Colour stability of anthocyanins from Isabel grapes (Vitis labrusca L.) in model systems

Development of alcohol vinegars macerated with ACAI (Euterpe precatoria Mart.) berries and their quality evaluations with emphasis on color, antioxidant capacity, and volatiles profile

In this work, the Amazonian native acai fruit, a superfruit recognized worldwide, was used through a simple operation of maceration in alcohol vinegar to transform it into an attractive and functional product containing the acai natural colorant and its bioactive compounds. The variables studied were the proportion of alcohol vinegar to acai (8:2 and 1:1) and maceration period (7, 14, and 21 days). The final vinegar was subjected to the determination of color parameters, antioxidant capacity (DPPH, ABTS), total phenolics content (TPC), volatile compounds extracted by stir bar sorptive extraction and identified by gas-chromatography-mass spectrometry analysis. The alcohol vinegars macerated with acai presented the color according to the content of acai added and maceration period employed, whereas antioxidant capacity and TPC were comparable to vinegars elaborated from fruits and red wine. Sixty volatiles compounds classified into five chemical groups were identified. The principal volatile compounds which contributed to the aroma in the products were 3-methyl-1-butanol, phenylethyl alcohol, benzaldehyde, o-cymene, p-cymenene, isoamyl acetate, and ethyl acetate. The most attractive product regarding the parameters studied was obtained from the use of the proportion of 1:1 of alcohol vinegar:acai and maceration period of 14 days. This product retained the most similar color to acai in natura, the highest values for antioxidant capacity measured by ABTS and TPC while being rich in volatile compounds due to the contributions mainly of alcohols, esters, aldehydes, and terpenes. PRACTICAL APPLICATION: This work demonstrates the feasibility to produce an alcohol vinegar with an attractive color and functional properties by the addition of acai resulting in to a wide spectrum of chemical compounds of acai through a very simple operation of maceration during 14 days of a proportion of 1:1 of alcohol vinegar:acai.

Deep learning application detecting SARS-CoV-2 key enzymes inhibitors

The fast spread of the COVID-19 over the world pressured scientists to find its cures. Especially, with the disastrous results, it engendered from human life losses to long-term impacts on infected people's health and the huge financial losses. In addition to the massive efforts made by researchers and medicals on finding safe, smart, fast, and efficient methods to accurately make an early diagnosis of the COVID-19. Some researchers focused on finding drugs to treat the disease and its symptoms, others worked on creating effective vaccines, while several concentrated on finding inhibitors for the key enzymes of the virus, to reduce its spreading and reproduction inside the human body. These enzymes' inhibitors are usually found in aliments, plants, fungi, or even in some drugs. Since these inhibitors slow and halt the replication of the virus in the human body, they can help fight it at an early stage saving the patient from death risk. Moreover, if the human body's immune system gets rid of the virus at the early stage it can be spared from the disastrous sequels it may leave inside the patient's body. Our research aims to find aliments and plants that are rich in these inhibitors. In this paper, we developed a deep learning application that is trained with various aliments, plants, and drugs to detect if a component contains SARS-CoV-2 key inhibitor(s) intending to help them find more sources containing these inhibitors. The application is trained to identify various sources rich in thirteen coronavirus-2 key inhibitors. The sources are currently just aliments, plants, and seeds and the identification is done by their names.

Sustainable Green Processing of Grape Pomace Using Micellar Extraction for the Production of Value-Added Hygiene Cosmetics

This study sought to evaluate the possibility of using grape pomace, a waste material from wine production, for the preparation of cosmetic components. Following the existing clear research trend related to improving the safety of cleansing cosmetics, an attempt was made to determine the possibility of preparing model shower gels based on grape pomace extract. A new method for producing cosmetic components named loan chemical extraction (LCE) was developed and is described for the first time in this paper. In the LCE method, an extraction medium consisting only of the components from the final product was used. Thus, there were no additional substances in the cosmetics developed, and the formulation was significantly enriched with compounds isolated from grape pomace. Samples of the model shower gels produced were evaluated in terms of their basic parameters related to functionality (e.g., foaming properties, rheological characteristics, color) and their effect on the skin. The results obtained showed that the extracts based on waste grape pomace contained a number of valuable cosmetic compounds (e.g., organic acids, phenolic compounds, amino acids and sugars), and the model products basis on them provided colorful and safe natural cosmetics.

Rapeseed as an Ornamental

Rapeseed (Brassica napus) is one of the most important oil crops worldwide. However, an intriguing new use for rapeseed has recently developed: as an ornamental. Tourism based on blossoming fields of these yellow flowers has become a new economic growth opportunity in China. From a breeding perspective, two main problems currently limit the potential of rapeseed as an ornamental. First, the flowering period is quite short (30 days on average), which limits economic income; second, the flower color in commercial cultivars is currently limited to bright yellow, which may pall quickly for sightseers. This review summarizes the possible problems of using rapeseed as an ornamental, and details factors affecting the flowering period, how the flowering period can be prolonged by integrating optimal cultivation measures or/and spraying with chemical reagents, and ways of creating and breeding rapeseed with diverse flower colors.

Fruit and Agro-Industrial Waste Extracts as Potential Antimicrobials in Meat Products: A Brief Review

The use of antimicrobials in meat products is essential for maintaining microbiological stability. The reformulation by substituting synthetic additives for natural ones is an alternative to provide cleaner label products. Therefore, this work performed a literature search about extracts from fruits and agro-industrial waste with antimicrobial activity that can be applied in meat products. Jabuticaba waste extracts are excellent sources of anthocyanins with antimicrobial and pigmentation potential, capable of being applied in meat products such as fresh sausage, without compromising sensory attributes. Residue from grapes is rich in antimicrobial phytochemicals, mainly catechins, epicatechins, gallic acid and procyanidins. Extracts from different grape by-products and cultivars showed inhibition of Staphylococcus aureus, Listeria monocytogenes, Pseudomonas aeruginosa, Escherichia coli O157: H7 and other bacterial strains. Antimicrobial effects against L. monocytogenes, Bacillus cereus, S. aureus and E. coli O157: H7 were identified in Opuntia extracts. In addition, its application in hamburgers reduced (p < 0.05) aerobic mesophilic bacteria, Enterobacteriaceae and Pseudomonas sp. counts, and at a concentration of 2.5%, improved the microbiological stability of salami without causing sensory and texture changes. These data reinforce the possibility of substituting synthetic preservatives for natural versions, a growing trend that requires researching effective concentrations to maintain the sensory and technological properties.

Influence of food matrix and food processing on the chemical interaction and bioaccessibility of dietary phytochemicals: A review

Consumption of phytochemicals-rich foods shows the health effect on some chronic diseases. However, the bioaccessibility of these phytochemicals is extremely low, and they are often consumed in the diet along with the food matrix. The food matrix can be described as a complex assembly of various physical and chemical interactions that take place between the compounds present in the food. Some studies indicated that the physiological response and the health benefits of phytochemicals are resultant in these interactions. Some food substrates inhibit the absorption of phytochemicals via this interaction. Moreover, processing technologies have been developed to facilitate the release and/or to increase the accessibility of phytochemicals in plants or breakdown of the food matrix. Food processing processes may disrupt the activity of phytochemicals or reduce bioaccessibility. Enhancement of functional and sensorial attributes of phytochemicals in the daily diet may be achieved by modifying the food matrix and food processing in appropriate ways. Therefore, this review concisely elaborated on the mechanism and the influence of food matrix in different parts of the digestive tract in the human body, the chemical interaction between phytochemicals and other compounds in a food matrix, and the various food processing technologies on the bioaccessibility and chemical interaction of dietary phytochemicals. Moreover, the enhancing of phytochemical bioaccessibility through food matrix design and the positive/negative of food processing for dietary phytochemicals was also discussed in this study.

Understanding Alstroemeria pallida Flower Colour: Links between Phenotype, Anthocyanins and Gene Expression

Flower colour is mainly due to the accumulation of flavonoids, carotenoids and betalains in the petals. Of these pigments, flavonoids are responsible for a wide variety of colours ranging from pale yellow (flavones, flavonols and flavanodiols) to blue-violet (anthocyanins). This character plays a crucial ecological role by attracting and guiding pollinators. Moreover, in the ornamental plants market, colour has been consistently identified as the main feature chosen by consumers when buying flowers. Considering the importance of this character, the aim of this study was to evaluate flower colour in the native Chilean geophyte Alstroemeria pallida, by using three different approaches. Firstly, the phenotype was assessed using both a colour chart and a colourimeter, obtaining CIELab parameters. Secondly, the anthocyanin content of the pigmented tepals was evaluated by high-performance liquid chromatography (HPLC), and finally, the expression of two key flavonoid genes, chalcone synthase (CHS) and anthocyanidin synthase (ANS) was analysed using real-time polymerase chain reaction (PCR). Visual evaluation of A. pallida flower colour identified 5 accessions, ranging from white (Royal Horticultural Society (RHS) N999D) to pink (RHS 68C). Moreover, this visual evaluation of the accessions correlated highly with the CIELab parameters obtained by colourimetry. An anthocyanidin corresponding to a putative 6-hydroxycyanidin was identified, which was least abundant in the white accession (RHS N999D). Although CHS was not expressed differentially between the accessions, the expression of ANS was significantly higher in the accession with pink flowers (RHS 68C). These results suggest a correlation between phenotype, anthocyanin content and ANS expression for determining flower colour of A. pallida, which could be of interest for further studies, especially those related to the breeding of this species with ornamental value.

Impact of Juice Extraction Method (Flash Détente vs. Conventional Must Heating) and Chemical Treatments on Color Stability of Rubired Juice Concentrates under Accelerated Aging Conditions

Low color stability of Rubired food and beverage coloring negatively impacts color yield during production and storage while also limiting the use of this type of food colorant in applications where color stability is a key requirement. This study investigated the impact on color stability of using flash détente (FD) for Rubired color extraction in comparison to a conventional must heating (CMH) extraction process, in conjunction with the use of commercial seed tannin, acetaldehyde, or acid to lower the pH. Rubired concentrate color was evaluated under accelerated aging conditions at 50, 60, and 70 °C, over zero, three, six, and nine days for the different treatments. FD concentrate had lower color stability, with a half-life of 203.3 h and activation energy of 59.2 kJ/mol at 50 °C compared to the CMH concentrate with 233.9 h and 65.2 kJ/mol. FD concentrate generated less 5-hydroxymethylfurfural (5-HMF) during accelerated aging regardless of treatment. Acetaldehyde, low pH, and the combination of these two treatments increased red color stability as well as violet and brown color, whereas seed tannin had no effect. Low pH treatments increased 5-HMF formation and browning, which was detrimental to concentrate quality. Although promising in terms of color stabilization, implementation of these treatments will require development of solutions to mitigate the production of 5-HMF.

Corinthian raisins (Vitis vinifera L., var. Apyrena) antioxidant and sugar content as affected by the drying process: a 3-year study

BACKGROUND

Corinthian raisins or Corinthian currants are dried grape products that account for approximately 3% of dried vine fruit production worldwide. Greece is the major Corinthian raisin producer. In this study Corinthian raisins were produced by applying two traditional drying methods, i.e. sun and shade drying. The drying process effect on the raisin phytochemical and sugar content was assessed; samples obtained over three consecutive crops were evaluated to prevail over climatic condition variations.

RESULTS

Total phenolic, flavanol, and anthocyanin content were higher in Corinthian raisins dried under shade as compared with the sun-dried ones; individual anthocyanidin-3-O-glucosides were also qualitatively and quantitatively higher under shade drying in most cases. Differences were observed in Corinthian raisin phytochemical content among the crop years evaluated. The drying process applied did not discriminatively affect the sugar content of Corinthian raisin.

CONCLUSION

Drying under shade was proven superior to sun drying with respect to Corinthian raisin phytochemicals and could be considered as an appealing drying method for the production of dried raisins and perhaps other dried fruits. © 2018 Society of Chemical Industry.

The study of transcriptome sequencing for flower coloration in different anthesis stages of alpine ornamental herb (Meconopsis 'Lingholm')

Meconopsis (Papaveraceae) is an interesting alpine herb, mainly distributed in the mountainous area of southwest China and high altitude zone in Tibetan-Himalaya. Different Meconopsis species showed a flower color alteration in different anthesis stages, Meconopsis 'Lingholm' is one of the localized species whose petal color changes from purple to blue during the flowering process. In general, the blue color flower is a rare kind, and usually hard to cultivate artificially. The molecular mechanism of flower color formation and color alteration of alpine flowers were reported by many research workers. To find critical genes that regulate Meconopsis 'Lingholm' color alteration and the mechanism of environmental adaptation, the current study performed transcriptome sequencing by using Meconopsis 'Lingholm' petals from different anthesis stages. There were totally 91,615 unigenes obtained from 31.4 Gb sequencing data, and differentially expressed genes between two consecutive flowering stages were obtained. Bioinformatics studies showed genes regulating petal color alteration were activated. Moreover, the functional analysis showed that Meconopsis 'Lingholm' showed a stress response to mechanical damage, non-biological stimulation and water deficiency in the bud stage, as well as showed a stress response to the cold from cracking stage to blooming stage. Furthermore, RNA-Seq results were verified using nine randomly selected genes by qPCR, which showed same expression trend with sequencing results. During this study, 20 candidate genes identified for further studies, which included five petal color related genes and 15 environmental response genes.

Enhancing the Potential Exploitation of Food Waste: Extraction, Purification, and Characterization of Renewable Specialty Chemicals from Blackcurrants ( Ribes nigrum L.)

Natural colorants were extracted from renewable botanical sources, specifically waste epicarp from the blackcurrant fruit pressing industry. A process was developed which used acidified water extraction followed by a solid-phase extraction (SPE) purification stage which allowed the production of an anthocyanin-rich extract in good yields (ca. 2% w/ w based on dry weight of raw material). The components in the extracts were extensively characterized by HPLC, mass spectrometry, IR, NMR, and UV-vis spectroscopy. HPLC confirmed presence of four anthocyanins: delphinidin-3- O-rutinoside (45%), cyanidin-3- O-rutinoside (31%), and the corresponding glucosides at 16% and 8%, respectively. On sequential liquid-liquid aqueous-organic partitioning of the post-SPE sample, monomeric anthocyanins (54.7%) and polymeric anthocyanins (18%) were found in the aqueous layer with 3- O-rutinosides of myricetin (3.1%) and quercetin (3.2%), while isopropylacetate achieved selective extraction of caffeic acid (3%), p-coumaric acid (5%), and myricetin (2.5%) and quercetin (3.2%) aglycons. 3- O-Glucosides of myricetin (3.1%) and quercetin (2%), along with nigrumin- p-coumarate (1%) and nigrumin ferulate (0.5%) were selectively extracted from the remaining aqueous fraction using ethyl acetate. This allowed for near total quantification of the blackcurrant extract composition.

Application of Anthocyanins from Blackcurrant ( Ribes nigrum L.) Fruit Waste as Renewable Hair Dyes

There is much concern about the toxicological effects of synthetic hair dyes. As an alternative approach, renewable waste blackcurrant ( Ribes nigrum L.) fruit skins from the fruit pressing industry were extracted using acidified water with a solid-phase purification stage. Anthocyanin colorants were isolated in good yields (2-3% w/ w) and characterized by HPLC. Sorption of anthocyanins onto hair followed a Freundlich isotherm; anthocyanin-anthocyanin aggregation interactions enabled high buildup on the substrate. Sorption energy of cyanidin-3- O-glucoside (monosaccharide) > cyanidin-3- O-rutinoside (disaccharide), but sorption properties of different anthocyanin glucosides were very similar. Intense blue-colored dyeing on hair could be achieved with λ_max-vis at 580 nm, typical of the anionic quinonoid base; it is suggested that hair provides an environment that enables the stabilization of the anionic quinonoid base on adsorption through association with cations in the hair and copigmentation effects. Dyeings were stable to multiple washes.

Black rice anthocyanin-rich extract and rosmarinic acid, alone and in combination, protect against DSS-induced colitis in mice

The aim of this study was to investigate the effect of black rice anthocyanin-rich extract (BRAE) and rosmarinic acid (RA), alone and in combination, on dextran sulfate sodium (DSS)-induced colitis in mice. Results showed that administration of BRAE and RA, alone and in combination, significantly decreased the disease activity index (DAI) and the histological score of colons in DSS-induced colitis mice. Moreover, the administration of BRAE and RA, alone and in combination, not only reduced myeloperoxidase (MPO) and nitric oxide (NO) levels, but also inhibited the expression of pro-inflammatory mediators including interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. Our results showed that BRAE decreased the histological score and TNF-α mRNA expression in a dose-dependent manner, while BRAE + RA dose-dependently attenuated the histological score and mRNA expression of IL-6. However, the benefits of RA were not dose-dependent within the dose range of 25-100 mg kg-1. The combination of BRAE and RA showed better inhibitory effect on the NO content and iNOS mRNA expression than BRAE or RA given alone, and was the most effective in ameliorating DSS-induced colitis at 100 mg kg-1. Notably, the BRAE and RA combination exhibited additive interactions in reducing MPO and NO levels, as well as the expression of some pro-inflammatory mediators (IL-6, IL-1β and iNOS), especially at 100 mg kg-1. In conclusion, dietary BRAE and RA, alone and in combination, alleviate the symptoms and inflammation of DSS-induced colitis in mice, and may provide a promising dietary approach for the management of inflammatory bowel disease.

Natural colorants: Pigment stability and extraction yield enhancement via utilization of appropriate pretreatment and extraction methods

Natural colorants from plant-based materials have gained increasing popularity due to health consciousness of consumers. Among the many steps involved in the production of natural colorants, pigment extraction is one of the most important. Soxhlet extraction, maceration, and hydrodistillation are conventional methods that have been widely used in industry and laboratory for such a purpose. Recently, various non-conventional methods, such as supercritical fluid extraction, pressurized liquid extraction, microwave-assisted extraction, ultrasound-assisted extraction, pulsed-electric field extraction, and enzyme-assisted extraction have emerged as alternatives to conventional methods due to the advantages of the former in terms of smaller solvent consumption, shorter extraction time, and more environment-friendliness. Prior to the extraction step, pretreatment of plant materials to enhance the stability of natural pigments is another important step that must be carefully taken care of. In this paper, a comprehensive review of appropriate pretreatment and extraction methods for chlorophylls, carotenoids, betalains, and anthocyanins, which are major classes of plant pigments, is provided by using pigment stability and extraction yield as assessment criteria.

Effect of UV Irradiation on the Nutritional Quality and Cytotoxicity of Apple Juice

UV-C irradiation operating at 254 nm wavelength on the polyphenolic and vitamin contents of apple juice including cytotoxicity analysis was studied. UV doses ranging from 0 to 150 mJ·cm^-2 were selected for the treatments. Polyphenols (catechin, epicatechin, chlorogenic acid, and phloridzin) and vitamins (riboflavin, thiamine hydrochloride, pyridoxal hydrochloride, pyridoxine, pyridoxamine dihydrochloride, cyanocobalamin, choline chloride, biotin, niacin, and niacinamide) were chemically profiled. It was observed that UV treatment of apple juice at disinfection doses caused minor reductions (p < 0.05) in the concentrations of two main polyphenols (i.e., chlorogenic acid and epicatechin). In contrast, significant (p < 0.05) decreases in vitamin concentrations were observed (p < 0.05). The irradiated juice was evaluated for cytotoxic effects. The irradiated apple juice showed no cytotoxic effects on normal intestinal cells, and both irradiated and nonirradiated samples are significantly comparable in inhibiting the growth of human colon cancer cells. Overall, these results indicated that UV-C treatment of apple juice neither significantly degraded polyphenols nor generated cytotoxic compounds.

What Gives a Wine Its Strong Red Color? Main Correlations Affecting Copigmentation

Copigmentation and enological parameters were studied in a collection of 250 red wines. Although several copigmentation studies have been performed with model solutions, little is known about the actual consequences directly in wine of anthocyanin interactions. To date, some studies have considered relationships between copigmentation and natural wine constituents, but none correlates copigmentation measurements with the real wide concentration in wine. In this work, published hypotheses based on model solutions such as phenolic acid copigmentation ability or the influence of copigmentation factors such as flavonols are empirically evaluated in a large sample of wines for the first time. The study confirms previous results obtained from solutions, whereas other factors suggested as being relevant seem to be unrelated to the studied effect at the concentration range naturally occurring in the wines studied. For instance, the important role of flavonols and hydroxycinnamic acids has been ratified, whereas ethanol, gallic acid, and some metals show significant inverse correlations with copigmentation. Unexpectedly, magnesium content in wine correlates with color, whereas the concentration of traditional copigments, such as quercetin, does not show any correlation with copigmentation.

The State of the Art in Biosynthesis of Anthocyanins and Its Regulation in Pigmented Sweet Oranges [(Citrus sinensis) L. Osbeck]

Anthocyanins are water-soluble pigments belonging to the flavonoid compound family involved in nature in several aspects of plant development and defense. By bestowing much of the color and flavor on fruits and vegetables, they are components of the human diet and, thanks to their radical-scavenging properties, are not considered exclusively as food products but also as therapeutic agents. Several cultivars of red (or blood) oranges [Citrus sinensis (L.) Osbeck], such as Tarocco, Moro, and Sanguinello, are characterized by the presence of anthocyanins in both the rind and fruit juice vesicles. The amount and composition of anthocyanins in the pigmented orange cultivar vary greatly depending on variety, maturity, region of cultivation, and many other environmental conditions. Most of the blood orange varieties require a wide day-night thermal range to maximize color formation. Therefore, the production of red oranges characterized by high anthocyanin levels is limited to a few regions and in particular to the Sicilian area around Mount Etna in Italy, where the characteristic climate conditions yield fruits of unique color intensity and quality. In this review, both the basic information and the most recent advances in red orange anthocyanins are reported, with intense attention given to their biosynthesis and regulation.

Recent advances on the development and regulation of flower color in ornamental plants

Flower color is one of the most important features of ornamental plants. Its development and regulation are influenced by many internal and external factors. Therefore, understanding the mechanism of color development and its regulation provides an important theoretical basis and premise for the cultivation and improvement of new color varieties of ornamental plants. This paper outlines the functions of petal tissue structure, as well as the distribution and type of pigments, especially anthocyanins, in color development. The progress of research on flower color regulation with a focus on physical factors, chemical factors, and genetic engineering is introduced. The shortcomings of flower color research and the potential directions for future development are explored to provide a broad background for flower color improvements in ornamental plants.

Effect of the Addition of Schisandra chinensis Powder on the Physico-chemical Characteristics of Sausage

The individual and interactive effects of Schisandra chinensis powder (SCP) and sodium nitrite additions on color, pH, water holding capacity, residual nitrite, 2-thiobarbituric acid reactive substances (TBARS), volatile basic nitrogen, texture properties, fatty acids, amino acids and sensory evaluation of cooked pork sausages were investigated after 20 d of storage at 4°C. The powders (0, 0.5 and 1.0%) were added to sausages either alone or in combination with nitrite (0 and 100 ppm). SCP added-sausages showed lower L* (lightness) and W (whiteness) values, and higher b* (yellowness) values than sausage containing no nitrite, and exhibited the highest a^* values at a 0.5% addition (p<0.05). Residual nitrite and TBARS values were found to be significantly reduced as the addition levels of SCP increased (p<0.05). As the addition of SCP increased, the sausage showed gradually decreased brittleness, cohesiveness, springiness, gumminess and chewiness, while adhesiveness increased. Polyunsaturated fatty acid, n-6 and n-6/n-3 fatty acid ratio concentrations were significantly higher in sausages containing SCP (p<0.05). The addition of SCP to sausage significantly (p<0.05) increased the ammonia content (by 0.5% SCP) and aromatic amino acid concentrations (by 1.0% SCP) (p<0.05). Inclusion of SCP in sausage meat resulted in a significant deterioration in quality characteristics of flavor, springiness, juiciness and overall acceptability (p<0.05). As expected, the observed changes in a*, W, pH, shear force, texture property, TBARS, fatty acid, amino acid and sensory score of sausages, depended on the rate of addition of nitrite (p<0.05). These results suggest that SCP addition is not an effective way of improving the sensory evaluation of sausages, but may beneficially affect TBARS, nitrite scavenging activity, fatty acid and amino acid content in pork sausages.

A new antioxidant beverage produced with green tea and apple

Green tea and apple are natural products with health benefits. These healthy properties are linked closely to the antioxidant compounds, mainly phenolic compounds. These antioxidant compounds have a potential for preventing and treating cancer, cardiovascular, inflammatory and neurodegenerative diseases in humans. The aim of the present work was to design a new beverage with high antioxidant power combining extracts of green tea and apple, studying the antioxidant composition and activity, organoleptic properties (colour) and stability status during storage at different temperatures. The majority compounds identified in the beverage were flavan-3-ols, being the (-)-epigallocatechin-3-gallate which had the highest concentration. After storage, floridzine was the compound with lower decrease of concentration. The new designed beverage had a good colour, and high antioxidant activity and stability at room temperature, so that the beverage needs no refrigeration, showing potential for the development of new healthy functional beverages.

New beverages of lemon juice with elderberry and grape concentrates as a source of bioactive compounds

Considering the health potential of lemon and berry fruits, different functional beverages rich in antioxidant phytochemicals, which demonstrated beneficial effects, were developed. To fulfill this objective, lemon juice was combined with 2 different concentrates, elderberry and grape, in a proportion of 5% (w/v). Bioactive composition (flavonoids and vitamin C) and color stability, as well as the antioxidant capacity of mixtures, during a period of 56 d of storage, were studied. A protective role of anthocyanins on ascorbic acid preservation was noted for both lemon-berry blends, keeping vitamin C stable until the end of the storage. In addition, the new drink combining lemon and elderberry performed better than the grape-lemon mixture in terms of health-promoting phytochemicals content, just as in vitro antioxidant capacity and color characteristics.

PRACTICAL APPLICATION

Beverages made from lemon juice and berries could contribute to develop new drinks with a prolonged preservation of bioactive compounds throughout storage, keeping an attractive color and a high antioxidant activity during long periods of time. The information obtained in the present work is in agreement to the rules of health and safety for juices established by the Directive of European Commission Dir2001/112/CE incorporated to the Spanish law through the RD1050/2003 regulation. Consequently, an improved performance of industrial products would be achieved.

Anthocyanins and their variation in red wines I. Monomeric anthocyanins and their color expression

Originating in the grapes, monomeric anthocyanins in young red wines contribute the majority of color and the supposed beneficial health effects related to their consumption, and as such they are recognized as one of the most important groups of phenolic metabolites in red wines. In recent years, our increasing knowledge of the chemical complexity of the monomeric anthocyanins, their stability, together with the phenomena such as self-association and copigmentation that can stabilize and enhance their color has helped to explain their color representation in red wine making and aging. A series of new enological practices were developed to improve the anthocyanin extraction, as well as their color expression and maintenance. This paper summarizes the most recent advances in the studies of the monomeric anthocyanins in red wines, emphasizing their origin, occurrence, color enhancing effects, their degradation and the effect of various enological practices on them.

Composition and stability of anthocyanins from purple Solanum tuberosum and their protective influence on Cr(VI) targeted to bovine serum albumin

Anthocyanins from the purple Solanum tuberosum newly cultivated by the Taian Academy of Agricultural Sciences were extracted and analyzed using high-performance liquid chromatography (HPLC) and UV-vis spectroscopy. Four individual anthocyanins were detected as the major components, and the total anthocyanin content was 273.5 ± 14.3 mg of cyanidin-3-glucoside equiv/100 g of dry seeds. Results of color stability showed that the purple S. tuberosum anthocyanins (PSTAs) are more stable under low pH and temperatures. Heat and general food additives have fine compatibility with PSTAs; however, they are very sensitive with oxidant and reduction. The influence of PSTAs on Cr(VI) targeted to bovine serum albumin (BSA) was also studied. The quenching of BSA fluorescence caused by Cr(VI) could be delayed by PSTAs. UV-vis and circular dichroism (CD) data suggested that PSTAs can protect the secondary and tertiary structures of BSA by probably interacting with Cr(VI) in advance.

A comparison of two determination methods for studying degradation kinetics of the major anthocyanins from blood orange

The thermal degradation of cyanidin 3-(6''-malonyl) glucoside and cyanidin 3-glucoside, which are the two major anthocyanins in blood orange juice, have been investigated using the pH-differential method and RP-HPLC method, respectively. Similar results could be obtained when the degradation kinetics of cyanidin 3-glucoside were studied by either the HPLC method or the pH-differential method. However, contrary results were obtained in the case of cyanidin 3-(6''-malonyl) glucoside. The HPLC analysis indicated that cyanidin 3-(6''-malonyl) glucoside was labile to eliminate a malonyl moiety to form cyanidin 3-glucoside before disappearing during thermal treatment and showed a lower thermal stability than cyanidin 3-glucoside, whereas the result obtained by the pH-differential method actually reflected the content of both cyanidin 3-(6''-malonyl) glucoside and its degradation intermediate. This caused an overestimate of the stability of cyanidin 3-(6''-malonyl) glucoside.

Influence of processing on quality parameters of strawberries

To determine the effects of different processing steps, such as enzymatic treatment of the mash and pasteurization, on selected quality parameters, strawberries were processed to juices and purees. To identify the processing steps causing the highest losses, samples were taken after each step, and ascorbic acid, total phenols, anthocyanins, and antioxidant capacity were analyzed. To assess the antioxidant capacity, three different methods were applied: the trolox equivalent antioxidant capacity (TEAC), the ferric reducing antioxidant power (FRAP), and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, showing correlation coefficients of 0.889 to 0.948. The antioxidant capacity decreased with processing steps except heat treatment, which partly caused an increase due to the formation of antioxidant active products. The content of ascorbic acid, in comparison to that in the frozen strawberries, decreased significantly during the processing of the fruit to puree by 77%. In the pressed cloudy juices, the loss of ascorbic acid was 37%. The decline of phenolic compounds, measured as total polyphenols and anthocyanins, was smaller (between 30-40%). Pressing and pasteurization were the most critical steps for the decrease of these compounds. The enzymatic treatment of the mash within 90 min supported the release of secondary plant metabolites, while ascorbic acid is reduced up to 20%.