Effect of industrial freezing on the physical and nutritional quality traits in broccoli.

Broccoli was blanched and frozen at industrial scale to ascertain the physical and nutritional changes that take place in industrial processing. Colour, texture, ascorbic and dehydroascorbic acids, glucosinolates, phenolic compounds, antioxidant capacity, mineral nutrients and microstructure were evaluated. Blanching and freezing caused a decrease in lightness and firmness. Losses of phenolic compounds and ascorbic acid + dehydroascorbic acid reached about 57% and 30%, respectively. The antioxidant capacity was similar in fresh and treated broccoli, and the glucosinolates remained constant. These results show that frozen broccoli retains antioxidants compounds, vitamin C and glucosinolates even after industrial processing, meaning that industrially frozen broccoli intended for human consumption can be considered rather similar to the fresh product.

Date Palm Trees Root-Derived Endophytes as Fungal Cell Factories for Diverse Bioactive Metabolites.

Endophytic fungi of healthy and brittle leaf diseased (BLD) date palm trees (Phoenix dactylifera L.) represent a promising source of bioactive compounds with biomedical, industrial, and pharmaceutical applications. The fungal endophytes Penicillium citrinum isolate TDPEF34, and Geotrichum candidum isolate TDPEF20 from healthy and BLD date palm trees, respectively, proved very effective in confrontation assays against three pathogenic bacteria, including two Gram-positive bacteria Bacillus thuringiensis (Bt) and Enterococcus faecalis (Ef), and one Gram-negative bacterium Salmonella enterica (St). They also inhibited the growth of three fungi Trichoderma sp. (Ti), Fusarium sporotrichioides (Fs), Trichoderma sp. (Ts). Additionally, their volatile organic compounds (VOCs) were shown to be in part responsible for the inhibition of Ti and Ts and could account for the full inhibition of Fs. Therefore, we have explored their potential as fungal cell factories for bioactive metabolites production. Four extracts of each endophyte were prepared using different solvent polarities, ethanol (EtOH), ethyl acetate (EtOAc), hexane (Hex), and methanol (MetOH). Both endophyte species showed varying degrees of inhibition of the bacterial and fungal pathogens according to the solvent used. These results suggest a good relationship between fungal bioactivities and their produced secondary metabolites. Targeting the discovery of potential anti-diabetic, anti-hemolysis, anti-inflammatory, anti-obesity, and cytotoxic activities, endophytic extracts showed promising results. The EtOAc extract of G. candidum displayed IC50 value comparable to the positive control diclofenac sodium in the anti-inflammatory assays. Antioxidant activity was evaluated using α,α-diphenyl-ß-picrylhydrazyl (DPPH), ß-carotene bleaching, reducing power (RP), and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonique) (ABTS) radical scavenging assays. The findings revealed strong anti-oxidant power with an IC50 of 177.55 µg/mL for G. candidum EtOAc extract using DPPH assay, probably due to high polyphenol and flavonoid content in both fungal extracts. Finally, LC-HRMS (Liquid Chromatography­High Resolution Mass Spectrometry) and GC-MS (Gas Chromatography­Mass Spectrometry) analysis of G. candidum and P. citrinum extracts revealed an impressive arsenal of compounds with previously reported biological activities, partly explaining the obtained results. Finally, LC-HRMS analysis indicated the presence of new fungal metabolites that have never been reported, which represent good candidates to follow for the discovery of new bioactive molecules.

The composition of cell walls from grape skin in Vitis vinifera intraspecific hybrids.

BACKGROUND: Monastrell is a red grape cultivar adapted to the dry environmental conditions of Murcia, SE Spain. Its berries seem to be characterized by a rigid cell wall structure, which could make difficult the winemaking process. Cabernet Sauvignon cultivar is used to complement Monastrell wines in this region owing to its high phenolic content with high extractability. This study explores the skin cell wall composition of grapes from plants resulting from intraspecific crosses of Vitis vinifera cultivars Monastrell × Cabernet Sauvignon. Moreover, the morphology of the cell wall material (CWM) from some representative samples was visualized by transmission optical microscopy. RESULTS: The total sugar content of CWM from nine out of ten genotypes of the progeny was lower than that from Monastrell. Seven out of ten genotypes showed lower phenolic content than Cabernet Sauvignon. The CWM from nine out of ten hybrids presented lower protein content than that from Monastrell. CONCLUSION: This study confirms that skin cell walls from Monastrell × Cabernet Sauvignon hybrid grapes presented major differences in composition compared with their parents. These data could help in the development of new cultivars adapted to the dry conditions of SE Spain and with a cell wall composition favouring extractability. © 2017 Society of Chemical Industry.

Cell wall compounds of red grapes skins and their grape marcs from three different winemaking techniques.

Different winemaking practices are aimed at increasing cell wall degradation to facilitate extraction of valuables molecules into the wine. However, little attention has been paid to the composition of marcs from different cultivars according to the influence of the winemaking procedures. We provide information on skin cell walls from Cabernet Sauvignon, Syrah and Monastrell grapes and examine how different winemaking practices (addition of enzymatic preparation and ß-galactosidase separately and dry ice addition) may affect the composition of marc skin cell wall material (CWM). The efficiency of CWM isolation from the grape skin and also its composition is influenced by the cultivar. A similar cultivar influence has been detected on CWM from the marc, being the differences also due to the enological technique. Our results help to increase our knowledge on the degradation of cell walls during vinification, while providing a valuable guideline to upgrade the value of these by-products.

Oligosaccharides of Cabernet Sauvignon, Syrah and Monastrell red wines.

Wine oligosaccharides were recently characterized and their concentrations, their composition and their roles on different wines remain to be determined. The concentration and composition of oligosaccharides in Cabernet Sauvignon, Syrah and Monastrell wines was studied. Oligosaccharide fractions were isolated by high resolution size-exclusion chromatography. The neutral and acidic sugar composition was determined by gas chromatography. The MS spectra of the oligosaccharides were performed on an AccuTOF mass spectrometer. Molar-mass distributions were determined by coupling size exclusion chromatography with a multi-angle light scattering device (MALLS) and a differential refractive index detector. Results showed significant differences in the oligosaccharidic fraction from Cabernet Sauvignon, Syrah and Monastrell wines. This study shows the influence that the grape variety seems have on the quantity, composition and structure of oligosaccharides in the finished wine. To our knowledge, this is the first report to research the oligosaccharides composition of Cabernet Sauvignon, Syrah and Monastrell wines.

Characterisation of cell-wall polysaccharides from mandarin segment membranes.

In an attempt to develop a process of enzymatic peeling of mandarin segments suitable for use on an industrial scale, the cell wall fraction of the segment membrane of Satsuma mandarin fruits was extracted to obtain a chelating agent-soluble pectin fraction (ChSS), a dilute sodium hydroxide-soluble pectin fraction (DASS), a 1M sodium hydroxide-soluble hemicellulose fraction (1MASS), a 4M sodium hydroxide-soluble hemicellulose fraction (4MASS) and a cellulose-rich residue (3.1, 0.9, 0.4, 0.7 and 1.6%w/w of fresh membrane, respectively). The ChSS pectin consisted mainly of galacturonic acid followed by arabinose and galactose. The DASS fraction contained less galacturonic acid and more neutral sugars than ChSS. Eighty-nine percent of the galacturonic acid present in the segment membranes was recovered in the above two pectin fractions. The two hemicellulosic fractions consisted of two different molecular weight populations, which also differed in their sugar composition. Arabinose, xylose, mannose, galactose and glucose were the main sugar constituents of these hemicellulose fractions. In addition to an (arabino)xylan and a xyloglucan, the presence of an arabinogalactan is suggested by the sugar composition of both hemicelluloses. The pectin fractions were also characterised by their degradability by the pectic enzymes polygalacturonase, pectinmethylesterase and rhamnogalacturonan hydrolase. However the degree of degradation of the pectin fractions by enzymes differed, and the amount of the polymeric materials resistant to further degradation and the oligomeric products also differed. Using pectic enzymes it is possible to obtain peeled mandarin segments ready to eat or for canning.

The composition of cell walls from grape marcs is affected by grape origin and enological technique.

The grape marc obtained after vinification could be a source of high value compounds and the different winemaking techniques could influence such compounds. The composition of skin cell walls from Monastrell grapes grown in three different locations near Murcia (S.E. Spain) has been studied. The grapes were winemaked with three different techniques (cold pre-fermentative maceration, ß-galactosidase enzyme addition and enzymatic preparation addition) and the marc skin cell walls were studied to determine their composition. The results suggest that terroir influenced the percentage of grape skin, the amount of cell wall material isolated from the grape skin, the carbohydrate composition of the cell wall material, and the lignin and protein content of the cell wall material from grape skin. A similar trend has been found within the influence of terroir on cell wall material isolated from the skin separated from the marc, being the differences also due to the enological technique.

Effect of enzyme additions on the oligosaccharide composition of Monastrell red wines from four different wine-growing origins in Spain.

The release of oligosaccharides during winemaking depends on the grape skin cell wall degradation, which can be facilitated by the use of enzymes. Oligosaccharide quantities and composition in wine could be influenced by the "terroir" effect. Monastrell wine was elaborated from grapes from four different "terroirs" (Cañada Judío, Albatana, Chaparral-Bullas and Montealegre). Monastrell wines were also treated with ß-galactosidase enzyme addition and commercial enzyme addition. The results showed significant differences in the Monastrell wine oligosaccharide fractions, according to the geographical origin of grapes. A higher quantity of oligosaccharides was found for three out of four terroirs studied when commercial enzymes were added. The use of commercial enzyme modified the Arabinose/Galactose and the Rhamnose/Galacturonic acid ratios in Cañada Judío and Albatana terroirs wines, and it modified the (Arabinose+Galactose)/Rhamnose ratio in Cañada Judío, Albatana and Chaparral-Bullas terroirs wines. Therefore, the "terroir" impacts the effect of commercial enzyme treatment on wine oligosaccharide composition.

Polysaccharide composition of Monastrell red wines from four different Spanish terroirs: effect of wine-making techniques.

Monastrell wines made from grapes grown in four different Spanish "terroirs" (Cañada Judío, Albatana, Bullas, and Montealegre) were studied. Different wine-making techniques were also used, including different refrigeration techniques (prefermentative cold maceration and dry ice addition) and the addition of two different enzymes (ß-galactosidase and commercial pectinase enzyme). The results pointed to significant differences in the Monastrell wine polysaccharide fractions according to the geographical origin of the grapes. The Rhamnogalacturonan II (RG-II) concentration was 2-fold higher in the Montealegre terroir than in the Bullas terroir. The use of enzymes also modified the polysaccharide content of the wines. RG-II levels were higher in the wines from three terroirs when commercial enzymes were added. The arabinose/galactose ratio of one of the wines was modified by the use of enzymes during wine-making, and some prefermentative cold maceration samples showed high values for several polysaccharides. This study shows the great importance of the "terroir effect" in the polysaccharide composition of wines.