Starch Digestion Enhances Bioaccessibility of Anti-Inflammatory Polyphenols from Borlotti Beans (Phaseolus vulgaris)

The consumption of beans has been associated with chronic disease prevention which may be attributed to the polyphenols present in the seed coat and endosperm. However, their bioaccessibility is likely to be limited by interactions with bean matrix components, including starch, protein and fibre. The aim of this project was to evaluate the effect of domestic processing and enzymatic digestion on the bioaccessibility of polyphenols from Borlotti beans (Phaseolus vulgaris) and to test their anti-inflammatory properties in a macrophage cell model. In vitro digestion of cooked beans released twenty times more polyphenols (40.4 ± 2.5 mg gallic acid equivalents (GAE)/g) than domestic processing (2.22 ± 0.1 mg GAE/g), with starch digestion contributing to the highest release (30.9 ± 0.75 mg GAE/g). Fluorescence microscopy visualization of isolated bean starch suggests that polyphenols are embedded within the granule structure. LC-MS analysis showed that cooked Borlotti bean contain flavonoids, flavones and hydroxycinnamic acids, and cooked bean extracts exerted moderate anti-inflammatory effects by decreasing mRNA levels of IL1β and iNOS by 25% and 40%, respectively. In conclusion, the bioaccessibility of bean polyphenols is strongly enhanced by starch digestion. These polyphenols may contribute to the health benefits associated with bean consumption

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%), whilst 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 ethylacetate. This allowed for near total quantification of the blackcurrant extract composition

Green extraction of polyphenols from citrus peel by-products and their antifungal activity against Aspergillus flavus

Aspergillus flavus is a pathogenic fungus associated with food safety issues worldwide. This study investigated the antifungal activity of citrus peel extracts prepared using food-grade solvents (hot water or ethanol). Mandarin (Citrus reticulata) peel ethanol extracts inhibited the mycelial growth of A. flavus (39.60%) more effectively than those of orange (32.31%) and lemon (13.51%) after 7 days of incubation. The growth of A. flavus could be completely inhibited by mandarin extracts at 300–400 mg mL−1, depending on the extraction solvent. Solid-phase extraction (SPE) separated the polyphenol-rich fractions, which showed up to 40% higher antifungal activity than crude extracts. Twelve polyphenols (2 phenolic acids and 10 flavonoids) were identified by HPLC-DAD, narirutin and hesperidin were the most abundant. In conclusion, citrus peels are promising bioresources of antifungal agents with potential applications in food and other industries

Selective enzymatic lipophilization of anthocyanin glucosides from blackcurrant (Ribes nigrum L.) skin extract and characterization of esterified anthocyanins

Anthocyanins (ANC) are hydrophilic and water-soluble polyphenolic plant pigments. The current barriers to successful application of ANC in food, cosmetic and pharmaceutical industries are predominantly related to performance, stability, formulation properties, and color. Enzymatic acylation of ANC could increase their stability without compromising bioactivity and chromatic features. Lipophilization of ANC-rich blackcurrant skin extract with Candida antarctica lipase B and octanoic acid was selective to cyanidin and delphinidin glucosides, but not the corresponding rutinosides. The reaction was chemo- and regioselective for acylation at the primary alcohol of the glucose moieties, greatly facilitating separation of the different glycoside derivatives

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. Anthocyanins 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 enabling high build-up 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 dyeings on hair could be achieved with λmax-vis at 580 nm, typical of the anionic quinonoid base – it is suggested that the 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

Nucleophile-Catalyzed Additions to Activated Triple Bonds. Protection of Lactams, Imides, and Nucleosides with MocVinyl and Related Groups

Additions of lactams, imides, (S)-4-benzyl-1,3-oxazolidin-2-one, 2-pyridone, pyrimidine-2,4-diones (AZT derivatives), or inosines to the electron-deficient triple bonds of methyl propynoate, tert-butyl propynoate, 3-butyn-2-one, N-propynoylmorpholine, or N-methoxy-N-methylpropynamide in the presence of many potential catalysts were examined. DABCO and, second, DMAP appeared to be the best (highest reaction rates and E/Z ratios), while RuCl3, RuClCp*(PPh3)2, AuCl, AuCl(PPh3), CuI, and Cu2(OTf)2 were incapable of catalyzing such additions. The groups incorporated (for example, the 2-(methoxycarbonyl)ethenyl group that we name MocVinyl) serve as protecting groups for the above-mentioned heterocyclic CONH or CONHCO moieties. Deprotections were accomplished via exchange with good nucleophiles: the 1-dodecanethiolate anion turned out to be the most general and efficient reagent, but in some particular cases other nucleophiles also worked (e.g., MocVinyl-inosines can be cleaved with succinimide anion). Some structural and mechanistic details have been accounted for with the help of DFT and MP2 calculations

Industrial application of anthocyanins extracted from food waste

Extracts rich with anthocyanin O-glycosides are obtained from sustainable waste food sources; one notable example is delphinidin- and cyanidin-O-glucosides extracted from blackcurrant – after juice production, waste blackcurrant skins are processed and extracted using acidified water, and subsequently purified using Solid Phase Extraction. Analytical HPLC in combination with chemical assays are used to determine the anthocyanin fingerprint, polyphenol and anthocyanin content of the extracts. Preservation of glycosylation in extraction enables advantageous formulation, stability, and application of the anthocyanin extracts in industrial applications. As anthocyanins are pH sensitive, they present some limitations in their applications due to their moderate stability and solubility in aqueous solutions (Pina et al. Chem. Soc. Rev., 2012, 41, 869). Herein, we tackle these limitations by understanding anthocyanin chemistry and exploiting biomimetic approaches. The delphinidin and cyanidin-rich blackcurrant extract can be used as blue semi-permanent hair dye. When dyeing from aqueous acidic medium (pH 3-4), despite λmax in solution being 517 nm for cyanidin and 526 nm for delphinidin (violet colour consistent with flavylium cation), λmax when adsorbed onto hair from aqueous medium is 570-580 nm (blue colour consistent with quinonoidal base); this suggests an in situ neutralisation by basic sites on the hair surface leading to formation of the anhydrobase form. The dyeings are stable over 12+ washes, with minimal colour loss, and no colour change; the systems may be used in combination with other natural dyes to provide a range of shades. In other applications, stable water-soluble and water-insoluble blue pigments may be obtained by combination of anthocyanin O-glycoside extracts with metal salts; pigments are formed using novel “biomimicry” process inspired by plant pigment formation in flowers. We have successfully applied these pigments as blue confectionery colorants and in novel printing methods for obtaining safety codes on eggshell

Sustainable film-forming biopolymers and their formulation for naturally-derived hair styling products

Hair styling products are typically based on synthetic polymers and copolymers including, poly(vinylpyrrolidone), polyquaternium-11, and polyquaternium-16, and are ultimately derived from petrochemicals. These polymers and copolymers are generally water and ethanol soluble and provide hold and film formation. Attention has turned to the use of naturally derived polymers that would offer more sustainable products; current alternatives are largely based on corn starch and modified corn starch, however, they exhibit major disadvantages including lack of ethanol solubility, opaque film formation and leave a starchy feel on the hair. The use of ethanol is highly desirable in hair styling compositions as its incorporation considerably decreases drying time after application to hair; 55% v/v ethanol is typical, although some aerosol formulations can be even higher. A novel film-forming hair styling product was developed using alginic acid and pectin. These biopolymers comprise α-L-guluronic acid, β-D-mannuronic acid, and α-D-galacturonic acid moieties, and are readily available from food industry waste and seaweed. Although sodium salts of these biopolymers are good film-formers from aqueous solution, poor hydration in water-miscible solvents effectively limits the quantity of ethanol to a maximum of 20% before precipitation occurs. It was found that inclusion of an amine ameliorated this problem; the biopolymer and the amine containing moiety interact to form an amine salt of the biopolymer in situ. Alginic acid or pectin was added to water until a fine colloidal suspension was obtained, to which the amine was added, forming an amine alginate polymer that dissolved fully in water, providing a solution with high clarity. Ethanol was slowly added to this aqueous solution of amine alginate/pectinate until the requisite amount of ethanol had been added; it was observed that these compositions could tolerate ethanol as part of the solvent system up to 80%. Triethanolamine and 2-amino-2-methyl-1-propanol, typically found in cosmetic preparations, were excellent for use in these formulation In addition, amino acids, particularly histidine, proline, and glycine could also be successfully employed. The resultant compositions were applied to human hair and dried quickly and had stiff hold. The polymers were easily removed from the hair with shampoo

Industrial application of anthocyanins extracted from food waste

Extracts rich with anthocyanin O-glycosides are obtained from sustainable waste food sources; one notable example is delphinidin- and cyanidin-O-glucosides extracted from blackcurrant – after juice production, waste blackcurrant skins are processed and extracted using acidified water, and subsequently purified using Solid Phase Extraction. Analytical HPLC in combination with chemical assays are used to determine the anthocyanin fingerprint, polyphenol and anthocyanin content of the extracts. Preservation of glycosylation in extraction enables advantageous formulation, stability, and application of the anthocyanin extracts in industrial applications. As anthocyanins are pH sensitive, they present some limitations in their applications due to their moderate stability and solubility in aqueous solutions (Pina et al. Chem. Soc. Rev., 2012, 41, 869). Herein, we tackle these limitations by understanding anthocyanin chemistry and exploiting biomimetic approaches. The delphinidin and cyanidin-rich blackcurrant extract can be used as blue semi-permanent hair dye. When dyeing from aqueous acidic medium (pH 3-4), despite λmax in solution being 517 nm for cyanidin and 526 nm for delphinidin (violet colour consistent with flavylium cation), λmax when adsorbed onto hair from aqueous medium is 570-580 nm (blue colour consistent with quinonoidal base); this suggests an in situ neutralisation by basic sites on the hair surface leading to formation of the anhydrobase form. The dyeings are stable over 12+ washes, with minimal colour loss, and no colour change; the systems may be used in combination with other natural dyes to provide a range of shades. In other applications, stable water-soluble and water-insoluble blue pigments may be obtained by combination of anthocyanin O-glycoside extracts with metal salts; pigments are formed using novel “biomimicry” process inspired by plant pigment formation in flowers. We have successfully applied these pigments as blue confectionery colorants and in novel printing methods for obtaining safety codes on eggshell

Scalable anthocyanin extraction and purification methods for industrial application

Blackcurrant (Ribes nigrum L.) fruit is used in the food industry to produce various beverages, jams and other preparations. Waste blackcurrant skins from fruit pressing are obtained in large quantities from this sustainable and food-grade source. The material can be processed and extracted in large scale using acidified water, and subsequently purified using Solid Phase Extraction. The blackcurrant extracts are intensely coloured due to the presence of anthocyanins and have potential to act as natural colorants in consumer products. Blackcurrant extract was analysed using analytical HPLC, LC-MS, 1H NMR spectroscopy and total monomeric anthocyanin content assay (TMAC). Four major anthocyanins along with eight other polyphenols were identified in the crude extract; these were rutinosides and glucosides of cyanidin and delphinidin. Flavonols namely quercetin and myricetin were found in the aglycon form as well as mono- and di-substituted forms. Caffeic and p-coumaric acid were also present in the extract. Liquid-liquid extraction allows partitioning of specific metabolites based on their physical properties (neutral or charged species, aglycons, glucosides or rutinosides). It was observed that migration of different polyphenols out of the aqueous layer is possible by taking advantage of parameters such as the polarity of the organic solvent employed or pH of the aqueous layer. Use of ethyl acetate facilitates removal of neutral compounds, such as myricetin and quercetin (aglycons and glucosides) along with hydroxycinnamic acids (caffeic and p-coumaric acids), out of the aqueous extract. Isopropyl acetate selectively removes hydroxycinnamic acids, myricetin and quercetin, with the four anthocyanins (Dp-3-glc, Dp-3-rut, Cy-3-glc, Cy-3-rut) along with rutinosides of myricetin and quercetin remaining in the aqueous layer. Myricetin and quercetin rutinosides could be subsequently removed by extraction in ethyl acetate at higher pH (6.29), leaving a purified anthocyanin fraction. Preparative HPLC was utilised to isolate these polyphenols which were then fully characterised