Haze in Apple-Based Beverages: Detailed Polyphenol, Polysaccharide, Protein, and Mineral Compositions

Producers of apple-based beverages are confronted with colloidal instability. Haze is caused by interactions between molecules that lead to the formation of aggregates. Haze composition in three apple-based beverages, namely, French sparkling cider, apple juice, and pommeau, was studied. Phenolic compounds, proteins, polysaccharides, and minerals were analyzed using global and detailed analytical methods. The results explained <75% (w/w) of haze dry mass. Polyphenols, represented mainly by procyanidins, were the main compounds identified and accounted for 10–31% of haze. However, oxidized phenolic compounds were probably underestimated and may represent a high proportion of haze. Proteins were present in all of the samples in proportions of <6% of haze except in two apple juice hazes, where they were the main constituents (18 and 24%). Polysaccharides accounted for 0–30% of haze. Potassium and calcium were the main minerals

Detailed Polyphenol and Tannin Composition and Its Variability in Tunisian Dates (Phoenix dactylifera L.) at Different Maturity Stages

The polyphenol profile of two Tunisian varieties of dates including flavanols, flavonols, flavones, and hydroxycinnamates was characterized. Three tissue zones (flesh, peel, and stone) and three maturity stages were considered. Phenolic compounds were analyzed using reversed phase high-performance liquid chromatography coupled to UV–visible and electrospray mass spectrometry. Procyanidin oligomers and polymers were characterized and quantified using phloroglucinolysis prior to HPLC analysis. Procyanidin polymers based on (−)-epicatechin structure were by far the most concentrated polyphenols in ripe dates, accounting for 95% of total polyphenols with an average concentration of 14 g/kg in the fresh edible parts of the fruit. Interestingly, procyanidins were also highly concentrated in the stones. The concentration and average degree of polymerization (DP<i>n</i>) of the procyanidins decreased according to maturity. Other phenolics, including caffeoylshikimic acid hexoside, caffeoyl-sinapoyl monohexoside and dihexoside, and acetylated flavonols, were tentatively identified for the first time in the fruit

Polyphenol Profiling of a Red-Fleshed Apple Cultivar and Evaluation of the Color Extractability and Stability in the Juice

Red-fleshed apples can be used for the production of innovative products such as rosé juices and ciders. Phenolic compounds including procyanidins (i.e., condensed tannins) and anthocyanins were quantified in the fruits and juices of a red-fleshed apple cultivar by chromatography coupled to UV–visible and mass spectrometry. Juice color was characterized by colorimetry. The influence of oxygen, pH, sulfites, ascorbic acid, and copper on the color stability of the juice was studied in an experimental design. Fruits were rich in polyphenols (0.5 g/100 g FW), with anthocyanins and procyanidins accounting for 9 and 73% of total polyphenols, respectively. Extractability of anthocyanins in the juice was 26%. Juice storage under air atmosphere at 35 °C resulted in significant browning with the anthocyanin level decreasing up to 86% after 14 days. In contrast, color was stable for storage under argon atmosphere. Sulfites, ascorbic acid, and copper have only a slightly influence on color stability in those conditions

HPLC-DAD-MS Profiling of Polyphenols Responsible for the Yellow-Orange Color in Apple Juices of Different French Cider Apple Varieties

The pigments responsible for the yellow-orange coloration of apple juices have remained largely unknown up to now. Four French cider apple juices were produced in conditions similar to those used in the cider-making industry. The oxidized juices, characterized using the CIE <i>L</i> <i>a</i> <i>b</i> parameters, displayed various colors depending on the apple variety and native phenolic composition. HPLC-DAD-MS revealed contrasting pigment profiles related to oxidized tanning and nontanning molecules. The latter were divided into two groups according to their polarity and their visible spectra. With regard to phenolic classes, flavanol monomers and hydroxycinnamic acids played an essential role in the formation of oxidation products. Interestingly, dihydrochalcones appeared to include precursors of some yellow compounds. Indeed, the yellow pigment phloretin xyloglucoside oxidation product (PXGOPj), derived from phloretin xyloglucoside, was clearly identified in apple juices as a xyloglucose analogue of the yellow pigment phloridzin oxidation product (POPj), previously characterized in a model solution by Le Guernevé et al. (<i>Tetrahedron Lett.</i> <b>2004</b>, <i>45</i> (35), 6673–6677)

Polyphenol Interactions Mitigate the Immunogenicity and Allergenicity of Gliadins

Wheat allergy is an IgE-mediated disorder. Polyphenols, which are known to interact with certain proteins, could be used to reduce allergic reactions. This study screened several polyphenol sources for their ability to interact with gliadins, mask epitopes, and affect basophil degranulation. Polyphenol extracts from artichoke leaves, cranberries, apples, and green tea leaves were examined. Of these extracts, the first three formed insoluble complexes with gliadins. Only the cranberry and apple extracts masked epitopes in dot blot assays using anti-gliadin IgG and IgE antibodies from patients with wheat allergies. The cranberry and artichoke extracts limited cellular degranulation by reducing mouse anti-gliadin IgE recognition. In conclusion, the cranberry extract is the most effective polyphenol source at reducing the immunogenicity and allergenicity of wheat gliadins

Phenolic compounds biosynthesis [15]–[20] (KEGG, 2012).

<p>In bold, enzymes identified in the support interval of QTLs. 4CL: 4-coumarate:CoA ligase; ANR: anthocyanidin reductase; ANS: anthocyanidin synthase; C3'H: <i>p</i>-coumarate 3′-hydroxylase; C4H: cinnamate 4-hydroxylase; CHI: chalcone isomerase; CHS: chalcone synthase; D2'GT: dihydrochalcone 2-<i>O</i>-glucosyltransferase; DFR: dihydroflavanol 4-reductase; F3'H: flavonoid 3′-hydroxylase; F3'5'H: flavonoid 3',5'-hydroxylase; FHT: flavanone 3-β-hydroxylase; FLS: flavonol synthase; HCT: shikimate <i>O</i>-hydroxycinnamoyl transferase; HQT: quinate <i>O</i>-hydroxycinnamoyl transferase; LAR: leucoanthocyanidin reductase; PAL: phenylalanine ammonia lyase; TAL: tyrosine ammonia lyase; UFGT: UDP-glucose 3-glucosyltransferase.</p

Properties of polymorphic SSR primers developed from ‘Golden Delicious’ genomic sequence for major candidate genes.

<p>*: enzymes which could not be mapped.</p>a<p>: F3’H: flavonoid 3′-hydroxylase; F3'5'H: flavonoids 3',5'-hydroxylase; FHT: flavanone 3-β-hydroxylase; UFGT: UDP-glucose 3-glucosyltransferase; DFR: dihydroflavanol 4-reductase; FLS: flavonols synthase; CHI: chalcone isomerase; CHS: chalcone synthase; HCT/HQT: shikimate/quinate hydroxycinnamoyltransferase.</p><p>Properties of polymorphic SSR primers developed from ‘Golden Delicious’ genomic sequence for major candidate genes.</p

Main interesting clusters of quantitative trait loci (QTL) for phenolic compounds in fruit and juice.

<p>Main QTL clusters obtained are represented with black bars on the right of the corresponding linkage groups (LG). Putative candidate genes identified <i>in silico</i> and their relative position on the map are specified on the left of the LG. Genetically mapped candidate genes are indicated on the right of the LG and underlined.</p

Broad sense genetic heritability of mean polymerization degree and phenolic compounds quantified in fruits harvested in 2008 (F08) and 2009 (F09) and in juices prepared in 2009 (J09) and 2010 (J10).

a<p>: DPn: mean polymerization degree.</p>b<p>: na: not available.</p><p>Broad sense genetic heritability of mean polymerization degree and phenolic compounds quantified in fruits harvested in 2008 (F08) and 2009 (F09) and in juices prepared in 2009 (J09) and 2010 (J10).</p

Selected candidate genes identified in the interval of 12 clusters of quantitative trait loci (QTL) using the BLAST2GO software.

a<p>: CHI: chalcone isomerase; CHS: chalcone synthase; DFR: dihydroflavanol 4-reductase; F3'H: flavonoid 3′-hydroxylase; F3'5'H: flavonoids 3',5'-hydroxylase; FLS: flavonols synthase; HCT/HQT: shikimate/quinate hydroxycinnamoyl transferase; UFGT: UDP-glucose 3-glucosyltransferase.</p>b<p>: contig containing the gene on the apple genome browser.</p>c<p>: longest hits which aligned with the sequence.</p>d<p>: numbered of alignment achieved.</p>e<p>: estimator of the quality of the alignment.</p>f<p>: average proportion of sequence similarity.</p><p>Selected candidate genes identified in the interval of 12 clusters of quantitative trait loci (QTL) using the BLAST2GO software.</p