Functional features of the exopolysaccharide extracts produced by Lactiplantibacillus strains isolated from table olives.

This study evaluates the functional characteristics of the exopolysaccharide (EPS) extracts produced by various strains of Lactiplantibacillus pentosus (LPG1, 119, 13B4, and Lp13) and Lactiplantibacillus plantarum (Lp15) isolated from table olives. None of the EPS crude extracts showed cytotoxicity when administered to THP-1 human macrophage cells at dosages ranging from 6.25 to 50 µg mL-1. Many exhibited anti-inflammatory properties (reduction of pro-inflammatory cytokines TNF-α and IL-6 production) and antioxidant activity (reduction of ROS%) when macrophages were stimulated with Escherichia coli lipopolysaccharide. Notably, the EPS extract produced by the L. pentosus LPG1 strain had the best results corroborated by western blot immune analysis for differential expression of COX-2, Nrf-2, and HO-1 proteins, with the most significant antioxidant and anti-inflammatory response observed at a dosage of 50 µg mL-1. Chemical analysis revealed that the EPS extract produced by this strain contains a heteropolymer composed of mannose (35.45%), glucose (32.99%), arabinose (17.93%), xylose (7.48%), galactose (4.03%), rhamnose (1.34%), and fucose (0.77%). Finally, we conducted response surface methodology to model the EPS extract production by L. pentosus LPG1 considering pH (3.48-8.52), temperature (16.59-33.41 °C) and salt concentration (0.03-8.77% NaCl) as independent variables. The model identified linear effects of salt and pH and quadratic effects of salt as significant terms. The maximum EPS extract production (566 mg L-1) in a synthetic culture medium (MRS) was achieved at pH 7.5, salt 7.0%, and a temperature of 20 °C. These findings suggest the potential for novel applications for the EPS produced by L. pentosus LPG1 as nutraceutical candidates for use in human diets.

Extraction of polyphenols associated with pectin from olive waste (alperujo) with choline chloride.

The main by-product from olive oil extraction (alperujo) was extracted with hot water, citric acid, natural deep eutectic solvent (choline chloride: citric acid), and only choline chloride. The purified extracts were composed of macromolecular complexes constituting polyphenols associated with pectin. The extracts were structurally characterized by FT-IR and solid-NMR spectroscopy and an in vitro test revealed distinct antioxidant and antiproliferative activity, depending on the extracting agents. The choline chloride-extracted complex contained the highest amount of polyphenols among the examined agents, which exhibited a strong antioxidant activity and significant antiproliferative capacity. However, the complex extracted by hot water showed the highest antiproliferative capacity in vitro against the colon carcinoma Caco-2 cell line. In this finding, choline chloride could be used as a novel, green and promising alternative to the conventional extracting agent for the production of complexes that combine the antioxidant activity of phenolic compounds and the physiological effects of pectic polysaccharides.

Date Seed: Rich Source of Antioxidant Phenolics Obtained by Hydrothermal Treatments.

The growing interest in natural compounds is helping to improve the management of agro-industrial by-products such as the date seed as sources of such compounds. In this work, the application of a hydrothermal treatment at 160 and 180 °C for 60 min was studied to achieve the solubilization of its phenolic components and sugars in order to obtain biologically active extracts. The percentage of phenols and total sugars in the final extracts were very similar, at 45 and 25% for the 160 and 180 °C treatments, respectively. The treatment at a higher temperature allowed greater solubilization of other components. The antioxidant activity was measured as free-radical scavenging capacity. For the DPPH• method, expressed as EC50, the results were 0.34 and 0.37 mg/L, the TEAC values for the ABTS• method were 6.61 and 3.28 mg/g dried extract, and the values obtained by the ORAC method were 12.82 and 9.91 mmol Trolox/g dried extract, for 160 and 180 °C, respectively. All these values are higher than those of other plant extracts and extracts obtained using the whole date. Therefore, the date seed is a very important source of phenols, and through thermal and chromatographic processes, it is possible to obtain extracts with high antioxidant activity.

Antiproliferative Activity of Olive Extract Rich in Polyphenols and Modified Pectin on Bladder Cancer Cells.

Bladder cancer (BC) is one of the most common human cancers. There is an interest in controlling and treating BC and other types of cancer via the use of natural substances and/or combination chemotherapy. Modified forms of pectin have been reported to possess anticancer bioactivity related to the interaction of galactosyl, a main component of pectin, with galectin-3, a carbohydrate-binding protein that is overexpressed on many types of cancer cells. In this study, the antiproliferative effect on BC of novel modified pectins extracted from olives was evaluated. Pectoliv extracts, with high polyphenol content associated to polysaccharides rich in pectin, exhibited an important antiproliferative capacity in vitro against four human BC cells lines, RT112, T24, J82, and SCaBER. Pectoliv treatment reduced the expression of galectin-1 and galectin-3 and significantly inhibited the agglutination of erythrocytes. Thus, Pectoliv may have the potential for development as a novel galectin-3 inhibitor.

Pectin-rich extracts from olives inhibit proliferation of Caco-2 and THP-1 cells.

Three olive modified pectin extracts have been produced by heat and acid treatment of the major by-product of olive oil production. Their effect on proliferation of the colon carcinoma Caco-2 and the leukemia monocytic THP-1 cell lines has been studied in order to determine possible anti-tumor properties. All extracts inhibited proliferation at some of the concentrations ranging from 1 to 10 mg ml-1. Interestingly none of the extracts inhibited the growth of confluent Caco-2 cells, showing the specificity of the antiproliferative effect for the transformed Caco-2 phenotype. All the extracts inhibited agglutination of red blood cells by galectin-3, a lectin involved in tumor growth, metastasis, and immune cell regulation that has been proposed as a mediator of the anti-tumor effects of modified pectins. In addition, activation of caspase-3 in THP-1 cells indicates that treatment with the pectin-rich extracts triggers apoptosis. These results point to a possible use as health-promoting food ingredients or supplements.

Cocoa bean husk: industrial source of antioxidant phenolic extract.

BACKGROUND: Cocoa bean husk (CBH) is the principal by-product of the cocoa industry and a significant agro-industrial residue. In this study, using different hydrothermal treatments of CBH, it is shown that CBH is an important source of bioactive compounds, including theobromine, epicatechin and catechin. RESULTS: Treatment over 150 °C significantly increased the yield of total and individual phenols and theobromine as well as the antioxidant capacity of the liquid fraction. A total of 52 different genotypes of CBH harvested in two seasons of production were analyzed. Overall, higher amounts of total phenols, theobromine and epigallocatechin were detected in samples from the 2015 season, while samples from 2014 had higher quantities of catechin and similar quantities of epicatechin. CONCLUSION: CBH treatment at 170 °C for 30 min produces an antioxidant-rich extract high in phenols (55 mg g-1 ), sugars (220 mg g-1 ) and theobromine (56 mg g-1 ) that is suitable for applications in the food, cosmetic and nutraceutical industries. © 2018 Society of Chemical Industry.

Effect of edible pectin-fish gelatin films containing the olive antioxidants hydroxytyrosol and 3,4-dihydroxyphenylglycol on beef meat during refrigerated storage.

The objective of this research was to evaluate the effect of the addition of two antioxidants naturally present in olives, hydroxytyrosol (HT) and 3,4-dihydroxyphenylglycol (DHPG), to a pectin-fish gelatin edible film on the preservation of raw beef meat during refrigerated storage. A new composite film that included beeswax was also prepared, resulting in a reduction in the film's oxygen permeability. Results showed that the meat samples wrapped with film containing antioxidants reduced the formation of oxidation products in the form of thiobarbituric acid reaction substances (TBARS) compared with control film without antioxidants. HT added at 0.5% to the film with beeswax suppressed the lipid oxidation of beef meat during 7 days of storage at 4 °C, possibly by the combined effect of acting as an oxygen barrier and the specific antioxidant activity. The interference of plasticizer agents (glycerol and sorbitol) incorporated to the film on the TBARS method was showed for the first time.

Molecular interactions between 3,4-dihydroxyphenylglycol and pectin and antioxidant capacity of this complex in vitro.

This study explored the interaction of pectin with 3,4-dihydroxyphenylglycol (DHPG), a potent phenolic antioxidant naturally found in olive fruit, via encapsulation into pectinate beads. MALDI TOF-TOF analysis supported the formation of complexes between DHPG and pectin. A combination of covalent bonds (ester bonds) and non-covalent interactions, mostly hydrogen bonding, were suggested as the cause of DHPG-pectin complex formation. Free radical scavenging assays confirmed that DHPG maintained its antioxidant activity after complexation and after a digestion simulated in vitro with gastric and intestinal fluids. Therefore, DHPG-pectin beads could reach the large intestine and contribute to a healthy antioxidant environment.

Physical and functional properties of pectin-fish gelatin films containing the olive phenols hydroxytyrosol and 3,4-dihydroxyphenylglycol.

This study describes the development of a composite edible film based on pectin and fish skin protein capable of protecting food from microbial attack and oxidative degradation. The film was prepared with glycerol as plasticizer and the antioxidant and antimicrobial phenolic compounds hydroxytyrosol (HT) and 3,4-dihydroxyphenylglycol (DHPG), extracted from olive fruit, as active agents. The influence of the concentration of plasticizer and active HT/DHPG on the mechanical and functional properties of the films was investigated, with values of water vapor permeability (WVP) between 0.13-0.22gmm/hm2kPa and oxygen permeability (OP) between 9.91-40.76cm3µm/m2dkPa. The release behavior in water at different pH values was also evaluated. The antimicrobial capacity of the novel food coating was tested on strawberries, a fruit with high perishability. The bioactive edible film containing HT/DHPG preserved the strawberries against mold during storage with a significant delay in visible decay.

Complexation of hydroxytyrosol and 3,4-dihydroxyphenylglycol with pectin and their potential use for colon targeting.

Hydroxytyrosol (HT) and 3,4-dihydroxyphenylglycol (DHPG) are two phenolic antioxidants naturally found in olive fruit with anti-inflammatory properties. This study explored the interaction of pectin with HT and DHPG via their encapsulation into pectinate beads. Purification by size exclusion chromatography, changes in the fluorescence spectrum of the HT and pectin, and MALDI TOF-TOF analysis suggested the existence of the phenol-pectin complexes. The entrapment efficiency, swelling properties, and in vitro release of HT and DHPG of the beads were studied. The results show that the beads can entrap the water soluble compounds HT and DHPG in sufficient amounts to reach the colon. The beads consisted of an important amount of pectin-bound HT or DHPG after two hours at gastric pH. This study highlights the potential use of HT-and DHPG-loaded pectinate gel beads for the colon-targeted delivery of these bioactive compounds to help prevent or relieve chronic inflammatory bowel disease.