Effect of steam treatment of alperujo on the composition, enzymatic saccharification, and in vitro digestibility of alperujo

The solid waste from two-phase olive oil extraction or "alperujo" was submitted to steam treatment at high pressure or temperature, 200 degrees C for 5 min, in the presence and absence of mild acid catalyst. This treatment made easier the separation of the solid and liquid fractions. Besides the recovery of certain valuable components from the liquid fraction (the antioxidant hydroxytyrosol, low molecular weight oligosaccharides, glucose, mannitol, etc.), the major components of the solid residue could be also exploited. In this study, changes in composition of alperujo due to steam treatment were determined. The process reduced appreciably the hemicellulose concentrations (75-88%), removed a substantial portion of Klason lignin and protein (50%), and led to an extensive solubilization of alperujo (55-67%). Cellulose was very resistant to autohydrolysis and acid-catalyzed hydrolysis, so the solid residue was enriched in fat (13-18 g/100 g of dry steam-treated alperujo) and cellulose (15-25 g/100 g of dry and defatted steam-treated alperujo). The steam-treated material can be efficiently saccharified with commercial cellulase. The best hydrolysis yields were attained, up to 80%, when the treated material was post-treated with NaOH. The possibility of using this steam-treated alperujo in animal feeding was evaluated by an in vitro digestibility test, using the pepsin-cellulase method. The treatment affected positively the nutritional characteristics of alperujo with an increase in its in vitro (dry and organic matter) digestibility (8-10% higher than untreated material). In vitro digestibility and cellulose accessibility to enzymatic hydrolysis were improved by the alkali post-treatment.     

Production in large quantities of highly purified hydroxytyrosol from liquid-solid waste of two-phase olive oil processing or "Alperujo"

The effect of hydrothermal treatment of two-phase olive waste (alperujo) on the solubilization of hydroxytyrosol was studied. Different conditions of saturated steam were assayed. A high amount of hydroxytyrosol was solubilized and increased with increasing steaming temperature and time, reaching 1.4-1.7 g/100 g of dry alperujo. The effect of acidic (H(2)SO(4)) and basic (NaOH) catalysts was also evaluated. Acid-catalyzed treatment was more effective at milder conditions, whereas the alkali-catalyzed conditions were not very suitable. In the present study, the extracted hydroxytyrosol was purified by means of a new, simple, and inexpensive chromatographic system, under international patent application (PCT/ES02/00058). From 1000 kg of alperujo, with 70% humidity, can be obtained approximately 4.5-5 kg of hydroxytyrosol. After a purification process, at least 3 kg of hydroxytyrosol, at 90-95% purity, would be obtained. The purified compound was identified by HPLC/UV and (1)H and (13)C NMR analyses, and its antioxidant activity was tested on refined olive oil without antioxidants by Rancimat method. The oxidative stability of refined olive oil was increased by a factor of 1.71 in the presence of 100 ppm of hydroxytyrosol.     

Fate of diuron and terbuthylazine in soils amended with two-phase olive oil mill waste

The addition of organic amendments to soil increases soil organic matter content and stimulates soil microbial activity. Thus, processes affecting herbicide fate in the soil should be affected. The objective of this work was to investigate the effect of olive oil production industry organic waste (alperujo) on soil sorption-desorption, degradation, and leaching of diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] and terbuthylazine [N2-tert-butyl-6-chloro-N4-ethyl-1,3,5-triazine-2,4-diamine], two herbicides widely used in olive crops. The soils used in this study were a sandy soil and a silty clay soil from two different olive groves. The sandy soil was amended in the laboratory with fresh (uncomposted) alperujo at the rate of 10% w/w, and the silty clay soil was amended in the field with fresh alperujo at the rate of 256 kg per tree during 4 years and in the laboratory with fresh or composted alperujo. Sorption of both herbicides increased in laboratory-amended soils as compared to unamended or field-amended soils, and this process was less reversible in laboratory-amended soils, except for diuron in amended sandy soil. Addition of alperujo to soils increased half-lives of the herbicides in most of the soils. Diuron and terbuthylazine leached through unamended sandy soil, but no herbicide was detected in laboratory-amended soil. Diuron did not leach through amended or unamended silty clay soil, whereas small amounts of terbuthylazine were detected in leachates from unamended soil. Despite their higher sorption capacity, greater amounts of terbuthylazine were found in the leachates from amended silty clay soils. The amounts of dissolved organic matter from alperujo and the degree of humification can affect sorption, degradation, and leaching of these two classes of herbicides in soils. It appears that adding alperujo to soil would not have adverse impacts on the behavior of herbicides in olive production.     

Total recovery of the waste of two-phase olive oil processing: isolation of added-value compounds

A process for the value addition of solid waste from two-phase olive oil extraction or "alperujo" that includes a hydrothermal treatment has been suggested. In this treatment an autohydrolysis process occurs and the solid olive byproduct is partially solubilized. From this water-soluble fraction can be obtained besides the antioxidant hydroxytyrosol several other compounds of high added value. In this paper three different samples of alperujo were characterized and subjected to a hydrothermal treatment with and without acid catalyst. The main soluble compounds after the hydrolysis were represented by monosaccharides xylose, arabinose, and glucose; oligosaccharides, mannitol and products of sugar destruction. Oligosaccharides were separated by size exclusion chromatography. It was possible to get highly purified mannitol by applying a simple purification method.     

Availability of triazine herbicides in aged soils amended with olive oil mill waste

Amendments are frequently added to agricultural soils to increase organic matter content. In this study, we examined the influence of alperujo, an olive oil mill waste, on the availability of two triazine herbicides, terbuthylazine and atrazine, in two different sandy soils, one from Sevilla, Spain, and the other from Minnesota. The effect of aging on herbicide sorption and bioavailability was also studied. Soils were amended with alperujo at a rate of 3-5% (w:w) in laboratory studies. Apparent sorption coefficients for the triazine herbicides were calculated as the ratio of the concentrations of each herbicide sequentially extracted with water, followed by aqueous methanol, at each sampling time. These data showed greater sorption of terbuthylazine and atrazine in amended soils as compared to nonamended soils, and an increase in the amount of herbicide sorbed with increasing aging time in nonamended soils. The triazine-mineralizing bacterium Pseudomonas sp. strain ADP was used to characterize triazine bioavailability. Less mineralization of the herbicides by Pseudomonas sp. strain ADP was observed in soils amended with alperujo, as compared to the unamended soils, and, despite the increase in sorption with aging in unamended soils, herbicide mineralization also increased in this case. This has been attributed to Pseudomonas sp. strain ADP first using alperujo as a more readily available source of N as compared to the parent triazines. In summary, addition of alperujo to the soils studied was shown to increase triazine herbicides sorption and hence to reduce its availability and potential to leach.     

Effect of a new thermal treatment in combination with saprobic fungal incubation on the phytotoxicity level of alperujo

Byproducts generated from food industries, such as olive oil mills, have been studied to decrease harmful pollution and their environmental consequences. In this work, a new thermal pretreatment and saprobic fungal incubation to detoxify alperujo (two-phase olive mill waste) have been evaluated in view of its use as fertilizer in agriculture. The sequential use of both methods simplifies the thermal conditions and incubation times of the fungal treatment. Optimization of the thermal treatment from 150 to 170 °C for 45 and 15 min, respectively, reduced the incubation time with Coriolpsis rigida from 20 to 10 weeks needed to reduce phytotoxic effects on tomato plants. Therefore, the combination of thermal and biological treatments will allow the development of the potential benefits of alperujo to improve nutrients in agricultural soil.     

Soil water availability in rainfed cultivation affects more than cultivar some nutraceutical components and the sensory profile of virgin olive oil

This research considered the varieties 'Frantoio' and 'Moraiolo' growing in rainfed olive trees (Olea europaea) and took place in Tuscany, central Italy. Soil moisture was monitored during the very meteorologically contrasting years 2002 and 2003 in two nearby olive groves. The plots had the same morphological and climatic conditions, but different soil types. Monocultivar oil samples were analyzed to determine fatty acids, minor polar compounds, and tocopherols content and were submitted to organoleptic analysis by a panel of trained tasters. The results highlighted that soil water regimen affects some nutraceutical components and the sensory evaluation of olive oil. Cultivar also affected yield components, polyphenols, and tocopherols content, but less than soil water availability. The plants on the soil inducing a relatively more intense and longer water deficit during summer (a Skeleti Calcaric Regosol) had an early ripening and gave the best results in terms of phenolic compounds and, consequently, antioxidant properties of the olive oil. The sensorial properties of the oil obtained from both cultivars on the Regosol were superior in both years of the trial.     

Effects of solid olive-mill waste addition to soil on sorption, degradation and leaching of the herbicide simazine

Abstract. A laboratory study was conducted to investigate the effects of adding an intermediary byproduct of olive oil extraction ( alperujo or solid olive-mill waste, SOMW) on the sorption, degradation and leaching of the herbicide simazine in a sandy loam soil. The effect of SOMW addition on soil porosity was also assessed. The soil was amended in the laboratory with SOMW at two different rates (5% and 10% w/w). Simazine sorption isotherms showed a great increase in herbicide sorption after SOMW addition to soil; sorption increased with the amount of SOMW added. Incubation studies showed extended persistence by reduced biodegradation of simazine in the soil amended with SOMW compared with the unamended soil. Although the addition of SOMW to soil increased the total porosity, breakthrough curves of simazine in handpacked soil columns showed that SOMW addition retarded the vertical movement of the herbicide through the soil and reduced the total amount of herbicide leached. It appeared that the longer residence time of simazine in the amended soil columns (>20 days) compared with that in the unamended soil column (<20 days) allowed enhanced degradation and/or irreversible sorption under column leaching conditions. The results revealed important changes in herbicide behaviour upon SOMW addition, confirming the need to assess these changes in order to optimize the combined use of organic wastes and soil-applied pesticides.     

橄榄油加工技术的研究

橄榄油是世界上名贵的木本植物油,我国引种油橄榄在榨油技术方面还存在诸多问题,集中表现为油质量差,出油效率低。该文采用加温融合与加压压榨方法,可使出油效率比国内一般榨油方法提高11.25％;采用倾析为主离心为辅的油水分离工艺和真空过滤技术,减少了油的杂质和水分,使油的质量达到国家和国际的特级橄榄油标准。     

Irrigation effects on quality, phenolic composition, and selected volatiles of virgin olive oils cv. Leccino

Field-grown olive trees (Olea europaea L. cv. Leccino) were used over two growing seasons to determine the effect of deficit irrigation regimes on virgin olive oil (VOO) quality. Drip irrigation was managed to maintain a predawn leaf water potential (PLWP): (a) higher than -1.1 MPa (full irrigation: FI); (b) between -1.0 and -3.3 MPa (deficit irrigation: DI); (c) higher than -4.2 MPa (severe deficit irrigation: SI). The fruit yield and oil yield of DI trees were over 90% of those of FI treatments in both years, respectively, whereas yields of SI trees ranged from 61 to 76%. The irrigation regime had minor effects on the free acidity, peroxide value, and fatty acid composition of VOO. The concentrations of phenols and o-diphenols in VOO were negatively correlated with PLWP. The concentrations of the dialdehydic form of decarboxymethyl elenolic acid linked to (3,4-dihydroxyphenyl)ethanol (3,4-DHPEA-EDA), the isomer of the oleuropein aglycon (3,4-DHPEA-EA), and the dialdehydic form of decarboxymethyl elenolic acid linked to (p-hydroxyphenyl)ethanol (p-HPEA-EDA) were lower in FI than in SI treatments. The concentrations of lignans (+)-1-acetoxipinoresinol and (+)-1-pinoresinol were unaffected by the irrigation regime. The tree water status had a marked effect on the concentration of volatile compounds, such as the C(6)-saturated and unsaturated aldehydes, alcohols, and esters.     

Factors limiting the synthesis of virgin olive oil volatile esters

The aim of the present work was to establish the limiting factors affecting the biosynthesis of volatile esters present in virgin olive oil (VOO). Oil volatile fractions of the main Spanish olive cultivars, Arbequina and Picual, were analyzed. It was observed that acetate esters were the most abundant class of volatile esters in the oils, in concordance with the high content of acetyl-CoA found in olive fruit, and that the content of C6 alcohols is limited for the synthesis of volatile esters during the production of VOO. Thus, the increase of C6 alcohol availability during VOO production produced a significant increase of the corresponding ester in the oils in both cultivars at two different maturity stages. However, the increase of acetyl-CoA availability had no effect on the VOO volatile fraction. The low synthesis of these C6 alcohols seems not to be due to a shortage of precursors or cofactors for alcohol dehydrogenase (ADH) activity because their increase during VOO production had no effect on the C6 alcohol levels. The experimental findings are compatible with a deactivation of ADH activity during olive oil production in the cultivars under study. In this sense, a strong inhibition of olive ADH activity by compounds present in the different tissues of olive fruit has been observed.     

Productive Efficiency of Decanters with Short and Variable Dynamic Pressure Cones

This paper presents the results of experimental trials carried out on third-generation, variable dynamic pressure cone decanters to assess machine performance and adjust the process parameters for optimum extraction yield.The results obtained led to the following conclusions: the regulation of the differential velocity screw/bowl allows a better performance of the decanter at low dilutions of the olive paste; it is possible to obtain high efficiency at a low dilution of the olive paste achieving a higher minor compounds content and the more advanced system of regulation leads to better results according to the variations of the ratio between liquid and solid phases, thus optimising operational performances in relation to the rheological features of olive pastes.The results indicate the potential for the optimisation of oil extraction efficiency from pastes obtained with a more precise choice of solid particle dimensions during the crushing phase.     

Analysis of total contents of hydroxytyrosol and tyrosol in olive oils

The most abundant phenolic compounds in olive oils are the phenethyl alcohols hydroxytyrosol and tyrosol. An optimized method to quantify the total concentration of these substances in olive oils has been described. It consists of the acid hydrolysis of the aglycons and the extraction of phenethyl alcohols with a 2 M HCl solution. Recovery of the phenethyl alcohols from oils was very high (<1% remained in the extracted oils), and the limits of quantification (LOQ) were 0.8 and 1.4 mg/kg for hydroxytyrosol and tyrosol, respectively. Precision values, both intraday and interday, remained below 3% for both compounds. The final optimized method allowed for the analysis of several types of commercial olive oils to evaluate their hydroxytyrosol and tyrosol contents. The results show that this method is simple, robust, and reliable for a routine analysis of the total concentration of these substances in olive oils.     

Functional lipid characteristics of Turkish Tombul hazelnut (Corylus avellana L.)

The quality of crude oil extracted from Tombul (Round) hazelnut, grown in the Giresun province of Turkey, was evaluated for its fatty acid, triacylglycerol (TAG), tocol, and phytosterol compositions. Oleic acid contributed 82.78% to the total fatty acids, followed by linoleic, palmitic, and stearic acids. Among 12 TAGs separated, 11 were identified (including one unknown): LLL, OLL, PLL, OOL, POL, PPL, OOO, POO, PPO, SOO, and PSO (where P, palmitoyl; S, stearoyl; O, oleoyl; and L, linoleoyl). The main components were OOO (71.31%), OOL (12.26%), and POO (9.45%), reflecting the high content of oleic acid present in hazelnut oil. Seven tocol isoforms (four tocopherols and three tocotrienols) and eight phytosterols as well as cholesterol were positively identified and quantified; among these, alpha-tocopherol (40.40 mg/100 g) and beta-sitosterol (134.05 mg/100 g) were predominant in hazelnut oil and contributed 78.74 and 81.28% to the total tocols and phytosterols present, respectively. Tocotrienols were detected in small amounts (1.02% to the total tocols). The crude hazelnut oil extracted from Turkish Tombul hazelnut, thus, serves as a good source of nutrients, bioactives, and health-promoting components.     

不同成熟度油橄榄油品品质研究

为明确不同成熟度油橄榄油品品质的变化规律,建立不同品种的质量体系,让企业和种植户能够根据自己的侧重点选择需要种植的品种,以提高生产效率和产品质量。以城固(Chenggu)、莱星(Leccino)、切姆拉尔(Chemlal de kabylie)0～7个成熟度的油橄榄果实为试验材料,对3个品种的出油率、酸价、过氧化值、多酚含量、主要脂肪酸等品质指标进行测定。结果表明,第7成熟度切姆拉尔的出油率最高,为13.6%;第0成熟度城固的最低,为2.1%。脂肪酸组成中油酸含量最高,为53.31%～71.64%;棕榈酸含量为12.91%～16.53%,棕榈一烯酸含量为0.42%～2.09%,硬脂酸含量为1.25%～2.96%,亚油酸含量为7.48%～18.24%;亚麻酸含量最低,为0.63%～1.51%。多酚含量,第1成熟度以城固最多,为281.91 mg/kg;第2成熟度以切姆拉尔最低,为73.53 mg/kg。多酚含量随着成熟度的增加会有一个先增加再减小的趋势;酸价(最高为0.67 mg/g)、过氧化值(最高为0.71 g/kg)远低于国标中对特级初榨橄榄油的限度。可见,3个油橄榄品种的油脂质量均比较高,其中切姆拉尔出油率较高,城固多酚含量较高。     

Static-dynamic superheated liquid extraction of hydroxytyrosol and other biophenols from alperujo (a semisolid residue of the olive oil industry)

Hydroxytyrosol and other olive biophenols (OBPs) such as tyrosol, verbascoside, apigenin-7-glucoside, and alpha-taxifolin have been extracted from alperujo by using static-dynamic superheated liquids. Multivariate methodology has been used to carry out a detailed optimization of the extraction. Under the optimal working conditions no further extraction of the target analytes was achieved after 27 min (up to 2800 and 1500 mg/kg of hydroxytyrosol and tyrosol, respectively), so complete removal of them within this interval was assumed. The extract was injected into a chromatograph-photodiode array detector assembly for individual separation-quantification. The efficacy of ethanol/water mixtures to extract OBPs from alperujo has been demonstrated and compared with that of a conventional stirring-based method. These less toxic extractant mixtures are of interest with a view to future human uses of OBPs.     

Comparison of static headspace, headspace solid phase microextraction, headspace sorptive extraction, and direct thermal desorption techniques on chemical composition of French olive oils

Static headspace (SHS), headspace solid phase microextraction (HS-SPME), headspace sorptive extraction (HSSE), and direct thermal desorption (DTD) were applied to the analysis of four French virgin olive oils from Corsica. More than 60 compounds were isolated and characterized by GC-RI and GC-MS. SHS was not suited to the characterization of olive oil volatile compounds because of low sensitivity. The SPME and HSSE techniques were successfully applied to olive oil headspace analysis. Both methods allow the characterization of volatile compounds (mainly C(6) aldehydes and alcohols), which contribute significantly to the "green" flavor note of virgin olive oils. The PDMS stir bar showed a higher concentration capacity than a DVB/CAR/PDMS SPME fiber due to the higher volume of polymeric coating. DTD was a very good tool for extracting volatile and especially semivolatile compounds, such as sesquiterpenes, but requires a significant investment like that for HSSE. Finally, SPME may be a more appropriate technique for routine quality control due to its operational simplicity, repeatability, and low cost.     

Influence of cultivar and concentration of selected phenolic constituents on the in vitro chemiopreventive potential of olive oil extracts

One of the main olive oil phenolic compounds, hydroxytyrosol (3,4-DHPEA), exerts in vitro chemopreventive activities (antiproliferative and pro-apoptotic) on tumor cells through the accumulation of H(2)O(2) in the culture medium. However, the phenol composition of virgin olive oil is complex, and 3,4-DHPEA is present at low concentrations when compared to other secoiridoids. In this study, the in vitro chemopreventive activities of complex virgin olive oil phenolic extracts (VOO-PE, derived from the four Italian cultivars Nocellara del Belice, Coratina, Ogliarola, and Taggiasca) were compared to each other and related to the amount of the single phenolic constituents. A great chemopreventive potential among the different VOO-PE was found following this order: Ogliarola > Coratina > Nocellara > Taggiasca. The antiproliferative and pro-apoptotic activities of VOO-PE were positively correlated to the secoiridoid content and negatively correlated to the concentration of both phenyl alcohols and lignans. All extracts induced H(2)O(2) accumulation in the culture medium, but this phenomenon was not responsible for their pro-apoptotic activity. When tested in a complex mixture, the olive oil phenols exerted a more potent chemopreventive effect compared to the isolated compounds, and this effect could be due either to a synergistic action of components or to any other unidentified extract constituent.     

New phenolic compounds hydrothermally extracted from the olive oil byproduct alperujo and their antioxidative activities

The application of a novel process based on the hydrothermal treatment of olive oil waste (alperujo) led to a final liquid phase that contained a high concentration of simple phenolic compounds. This study evaluated the effects of time (15-90 min) on the composition of the phenolic compounds isolated at a fixed temperature of 160 °C. Phenolic compounds were extracted with ethyl acetate. Both qualitative and quantitative HPLC analyses of the extracts showed variation of the concentrations of phenolic compounds with time. In addition, new phenols that were not present in the untreated control have been characterized. The antioxidant activities of different phenolic extracts was measured by various assays conducted in vitro: antiradical capacity (using DPPH and ABTS radicals), ferric reducing power (P(R)), inhibition of primary and secondary oxidation in lipid systems, and other tests, such as inhibition of tyrosinase activity. The results show that the phenolic extracts inhibited oxidation in aqueous and lipid systems to a significantly greater extent than the untreated control, and they performed as well as or better than vitamin E in this capacity.     

Alkyl esters of fatty acids a useful tool to detect soft deodorized olive oils

Fatty acid alkyl esters (FAAEs) are a family of natural neutral lipids present in olive oils and formed by esterification of free fatty acids (FFAs) with low molecular alcohols. Inappropriate practices during the olive oil extraction process and bad quality of the olive fruits promote their formation. Quantification can be done by isolation with a silica gel solid phase extraction cartridge followed by analysis on a gas chromatograph equipped with a programmed temperature vaporizer injector using a polar capillary column. The application of the method to more than 100 Spanish olive oils from different categories, varieties, and geographical origin allowed for establishing the average content of FAAEs and distinguishing the Spanish protected denomination of origin (PDO) and extra virgin olive oils from other categories of olive oils. Those other categories of oils can be subjected to a mild refining process, which leads to blending with extra virgin olive oils. Studies on low quality oils subjected to mild refining showed that FAAEs remain after that process. Thereby, blends of extra virgin olive and mildly refined low quality olive oils can be detected by their alkyl ester concentrations.