Isabella D’Antuono

Verbascoside, Isoverbascoside, and Their Derivatives Recovered from Olive Mill Wastewater as Possible Food Antioxidants

Olive oil processing industries generate substantial quantities of phenolic-rich byproducts, which could be valuable natural sources of antioxidants. This work is focused on the recovery and structural characterization of antioxidant compounds from olive mill wastewater (OMWW), a polluting byproduct of the olive oil production process. Phenolics were extracted from the waste material using a membrane technology coupled to low-pressure gel filtration chromatography on a Sephadex LH-20. The LH-20 fraction was, in turn, characterized for its phenolic composition by HPLC-DAD-MS/MS analyses. Verbascoside, isoverbascoside, β-hydroxyverbascoside, β-hydroxyisoverbascoside, and various oxidized phenolics were identified. Uptake of verbascoside, purified from the LH-20 fraction, by HT-29 cells, an established model system for studying drug transport properties, was also assayed. Finally, the antioxidant activities of the LH-20 fraction and verbascoside were characterized by two different techniques. Individual verbascoside was more active as a scavenger of reactive oxygen species and as a chemopreventive agent protecting low-density lipoproteins from oxidative damage than the LH-20 fraction.

Relationship between Quality Parameters and the Overall Appearance in Lettuce during Storage

Fresh-cut and whole iceberg lettuce were stored in refrigerated condition and the main sensory (overall appearance: OA, browning index: BI), physical (colour variation: E*), chemical (respiration activity: RA, ammonia content: A) and biochemical (total chlorophyll: TC, antioxidant activity: AA, total phenols: TP, o-quinones: o-q, polyphenol oxidase: PPO, phenylalanine ammonia-lyase: PAL and peroxidase: POD) traits were followed during the trial. Significant relationships among these parameters were assessed by principal component analysis (PCA) in order to find the main traits related to OA, in fresh-cut lettuce. Results from PCA showed that OA was inversely correlated with BI (r=-1.00), E* (r= -0.98), A (r= -0.94), AA (r= -0.86), TP (r= -0.82), o-q (r= -0.89), and PAL (r= -0.80). Moreover, OA was positively related with RA (r= 1.00) and PPO activity (r= 0.96). Ammonia resulted significantly correlated with the main sensory, physical, chemical and biochemical parameters. Thus, this parameter, with E* could be used as indicator of the product quality and acceptability in control quality procedures. In conclusion, rating scale used to estimate OA, resulted a valid method to evaluate the iceberg lettuce quality, since it showed significant relationships with the main analytical parameters.

Real-time monitoring of glucose and phenols intestinal absorption through an integrated Caco-2TC7cells/biosensors telemetric device: Hypoglycemic effect of fruit phytochemicals

An integrated device for real-time monitoring of glucose and phenols absorption, that consists of a sensors/biosensors system (SB) and a Caco-2TC7 human intestinal cell culture, is described in this study. The SB is composed of a glucose oxidase-based biosensor, a sentinel platinum sensor, a laccase/tyrosinase-based biosensor and a sentinel carbon sensor, all located in the basolateral compartment (BC) of a cell culture plate. Caco-2TC7 cells, differentiated on culture inserts, separated the apical compartment that simulates the intestinal lumen, from the BC which represented the bloodstream. The system recorded currents relative to glucose (1mM) absorption, obtaining bioavailability values (5.1%) comparable to HPLC analysis (4.8%). Phloridzin and phloretin, specific phenolic inhibitors of SGLT1 and GLUT2 glucose transporters, reduced the glucose transport of almost 10 times. They were minimally absorbed in the BC with a bioavailability of 0.13% and 0.49% respectively. The hypoglycemic potential of blueberry and pomegranate juices was also studied. In particular, the amount of glucose absorbed through the Caco-2TC7 monolayer was 8‰ for pomegranate and 1.7‰ for blueberry, demonstrating the potential hypoglycemic effect of the juices. Polyphenols absorption was also monitored by the SB and an increase was recorded during the first 50min in presence of both blueberry and pomegranate juices, then a constant decrease occurred. The proposed device has been developed as innovative tool for the dynamic monitoring of natural compounds effects on glucose absorption, in order to manage postprandial hyperglycemia.

In vitro activity of antimicrobial compounds against Xylella fastidiosa, the causal agent of the olive quick decline syndrome in Apulia (Italy)

Olive quick decline syndrome (OQDS) causes severe damages to the olive trees in Salento (Apulia, Italy) and poses a severe threat for the agriculture of Mediterranean countries. DNA-based typing methods have pointed out that OQDS is caused by a single outbreak strain of Xylella fastidiosa subsp. pauca referred to as CoDiRO or ST53. Since no effective control measures are currently available, the objective of this study was to evaluate in vitro antimicrobial activities of different classes of compounds against Salento-1 isolated by an OQDS affected plant and classified as ST53. A bioassay based on agar disk diffusion method revealed that 17 out of the 32 tested antibiotics did not affect bacterial growth at a dose of 5 μg disk-1. When we assayed micro-, ultra- and nano-filtered fractions of olive mill wastewaters, we found that the micro-filtered fraction resulted to be the most effective against the bacterium. Moreover, some phenolics (4-methylcathecol, cathecol, veratric acid, caffeic acid, oleuropein) were active in their pure form. Noteworthy, also some fungal extracts and fungal toxins showed inhibitory effects on bacterial growth. Some of these compounds can be further explored as potential candidate in future applications for curative/preventive treating OQDS-affected or at-risk olive plants.

Artichoke Polyphenols Produce Skin Anti-Age Effects by Improving Endothelial Cell Integrity and Functionality

Artichoke is a characteristic crop of the Mediterranean area, recognized for its nutritional value and therapeutic properties due to the presence of bioactive components such as polyphenols, inulin, vitamins and minerals. Artichoke is mainly consumed after home and/or industrial processing, and the undersized heads, not suitable for the market, can be used for the recovery of bioactive compounds, such as polyphenols, for cosmetic applications. In this paper, the potential skin anti-age effect of a polyphenolic artichoke extract on endothelial cells was investigated. The methodology used was addressed to evaluate the antioxidant and anti-inflammatory activities and the improvement of gene expression of some youth markers. The results showed that the artichoke extract was constituted by 87% of chlorogenic, 3,5-O-dicaffeoylquinic, and 1,5-O-dicaffeoylquinic acids. The extract induced important molecular markers responsible for the microcirculation and vasodilatation of endothelial cells, acted as a potential anti-inflammatory agent, protected the lymphatic vessels from oxidative damage by ROS formation, and enhanced the cellular cohesion by reinforcing the tight junction complex. In addition, the artichoke extract, through the modulation of molecular pathways, improved the expression of genes involved in anti-ageing mechanisms. Finally, clinical testing on human subjects highlighted the enhancement by 19.74% of roughness and 11.45% of elasticity from using an artichoke extract cosmetic formulation compared to placebo cream.

Use of Olive Oil Industrial By-Product for Pasta Enrichment

Background: During recent years food industries generally produce a large volume of wastes both solid and liquid, representing a disposal and potential environmental pollution problem. Objective: The goal of the study was to optimize, from both sensory and nutritional points of view, the formulation of durum wheat spaghetti enriched with an olive oil industrial by-product, indicated as olive paste. Methods: Three consecutive steps were carried out. In the first one, the olive paste was air-dried at low temperature, milled to record olive paste flour and properly analyzed for its biochemical composition. In the second step, the olive paste flour was added to the pasta dough at 10% and 15% (w/w). In the last step, different concentrations of transglutaminase were added to enriched pasta (10% olive paste) to further improve the quality. Sensory properties and nutritional content of enriched and control pasta were properly measured. Results: Spaghetti with 10% olive paste flour and 0.6% transglutaminase were considered acceptable to the sensory panel test. Nutritional analyses showed that addition of 10% olive paste flour to pasta considerably increased content of flavonoids and total polyphenols. Conclusions: The proper addition of olive paste flour and transglutaminase for pasta enrichment could represent a starting point to valorize olive oil industrial by-products and produce new healthy food products.

Computational studies on a new cationic peroxidase isoenzyme from artichoke leaves

Previously we presented the purification, biochemical characterization, and cloning of a cationic peroxidase isoenzyme (CysPrx) from artichoke (Cynara cardunculus subsp scolymus (L.) Hegi) leaves. The protein was shown to have some interesting properties, suggesting that CysPrx could be a considered as a potential candidate for industrial application. In addition, from the CysPrx sequence, two full-lengh cDNAs: CysPrx1 and CysPrx2, differing for three amino acids, were isolated. A three-dimensional model was predicted from CysPrx1 by homology modeling, using two different computational tools. Herein we discuss the roles of particular amino acid residues and structural motifs or regions of both deduced sequences with the aim to find new understandings between the new plant peroxidase isoenzymes and their physiological substrates. Additionally, the obtained information may lead to new methods for improving the stability of the enzyme in several processes of biotechnological interest for peroxidase applications.