the soy sauce powders become vulnerable to degradation and changes in their physicochemical properties.     

Degradation Kinetics and Storage Stability of Vacuum Spray-Dried Micro Wet-Milled Orange Juice (<Emphasis Type="Italic">Citrus unshiu</Emphasis>) Powder

The aim of this work was to evaluate the degradation kinetics and stability of micro wet milled orange juice powders obtained by vacuum spray drying, using maltodextrin as a carrier agent. Powders were produced with four combinations of orange juice solids/maltodextrin solids 60:40, 50:50, 40:60, and 30:70 by weight. Ascorbic acid degradation, color, and antioxidant activity of powders were evaluated throughout 90 days. Powders were stored at 10, 25, and 35 °C and relative humidity of 33%. Temperature and storage time negatively influenced the stability of ascorbic acid and color, whereas antioxidant activity increased at the beginning of storage at a higher temperature then decreased slightly after 60 days. For stability study, powders were stored at different water activities (0.11 to 0.84) in order to determine the plasticizing effects of water on glass transition temperature. Both water activity and glass transition temperature were used to predict the critical conditions for storage. Vacuum spray dried powder produced with a ratio of 30:70 (orange juice solids/maltodextrin solids) was considered as the most stable, since it showed highest critical water activity (a_w?=?0.61) and lowest moisture content (0.11 g water/g of dry solid) among the four powders. Vacuum spray drying using superheated steam as the heating medium was proven to be an effective way of producing orange juice powders with minimum loss of nutrients.     

Chemical characterisation of anthocyanins in tamarillo (Solanum betaceum Cav.) and Andes berry (Rubus glaucus Benth.) fruits

The anthocyanin composition of tamarillo (Solanum betaceum Cav., red variety) and Andes berry (Rubus glaucus Benth.) was determined by HPLC–PDA and HPLC–ESIMS. From the anthocyanin-rich extracts (AREs), pure compounds (1–7) were obtained by MLCCC (multilayer countercurrent chromatography) and further preparative HPLC, and their unequivocal structures were obtained by 1D and 2D NMR analyses. The new anthocyanin delphinidin 3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside-3′-O-β-d-glucopyranoside, as well as the known cyanidin-3-O-rutinoside, pelargonidin-3-O-rutinoside, and delphinidin-3-O-rutinoside were identified as constituents of tamarillo fruit. Although the anthocyanin composition of Andes berry had been reported before in the literature, the unequivocal structure elucidation of the major compound, cyanidin-3-O-α-l-rhamnopyranosyl-(1 → 6)-O-β-d-xylopyranosyl-(1 → 2)-β-d-glucopyranoside, was achieved for the first time.     

Effect of Addition of Native Agave Fructans on Spray-Dried Chayote (<Emphasis Type="Italic">Sechium edule</Emphasis>) and Pineapple (<Emphasis Type="Italic">Ananas comosus</Emphasis>) Juices: Rheology,Microstructure, and Water Sorption

The effect of the combination of maltodextrin DE 10 (MD) and native agave fructans (FR) in concentrations of 0, 2, and 4% (w/v) on the rheological properties, microstructure, and water sorption of spray-dried chayote and pineapple powders was evaluated. A 10% (w/v) maltodextrin treatment was used as a control to compare treatments added with fructans. The scanning electron micrographs revealed spherical particles in a range from 16 to 105 μm with shrinkage, whereby greater caking and agglomeration occurred among particles in treatments with native agave fructans. The flow behavior of all juices can be described by the Bingham model with low plastic viscosities (0.0026 to 0.0030 Pa s^?1); the isotherms of the powders show a sigmoid shape pointing to the easy union of the fructans with water molecules. These types of isotherms are common for non-porous foods, and are indicative of physical adsorption in multi-layers where the adsorbate conserves its identity.     

Rheological properties and stability of oil-in-water emulsions containing tapioca maltodextrin in the aqueous phase

The present research focuses on the effect of the concentration and dextrose equivalent (DE) values of tapioca maltodextrin in the aqueous phase on rheological behavior and stability of oil-in-water emulsions prepared with Tween80. The critical flocculation concentrations (CFCs) of oil-in-water emulsions containing tapioca maltodextrin with DE of 16 (DE16), 12 (DE12) and 9 (DE9) were 11%, 9% and 7% (w/w) respectively, as revealed by transmittance measurement. Coalescence was observed as maltodextrin concentration increased above the CFC. The rheological parameters of flow behavior index (n) and consistency index (k) have been well-described by the Herschel–Bulkley model. The relative consistency index (k_relative) increased markedly when the concentration of maltodextrin exceeded the CFC because of depleting flocculation. The consistency index (k_emulsion) and yield stress (τ₀) of emulsions containing tapioca maltodextrin increased with increasing maltodextrin concentration or decreasing DE. The emulsions containing maltodextrin showed Newtonian flow behavior when the maltodextrin concentration was below the CFC. At maltodextrin concentrations above the CFC, emulsions containing maltodextrin exhibited shear thinning behavior. An increase in the maltodextrin concentration resulted in a decrease in the n_emulsion until maltodextrin concentration reached 20% (w/w) for DE9, DE12 and 25% (w/w) for DE16. Further increase in the maltodextrin concentration resulted in an increased the n_emulsion because of predominant influence of the continuous phase.     

Spray-Drying of Probiotic Cashew Apple Juice

Data on spray-drying of fruit juices containing probiotic bacteria are scarce. The main challenge is to avoid the viability losses of the microorganism during drying and storage. In the presented study, the dehydration by spray-drying of cashew apple juice containing Lactobacillus casei NRRL B-442, and the influence of the storage temperature (25 and 4 °C) on the viability of L. casei NRRL B-442 and on the physical properties of the powder during 35 days of storage were evaluated. Probiotic cashew apple juice was dehydrated according to the following conditions: inlet temperature of the drying air (120 °C), feed flow rate of juice (0.3 L/h), hot air flow (3.0 m³/min), and pressurized air flow (30 L/min). The outlet temperature was 75 °C. The carriers used were 20 % (w/v) maltodextrin or 10 % (w/v) maltodextrin + 10 % (w/v) gum arabic. Microbial survival rates higher than 90 % were obtained for the powder stored at 4 °C for 35 days (both carriers) and higher than 70 % up to 21 days for the powder obtained using only maltodextrin at 25 °C. Higher yields were obtained only by maltodextrin which was used as carrier (72 %) compared to the yield obtained when the mixture of maltodextrin and gum arabic was applied (60 %). The water activity was kept low (Aw?<?0.30) during the storage, and the characteristic color of the product was maintained.     

Influence of harvest year and harvest time on soluble solids,titrateable acid,anthocyanin content and aroma components in sour cherry <Emphasis Type="Italic">(Prunus cerasus L. cv. "Stevnsbær")</Emphasis>

Sour cherries (Prunus cerasus L.) cv "Stevnsbær" were harvested 7-10 times per year for 3 years and the quality of the fruits was evaluated by analysing soluble solids, titrateable acid, anthocyanin and aroma content. The content of soluble solids and anthocyanin showed a characteristic pattern during the harvest season with a maximum content in the middle of the harvest season. The acid content decreased in the last part of the harvest season. There were large differences in the content of soluble solids, acid and anthocyanin between years, which to some extend could be related to the weather in the 3 years with low concentrations in the cold and rainy year. The maximum soluble solid content varied from 19% to 29% within the 3 years. There were no clear tendencies in the development of aroma components during the harvest season. The four important aroma components benzaldehyde, benzyl alcohol, eugenol and vanillin showed differences from year to year and there was a tendency to low concentrations in the cold and rainy year.     

Effect of dextrose equivalency of maltodextrin together with Arabic gum on properties of encapsulated beetroot juice

Maltodextrin (MD) with a dextrose equivalency of 10 and 20 (10DE and 20DE) and Arabic gum (AG) were used as encapsulating materials for beetroot juice by spray drying. The produced encapsulates were evaluated in terms of encapsulation yield, moisture content, hygroscopicity, bulk density, color parameters (L^*, a^*, b^* and TCD), radical scavenging activity (RSA), total phenolic content (TPC) and betalain content. The binary blend of encapsulating material significantly (P < 0.05) affected the studied responses. The highest bulk density (0.549 g/mL) was observed in encapsulates based on MD (20DE) as the encapsulating material. A highest encapsulating yield of 73.27 % and a redness (a^*-value) of 39.03 was referred to the formulation of MD (DE10) and AG. Formulation with MD (20DE) and MD (DE20) + AG kept better retention of functional assets (RSA and TPC) in microencapsulates produced. The increase in the value of betalain content (208.06 mg/100 g dm) was well correlated with redness (a^*-value). The studied responses ties of all encapsulate produced with formulation MD (DE10) + AG was found to be satisfactory with an exception for their lower bulk density.     

Effect of postharvest dehydration on the composition of pinot noir grapes (Vitis vinifera L.) and wine

This study was conducted in order to improve our understanding of how phenolics and aroma compounds change in wine grapes during postharvest dehydration. Pinot noir grapes grown in the Willamette Valley of Oregon were harvested at 22.0 and 24.0 °Brix. Grapes harvested at 22.0 °Brix were divided into three equal lots with one lot immediately used for wine production, and the remaining two lots placed inside an air tunnel with an air speed of 1.0–1.8 m s⁻¹, 38% relative humidity and a temperature of 22 °C. The soluble solids content and weight loss were measured daily and wines were made from grapes when they reached 24.8 and 26.7 °Brix. The soluble solids of grapes increased about 1 °Brix per day; therefore, on the third and fourth day the berries reached the desired concentration; weight loss was 14 and 16%, respectively. Results from berry phenolic analysis indicated that per berry anthocyanin amount remained unchanged during dehydration. The composition of proanthocyanidins isolated from berries changed during dehydration. Volatile compounds in wines made from dehydrated grapes contained more terpenes and norisoprenoids (β-ionone, β-damascenone) when compared to wine made from the original fruit. Wines made from increasingly dehydrated grapes tended to resemble the composition and flavour profile of wines made from grapes left on the vine (i.e. with extended ripening). The results of this study suggest that postharvest flavour changes consistent with changes during fruit ripening can occur in grapes when harvested early and allowed to dehydrate under controlled conditions prior to fermentation.     

Anthocyanin profile in berry skins and fermenting must/wine, as affected by grape ripeness level of Vitis vinifera cv. Shiraz/R99

The release of anthocyanin compounds from berry skins into the wine is affected by several viticulture and oenological practices. Ripeness level seems to play a significant role. The study aimed to evaluate the extraction kinetics of individual anthocyanins from grape skins into wine under controlled conditions of small-scale vinification of Shiraz grapes, harvested at three ripeness levels (23, 25 and 28°Brix). The anthocyanin profile of intact berry skins, fermenting musts/wines and crushed skins during the period between crushing and pressing was analysed by HPLC. Ripeness level greatly impacted on the skin?/?juice ratio (ranging from 169?± 4.5?g?L^?1 at 23°B, 185?±?7.2?g?L^?1 at 25°B and 256?±?10.7?g?L^?1 at 28°B) and on grape anthocyanin concentration (ranging from 0.80?±?0.13?g?kg^?1 at 23°B, 0.78?±?0.07?g?kg^?1 at 25°B and 1.21?±?0.13?g?kg^?1 at 28°B) and profile (%) at harvest. In addition, it affected the rate and amount of individual anthocyanin extraction from skins into wine and their transformation during fermentation, consistent with the relevant chemical group classification (3-glucoside, 3-acetyl-glucoside, 3-p-coumaroyl-glucoside). At pressing, the anthocyanin concentration of the three wines was similar (319?mg?L^?1, on average), but the anthocyanin profile was different, particularly the ratio of 3-glucoside?/?3-p-coumaroyl-glucoside derivatives, which was on average 3.55 at 23°B and 25°B and 2.6 at 28°B. Viticultural choices, such as to harvest earlier or later, influencing the chemical and physical composition of the berries, may influence the extraction kinetics of individual anthocyanins and their destiny in the fermenting must, offering to winemakers different basic wines suitable for the production of different wine products. These findings are valuable to improve viticultural and oenological practices for Shiraz wine production, allowing the improvement of wine quality and the purposeful creation of different styles of wine.     

Anthocyanin Profiling Method Based on Isocratic Elution for Comparable Speed,Reproducibility, and Quantitation with Gradient Elution

The present work aims at developing a simple and rapid method for the quantification of anthocyanins irrespective of acylation present or not. The proposed analytical approach is based on isocratic elution mode in order to avoid the complexity of gradient elution system. The optimal conditions for the separation of anthocyanins were obtained as 14 % acetonitrile in water containing 2 % trifluroacetic acid with a flow rate of 0.6 ml min^?1 when analyzed in Syzygium cumini (Jamun) anthocyanins. The method was successfully separated eight anthocyanins present in Jamun using C₁₈ column as a stationary phase. Anthocyanins characterization was done by using electrospray ionization mass spectrometry (ESI-MS). LOD and LOQ value was calculated based on signal-to-noise ratio (S/N ratio) and ordinary least square regression (OLSR) approaches. LOD were obtained as 0.9, 0.4, and 0.3 μg ml^?1 by S/N ratio method and 0.27, 1.2, and 1.0 μg ml^?1unit by OLSR method for M₃-G, C₃-G and D₃-G, respectively. In the isocratic elution mode, critical pair resolution was 1.95 whereas it was 0.85 under the gradient elution mode. Interestingly, ratio of peak area and peak height in gradient and isocratic elution was virtually same for almost all the evaluated peaks. More importantly, the method was validated with other three sources of anthocyanins (black carrot, red cabbage, and berry) and found variable resolution and response. After analyzing all the data, it may be concluded that the proposed method is useful for separation and identification of anthocyanin irrespective of acylation present in it when the number of anthocyanin is ≤10.