Myrtle hydroalcoholic extracts obtained from different selections of Myrtus communis L.

Hydroalcoholic extracts obtained from myrtle berries of five different selections were studied to obtain unique clones. During the typical 40 day maceration period, dry matter, pH, colour, and anthocyanins, were analyzed. Variability among myrtle selections was observed both in fresh berries (yield berries/plant, weight of the berries, number and weight of seeds per berry) and in the hydroalcoholic extract physical–chemical characteristics (dry matter, colour intensity, tint and anthocyanins). Reversed-phase high performance liquid chromatography (RP-HPLC) analysis with photodiode array detection (PDA) was used for anthocyanins characterization in myrtle hydroalcoholic extracts. Anthocyanin qualitative composition was the same in all selections, but varied strongly in its total amount. D was the selection with the characteristics most suitable for industrial use.     

Characterisation of volatiles and polyphenols for quality assessment of alcoholic beverages prepared from Corsican Myrtus communis berries

In the present work, the essential oil compositions of Myrtus communis berries from ten Corsican localities were studied and no chemical variability was observed. HS–SPME, GC and GC/MS analysis were carried out for the characterisation of volatile fractions of M. communis berries and two derived commercial alcoholic beverages (liqueur and eau-de-vie). Quantitative variations due to the distillation process were observed between the two beverages. The volatile compositions of Corsican myrtle alcoholic products were characterised by high amounts of monoterpene hydrocarbons and oxygenated monoterpenes with α-pinene and 1,8-cineole as major components. The polyphenolic compositions of the berry extract and the liqueur were also established using HPLC–DAD and LC–MS–MS; high concentrations of flavonol glycosides, flavonols and flavanols were reported.     

Effect of maturation and cold storage on the organic acid composition of myrtle fruits

BACKGROUND: The effect of maturation and senescence on the chemical composition of two myrtle cultivars was studied in mature, overripe and cold‐stored fruits in order to find the most appropriate harvesting period and best storage technology for industrial purposes. RESULTS: After cold storage at 10 °C for 15 days, berry weight loss ranged from 12.5 to 18.4%, with the highest losses in less mature fruits. Titratable acidity decreased during maturation and cold storage in both cultivars. Reducing and total sugars increased during maturation. Anthocyanin concentration increased during maturation but decreased in overripe berries. The major organic acids in myrtle fruits were quinic, malic and gluconic acids. In fresh and cold‐stored fruits, malic acid rose to 3 g kg^?1 and decreased thereafter. Quinic acid peaked at 90 or 120 days after bloom and decreased thereafter to reach low concentrations in mature fruits. CONCLUSION: Cold storage for 15 days at 10 °C does not affect myrtle fruit quality for liqueur production. Anthocyanin concentration is the best indicator of harvest time for industrial purposes. Gluconic acid concentration is high in mature, overripe and cold‐stored berries. This parameter can be used as a marker of the onset of fruit senescence. Copyright © 2012 Society of Chemical Industry     

Evaluation of a simple and promising method for extraction of antioxidants from sea buckthorn (Hippophaë rhamnoides L.) berries: Pressurised solvent-free microwave assisted extraction

The pressurised solvent-free microwave assisted extraction (PSFME) technique has been developed and optimised for extraction of antioxidants from Hippophaë rhamnoides L. berries using a two-level full factorial design. The effects of factors (extraction time, irradiation power, number of cycles) and their first order interactions were evaluated from antioxidant activity of extracts using the 2,2′-diphenyl-1-picrylhydrazil (DPPH) free radical scavenging method, the ferric reducing ability of plasma (FRAP) assay, and the estimation of total phenolic content using the Folin–Ciocalteu method. The best extraction conditions were obtained, in a laboratory scale extractor of 50 mL filled with 4 g fresh berries, using a 1000 W microwave power applied during 50 s and repeated five cycles. PSFME was then compared to other common extraction techniques such as pressing, maceration and pressurised liquid extraction. It is appeared that PSFME leads to the most active and richest extract in phenolic content including molecules such as quercetin and isorhamnetin not extracted with other techniques. Furthermore PSFME respect green chemistry, it is rapid, cheap and does not need sample preparation and/or evaporation step.     

Determination of color, pigment, and phenolic stability in yogurt systems colored with nonacylated anthocyanins from Berberis boliviana L. as compared to other natural/synthetic colorants

ABSTRACT:  Anthocyanins are of interest to the food industry because of their antioxidant power, attractive color, and stability in high acid foods. Powder from the Peruvian berry Berberis boliviana Lechler, rich in nonacylated anthocyanins (7% to 8% dry weight), was incorporated into yogurt samples containing 3 different fat levels. Color (CIE L , a , b , chroma, and hue angle), pigment (monomeric anthocyanin and polymeric color), and total phenolics were monitored over 8 wk of storage and compared to yogurt treatments containing purple carrot acylated anthocyanins, red beet betalaines, or FD&C Red nr 40. Anthocyanin profiles were analyzed by HPLC coupled to photodiode array and mass detectors. Color of yogurt containing B. boliviana anthocyanins at 20 mg cyanidin-3-glucoside (cy-3-glu) equivalents/100 g yogurt ( L *= 65, chroma = 14, and hue angle = 335°) was similar to commercial blueberry yogurt ( L *= 65, chroma = 10.5, and hue angle = 341°). High color, pigment, and phenolic stability were observed in yogurts colored with B. boliviana , independent of the fat matrix. Acylated anthocyanins from purple carrot extracts exhibited increased stability with higher fat content. Anthocyanin degradation followed 1st-order kinetics. Pigment half-lives were 125 and 104 d for nonacylated anthocyanins at 10 and 20 mg cy-3-glu equivalents/100 g yogurt and 550.2, 232.6, and 128.9 d for acylated anthocyanins at 20 mg of cy-3-glu equivalents/100 g of 4%, 2%, and 0% fat yogurt. Addition of B. boliviana whole berry powder to yogurt matrices produced an attractive, stable anthocyanin-rich product, eliminating the need for industrial colorant extraction.     

Colour stability of canned strawberries using black carrot and elderberry juice concentrates as natural colourants

Besides texture degradation and aroma loss colour fading and browning of processed fruits, in particular strawberries, displaying comparatively low amounts of non-acylated anthocyanins, still pose a serious problem. Therefore, in the present study the colour of texture-improved canned strawberries was stabilised using commercial concentrates from black carrots and elderberries as natural colourants. CIE L ^* a ^* b ^* values of the fruit surface and of the brine solutions were monitored over a period of 24 weeks under light exposure. Furthermore, the contents of individual anthocyanins were analysed by HPLC-DAD. The colour of the processed control fruits (without added colourant) was unacceptable even at the beginning of the storage. Their anthocyanin contents were reduced by more than 85% at the end of the storage period. In contrast, the colour of canned strawberries containing black carrot and elderberry anthocyanins was significantly improved. Colour difference values ΔE ^* of black carrot-coloured strawberries were found to be smaller than those of the samples containing elderberry concentrate as a colourant. This could be ascribed to the presence of acylated anthocyanins in the first exhibiting exceptional storage stability, while all non-acylated pigments were degraded. The chill brining process for fruit firming markedly affected pigment stability, which can be attributed to enzymes that are still active at cold storage conditions.     

Anthocyanins,Antioxidative, and Antimicrobial Properties of American Cranberry (Vaccinium macrocarpon Ait.) and their Press Cakes

ABSTRACT: Amounts of total phenolics, anthocyanins, and ascorbic acid in 4 American cranberry varieties harvested at 4 stages of maturity were measured. The larger amount of phenolic compounds was found in berries of “Black Veil” cultivar (504 mg/100 g) at II stage of maturity. Significantly larger amounts of anthocyanins were determined in the overripe berries of the cultivars “Ben Lear” and “Black Veil.” The amount of ascorbic acid in berries increased during ripening from I to III stage, and slightly decreased in the overripe berries. The biggest quantities of ascorbic acid were found in the ripe berries of “Ben Lear” cultivar (15.8 mg/100 g). The distribution of anthocyanins pigments was determined by HPLC‐UV/MS in mature berries. The composition of individual anthocyanins in berries was quite similar in all the studied cranberry cultivars. While skins of cranberries are rich in anthocyanins and other phenolic compounds, the extracts of the by‐products of cranberries juice—berry cakes, were analyzed and obtained results were compared with the properties of extracts made from whole berries. The anthocyanins and total phenolics content, radical scavenging activity, antimicrobial activity of the whole berries, and their press cakes extracts were measured. All investigated extracts from berries and their press cakes showed good radical scavenging activity and revealed antimicrobial properties. It was found that Bacillus cereus (ATCC 10876) and Micrococcus luteus (ATCC 9341) were the most sensitive among 10 tested Gram‐negative and Gram‐positive bacteria.     

Optimization on anthocyanins extraction from wine grape skins using orthogonal test design

To optimize the extraction of anthocyanins from grape skins, orthogonal test with 4 factors and 3 levels was designed and the analysis of extracts was conducted using high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The results showed that the optimal extraction for obtaining the highest amounts of anthocyanins was carried out by formic acid/methanol solvent (5/95, v/v), with ultrasonication for 10 min, extraction temperature at 25°C, and extraction time for 1.5 hr. The precision and accuracy of this method were established. This work will provide a basis for further study involving in anthocyanins of grape berries.     

Ultrasound‐assisted extraction and characterization of anthocyanins from purple corn bran

Purple corn is abundant in anthocyanins, which has attractive colors and potential applications in beneficial health. This study aimed to determine the optimal ultrasound‐assisted extraction conditions for purple corn anthocyanins (PCA), and to confirm the anthocyanins from purple corn bran extracts by HPLC‐DAD‐ESI‐MS/MS. Ultrasonic‐assisted extraction (UAE) is more time‐efficient by comparison of traditional extraction. Meanwhile extraction with corn bran could save the consumption of extractant and improve the extraction yield. The optimal UAE conditions were obtained with the extraction time 35 min, the ultrasonic times 90, solid–liquid ratio 1:8, and the ultrasonic power 400 W. At these conditions, total anthocyanins content was determined as 3.625 ± 0.105 g kg^?1, and the extraction yield was 92.45%. The HPLC/MS‐MS results showed that the purple corn bran extracts consisted of six kinds of anthocyanins.

Practical applications

Purple corn is abundant in anthocyanins, which has potential applications in beneficial health, such as antioxidants. The purpose of this study was to find the optimal UAE conditions for purple corn anthocyanins using ultrasound‐assisted extraction and identify the anthocyanins from the purple corn bran. The results of this study are suitable for the industrial production of purple corn anthocyanins.     

Color quality of Oregon strawberries--impact of genotype, composition, and processing

ABSTRACT:  This investigation was to evaluate fruit color and study the effect of processing on color quality of strawberry products. Three color instruments with different viewing angles, viewing areas, and sample presentation geometries were compared for their effectiveness in measuring CIE L *C* h ^o color values for fresh fruits of 6 strawberry genotypes. There were significant differences between genotypes as well as between instruments. Fruits from the Totem genotype were frozen, canned, and made into jam. Color changes were measured along with the following compositional determinations: total monomeric anthocyanins (ACN), total phenolic content (TPC), and percent polymeric color. ACN in fresh strawberries ranged from 37.1mg to 122.3 mg per 100 g of fresh fruit. Freezing resulted in an apparent increase in ACN and transfer of 70.2% of the anthocyanins from the berries into juice. Physical transfer of pigments to syrup also occurred with canning: there was approximately 70% loss in ACN, about 20% increase in polymeric color, and 23.5% decrease in TPC. Pronounced color change and substantial losses in ACN and TPC of strawberry jams occurred during processing and 9 wk of storage. Storage of jams at 38 °C compared to 21 °C over a period of 9 wk resulted in marked losses of ACN and TPC.     

Color evolution of aqueous solutions obtained by thermal processing of carrot (Daucus carota L.) roots: influence of light

ABSTRACT:  The color of aqueous solutions obtained by heating carrot ( Daucus carota L.) roots in water ("stocks") is different when the thermal treatment is applied with or without exposure to light. CIE L *, a *, and b * scale values of stocks processed for different times were recorded and 4 patterns were initially observed. To explain the 1st part of this evolution (patterns 1 and 2), pectin extraction and β-elimination in stocks were studied. Light dependence was investigated to explain patterns 3 and 4. A model with 2 compounds is proposed to explain all the color variations.     

Effect of enzyme‐aided pressing on anthocyanin yield and profiles in bilberry and blackcurrant juices

Bilberries (Vaccinium myrtillus) and blackcurrants (Ribes nigrum) were treated with extensive dosages of commercial cell wall degrading enzyme preparations, i.e. Econase CE, Pectinex Ultra SP‐L, Pectinex Smash, Pectinex BE 3‐L and Biopectinase CCM. The enzymes were dosed based on the polygalacturonase activity. The juice yield was improved in both berries as a result of the enzymatic treatment. The improvement was more pronounced with blackcurrants owing to their thicker cell walls. The impact of the enzymatic treatment on anthocyanins present in the juices was investigated using HPLC‐DAD. The enzyme preparations affected the contents and composition of anthocyanins in the juices. Pectinex Ultra SP‐L, Pectinex Smash, Pectinex BE 3‐L and Biopectinase CCM increased the total content of anthocyanins by 13–41% in the bilberry juices and by 18–29% in the blackcurrant juices. Econase CE, however, produced a dramatic decrease in the total anthocyanin content in the bilberry juice due to its enzyme profile, whereas no such effect was observed with the blackcurrant juice. All the enzyme mixtures tested produced a total or extensive loss of anthocyanidin galactosides in bilberry juice. Commercial enzyme preparations used in the production of berry juices can improve extraction of anthocyanins into the juice. However, they may effectively hydrolyse certain glycosides and thus affect the profile of extracted anthocyanins. Copyright © 2005 Society of Chemical Industry     

An enzyme-based extraction process for the purification and enrichment of vegetable proteins to be applied in bakery products

In the current study an efficient aqueous extraction procedure using glucoamylase was developed to produce food grade protein extracts from lentils and white beans. The extracts contained 50.3 ± 0.6 and 49.2 ± 0.05 g protein per 100 g dry extract, respectively. The nutritional value of lentil and white bean protein extracts proved to be satisfying according to the amino acid composition, where methionine was the limiting amino acid. The produced extracts were tested for their technological properties. Both lentil and white bean protein extracts showed similar or even better technological properties regarding foaming and emulsifying capacities, heat stability and gelling properties compared to soy and pea protein extracts. Food application tests in white bread, pound cake and sponge cake proved lentil and white bean protein extracts to be potential alternatives to soy protein in replacing proteins from animal origin.     

Improving the Extraction of Juice and Anthocyanins from Blueberry Fruits and Their By-products by Application of Pulsed Electric Fields

Pulsed electric field (PEF) treatments (1–10 kJ/kg at 3 kV/cm) were applied before pressing of blueberry fruits to improve the yield and quality of expressed juice as well as the recovery of anthocyanins from blueberry by-products (press cake) via solid–liquid extraction. A PEF pre-treatment at 1 kJ/kg was sufficient to significantly increase the juice yield (by 32%) with respect to the untreated sample. Higher energy input (10 kJ/kg) was most favorable for the largest increment of anthocyanin content (55%) and antioxidant capacity (36 and 41%, determined by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) assay, respectively) in juice. Extracts obtained from the press cake of PEF-treated blueberries at 10 kJ/kg possessed an anthocyanin content (75%) and antioxidant capacity (71 and 109%, determined by FRAP and DPPH assay, respectively) higher than that of the extracts obtained from non-treated berries press cake. HPLC analyses revealed the major classes of the detected anthocyanins as glycosides of delphinidin, cyanidin, petunidin, peonidin, and malvidin, and no significant degradation of individual anthocyanins due to PEF application was observed. The present PEF pre-treatment could be a promising approach to facilitate efficient extraction of juice and antioxidants especially anthocyanins from blueberry and their by-products.     

Chemical composition and antioxidant activities of Myrtus communis L. berries extracts

Myrtle (Myrtus communis L.) berries extracts were prepared with solvents at different polarity (water, ethanol, and ethyl acetate) and analysed using different in vitro tests in order to evaluate their antioxidant properties. Antiradical and total antioxidant activities were measured with DPPH and FRAP tests, respectively. Their ability to protect biological molecules was assessed using the cholesterol and LDL oxidation assays. In addition, phenolic compounds and unsaturated fatty acids composition was analysed by HPLC–DAD and HPLC–MS/MS. Ethanol and water extracts showed the highest amount of extracted compounds, but the highest antiradical and antioxidant activities were found in ethanol and ethyl acetate extracts. These extracts were also the ones with the highest content of phenolic compounds. In addition, our results showed a highly significant correlation between the amount of total phenols and antiradical (R² = 0.9993) or antioxidant activities (R² = 0.9985) in these extracts. HPLC–DAD and HPLC–MS analyses showed significant quantitative and qualitative differences among these three extracts. The ethyl acetate extract had the highest protective effect in assays of thermal (140 °C) cholesterol degradation and Cu²⁺-mediated LDL oxidation, inhibiting the reduction of polyunsaturated fatty acids and cholesterol, and the increase of their oxidative products. These results suggest that because of these properties, myrtle berries could be used in dietary supplements preparations or as food additives.     

Comparative antioxidant activity and 1H NMR profiling of Mediterranean fruit products

In this study the antioxidant activity of methanol extracts obtained from Mediterranean fruit products (prickly pear fruit jam and cream, myrtle berries jam, orange and mandarin-orange marmalades) was evaluated and compared in several in vitro models of oxidative stress. The compositional profile of methanol extracts (carbohydrates, organic acids, amino acids, and main phenolic compounds) was characterized by ¹H NMR spectroscopy and the total phenol content was estimated by the Folin–Ciocalteu procedure. All extracts showed protective effect against thermal-cholesterol degradation, strictly correlated to total phenols. Extracts from prickly pear cream and myrtle berries jam preserved liposomes from Cu^2 +-induced oxidation, inhibiting the reduction of polyunsaturated fatty acids and the increase of malondialdehyde. Extracts from prickly pear cream and citrus marmalades significantly reduced the reactive oxygen species generation induced by tert-butylhydroperoxide in Caco-2 cell culture. The results of this work qualify all tested Mediterranean fruit preserves as a good source of biologically active components with considerable antioxidant potential.     

Hyperspectral imaging for the investigation of quality deterioration in sliced mushrooms (Agaricus bisporus) during storage

In this study, the potential application of hyperspectral imaging (HSI) for quality prediction of white mushroom slices during storage at 4 °C and 15 °C was investigated. Mushroom slice quality was measured in terms of moisture content, colour (CIE Lightness, L* and yellowness, b*) and texture (hardness, H and chewiness, Ch). Hyperspectral images were obtained using a pushbroom line-scanning HSI instrument, operating in the wavelength range of 400–1,000 nm with spectroscopic resolution of 5 nm. Multiple linear regression (MLR) and Principal Component Regression (PCR) models were developed to investigate the relationship between reflectance and the various quality parameters measured. 20 optimal wavelengths for quality prediction were selected after performing an exhaustive search for the best subsets of predictor variables on a calibration set of 84 samples. PCR applied to the set of optimal wavelengths gave the best performance as compared to MLR and PCR on the entire wavelength range. When applied to an independent validation set of samples, PCR models developed on the calibration set were capable of predicting moisture content with RMSEP of 0.74% w.b. and R ² of 0.75, L* with RMSEP of 0.47 and R ² of 0.95, b* with RMSEP of 0.66 and R ² of 0.75, H with RMSEP of 0.49 N and R ² of 0.77 and Ch with RMSEP of 0.27 N and R ² of 0.72. Virtual images showing the distribution of moisture content on the mushroom surface were generated from the estimated PCR model. Results from this study could be used for the development of a non-destructive monitoring system for prediction of sliced mushroom quality.     

Enzyme‐assisted solvent extraction for extraction of blueberry anthocyanins and separation using resin adsorption combined with extraction technologies

Blueberry anthocyanins are the major active ingredients of blueberry with a variety of biological activities. The scale extraction and separation of blueberry anthocyanins could contribute to their application in drugs, cosmetics, food additives and so on. In this study, using combined technologies to high‐efficient extraction and separation of blueberry anthocyanins was developed. Under the optimum extraction conditions of first 0.3% cellulose and pectinase with 2:1 (m/m) at 37 °C for 4 h and then 1% citric acid‐acidified 75% (v/v) ethanol at 37 °C for 6 h, as high as 25% extraction rate of blueberry anthocyanins was obtained. By ethyl acetate extraction in triplicate and then D101 resin column chromatography, up to 49.6% purity of blueberry anthocyanins was obtained based on UV–vis analysis. The scale‐up extraction and separation of blueberry anthocyanins were carried out. This method was simple but effective, and easy scalable at industrial purpose.     

Physical-Chemical Characteristics of Partially Clarified Guava Juice and Concentrate

Partially clarified guava juice concentrate was prepared from single strength guava puree (5.5°Brix) by treatment with pectinase (2 hr at 50°C), extraction of juice with a rack-and-cloth press, and vacuum concentration to 23°Brix. The concentrate had the following characteristics: density, 1.10; pH, 3.16; total acids, 4.67%; ash, 1.51%; moisture, 72.4%; ascorbic acid, 867 mg%; viscosity, 4.4 cp; and CIE L* 39.2, CIE a* 10.33, CIE b* 27.11.     

HPLC/DAD/ESI-MS analyses and anti-radical activity of hydrolyzable tannins from different vegetal species

In the present work, several tannin extracts from myrtle and pomegranate were analyzed and characterized using HPLC/DAD/ESI-MS methods. Both aqueous and hydroalcoholic myrtle leaf extracts were found to be rich in galloyl-glucosides, galloyl-quinic acids, ellagitannins and flavonoids. In these extracts we observed a predominance of galloyl-glucosides and galloyl-quinic derivatives with respect to ellagic derivatives; 87.14% and 12.86%, respectively, average gallic and ellagic derivatives with respect to total tannins content. In pomegranate extracts, substantial differences were found in polyphenol contents between peel and seed extracts with regard to the relative abundance of gallic and ellagic acid derivatives: 28.81% and 71.19%, respectively, as average total gallic and ellagic derivatives in peel extracts; 61.30% and 38.70%, in seed extracts. The antiradical properties were evaluated and compared to those of two commercial extracts of chestnut bark and grape seeds. The collected data could suggest the use of myrtle and pomegranate extracts as nutraceuticals and functional foods for their important antioxidant properties.