Effect of Alcalase™ on olive pomace protein extraction

The effect of Alcalase^™ treatment on olive pomace protein extraction has been studied. Alcalase improves protein extraction from 5 to 30% of total protein. This improvement is not accompained by an increase in degree of protein hydrolysis, probably because protease activity is inhibited by secondary metabolites and the substrate is highly denatured and resistant to hydrolysis. The increase in protein extraction is attributed to fiber solubilization as a result of secondary activities of Alcalase. Protein extracts with a high content of soluble fiber have improved functional properties, with respect to olive pomace, such as water and oil absorption. Emulsifying and foaming activities were inappreciable. The products obtained represent a suitable source of soluble fiber and protein and may contribute to the improvement of the economic status of olive pomace by-product.     

Fatty acid esters with short‐chain alcohols in two‐phase olive pomace oils

Two‐phase decanter olive pomace (TPOP) is the by‐product of a centrifugation system, used to produce olive oil, that separates olive oil and moist pomace. The water content in these olive pomaces is about 70%, while it was 45‐50% in the olive pomace stemming from three‐phase systems (oil, water, and pomace) and 30% in the old press system. The aim of this work is focused on quantification and changes undergone during olive pomace storage in ponds of esters of fatty acids with short‐chain linear alcohols, which can be considered as a refining loss. The results indicate that oil deterioration increases very rapidly, in particular when oil is extracted from the TPOP surface. Special attention should be paid to the storage of TPOP, establishing a maximum of 2 months in all cases.     

Chemical modification of hemp fibers by silane coupling agents

Natural hemp fibers were chemically modified using silane coupling agents to reduce their hydrophilic character. The existence of a chemical bond between coupling agents and hemp fibers was confirmed by ATR‐FTIR spectroscopy, ²⁹Si Nuclear Magnetic Resonance (NMR), thermogravimetric analysis (TGA), energy dispersive spectroscopy (EDS), and BET surface area measurements. It was shown that the initial concentration and the chemical structure of the organosilane coupling agent have an effect on the grafted quantity on the hemp fiber surfaces. The grafted quantity increased proportionally to the initial concentration of silane molecules. The presence of polar amino end group (NH₂) in silane structure can cause an increase in the grafted quantity, compared with results obtained in the case of silane molecules containing methacryloxy groups. This effect is attributed to the formation of hydrogen bonds between NH₂ and unreacted hydroxyl groups of hemp fibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Assessment of olive pomace wastes as flame retardants

Olive pomace (OP) is a lignocellulosic waste from olive oil industry. In order to valorize these wastes as flame retardant (FR) fillers into polymers, OP residues are milled and screened into three different fractions. Two strategies are then investigated. The first one is to modify OP particles by phosphorus molecules using radiation grafting as already done successfully with flax. Nevertheless, pyrolysis combustion flow calorimetry analyses show that the introduction of phosphorus does not promote charring of OP and flame retardancy is not significantly improved whichever the considered fraction. The second strategy is to replace pentaerythritol by OP as char source into well-known FR systems based on ammonium polyphosphate. The incorporation of such system into ethylene-vinyl acetate copolymer leads to satisfying FR performances according to cone calorimeter tests. Moreover, the presence of high amount of extractives into OP such as oleic acid does not appear detrimental. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 47715.     

Stability of refined olive oil and olive‐pomace oil added by phenolic compounds from olive leaves

Refined olive oil and olive‐pomace oil were enriched with olive leaf phenolic compounds in order to enhance its quality and bring it closer to virgin olive oil. The changes that occurred in the concentrations of pure oleuropein, oleuropein aglycone, hydroxytyrosol acetyl and α‐tocopherol at 400 µg/kg of oil during the storage of refined olive oil and olive‐pomace oil under accelerated conditions (50 °C) were investigated. In a period of 4 months, α‐tocopherol decomposed by 75% whereas less than 40% of the phenols were lost. During storage, enzymatic olive leaf extract hydrolysate that contains two major compounds, hydroxytyrosol and oleuropein aglycone showed the highest antioxidant activity and the lowest detected stability, followed by oleuropein. The oleuropein in olive leaf extracts exhibited similar degradation profiles, reducing by 60–50% and 80% for the olive oil and olive‐pomace oil in 6 months, respectively. The acetylated extract, however, displayed a loss of 10 and 5% in olive oil and olive‐pomace oil, respectively. In the fatty acid composition, an increase in oleic acid and a decrease in linoleic acid were observed. The antiradical activities of the olive oil and olive‐pomace oil enriched with olive leaf phenolic compounds at 400 ppm showed that enzymatic hydrolysate extract had the highest protective effect against oil oxidation. Based on the Rancimat method, the oils with added leaf enzymatic hydrolysate extract had the lowest peroxide value and the highest stability. After 6 months of storage and at 120 °C, the oxidative resistance of refined olive oil and olive‐pomace oil reached 0.71 and 0.89 h, respectively, whereas that of the non‐enriched samples fell to zero.     

Elimination of polycyclic aromatic hydrocarbons by bleaching of olive pomace oil

A detailed study of the efficacy of the bleaching process for elimination of polycyclic aromatic hydrocarbons in Spanish olive pomace oils has been carried out. For this purpose active carbon with bleaching earth was used as absorbent. The amount of benzo‐(α)‐pyrene was determined by reversed‐phase high‐performance liquid chromatography with a Fluorimetric detector. The use of exhausted filter‐cakes in countercurrent processes with a cake formed of active carbon and bleaching earth is very efficient for reducing the initial content of benzo‐(α)‐pyrene before the addition of fresh adsorbent, thus reducing the amounts of carbon and earth required.     

Improvement of fluidized‐bed dryers for drying solid waste (olive pomace) in olive oil mills

Olive pomace from the two‐phase method of olive oil extraction (two‐phase olive pomace) must be dried from about 65% [wet basis (wb)] to about 8%, in order to extract part of the remaining pomace oil (about 3 wb‐%). An innovative dryer based on a fluidized bed is developed in this study. The objective is to improve olive pomace drying with low energy cost and high product quality by using optimal operating conditions, e.g. temperature and air flow rate, feeding solid moisture, and a control system. The bed operating temperature was set at 125 °C to obtain a good olive pomace oil quality and to reduce the thermal power consumption and drying time. The dried material is rather homogeneous and contains a negligible amount of polycyclic aromatic hydrocarbons. The fluidized bed was further improved with a moving bed joined by a conical device to the fluidized‐bed freeboard. This is a powerful combination in which the moving bed acts as a pre‐dryer of the wet solid and also as a filter of the output gas, with more than 99.9% of fines retention. The mean power consumption of the improved fluidized‐moving‐bed plant is 1 kWh/kg_water; this means a significant reduction of power cost with respect to the rotary dryers, which require about 1.4 kWh/kg_water.     

Study of the acid pretreatment and biodiesel production from olive pomace oil

The objective of this work was to study the two‐step acid base homogenous catalyzed transesterification of olive pomace oil, with the ultimate purpose of producing biodiesel under mild reaction conditions by optimizing the process. Optimization of the experimental procedure was conducted by a factorial design of 2³ under the acidic pretreatment step and during the basic transesterification. The optimal production of methyl esters (97.8%) was achieved for the experimental conditions H₂SO₄ = 20 wt%/CH₃OH = 35:1/T = 40^°C and KOH = 0.6+ fatty acid value /CH₃OH = 9:1/ T = 60^°C, in the acidic and basic stage of the process, respectively. Finally, to properly assess the quality of the biofuel produced, it was tested for all the European Standard properties.     

Separation of wax esters from olive oils by high-performance liquid chromatography

To detect adulteration of olive oil with solvent-extracted oils, the determination of the wax ester content has become more important during recent years. Hence, a greater number of wax ester analyses need to be performed by quality control laboratories. The most common method in use requires a liquid chromatographic (LC) separation of the less polar fraction, which contains the wax esters, from the glyceride matter on a hand-filled silica gel column. The aim of this project was to verify the possibility of replacing LC with high-performance liquid chromatography by taking advantage of the greater reliability and repeatability of this technique, as well as of the possibility of making the separation automatic. The paper describes how to perform the analysis and the statistical test that was carried out; furthermore, a comparison has been made with the usual method and results are in good agreement.     

Chemical structure of long-chain esters from “sansa” olive oil

The major objective of this study was to determine the chemical structure of long-chain esters present in lower-grade olive oil. The classes of esters composing the hexanediethyl ether (99∶1) extract of the wax fraction from a pomace olive oil were: (i) esters of oleic acid with C₁−C₆ alcohols, (ii) esters of oleic acid with long-chain aliphatic alcohols in the range C₂₂−C₂₈ and (iii) benzyl alcohol esters of the very long-chain saturated fatty acids C₂₆ and C₂₈. The analysis and the structure assignments were carried out by gas chromatography coupled with mass spectrometry and by comparison with synthetic authentic model compounds. This work provided precise data on the chemical nature of the wax esters present in olive oil and should represent a means to detect adulteration of higher-grade olive oil with less expensive pomace olive oil and seed oils.     

Heavy metal removal by olive pomace: biosorbent characterisation and equilibrium modelling

This paper concerns with metal biosorption onto an agricultural waste, olive pomace. Experimental tests of adsorbent characterisation (potentiometric titration, IR analyses, selective extractions) and titration modelling (accounting for adsorbent heterogeneity by the introduction of a two-peak proton affinity distribution function) evidence that carboxylic and phenolic groups are the main active sites involved in metal removal. Potentiometric titration and single metal system biosorption tests (Pb, Cu, Cd) onto native and treated olive pomace samples are represented by an equilibrium model describing the competition among heavy metals and hydrogen ions in solution.     

Chemical modification of multiwalled carbon nanotube with the liquid phase method

In this study, multiwalled carbon nanotubes (MWNTs) were purified by using chemical method with different proportion of nitric acid and sulfuric acid liquid phase mixture. Carboxyl groups and other functional groups could be modified on the MWNTs surface. However, oxidation can damage the structure of carbon atoms on the surface of the carbon nanotube. Furthermore, the characteristic properties of MWNTs specimens were demonstrated by Raman spectrograph and Fourier transform infrared spectrum. The thermal properties and morphology of MWNTs were checked by Thermogravimetric analysis and Scanning electron microscope. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

磷脂的化学改性与生物改性技术

介绍了磷脂化学改性与生物改性技术。化学改性的技术包括磷脂改性机理、磷脂的乙酰化、羟基化、氢化和硫酸化(氯化—硫酸化、醇解—硫酸化、溶剂稀释—硫酸化等)工艺。生物改性技术包括生物酶改性机理、磷脂酶A2的改性和磷脂酶D的改性。它们为改善磷脂的品质和功能提供了重要的方法。     

Chemical modification of alkyd resin by a DOPO derivative and its flame retardancy

9,10‐Dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) and its derivatives have been widely used as effective flame retardants. In this study, 6‐((bis(2‐hydroxyethyl) amino) methyl)‐6H‐dibe‐nzo[c,e][1,2]oxaphosphinine‐6‐oxide (DHDOPO) was synthesized from DOPO, paraformaldehyde, and diethanolamine, and subsequently used as a reactant for synthesis of flame retarded alkyd resin (FR‐ALK). Thermogravimetric analysis (TGA) showed that DHDOPO had relatively high thermal stability and would not decompose at synthesis temperature of ALK. The thermal stability and flame retardancy of ALKs were improved by introduction of DHDOPO. As the mass fraction of phosphorus in FR‐ALK increased the decomposition temperature, the char yield in TGA experiments, the fire residue, and time to ignition in cone calorimeter tests increased, and peak heat release rate (PHRR) and total heat release (THR) decreased. Compared with the non‐flame retarded ALK the PHRR and THR values of FR‐ALK containing 2.5 wt % phosphorus decreased, respectively, by 43.1% and 58.5%. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45643.     

Chemical modification of cellulase by maleic anhydride and N-bromosuccinimide for improved detergent stability

The use of cellulases in detergents is gaining ground rapidly due to their ability to maintain clear colors, a smooth surface, and softness in cotton fabrics. This is due to the hydrolytic action on the fuzz and pill, which scatters light thereby giving a worn and faded look to the garments. Detergent cellulases must be stable to conditions of alkaline pH and to other components present in the formulation. Most literature in this area is patented. Our previous work demonstrated an excellent alkali stability of commercially available acid cellulases modified by maleic anhydride and N-bromosuccinimide. The present work reports on screening for cellulases in commercially active detergents and the stability of these chemically modified cellulases vis-à-vis native cellulase in biodetergents and in detergents without enzymes at 30, 50, and 85°C for up to 120 min. The results obtained showed that modified cellulases have distinctly better stability than the native cellulase in the chosen detergents.     

壳聚糖的化学改性及其应用

综述了近年来壳聚糖化学改性研究,从酯化反应、醚化反应、N-烷基化反应、Schiff碱反应、酰化反应、交联和接枝共聚反应等介绍壳聚糖化学改性研究发展现状;并着重阐述了壳聚糖及其衍生物在日用化学品、农业、食品加工业、医药、环保和纺织业等领域中的应用;展望了壳聚糖研究应用的发展方向,尤其是在日用化学品中的应用前景。     

Chemical modification of chloromethylated polystyrene with pyridylazo‐β‐naphthol

Chloromethylated polystyrene was chemically modified through alkylation of pyridylazo‐β‐naphthol (PAN) in the presence of a phase‐transfer catalyst. The chemical modification was achieved through O‐alkylation as well as N‐alkylation of PAN, leading to formation of polymer‐supported quaternary ammonium salt in the latter case. Both types of a polymer‐supported PAN moiety were detected by FTIR spectroscopic analysis. The complexation behavior of the polymer‐supported PAN as an ion‐exchanger toward some metal ions was studied. Thermogravimetric and differential thermogravimetric analyses data were used to study the kinetics of the thermal decomposition process of the ion‐exchanger. Some thermodynamic parameters for the ion‐exchanger were calculated by applying the rate theory of the first‐order reaction. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3044–3048, 2000     

Chemical modification of molten polyethylene by thermal decomposition of peroxyesters

The functionalization of polyethylene was realized by the thermal decomposition of peroxyesters in molten polymer in the absence of any other additive. Ester and acid functions were introduced onto the polymer operating with various peroxyesters. This grafting resulted from the combination of a polymer radical, generated in the abstraction of a hydrogen from polyethylene by an alkoxy radical, with an acyloxy or carbon‐centered radical arising from the perester. A complete methodology was set up to identify and to titrate the functions present onto the polyethylene and to determine the extent of crosslinked polymer. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 699–707, 2003