Nutraceutical Oils Produced by Olives and Citrus Peel of Tuscany Varieties as Sources of Functional Ingredients

The essential oils extracted from the peels of two Tuscany Citrus of the Massa province have been characterised. Moreover, the flavedo of these species has been used in the production of two Citrus olive oils (COOs) obtained with an innovative method in which the citrus peels are cryomacerated and then pressed with the olives. The presence of functional compounds, such as carotenoids, naringenin and minor phenolics, classifies these COOs as nutraceuticals with the potential to develop enriched foods able to promote a healthy diet. Moreover, the increased presence of tyrosol and hydroxytyrosol, compared to the unflavoured oil, further highlights the nutritional value to the two COOs, being these phenolic compounds recognized as good possible therapeutic candidates for the inhibition of neurodegenerative diseases as the Parkinson's disease. In this perspective, the citrus peels, rich in bioactive compounds, have been valued transforming their waste nature in an innovative resource

The effects of packaging and storage temperature on the shelf-life of extra virgin olive oil

This research aimed to study the effects of packaging and storage temperature on the shelf-life of an extra virgin olive oil (EVOO) as it can occur in most points of sale. The evolution of the chemical and sensory characteristics of an EVOO, initially stored in stainless steel silos under nitrogen at 12–18 °C, was evaluated after packaging. Tinplate tin (TT) and greenish glass (GG), the most used packaging containers, and temperatures of 6 and 26 °C were taken into consideration. After 125 days from packaging all the samples maintained clearness, green and yellow reflections and the positive sensory notes of bitterness and pungency of the starting EVOO. Shelf-life of EVOO was significantly affected by different storage conditions: oil samples stored in GG at 6 °C preserved for the most part the positive attributes, whereas those stored in TT at 26 °C showed a significant presence of the rancid flavor due to oxidative processes. Moreover, samples stored in GG at 6 °C maintained the highest bitterness intensity and did not show defects at the end of the storage period. The results suggest that storage in GG at a low temperature could represent a promising storage condition to slow-down the oil degradation during market storage

Alterazioni delle membrane biologiche indotte da stress idrico: le proteine

The most important functions of the plant cell depend on the functionality of its membranes which is impaired if proteins and lipids are damaged. When water content reaches a value below 20% membrane dry weight, proteins undergo functional and quali-quantitative alterations. Functional alterations involve changes in protein mobility and in the conformational status and they may be analysed by electron spin resonance (ESR) technique. Following water stress membrane proteins have a lower mobility (as it is shown by the higher rotational correlation time in comparison with the control values) and the oxidation of the SH-groups occurs. As a consequence, the functionality of the proteins which need conformational changes to exert their action is impaired. Under water stress there is a reduction of preformed polyribosome and /or the preferential synthesis of "stress proteins" causing quali-quantitative alterations of membrane proteins. For this reason, water deficit determines changes in total membrane proteins, polypeptide composition as well as in the protein/lipid, hydrophilic protein/hydrophobic protein and protein/chlorophyll ratios. However, plants possess defence mechanisms which allow them to maintain structural integrity of membrane and to avoid damages caused by activated oxygen species such as superoxide anion radical and hydrogen peroxide, whose production increases under water deficit conditions. Antioxidants such as ascorbic acid and glutathione as well as the enzymes related to their metabolism (ascorbate peroxidase, glutathione reductase and dehydroascorbate reductase) remove these toxic species by the glutathione/ascorbate cycle before membranes and the SH-groups of proteins are damaged

Implication of phospholipase D in response of Hordeum vulgare root to a short-term potassium deprivation

SUMMARY To verify a possible implication of lipids and some other compounds such as hydrogen peroxide (H2O2) and glyceraldehydes-3-phosphate dehydrogenase (G3PDH) in the response of Hordeum vulgare to an early potassium deprivation, plants were grown in hydroponics for 30 days with a modified Hewitt nutrient solution containing 3 mM K+ and then incubated for increasing time ranging from 2 h up to 36 h in the same medium deprived of K+. In contrast to leaves, root K+ concentration showed its greatest decrease after 6 h of treatment. The main lipids of the control barley roots were phospholipids (PL), representing more than 50% of the total lipids. PL did not change with treatment whereas free sterols (FS) amounts decreased following K+ deprivation, showing an about 17% reduction after 36 h. As regards the individual PL, 30 h K+ deprivation caused a reduction in phosphatidylcholine (PC), phosphatidylserine (PS) and phosphatidylinositol (PI) levels whereas phosphatidylglycerol (PG), phosphatidylethanolamine (PE) and phosphatidic acid (PA) increased. The maximum PA accumulation as well as the highest phospholipase D (PLD) activation, estimated by an accumulation of phosphatidylbutanol (PtBut), were observed after 24 h of K+ starvation. At the root level, after 6 h of incubation in –K solution, H2O2 level showed the maximum value. At the same time G3PDH activity reached the minimum. On the basis of a concomitant stimulation of PLD activity and, consequently, PA accumulation, enhancement of H2O2 production, and inhibition of G3PDH activity we can suggest a possible involvement of these three compounds in an early response to K+ deprivation

Clorofilla, pura energia naturale

La clorofilla, presente nei vegetali verdi, svolge una benefica azione antiossidante che si protrae a lungo nel tempo.Essa quindi non solo può rappresentare un ottimo integratore alimentare per migliorare il nostro stato di salute ma, soprattutto, può essere portata ogni giorno in tavola arricchendo i nostri piatti con ortaggi a foglia verde per prevenire le più comuni malattie. Le sue proprietà sembrano essere collegate alla sua struttura molecolare che risulta simile a quella dell’emoglobina, con la differenza che la Clorofilla contiene un atomo di magnesio al posto del ferro.È proprio la presenza del ferro a favorire la produzione di radicali liberi dell’ossigeno che determinano poi reazioni ossidative a livello cellulare, arrecando danno alle membrane e alle principali macromolecole delle cellule, rendendole così suscettibili a sviluppare una serie di patologie tra le quali il cancro

Sunflower seedlings subjected to incresing water deficit stress: oxidative stress and defence mechanisms

Sunflower seedlings (Helianthus annuus cv. Licia Stella) reached a mild, moderate and severe level of water deficit stress after 5,8 and 11 days of soil water depletion, respectively. At a moderate level of water deficit stress, an elestic adjustment occurred. At the same time, in response to a minor osmotic potential and an intermediate rate of water potential decrease, glutathione level increased and enzyme activities related to the ascorbate/glutathione cycle were induced. At severe water deficit stress, the efficiency of this defence mechanism fell, oxidative processes intensified and soluble protein content decreased further. The results of the present experiment suggest that during water deficit stress the water status of the plants plays a key role in the activation of defence mechanisms

The role of dietary chlorophylls: an EPR study on the antioxidant activities of tomato lipid extracts

Identification of the components responsible for the antioxidant activity of lipid extracts from tomato with some lipid antioxidants was obtained by EPR using the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). Lipid extracts were obtained from leaves, roots and berries of tomato grown in hydroponics. Both fast lipophilic antioxidants (FLA) and slow lipophilic antioxidants (SLA) were present in leaves and berries whereas only SLA could be identified in the root lipid extract. Simulation of the decay kinetic of DPPH by leaves was obtained with a chlorophyll b/β-carotene mixture whereas lycopene, which reduced DPPH with a stoichiometry 1:1, behaved as a SLA. Antioxidant activity of lipid extract from leaves showed values 56-and 45-fold higher than the antioxidant activity of lipid extract from root and berries, respectively and it was mainly due to the presence of chlorophyll, representing in the leaf 38% of FLA

Reactive Oxygen Species and Photosynthetic Functioning: Past and Present

The present chapter begins by presenting the basic introduction to Reactive Oxygen Species (ROS), then detailng the current knowledge in ROS research. In particular, Electron Paramagnetic Resonance (EPR) technique applicability in photosynthesis research was considered. Kinetics of superoxide formation by illuminated thylakoids was shown. The progress of the knowledge on the different sites of photosynthetic membranes involved in ROS formation was reported and the main defense mechanisms occurring in the chloroplast to detoxify from ROS were decribed

Sunflower seedlings subjected to increasing stress by water deficit: Changes in superoxide production related to the composition of thylakoid membranes

Free radicals, such as the superoxide anion, can damage the photosynthetic apparatus. At the same time they are increasingly formed as by-products of electron transport during stress conditions. For this reason, we studied the kinetics of formation and decay of superoxide anions in relation to changes, induced by increasing water deficit, in the composition of thylakoids. Seedlings of sunflower (Helianthus annuus L. cv. Licia Stella) were subjected to either a mild, a moderate, or a severe water deficit. Upon illumination of thylakoid membranes containing Tiron, we found first order kinetics of formation and decay of the Tiron semiquinone radical. At each stress intensity a higher rate of superoxide formation than in the control was observed. The different decay rates suggested a changed chemical environment around the radical. In comparison with the control, the levels of carotenoids and hydrophobic proteins in the thylakoids decreased, and the lipid/protein ratio increased after a mild water deficit. After moderate drought, the increased levels of hydrophilic proteins and carotenoids seem unsufficient to limit the improved capacity to leak electrons from the thylakoids. After a severe water stress, a decrease in unsaturation and in linolenic acid as well as a loss of lipolytic antioxidants took place, which may have rendered the thylakoids more sensiive to attack by activated forms of oxygen. The results suggest that during water deficit, the interactions among membrane components change in relation to a changed chemical composition. Such changes are probably among the causes for changes in the conformation of proteins and in the position of various molecular species in he lipid bilayer, so that they become more exposed to molecular oxygen

Metabolismo degli acidi grassi

Il volume, promosso dalla Società Italiana di Chimica Agraria, rappresenta l’opportunità di offrire agli studenti, in particolare dei corsi di studio triennali dell’area agraria e forestale, uno strumento didattico capace di fornire le basi necessarie per la comprensione delle trasformazioni biochimiche che la materia subisce all’interno degli organismi viventi, delle relazioni tra queste trasformazioni e gli aspetti quali-quantitativi e tecnologici delle produzioni agrarie. Le trasformazioni biochimiche: la catalisi enzimatica - vista d’insieme del metabolismo cellulare - le membrane biologiche e il trasporto di soluti - il metabolismo glucidico: i carboidrati - la glicolisi - il ciclo di Krebs e la fosforilazione ossidativa - la fotosintesi: la conversione dell’energia luminosa in energia chimica - utilizzo dell’energia e biosintesi dei carboidrati - il metabolismo lipidico: i lipidi - metabolismo degli acidi grassi - il metabolismo azotato: acquisizione e assimilazione dell’azoto - i nucleotidi e gli acidi nucleici: aspetti strutturali e funzionali degli acidi nucleici - la sintesi delle proteine - I metaboliti secondari delle piante: ruolo dei metaboliti secondari nelle piante - la nutrizione minerale delle piante e i rapporti con il suolo: i principi della nutrizione delle piante e il sistema suolo-pianta - indice analitico