Novel Processes for the Extraction of Phenolic Compounds from Olive Pomace and Their Protection by Encapsulation

Olive pomace, the solid by-product derived from olive oil production consists of a high concentration of bioactive compounds with antioxidant activity, such as phenolic compounds, and their recovery by applying innovative techniques is a great opportunity and challenge for the olive oil industry. This study aimed to point out a new approach for the integrated valorization of olive pomace by extracting the phenolic compounds and protecting them by encapsulation or incorporation in nanoemulsions. Innovative assisted extraction methods were evaluated such as microwave (MAE), homogenization (HAE), ultrasound (UAE), and high hydrostatic pressure (HHPAE) using various solvent systems including ethanol, methanol, and natural deep eutectic solvents (NADESs). The best extraction efficiency of phenolic compounds was achieved by using NADES as extraction solvent and in particular the mixture choline chloride-caffeic acid (CCA) and choline chloride-lactic acid (CLA); by HAE at 60 °C/12,000 rpm and UAE at 60 °C, the total phenolic content (TPC) of extracts was 34.08 mg gallic acid (GA)/g dw and 20.14 mg GA/g dw for CCA, and by MAE at 60 °C and HHPAE at 600 MPa/10 min, the TPC was 29.57 mg GA/g dw and 25.96 mg GA/g dw for CLA. HAE proved to be the best method for the extraction of phenolic compounds from olive pomace. Microencapsulation and nanoemulsion formulations were also reviewed for the protection of the phenolic compounds extracted from olive pomace. Both encapsulation techniques exhibited satisfactory results in terms of encapsulation stability. Thus, they can be proposed as an excellent technique to incorporate phenolic compounds into food products in order to enhance both their antioxidative stability and nutritional value.     

Comparison of Antibacterial and Antioxidant Properties of Red (cv. Negramaro) and White (cv. Fiano) Skin Pomace Extracts

Wine pomace has attracted the attention of the food industry, due to its high content in bioactive compounds, and its multiple healthy activities. In this work, whole and separated skin pomaces from fermented (red) and un-fermented (white) grape by-products were characterized for their antioxidant and antimicrobial activities in order to exploit them as functional food ingredient. Antioxidant activity, measured by both ORAC and TEAC assays, was higher in whole than in skin pomace extracts. The characterization of phenolic composition in whole and skin pomace extracts confirmed the peculiarity of some compounds such as anthocyanins (107.84 + 10.3 mg/g TP) in red skin pomace and a great amount of flavanols (80.73 + 4.04 mg/g TP) in white skin pomace. Whole and skin pomace extracts displayed the same antibacterial activity at 250 µg gallic acid equivalents (GAE)/mL. Red and white skin pomace extracts showed a Minimum Inhibitory Concentration (MIC) of 31.25–62.5 GAE/mL against Staphylococcus aureus and Enterococcus faecalis. Pseudomonas spp. were more sensitive to red skin pomace extracts rather than white skin pomace extracts. Given these results, both red and white pomace extracts could be exploited for future application in food, pharmaceutical and cosmetic industry.     

Effect of alprazolam on rat serum metabolic profiles

We developed a serum metabolomic method by gas chromatography–mass spectrometry (GC–MS) to evaluate the effect of alprazolam in rats. The GC–MS with HP‐5MS (0.25 μm × 30 m × 0.25 mm) mass was conducted in electron impact ionization (EI) mode with electron energy of 70 eV, and full‐scan mode with m /z 50–550. The rats were randomly divided to four groups, three alprazolam‐treated groups and a control group. The alprazolam‐treated rats were given 5, 10 or 20 mg/kg (low, medium, high) of alprazolam by intragastric administration each day for 14 days. The serum samples were corrected on the seventh and fourteenth days for metabolomic study. The blood was collected for biochemical tests. Then liver and brain were rapidly isolated and immersed for pathological study. Compared with the control group, on the seventh and fourteen days, the levels of d ‐glucose, 9,12‐octadecadienoic acid, butanoic acid, l ‐proline, d ‐mannose and malic acid had changed, indicating that alprazolam induced energy metabolism, fatty acid metabolism and amino acid metabolism perturbations in rats. There was no significant difference for alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, urea and uric acid between controls and alprazolam groups. According to the pathological results, alprazolam is not hepatotoxic. Metabolomics could distinguish different alprazolam doses in rats.     

Cell protection from Ca2+-overloading by bioactive molecules extracted from olive pomace

We are reporting in the present study that molecules extracted from olive pomace prevent cell death induced by Ca²⁺-overloading in different cell types. Exposure of cells to these molecules counteracts the Ca²⁺-induced cell damages by reducing the activation of the Ca²⁺-dependent protease calpain, acting possibly through the modification of the permeability to Ca²⁺ of the plasma membrane. The purification step by RP-HPLC suggests that effective compound(s), differing from the main biophenols known to be present in the olive pomace extract, could be responsible for this effect. Our observations suggest that bioactive molecules present in the olive pomace could be potential candidates for therapeutic applications in pathologies characterised by alterations of intracellular Ca²⁺ homeostasis.     

Effect of Tridax procumbens (Linn.) on bile duct ligation-induced liver fibrosis in rats

The present study was undertaken to clarify whether methanolic extract of Tridax procumbens prevents liver fibrosis in rat. The hepatic fibrosis was induced by 28 days of bile duct ligation in rats. The 4-week treatment with Tridex procumbens reduced the serum aspartate aminotransferase (U?L?1), glutamate pyruvate transaminase (U?L?1), alkaline phosphatase (IU?L?1), lactate dehydrogenase (IU?L?1), total bilirubin (mg?dL?1), direct bilirubin (mg?dL?1) and hydroxyproline (mg?gm?1) content in liver and improved the histological appearance of liver section. The results of this study led us to conclude that T. procumbens can reduce the degree of hepatocellular damage and may become antifibrotic agent for liver fibrosis.     

Phenolic compounds and antioxidant activity of olive leaf extracts

The total phenolic content and antioxidant activities of olive leaf extracts were determined. Plant material was extracted with methanol and fractionated with solvents of increasing polarity, giving certain extracts. The qualitative changes in the composition of the extracts were determined after the storage of leaves for 22?h at 37°C, before the extraction. Total polyphenol contents in extracts were determined by the Folin-Ciocalteu procedure. They were also analysed by liquid chromatography-mass spectrometry. Their antioxidant activities were evaluated using the diphenyl picrylhydrazyl method and the β-carotene linoleate model assay. Moreover, the effects of different crude olive leaf extracts on the oxidative stability of sunflower oil at 40°C and sunflower oil-in-water emulsions (10% o/w) at 37°C, at a final concentration of crude extract 200?mg?kg(-1) oil, were tested and compared with butylated hydroxyl toluene.     

Phytochemical and in vitro screening of some Ficus and Morus spp. for hypolipidaemic and antioxidant activities and in vivo assessment of Ficus mysorensis (Roth)

Phytochemical screening of air-dried leaves and fruit juice of certain Ficus and Morus spp. have been studied. In an in?vitro study, the ethanol and hexane extracts of the investigated plants were evaluated against hyperlipidaemia by estimating the rate limiting enzyme of cholesterol biothenysis; β-hydroxy-β-methylglutaryl coenzyme A reductase (HMG-CoA reductase). The antioxidant activity was evaluated by reduction of DPPH(-) free radical. Extra phytochemical screening of Ficus extracts was undertaken, which recorded potent hypolipidaemic and antioxidant activities. The more pronounced extract, Ficus mysorensis (hexane extract), was evaluated in?vivo by estimation of the lipid profile and certain antioxidant parameters in hypercholesterolemic rats. The hexane fraction was chromatographed and six isolated compounds were identified. Furthermore, its saponifiable fraction was identified by a MS/MS technique. In conclusion, F. mysorensis recorded hypolipidaemic and antioxidant effects. Detailed studies of the isolated compounds must be undertaken for an evaluation against hypercholesterolemia and free radical elevation.     

A Potential Valorization Strategy of Wine Industry by-Products and Their Application in Cosmetics—Case Study: Grape Pomace and Grapeseed

Grape pomace and grapeseed are agro-industrial by-products, whose inadequate treatment generates socioeconomic and environmental concerns. Nevertheless, it is possible to valorize them by extracting their bioactive compounds, such as antioxidants (phenolic compounds), vitamin E and fatty acids. The bioactive compounds were extracted using solid-liquid extraction. The yields for phenolic compounds were 18.4 ± 0.4% for grape pomace, and 17.4 ± 0.4%, for grapeseed. For the oil, the yields were 13.3 ± 0.2% and 14.5 ± 0.3% for grape pomace and grapeseed. Antioxidant capacity was assessed by the assay with 2,2-diphenyl-1-picrylhydrazyl (DPPH), and showed that phenolic extract has higher antioxidant capacity than the oils. Grape pomace and grapeseed extracts exhibit, correspondingly, values of 90.8 ± 0.8 and 87.5 ± 0.5 of DPPH inhibition and IC₅₀ of 48.9 ± 0.5 and 55.9 ± 0.7 μg_extract·mL_DPPH⁻¹. The antimicrobial capacity was assessed by the disk diffusion test, and revealed that, phenolic extracts inhibit the growth of Staphylococcus aureus and Staphylococcus epidermidis. The obtained extracts were incorporated in 10 face cream formulations, with slight modifications in quantities of formulation stabilizers. Their stability was studied for 35 days, and this revealed the possibility of incorporating extracts and oils obtained from by-products as antioxidants in cosmetics, and replacing synthetic ones. As a future recommendation, microencapsulation of the extracts should be performed, in order to increase their stability.     

Analgesic and anti-inflammatory properties of Thespesia populnea leaf extracts

Analgesic and anti-inflammatory activities of the aqueous and ethanol extracts of Thespesia populnea Soland. ex. Correa (Malvaceae) leaves were evaluated in animal models. Orally-administered aqueous and ethanol extracts (100, 200 and 400?mg?kg?1 bw) showed significant analgesic activity in chemical-, mechanical- and thermally-induced pain test models in mice. The extracts also reduced paw oedema induced by carrageenan in rats. The results obtained in this study suggest that Thespesia populnea extracts have analgesic and anti-inflammatory properties.     

The concentration of oleocanthal in olive oil waste

The aim of this study was to determine the concentration of oleocanthal in olive pomace waste and compare this to its concentration in extra-virgin olive oil (EVOO). The concentration of oleocanthal in freshly pressed EVOO and its subsequent waste was analysed at early, mid and late season harvests. Oleocanthal concentrations were quantified using high-performance liquid chromatography-mass spectrometry. In oil, oleocanthal concentration was as follows: 123.24 ± 6.48 mg kg(-1) in early harvest, 114.20 ± 17.42 mg kg(-1) in mid harvest and 152.22 ± 10.54 mg kg(-1) in late harvest. Its concentration in waste was determined to be: 128.25 ± 11.33 mg kg(-1) in early harvest, 112.15 ± 1.51 mg kg(-1) in mid harvest and 62.35 ± 8.00 mg kg(-1) in late harvest. Overall, olive pomace waste is a valuable source of oleocanthal.     

Effect of fruit extract on renal stone formation and kidney injury in rats

This study investigated the effect of oral administration of Cactus fruit extracts on calcium oxalate deposition, malondialdehyde (MDA) and superoxide dismutase (SOD) activity in rat model. About 42 rats were used for the study. The animals were divided into seven groups. Control group maintained on regular rat food and drinking water throughout the study period, whereas in other groups nephrolithiasis was induced by ethylene glycol. Rats in kidney stone group were sacrificed after 28 days and all remaining groups after 58 days. Treatment groups were treated with 1 and 100 mg/kg of aqueous and ethanolic extracts of Cactus fruit for 30 days. After treatment, SOD activity was increased and MDA was decreased significantly. CaOx depositions were decreased significantly, especially in ethanolic extract of Cactus fruit in high dose (100 mg/kg).     

Optimization of microwave-assisted extraction of polyphenols from apple pomace using response surface methodology and HPLC analysis

A simple and efficient microwave-assisted extraction of polyphenols from industrial apple pomace was developed and optimized by the maximization of the yield using response surface methodology. A Box-Behnken design was used to monitor the effect of microwave power, extraction time, ethanol concentration and ratio of solvent to raw material (g/mL) on the polyphenols yield. The results showed that the optimal conditions were as follows: microwave power 650.4?W, extraction time 53.7?s, ethanol concentration 62.1% and ratio of solvent to raw material 22.9:1. Validation tests indicated that the actual yield of polyphenols was 62.68±0.35?mg gallic acid equivalents per 100?g dry apple pomace with RSD=0.86% (n=5) under the optimal conditions, which was in good agreement with the predicted yield and higher than those of reflux and ultrasonic-assisted extraction methods. HPLC analysis indicated that the major polyphenols of apple pomace consisted of chlorogenic acid, caffeic acid, syrigin, procyanidin B2, (-)-epicatechin, cinnamic acid, coumaric acid, phlorizin and quercetin, of which procyanidin B2 had the highest content of 219.4?mg/kg.     

Gross and net rates of nitrogen mineralisation in soil amended with composted olive mill pomace

Olive mill pomace is the major waste product in the olive oil industry and composting these by-products for the purpose of recycling nutrients and organic matter is a sound environmental strategy. Yet little is known about the quantity and timing of nitrogen (N) release from composted olive mill pomace. This paper assesses both gross (using the (15)N dilution technique) and net (aerobic incubation) nitrogen (N) mineralisation and N(2)O emissions of soil amended with seven commercially available composts of olive mill pomace (COMP). All are currently produced in Andalusia and differ in the proportions of raw materials co-composted with the pomace. The absence of significant differences in net N or gross mineralisation and nitrification in COMP-amended soil compared with a control, except for COMP combined with poultry manure, highlighted the recalcitrant nature of the COMP-N. Applications of COMP are hence unlikely to supply available N in available forms, at least in the short-term. Furthermore, N(2)O emissions from COMP-amended soil were negligible and, therefore, applications in the field should not result in increased N loss through denitrification.     

Natural source compatibilizers for olive waste/recycled polypropylene matrix composites

A simple, environmentally friendly process was developed for surface hydrophobization of cellulose-rich waste to improve their compatibility with recycled polypropylene (rPP), helping reduce costs while recycling environmentally problematic waste such as solid olive waste (also called olive pomace). In this study, an improvement of the interfacial bonding strength between the hydrophilic waste particles and the hydrophobic matrix was achieved by surface hydrophobization of the waste using a ring-opening polymerization reaction of epoxidized soy-bean oil (ESBO) with SnCl₂ as a catalyst. The treatment on cellulose based filter paper led to a contact angle of 128°. The composite containing treated olive pomace has shown an increase in the elongation of 92% and an increase in the stress at yield of 15%, indicating improved compatibility.     

13C nuclear magnetic resonance spectroscopy to determine olive oil grades

¹³C nuclear magnetic resonance spectroscopy was used in a first attempt to differentiate olive oil samples by grades. High resolution ¹³C NMR Distortionless Enhancement by Polarization Transfer (DEPT) spectra of 137 olive oil samples from the four grades, extra virgin olive oils, olive oils, olive pomace oils and lampante olive oils, were measured. The data relative to the resonance intensities (variables) of the unsaturated carbons of oleate (C-9 and C-10) and linoleate (L-9, L-10 and L-12) chains attached at the 1,3- and 2-positions of triacylglycerols were analyzed by linear discriminant analysis. The 1,3- and 2- carbons of the glycerol moiety of triacylglycerols along with the C-2, C-16 and C-18 resonance intensities of saturated, oleate and linoleate chains were also analyzed by linear discriminant analysis. The three discriminanting functions, which were calculated by using a stepwise variable selection algorithm, classified in the true group by cross-validation procedure, respectively, 76.9, 70.0, 94.4 and 100% of the extra virgin, olive oil, olive pomace oil and lampante olive oil grades.     

Comparison of polyphenol extractions from olive pomace and solid fraction of olive mill waste water

The solid fraction of olive mill waste water (OMWW) was separated from OMWW and then the solutes in the solid fraction of OMWW were extracted with ethanol. The detection of polyphenols in the ethanol extract showed the presence of polyphenols in the solid fraction of OMWW. Effects of solvent-to-solid ratio, extraction and agitation time on the extraction of polyphenols from the solid fraction of OMWW were examined and the maximum amount of polyphenol was extracted from the solid fraction of OMWW with a solvent-to-solid ratio of 15 at 70?min of extraction and 10?min of agitation time. Percent yields and purities of the polyphenols extracted from solid fraction of OMWW were higher than those of the polyphenols extracted from olive pomace with ethanol at 70?min of extraction and 10?min of agitation time with solvent-to-solid ratio of 15.     

Efficacy of Ficus spp. on renal injury induced by hypercholesterolaemia

The ethanol and hexane extracts of Ficus microcarpa, Ficus religiosa and Ficus mysorensis leaves were evaluated against renal injury induced by hypercholesterolaemia. Phytochemical screening of the investigated plants was undertaken. For the in vivo study, all rats were orally given cholesterol (30?mg?kg?1 body weight, BW) and leaves extract (500?mg?kg?1 BW) five times per week for 9 weeks. Hypercholesterolaemic rats showed significant increases in urea nitrogen and creatinine while serum protein and albumin levels, nitric oxide (NO), Na?-K?-ATPase and phospholipids in kidney tissue were all decreased. Treatment with leaves extract improved kidney function indices (urea nitrogen, creatinine, serum protein and albumin), kidney disorder biochemical parameters (NO, Na?-K?-ATPase and phospholipids), haematological profile (haemoglobin, RBCs and WBCs) and kidney histopathology. In conclusion, Ficus spp. succeeded in improving renal injury induced by hypercholesterolaemia, with the most potent effects seen while using Ficus microcarpa hexane extract.     

Effect-Directed Profiling of 17 Different Fortified Plant Extracts by High-Performance Thin-Layer Chromatography Combined with Six Planar Assays and High-Resolution Mass Spectrometry

An effect-directed profiling method was developed to investigate 17 different fortified plant extracts for potential benefits. Six planar effect-directed assays were piezoelectrically sprayed on the samples separated side-by-side by high-performance thin-layer chromatography. Multipotent compounds with antibacterial, α-glucosidase, β-glucosidase, AChE, tyrosinase and/or β-glucuronidase-inhibiting effects were detected in most fortified plant extracts. A comparatively high level of antimicrobial activity was observed for Eleutherococcus, hops, grape pomace, passiflora, rosemary and Eschscholzia. Except in red vine, black radish and horse tail, strong enzyme inhibiting compounds were also detected. Most plants with anti-α-glucosidase activity also inhibited β-glucosidase. Green tea, lemon balm and rosemary were identified as multipotent plants. Their multipotent compound zones were characterized by high-resolution mass spectrometry to be catechins, rosmarinic acid, chlorogenic acid and gallic acid. The results pointed to antibacterial and enzymatic effects that were not yet known for plants such as Eleutherococcus and for compounds such as cynaratriol and caffeine. The nontarget effect-directed profiling with multi-imaging is of high benefit for routine inspections, as it provides comprehensive information on the quality and safety of the plant extracts with respect to the global production chain. In this study, it not only confirmed what was expected, but also identified multipotent plants and compounds, and revealed new bioactivity effects.     

Effect of andrographolide on cysteamine-induced duodenal ulcer in rats

The aim of this study was to evaluate the gastroprotective efficacy of andrographolide isolated from Andrographis paniculata in rats induced with duodenal ulcers. Duodenal ulcers were induced by cysteamine administration in rats pretreated with 3?mg?kg?1 BW?day?1 of andrographolide for 30 days. Ulcer score, myeloperoxidase activity, TBARS level, GSH/GSSG ratio and enzyme antioxidants were measured in the duodenal tissue. Brush border and basolateral membranes were isolated to assay sucrase, maltase, alkaline phosphatase and total ATPases. Ulcer score was significantly minimised in rats pretreated with andrographolide. Elevation in myeloperoxidase and TBARS levels were found to be minimised significantly due to andrographolide treatment. Membrane-bound enzyme activities and the thiol redox status of glutathione were significantly maintained in duodenal mucosa of rats that received andrographolide. This study reveals that the major component of A. paniculata, andrographolide, has potent antiulcer properties that are most likely caused by minimising inflammatory changes, counteracting free radical formation and maintaining the thiol redox status in the duodenum.     

Ethanolic extract of Rubia peregrina L. (Rubiaceae) inhibits haloperidol-induced catalepsy and reserpine-induced orofacial dyskinesia

In the traditional Sardinian system of medicine, Rubia peregrina L. (Rubiaceae) is reported as an aphrodisiac herb. Since the aphrodisiacs may also have antioxidant and dopaminergic activities, the aim of this study was to study the effect of ethanolic extract of aerial parts of R. peregrina for the scavenging of free DPPH radicals and the inhibition of haloperidol-induced catalepsy in mice and reserpine-induced orofacial dyskinesia in rats. The extract exhibited significant antioxidant activity in a free radical DPPH assay with IC(50)?=?55.6?μg?mL(-1), which was very close to IC(50) of ascorbic acid. The extract of R. peregrina (100 and 200?mg?kg(-1) intraperitoneally, i.p.) significantly inhibited haloperidol (1?mg?kg(-1) i.p.) - induced catalepsy in mice (p?相似文献