Microclimate of Grape Bunch and Sunburn of White Grape Berries: Effect on Wine Quality.

This research aimed to evaluate the composition of wines made with white grapes which are particularly susceptible to sunburn symptoms due to the absence of anthocyanin. Sunburn is a complex physiological dysfunction leading to browning or necrosis of berry tissues. In vintage 2021, the canopy of ‘Verdeca’ grapevines grown in Salento, South Italy, was differently managed by sun exposing or shading the bunches. Micrometeorological conditions were studied at different levels. Grapes were vinified, comparing the winemaking with and without skin maceration. The vegetative-productive balance of plants was not substantially modified. On the contrary, a significant effect was observed on the quality and quantity of grapes produced: smaller berries with sunburn symptoms were found on unshaded bunches. This influenced the percentage distribution among skin, pulp and seeds, causing a decrease in must yield of up to 30%. The pH was significantly higher in macerated wines made using shaded grapes, due to a lower titratable acidity and to significant impacts on the acid profile. Obviously, maceration produced a higher extraction of phenolics in wines, which reached their maximum in wines made with sunburned grapes. The absorbance at 420 nm, index of yellow color, was also significantly higher in sunburned grapes, indicating greater oxidation. Even though excessive grape sun-exposure could negatively affect the perception of white wines made without maceration (resulting in more oxidative character), the sensory quality of orange/amber wines was not significantly impacted by the presence of sunburned grapes. Thus, this winemaking technique could be particularly interesting to set up a production strategy adapted to viticultural regions strongly affected by climate change

Nutritional value and bioactivity assessment methods of beverage and wines

In recent times, beverages are more widely regarded as functional food. There has been growing recognition of the key role of foods and beverages in disease prevention, treatment and its important role in assessing the medicinal properties is due to the biologically active substances of beverages, such as phenolic compounds, organic acids, amino acids, etc. Beverages are an excellent source for nutrients and bioactive compounds, including plant extracts, fiber, prebiotics and probiotics, vitamins, minerals, antioxidants, ω‐3 fatty acids. Bioactive compounds have an effect on the body as whole or specific tissues or cells. Bioactive compounds are capable of modulating metabolic processes and demonstrate positive properties such as antioxidant effect, inhibition of receptor activities, inhibition or induction of enzyme, and induction and inhibition of gene expression. Nowadays, increasing attention to polyphenols is due to the prevention of cancer, oxidative stress-associated diseases. Apart from antioxidant activities, polyphenols are a key role in biological functions, including cardiovascular diseases and modulation of carcinogenesis. The food and nutritional sciences can further help us to understand the influence of food on disease risk, pathogenesis, progression, and outcomes in obesogenic, carcinogenic, atherosclerotic, atherogenic, toxic and teratogenic environments. Nutritional value and biologically active compounds concentration differs in alcoholic or non-alcoholic beverages and depends on biotic/abiotic factors, fermentation, and overall technology types For bioactivity assessment, Capillary Electrophoresis, HPLC for oligomers and polymers separation, Liquid chromatography-mass spectrometry method, and spectrophotometry methods were used. We examined the total polyphenols content in beer wort, beer, wines, fresh and commercial juices, by Folin–Ciocalteu/Denis’ method, flavonoids by AlCl3 method in different types of wines, and Elements in white and red wines with Inductively Coupled Plasma Optical Emission spectroscopy.Pastaruoju metu gėrimai plačiau vertinami kaip funkcinis maistas. Vis labiau pripažįstamas pagrindinis maisto produktų ir gėrimų vaidmuo ligų prevencijoje, gydyme, o svarbų vaidmenį vertinant gydomąsias savybes lemia biologiškai aktyvios gėrimų medžiagos, tokios kaip fenolio junginiai, organinės rūgštys, amino rūgštys ir kt. Gėrimai yra puikus maistinių medžiagų ir bioaktyvių junginių, įskaitant augalų ekstraktus, skaidulas, prebiotikus ir probiotikus, vitaminus, mineralus, antioksidantus, ω - 3 riebalų rūgštis, šaltinis. Bioaktyvūs junginiai turi poveikį visam kūnui arba tam tikriems audiniams ar ląstelėms. Bioaktyvūs junginiai gali moduliuoti medžiagų apykaitos procesus ir pasižymi tokiomis teigiamomis savybėmis kaip antioksidacinis poveikis, receptorių veiklos slopinimas, fermentų slopinimas ar indukcija ir genų ekspresijos indukcija bei slopinimas. Šiais laikais vis daugiau dėmesio polifenoliams lemia vėžio, su oksidaciniu stresu susijusių ligų prevencija. Be antioksidacinės veiklos, polifenoliai yra pagrindinis vaidmuo atliekant biologines funkcijas, įskaitant širdies ir kraujagyslių ligas bei kancerogenezės moduliavimą. Maisto ir mitybos mokslai gali mums padėti suprasti maisto įtaką ligų rizikai, patogenezei, progresavimui ir nutukimo, kancerogeno, aterosklerozės, aterogeno, toksiškumo pasekmėms teratogeninėje aplinkoje. Paprastai mitybos vertinimo metodai yra pagrįsti dietiniais, laboratoriniais-biocheminiais, antropometriniais ir klinikiniais stebėjimais. Maisto ir mitybos mokslai gali mums padėti suprasti maisto įtaką ligų rizikai, patogenezei, ligų progresavimui ir nutukimo, kancerogeno, aterosklerozės, aterogeno, toksiškumo pasekmėms teratogeninėje aplinkoje. Maistinė vertė ir biologiškai aktyvių junginių koncentracija skiriasi alkoholiniuose ar nealkoholiniuose gėrimuose. Tai taip priklauso nuo biotinių ir abiotinių veiksnių, fermentacijos bei gamybos technologijos rūšių. Bioaktyvumui įvertinti buvo naudojama kapiliarinė elektroforezė, HPLC oligomerų ir polimerų atskyrimui, skysčių chromatografijos - masių spektrometrijos ir spektrofotometrijos metodai. Mes ištyrėme bendrą polifenolių kiekį alaus misoje, aluje, vynuose, šviežiose ir komercinėse sultyse Folin – Ciocalteu / Denis metodu, flavonoidus AlCl3 metodu skirtingų tipų vynuose ir elementus baltuose ir raudonuose vynuose su induktyviai sujungta plazmos emisijos spektroskopija.Gamtos mokslų fakultetasBiologijos katedr