The effect of enzymatic treatment on blackcurrant (Ribes nigrum) juice flavour and its stability

The effects of different enzymatic treatments on the sensory profile and chemical composition, especially various phenolic compounds, sugars and fruit acids, of blackcurrant juices were investigated. In addition to pectinolytic activities, the enzymes had different cellulolytic, hemicellulolytic and glycolytic activities. The enzymatic treatments improved significantly the yield of juice, but with more fermented and astringent characteristics than juices without enzymatic hydrolysis. Enzymes with higher glycosidase activity increased astringency and the content of phenolic compounds in the juice. When the incubation temperature was elevated the contents of fruit acids increased whereas sugars and the perceived sweetness were the highest in the juices without enzymatic treatments. Despite of the significant changes in chemical composition, the sensory properties did not change significantly during 6 weeks of storage. Optimisation of the enzymatic process is crucial for juice making as maximising the juice yield or the content of phenolic compounds may produce unwanted sensory properties to the juice.     

Analysis of Phenolic Compounds of Dabai (Canarium odontophyllum Miq.) Fruits by High-Performance Liquid Chromatography

Dabai (Canarium odontophyllum Miq.) fruit is a popular seasonal indigenous fruit of Sarawak, Malaysia that is always appreciated as an exotic fruit by the local community. The present study was designed to identify and quantify the phenolic compounds of dabai fruits from different divisions of Sarawak. Difference between the purple and red varieties of the fruits was also investigated. Analysis of phenolic compounds was performed by reversed phase high-performance liquid chromatography coupled with diode array detector. Three detection wavelengths (280, 254 and 329 nm) were used to monitor all phenolic compounds (except for anthocyanidins) since they display absorbance maxima at different wavelengths. Characteristic spectra of eluted peaks provide useful information in confirming the identities of peaks. Hydrolysis of phenolic compounds of dabai fruits was insufficient under the milder conditions (30 °C, 2 h) employed thus resulted in unidentified peaks. Two phenolic acids (ellagic and vanillic acids), five flavonoids (catechin, epicatechin, epicatechin gallate, epigallocatechin gallate, apigenin) and ethyl gallate were detected in the fruits. Furthermore, three anthocyanidins (cyanidin, pelargonidin and delphinidin) and four anthocyanins (malvidin-3,5-di-O-glucoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and peonidin-3-O-glucoside) were detected. All these phenolic compounds were reported in dabai fruits for the first time. The fruit variety affected the anthocyanidins and anthocyanins profile (p < 0.01) but had little or no effect on the phenolic acids and flavonoids profile of the fruits. Within the same variety, diversity in environmental conditions had an impact on the quantitative differences of phenolic compounds (p < 0.05).     

Stability of Pycnogenol® as an ingredient in fruit juices subjected to in vitro gastrointestinal digestion

BACKGROUND: The enrichment of fruit juices with concentrated polyphenolic extracts is an expedient strategy to compensate possible phenolic loss through gastrointestinal processing. Pycnogenol®, a standardised procyanidin‐rich extract from pine bark, has been proposed as a potential candidate for polyphenol enrichment of foods. In this study the effects of in vitro digestion on the phenolic profile of fruit juices enriched with Pycnogenol® were investigated. RESULTS: After in vitro digestion the level of detectable total phenolic compounds (expressed as gallic acid equivalent) was higher in both pineapple and red fruit juices enriched with Pycnogenol® than in non‐enriched commercial juices. Five phenolic monomeric compounds were identified by high‐performance liquid chromatography, namely chlorogenic acid, caffeic acid, ferulic acid, gallic acid and taxifolin, the last two being predominant. In vitro digestion of both Pycnogenol®‐enriched pineapple and red fruit juices led to a significant (P < 0.05) increase in detectable chlorogenic and ferulic acids, indicating that hydrolysis of more complex molecules occurs. On the other hand, in vitro digestion of non‐enriched juices was associated with a decrease in gallic and caffeic acids in pineapple juice and with a decrease in ferulic acid in red fruit juice. In no case did in vitro digestion increase the amount of detectable phenolic compounds in non‐enriched juices. CONCLUSION: The stability of Pycnogenol® after in vitro gastrointestinal digestion makes it a good choice for phenolic enrichment of fruit juices. Copyright © 2010 Society of Chemical Industry     

Selection of elderberry (Sambucus nigra L.) genotypes best suited for the preparation of elderflower extracts rich in flavonoids and phenolic acids

The importance of raw material and extraction parameters for obtaining a high content of flavonoids and phenolic acids in elderflower extracts was investigated. Nine phenolic acids (3-O-, 4-O-, and 5-O-caffeoylquinic acid, 3-O- and 5-O-p-coumaroylquinic acid, 1,5-di-O-, 3,4-di-O-, 3,5-di-O- and 4,5-di-O-caffeoylquinic acid) and six flavonol glycosides (quercetin-3-O-rutinoside, quercetin-3-O-glucoside, kaempferol-3-O-rutinoside, isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-glucoside, and quercetin-3-O-6″-acetylglucoside) were identified and quantified in elderflowers and/or extracts thereof by liquid chromatography-mass spectrometry (LC-MS) and high-performance liquid chromatography-diode array detection (HPLC-DAD), respectively. The yield of elderflower extracts depended significantly on processing conditions and raw material properties and the maximum yield of elderflower extract was obtained by extraction for a maximum of 10 days at 4 °C using an extraction liquid consisting of a maximum of 20 w/w % sugars and 5% citric acid. The effects of the extraction liquid composition and raw material on the concentration of phenolic acids and flavonol glycosides in elderflower extracts were determined by factor analysis. Several elderberry genotypes were found to be useful for processing of elderflower extracts with a relative high concentration of phenolic acids and flavonol glycosides.     

Physicochemical characterization of special persimmon fruit beers using bohemian pilsner malt as a base

This study involved the production of special fruit ale beers with different concentrations (100:0%, 75:25%, 50:50% and 25:75% v /v) of barley malt and persimmon juice from the ‘Rojo Brillante’ variety. Fermentation took place under beer quality control parameters and the influence of persimmon juice on beer quality was investigated. Colour, turbidity, pH, titratable acidity, total soluble solids, sugars, organic acids, total phenolic compounds, antioxidant capacity and ethanol formation were determined during the fermentation process. These fruit beers, whose alcoholic contents were within the standards (3.6–5.63% v /v ethanol), were characterized by a normal acid pH (3.97–4.13) with citric and lactic acids the most abundant organic acids, a clear golden colour without turbidity [2.05–2.83 European Brewery Convention units], intermediate total phenolic compound values (283.0–327.1 mg GAE/L) and antioxidant activities between 1.65 and 5.78 mm TE/L. The persimmon beverage which contained 75% fruit juice was the most valued and preferred by the panelists followed by the 50:50% wort–persimmon beer. Copyright © 2017 The Institute of Brewing & Distilling     

Application of Phenolic Extracts from Selected Plants in Fruit Juice

Plant phenolics have gained considerable interest in recent years for their potential effects against food related microorganisms. In the present study, phenolic extracts from the leaves of three plants namely Moringa oleifera, Morus indica, and Mentha spicata were prepared by a mixture of methanol/acetone/water. The UV spectra of extracts were recorded and contents of total phenolics determined. The extracts were incorporated in pineapple juice and their solubility and stability were studied. In addition, the acceptability of treated juice samples was sensory evaluated. The solubility of M. indica and M. oleifera extracts was found to be more than that of M. spicata. The two extracts were also stable in the pH environment of pineapple juice when stored at 4°C for two weeks. The pineapple juice treated with M. indica extract was more acceptable compared to that of M. oleifera, according to sensory evaluation. Therefore, the effect of addition of phenolic extract from M. indica on the shelf life of pineapple juice stored at 4°C was investigated by monitoring the changes in titrable acidity and sensory parameters for 8 weeks. Results indicated that the extracts of natural phenolic compounds can be used to improve the quality and safety of foods.     

Phenolic Compounds from the Leaves of Vitis labrusca and Vitis vinifera L. as a Source of Waste Byproducts: Development and Validation of LC Method and Antichemotactic Activity

The cultivation of Vitis (Vitaceae) grape varieties is one of the most important economic activities in agribusiness in southern Brazil. Vitis varieties are rich in polyphenolic compounds with several pharmacological and biological activities, such as antioxidant action. In this context, this study analyzed qualitatively and quantitatively the anthocyans and flavonoids found in the leaves of grape varieties Vitis vinifera and Vitis labrusca. For this purpose, vine leaf extracts were prepared and the chemical profile of each was characterized by LC/MS-MS. Two high performance liquid chromatography-validated methods were performed using UV/VIS-LC-DAD detector to quantify phenolic compounds. The main anthocyanins isolated from vine leaves were cyanidin-3-O-glucoside and peonidin-3-O-glucoside. The flavonoids identified were rutin, quercetin-3-O-galactoside, quercetin-3-O-glucoside, and quercetin-3-O-glucuronide, which was the predominant compound. The Waters X-Terra® RP18 column allowed the effective separation of quercetin-3-O-glucuronide from the other flavonoids for the first time, besides the partial separation of quercetin-3-O-galactoside from quercetin-3-O-glucoside. Furthermore, another phenolic compound was confirmed by MS spectrometry, using direct infusion, as being trans-caftaric acid. The present study also investigates the antichemotactic activity in vitro of grape crude extracts, fractions, and isolated compounds. It was demonstrated that almost all fractions and isolated compounds showed increased antichemotactic effect in response to LPS with a more pronounced values of IC₅₀ for anthocyanins fraction, rutin, quercetin-3-O-galactoside, and trans-caftaric acid (0.9, 1.6, 3.7, and 5.1 ng/mL, respectively).     

Identification of a new phenolic compound from Chinese olive (<Emphasis Type="Italic">Canarium album</Emphasis> L.) fruit

Chinese olive (Canarium album L.), a native and a well-known tropical fruit tree in the southeast of China, contains large amount of phenolics and possesses great pharmacological activities. In this study, phenolics were extracted from Chinese olive fruit pulp using 80% (v/v) aqueous acetone, and acetone extracts were further fractioned with petroleum ether, ethyl acetate and n-butanol sequentially. From n-butanol fraction, a new phenolic compound was isolated and purified through AB-8 adsorption resin column chromatography, polyamide column chromatography and TSK Toyopearl HW-40 (S) column chromatography, and the structure of the new compound was established as 3-O-galloyl quinic acid butyl ester by electrospray ionization mass spectrometry (ESI-MS), 1D- and 2D-NMR (DEPT, COSY, HMBC, HMQC) and UV–vis techniques.     

Antioxidant activity and antimicrobial properties of phenolic extracts from acerola (Malpighia emarginata DC) fruit

The antioxidant activity and antimicrobial property of phenolic extracts from acerola (Malpighia emarginata DC) fruit were assessed. The contribution of ascorbic acid and phenolic compounds in the total antioxidant capacity of the extracts was also evaluated. The extracts showed high total phenolic values and possessed high antioxidant activity as expressed by 2,2′‐diphenylpicrylhydrazyl (DPPH) and oxygen radical absorbance capacity assays (ORAC). The ascorbic acid content ranged from 405 to 1744 mg/100 g of fruit on a fresh weight basis. The antioxidant capacity of the phenolic fractions was in the following order: anthocyanins<phenolic acids<flavonoids. The phenolic fractions contributed 7.1–36.5% of the antioxidant activity expressed by ORAC, whereas the contribution of ascorbic accounted for 18–39% of the total activity. Selected extracts from the flavonoids fraction showed some activity against Staphylococcus aureus.     

Spray-drying microencapsulation of pomegranate juice increases its antioxidant activity after in vitro digestion

Most of the work on pomegranate antioxidant and antibacterial activity has been carried out with solvent extracts of different plant or fruit parts. Biosensitive compounds in juice may be subject to oxidation, reducing their biological activities. Microencapsulation can be used to protect compounds, allowing its incorporation into functional foods. This study aimed at investigating antioxidant activity after in vitro digestion of microencapsulated juice. Pomegranate juice was encapsulated by spray drying its maltodextrin and gum arabic. The average diameter of the microcapsules was 10–50 µm. We evaluated the bioaccessibility of microencapsulated phenolic compounds by using an in vitro enzymatic digestion. The total phenolic content in digested microencapsulated juice was three times greater than in undigested, indicating that the compounds were made bioaccessible. Digestion also increased antioxidant activity, as measured by ABTS●+ or by DPPH●. Additionally, microencapsulated pomegranate juice showed antibacterial activity against the nine bacteria species tested.     

Sugars, organic acid and phenolic compounds of Ziziphus mauritiana Fruit

This study was conducted to identify soluble sugars, non-volatile acids and phenolic compounds in Ziziphus mauritiana fruit. Soluble sugars in Ziziphus mauritiana fruit were qualitatively determined by TLC. The sugars identified to be present in Ziziphus mauritiana were galactose, fructose and glucose. TLC was also used for qualitative analysis of phenolic compounds; five spots of phenolic compounds were observed. Only two of the observed spots were identified using the R_f values of the standards that were available. The two phenolic compounds identified by TLC were caffeic acid and p-coumaric acid. Phenolic compounds were also quantified using HPLC. Twelve peaks of phenolic compounds were detected. Among these, p-hydroxybenzoic acid, caffeic, ferulic acid and p-coumaric acid were the most abundant with concentrations of 365.94, 30.76, 19.64 and 19.28 mg/kg dry mass respectively, whereas vanillic acid was the least abundant with a concentration of 2.52 mg/kg. The organic acids were qualitatively analysed by PC and citric acid, malonic acid and malic acid were identified in the Ziziphus mauritiana fruit.     

Comparison of phenolic and chromatic characteristics of dry red wines made from native Chinese grape species and vitis vinifera

The phenolic and chromatic characteristics of dry red wines made from native Chinese species (Vitis amurensis and its hybrids, and V. davidii) and V. vinifera were evaluated by high-performance liquid chromatography/triple-quadrupole tandem mass spectrometry and spectrophotometer, respectively. V. amurensis and its hybrids wines had higher phenolic percentage of non-coumaroylated 3, 5-O-diglucosidic anthocyanins, V. davidii wines had higher phenolic percentage of coumaroylated 3, 5-O-diglucosidic anthocyanins, kaempferol-3-O-glucoside, and quercetin-3-O-rhamnoside, V. vinifera wines had higher phenolic percentage offlavan-3-ols and 3-O-monoglucosidic anthocyanins. Wines of native Chinese species had relatively higher blue % value and lower red % value. By the use of principal component analysis and Pearson correlation analysis, specific phenolic compounds could be recognized as phenolic fingerprints of different wines, which not only play an important role in wine differentiation, but also explain their chromatic differences.     

Antioxidative activities of chromatographic fractions obtained from root,fruit and leaf of Mengkudu (Morinda citrifolia L.)

Crude extracts of root, leaf and fruit of Morinda citrifolia were fractionated on a Sephadex LH-20 column with ethanol as eluate. Based on UV absorption intensity of phenolic compound (725 mm) the Sephadex LH-20 column was able to separate fruit, leaf and root extracts into six, five and five fractions, respectively. The results showed that all the fractions tested exhibited considerably high antioxidative activity in the ferric thiocyanate assay and thiobarbituric acid test and the activities of some of the fractions were as good as those of either tocopherol or BHT. The fractions from different parts of the plants were found to contain different amounts of total phenolic compounds, which, interestingly, do not correspond to the antioxidative activity measured. This is probably due to the presence of different phenolics in the samples, with different antioxidative activities which involves various mechanisms inhibiting the oxidation process. The study suggested that root, leaf and fruit of M. citrifolia might contribute significantly to exogenous antioxidant which is crucial in combating oxidative stress.     

Mass-spectrometry evidence confirming the presence of pelargonidin-3-O-glucoside in the berry skins of Cabernet Sauvignon and Pinot Noir (Vitis vinifera L.)

Background and Aims: Anthocyanins are a group of important phenolic compounds which are responsible for the colour of red grape and wine. This study aimed to confirm the existence of pelargonidin-3-O-glucoside in Vitis vinifera grape berry skins. Methods and Results: The anthocyanin profiles in the berry skins of Cabernet Sauvignon and Pinot Noir were analysed by high performance liquid chromatography – electronic spray ionization – tandem mass spectrometry. Besides 17 anthocyanins that are commonly determined in the berries of these two varieties, pelargonidin-3-O-glucoside was also detected at trace levels. Conclusions: The mass-spectrometry evidence confirmed the existence of pelargonidin-3-O-glucoside in non-teinturier V. vinifera grapes. Significance of the Study: This finding will be beneficial for the further understanding of anthocyanin profile and its biosynthesis in grape berries.     

LC-MS–MS characterisation of curry leaf flavonols and antioxidant activity

Curry leaf (Murraya koenegii) is a common flavouring agent in Indian foods. This study characterised the flavonol profile of curry leaf extracted with different solvents and the relative antioxidant capacity of these extracts by quantifying phenolic constituents. Flavonols were extracted using ethanol, methanol, or acetone prior to identification and quantification using liquid chromatography coupled to atmospheric pressure chemical ionisation (APCI) mass spectrometry in tandem mode (LC-MS–MS) with negative ion detection. Major curry leaf flavonols included myricetin-3-galactoside, quercetin-O-pentohexoside, quercetin-3-diglucoside, quercetin-3-O-rutinoside, quercetin-3-glucoside, quercetin-3-acetylhexoside, quercetin-O-xylo-pentoside, kaempferol-O-glucoside, and kaempferol-aglucoside. Lag-time and TBARS tests demonstrated that curry leaf phenolics prevent cupric-ion induced oxidation of LDL. The best extraction yield was obtained with 80% ethanol. Acetone extracts provided better antioxidant activity expressed as increased lag-time formation, than did ethanol or methanol extracts. Curry leaf is a rich source of flavonols that have biological activity in vitro and further studies are warranted in regards to the potential health benefits and identification of the novel flavonols whose identities remain unknown.     

Evolution of polyphenols in red wines from Vitis vinifera L. during aging in the bottle

The evolution of non-anthocyanin phenolic compounds (as measured by high-performance liquid chromatography) in young red wines from Vitis vinifera L. cv Tempranillo, Graciano and Cabernet Sauvignon (vintage 2000) from Navarra (Spain) was studied during 26 months of aging in the bottle. Hydroxybenzoic acids and derivatives (gallic, protocatechuic, vanillic and syringic acids, and methyl and ethyl gallates), hydroxycinnamic acids and derivatives (trans-caftaric, cutaric, caffeic and p-coumaric acids, and hexose esters of trans-p-coumaric acid), stilbenes (trans- and cis-resveratrol-3-O-glucosides, and trans- and cis-resveratrol), phenolic alcohols and other related compounds (tyrosol and tryptophol), flavanols [procyanidins B1 and B2, (+)-catechin and (–)-epicatechin] and flavonols (myricetin-3-O-glucoside, quercetin-3-O-galactoside and quercetin-3-O-glucuronide, kaempherol-3-O-glucoside, myricetin and quercetin) presented different evolution patterns during aging, in some cases also being different depending on the grape variety studied. The changes that occurred during aging in the bottle were the decrease of the concentration of trans-caftaric and cutaric acids accompanied by an increase of trans-caffeic acid and, especially of trans-p-coumaric acid. The greater increase of trans-p-coumaric acid was also associated with the disappearance of p-coumaroyl-acylated anthocyanins that occurs during aging in the bottle. Flavanols registered a major decrease, with the disappearance rate being greater for the dimeric procyanidins than for the monomeric flavanols, and the order of the disappearance rate by variety was as follows: Tempranillo相似文献   

Bioactive Components and Health-Promoting Properties of Yuzu (Citrus ichangensis × C. reticulate)

Yuzu (Citrus ichangensis × C. reticulate) fruit is an important functional food that possesses several health-promoting properties. It has been widely used in commercial medical products, healthy foods, and cosmetics in many countries. Yuzu is a rich source of wide variety of non-nutritive compounds, such as flavonoids, anthocyanins, phenolic acids, carotenoids, and tannins; as well as nutritive compounds such as sugars, proteins, vitamins, fibers, and minerals. Yuzu fruit (juice, peel, and seeds) and its bioactive compounds have been demonstrated to have numerous functional properties, such as antioxidant, anti-inflammatory, anticancer, antiplatelet, angiogenesis, and antimicrobial properties, both in vitro and in vivo. These diverse applications provided by the yuzu fruit (juice, peel, and seeds) and its bioactive compounds are of great industrial importance. This review summarizes the composition, nutritional values, and functional properties of yuzu fruit, and their biological activity in relation to their potential impact on human health.     

Comparison of phenolic composition and antioxidant properties of two native Chilean and one domestic strawberry genotypes

The phenolic composition of extracts from the forms chiloensis and patagonica of Fragaria chiloensis were compared with that of the commercial strawberry Fragaria × ananassa cv. Chandler by high performance liquid chromatography with diode-array detector (HPLC–DAD) and high performance liquid chromatography with electrospray ionization mass spectroscopy detector (HPLC–ESI–MS). The phenolic constituents in the three species were mainly proanthocyanidins, hydrolysable tannins, anthocyanins and flavonol glycosides. In both native strawberry species the main flavonol glycoside was quercetin 3-O-glucuronide and the minor anthocyanins identified were cyanidin-malonyl-glucoside and pelargonidin-malonyl-glucoside. The highest anthocyanin content was found in the commercial red strawberry while ellagic acid was the main phenolic in the native white strawberry. From the methanolic fruit extract of the native Chilean strawberry Fragaria chiloensis ssp. chiloensis f. chiloensis four known antioxidants were isolated by selective fractionation using the bleaching of the free radical scavenger 1,1-diphenyl-2-picrylhydrazyl (DPPH) as the guiding assay. The antioxidant properties (measured as the bleaching of the DPPH radical) were determined for methanol extracts of the three fruits, for fractions of F. chiloensis ssp. chiloensis f. chiloensis, and for the isolated compounds cyanidin-3-glucoside, pelargonidin-3-glucoside, quercetin-3-glucuronide and ellagic acid. This study allows a clear chemical differentiation between the commercial strawberry and the Chilean white strawberry.     

Utilization of mango peels as a source of pectin and polyphenolics

Two different options for the combined recovery of pectin and phenolic compounds from mango peels, a byproduct of industrial mango processing, were developed. After extraction of dried mango peels with diluted sulfuric acid, the phenolic compounds were adsorbed using a styrene–divinylbenzene copolymerisate resin, and pectin was obtained from the effluent by precipitation with ethanol. Phenolic compounds were recovered from the resin with methanol and the eluate was lyophilized (Process I). Alternatively, the pectin was precipitated by adding the crude extract to ethanol. After removal of the organic solvent, the phenolic compounds were obtained from the aqueous phase of the precipitation bath using the adsorbent resin as described before (Process II). While in total, 129.4 mg/g polyphenols were detected in the lyophilizate obtained from Process I, only 71.0 mg/g dm could be recoverd from Process II. The profiles of the polyphenols were almost identical, revealing that during pectin precipitation preferential adsorption of polyphenolic compounds to the pectin may be excluded. Besides the characterization of the pectins and the phenolic compounds, investigations into the influence of the drying temperature on the polyphenolic content of the peels were carried out, indicating a significant loss of flavonol glycosides depending on heat exposure. On the other hand, some xanthone glycosides were formed during the drying process. Furthermore, antioxidative capacities of the lyophilized eluates were investigated using the DPPH, TEAC and FRAP assays. The antioxidative capacity of the extracts exceeded that of mangiferin and quercetin 3-O-glucoside, respectively, thus demonstrating mango peels to be a suitable source of health-beneficial compounds. The lyophilizates obtained from Process I showed higher antioxidative capacities in all three assays. These findings indicate a correlation between the amount of phenolic compounds and the antioxidative capacity.

Industrial relevance

Byproducts of mango processing amount to 35–60% of the total fruit weight. Their complete exploitation for further product recovery is a promising measure from both an environmental and economic point of view. In our previous study mango peels were found to be a rich source of pectin, with a high degree of esterification and phenolic compounds, like flavonol O- and xanthone C-glycosides. Therefore, two alternative processes for the combined recovery of pectin and polyphenols, which can easily be integrated in an existing pectin production process, were developed in the present study.