Effect of HHP and UHPH High-Pressure Techniques on the Extraction and Stability of Grape and Other Fruit Anthocyanins

Altres ajuts: MALTA CONSOLIDER TEAM Research Network RED2022-134388-TThe use of high-pressure technologies is a hot topic in food science because of the potential for a gentle process in which spoilage and pathogenic microorganisms can be eliminated; these technologies also have effects on the extraction, preservation, and modification of some constituents. Whole grapes or bunches can be processed by High Hydrostatic Pressure (HHP), which causes poration of the skin cell walls and rapid diffusion of the anthocyanins into the pulp and seeds in a short treatment time (2-10 min), improving maceration. Grape juice with colloidal skin particles of less than 500 µm processed by Ultra-High Pressure Homogenization (UHPH) is nano-fragmented with high anthocyanin release. Anthocyanins can be rapidly extracted from skins using HHP and cell fragments using UHPH, releasing them and facilitating their diffusion into the liquid quickly. HHP and UHPH techniques are gentle and protective of sensitive molecules such as phenols, terpenes, and vitamins. Both techniques are non-thermal technologies with mild temperatures and residence times. Moreover, UHPH produces an intense inactivation of oxidative enzymes (PPOs), thus preserving the antioxidant activity of grape juices. Both technologies can be applied to juices or concentrates; in addition, HHP can be applied to grapes or bunches. This review provides detailed information on the main features of these novel techniques, their current status in anthocyanin extraction, and their effects on stability and process sustainability

Altered bone marrow lymphopoiesis and interleukin-6-dependent inhibition of thymocyte differentiation contribute to thymic atrophy during Trypanosoma cruzi infection

Thymic atrophy occurs during infection being associated with apoptosis of double positive (DP) and premature exit of DP and double negative (DN) thymocytes. We observed for the first time that a significant bone marrow aplasia and a decrease in common lymphoid progenitors (CLPs) preceded thymic alterations in mice infected with Trypanosoma cruzi. In addition, depletion of the DN2 stage was previous to the DN1, indicating an alteration in the differentiation from DN1 to DN2 thymocytes. Interestingly, infected mice deficient in IL-6 expression showed higher numbers of DP and CD4+ thymocytes than wild type infected mice, while presenting similar percentages of DN1 thymocytes. Moreover, the drop in late differentiation stages of DN thymocytes was partially abrogated in comparison with wild type littermates. Thus, our results suggest that thymic atrophy involves a drop in CLPs production in bone marrow and IL-6-dependent and independent mechanisms that inhibits the differentiation of DN thymocytes.Fil: Carbajosa, Sofía. Universidad Autónoma de Madrid; EspañaFil: Gea, Susana. Universidad Autónoma de Madrid; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Chillón-Marinas, Carlos. Universidad Autónoma de Madrid; EspañaFil: Poveda, Cristina. Universidad Autónoma de Madrid; EspañaFil: Maza, María del Carmen. Universidad Autónoma de Madrid; EspañaFil: Fresno, Manuel. Universidad Autónoma de Madrid; EspañaFil: Gironès, Núria. Universidad Autónoma de Madrid; Españ

TCFL5 deficiency impairs the pachytene to diplotene transition during spermatogenesis in the mouse

Spermatogenesis is a complex, multistep process during which spermatogonia give rise to spermatozoa. Transcription Factor Like 5 (TCFL5) is a transcription factor that has been described expressed during spermatogenesis. In order to decipher the role of TCFL5 during in vivo spermatogenesis, we generated two mouse models. Ubiquitous removal of TCFL5 generated by breeding TCFL5fl/fl with SOX2-Cre mice resulted in sterile males being unable to produce spermatozoa due to a dramatic alteration of the testis architecture presenting meiosis arrest and lack of spermatids. SYCP3, SYCP1 and H1T expression analysis showed that TCFL5 deficiency causes alterations during pachytene/diplotene transition resulting in a meiotic arrest in a diplotene-like stage. Even more, TCFL5 deficient pachytene showed alterations in the number of MLH1 foci and the condensation of the sexual body. In addition, tamoxifen-inducible TCFL5 knockout mice showed, besides meiosis phenotype, alterations in the spermatids elongation process resulting in aberrant spermatids. Furthermore, TCFL5 deficiency increased spermatogonia maintenance genes (Dalz, Sox2, and Dmrt1) but also increased meiosis genes (Syce1, Stag3, and Morc2a) suggesting that the synaptonemal complex forms well, but cannot separate and meiosis does not proceed. TCFL5 is able to bind to the promoter of Syce1, Stag3, Dmrt1, and Syce1 suggesting a direct control of their expression. In conclusion, TCFL5 plays an essential role in spermatogenesis progression being indispensable for meiosis resolution and spermatids maturatio

Polymeric pigments formed in sequential fermentation of red fresh musts by adding flavan-3-ols

Red wine pigments are susceptible to degradation by light, SO2 and changes in pH and temperature1,2. The formation of pyranoanthocyanins and polymeric pigments during fermentation and wine aging promote the stability of such pigments3. Glycolytic metabolites (e.g. acetaldehyde and pyruvic acid) may interact with anthocyanins and flavan-3-ols to form more stable molecules4 without a drastic change in hue values. Procyanidins are molecules from the flavanoids family that may condense with anthocyanins5. The contribution of non-Saccharomyces yeasts (e.g. L. thermotolerans, M. pulcherrima and T. delbrueckii), in sequential fermentation with S. cerevisiae and S. pombe, to the production of stable pigments was assessed in this project. with the use of HPLC-DAD/MS-ESI. The red musts have been enriched with flavanols prior fermentation. Fermentative volatiles and sensorial analysis were also performed to characterize experimental wines produced

Use of Hanseniaspora spp. in sequential fermentation with Saccharomyces cerevisiae to improve the aromatic complexity of Albillo Mayor white wines

Hanseniaspora spp apiculate yeasts can be found on ripe grape skins and during the first six days of the alcoholic fermentation. Generally, these yeasts have poor characteristics for its industrial application in winery as they are related with low fermentative power, low resistance to SO2 and even high volatile acidity production. However, some species have a better fermentative capacity and are producers of certain floral and fruity volatiles. This is the case of the two strains used in this study. Hanseniaspora vineae (HV) has a fermentative power around 8-10% v/v, low volatile acidity production and produces high levels of 2-phenylethyl acetate. Similarly, Hanseniaspora opuntiae (HO) also produces a low volatile acidity providing sweet and floral aromas, but has a fermentative power around 6% v/v, which means that it must be used in sequential fermentation with Saccharomyces cerevisiae (SC). In addition, several studies indicate that both species can increase the mouthfeel and wine body. The aim of this study was to evaluate the use of HV and HO in sequential fermentation with SC to improve the sensory profile of high quality white wines from the neutral grape variety Albillo Mayor. Fermentations were performed in triplicate in 150 L stainless steel barrels with grapes from the 2021 vintage. Pure SC fermentations were used as controls. After the fermentation, the polysaccharide content and the colour was measured, and an intensive study of the aromatic profile was done

Strategies to Improve the Freshness in Wines from Warm Areas

Trends in wine consumption are continuously changing. The latest in style is fresh wine with moderate alcohol content, high acidity, and primary aromas reminiscent of grapes, whereas certain fermentative volatiles may also influence the freshness of the wine. In addition, the effects of climate change on the composition of the grapes (high sugar content and low acidity) are adverse for the quality of the wine, also considering the microbiological stability. Herein, different strategies aiming at improving wine freshness are presented, and their performance in winemaking is discussed: among them, the addition of organic acids able to inhibit malolactic fermentation such as fumaric acid; the use of acidifying yeasts for alcoholic fermentation, such as Lachancea thermotolerans; and the selection of non-Saccharomyces yeasts with β-glucosidase activity in order to release terpene glycosides present in the must

Optical and AFM microscopy of grape juices treated with UHPH: Effects of microstructure and nanostructure

UHPH treatment of Vitis vinifera must for winemaking leads to fragmentation of colloidal particles into smaller structures. The shear and fracture forces experienced by grape juice during valve pressurization are sufficient to reduce the particle size of grape juice to below 500 nm. As a result, the applied force can disrupt bacterial and yeast cell structures, altering or breaking down proteins, polysaccharides and enzymes. This effect is not observed for low molecular weight compounds such as monomeric pigments and phenolic structures, varietal aroma precursors, fermentable sugars, etc. Treated and untreated samples can be compared using optical and atomic force microscopy. Optical microscopy images show reduction or elimination of bacteria and yeast and changes in microstructure. On the other hand, in addition to describing topography in the nanometer range, AFM can also measure particles in comparison to other techniques such as laser diffraction (LD). This work contributes to the characterization and better understanding of the effects of UHPH on grape juice for winemaking

Emerging Technologies to Increase Extraction, Control Microorganisms, and Reduce SO₂

This chapter reviews the main non-thermal technologies with application in enology and their impact in: the extraction of phenolic compounds from grapes, the elimination of indigenous microorganisms, and the subsequent effect in SO2 reduction. The technologies are physical processes with null or low repercussion in temperature and therefore gentle with sensory quality of grapes. High hydrostatic pressure (HHP), ultra high pressure homogenization (UHPH), pulsed electric fields (PEFs), electron-beam irradiation (eBeam), ultrasound (US), and pulsed light (PL) have interesting advantages and some drawbacks that are extensively reviewed highlighting the potential applications in current technology

Use of red grape juice (concentrated and treated by UHPH) as a base to produce isotonic drinks

The physical-chemical composition, sensory characteristics, and nutritional value of the grape juice can provide sports drink (isotonic beverage) with antioxidant compounds that complement the beneficial effect of these drinks to the rehydration and replacement of minerals and carbohydrates, during physical activity. Grape juice contains mainly water, sugars, organic acids, and phenolic compounds. By diluting the sugar content of the must to 40-50 g/L, it will allow us to obtain a drink with beneficial properties for health, avoiding the addition of sweeteners. Phenolic compounds play an important role in the prevention of various diseases through their biological activities related to antioxidant, anti-inflammatory, anticancer, anti-aging, antimicrobial and cardioprotective properties. Several studies have shown that grape juice allows to improve the performance of the activity, protect against oxidative damage, and reduce inflammation during, sports activities. The polyphenolic substances present in grape musts provide sensory characteristics of interest, mainly color and aroma, important indicators for consumers when choosing this type of beverage. The anthocyanin content of musts from red varieties, gives the drink a more natural and attractive character for the consumer without the use of synthetic dyes. It is important to recognize the demand of consumers for new innovative, and healthy products, so we focus on the development of a natural, functional drink using red grape musts as a base (concentrated or treated with UHPH) as a source of polyphenols and sugars, showing interesting organoleptic properties without chemical additives, and that allows to replenish electrolytes and energy