初榨橄榄油中多酚类化合物含量随油橄榄果 生长发育的累积变化

旨在为甘肃陇南橄榄油的质量评价和油橄榄鲜果采收时间提供指导,探究了不同品种初榨橄榄油（VOO）中多酚类化合物（PPs）随油橄榄果生长发育的累积变化。以甘肃陇南不同成熟度的8个品种油橄榄鲜果为原料,采用压榨法获得VOO,利用反相高效液相色谱法同时测定VOO中的9种PPs含量。结果表明：VOO中总多酚的含量主要由酪醇和橄榄苦苷决定,橄榄苦苷是含量最高的PPs,且其含量随油橄榄果成熟度指数（MI）变化最明显;VOO中木犀草苷含量均较低,阿魏酸和芹菜素仅在个别品种中检测到,芦丁在所测油品中均未检测到;‘阿斯’‘鄂植8号’‘中山24号’和‘佛奥’4个品种VOO的PPs评估数据表现良好,分别在MI为0～1.0、2.0～4.0、0～2.0和5.0～7.0表现最佳,建议这4个品种油橄榄鲜果的采收时间分别为9月下旬、11月上旬、9月下旬至10月上旬以及11月下旬,而‘切姆拉尔’VOO在PPs种类和总含量等评估数据中表现不佳。综上,可以依据不同MI的油橄榄鲜果制备的VOO中多酚含量,尤其是酪醇和橄榄苦苷含量,确定不同品种油橄榄鲜果的采收时间,并进行VOO的品质评价。     

Estimate of dietary exposure to sulphites in child and adult populations in the Basque Country

Sulphites are widely used as a preservative and antioxidant additive in food. The aim of this study was to assess dietary sulphite intake in adults aged 35–65 years and in children aged 4–18 years living in the Basque Country, northern Spain. We determined sulphite concentrations in 909 samples covering 16 food types. The maximum permitted levels were exceeded in 17% of samples. Making recommended assumptions for non-quantifiable results, estimates of mean lower and upper bounds were calculated for sulphite concentrations in each food type. These sulphite data were combined with consumption data derived from 8417 adults from the European Prospective Investigation in Cancer and Nutrition cohort in Gipuzkoa, recruited in 1992–1995 using a diet history method, and 1055 children from the Basque Country Nutrition Children Survey, conducted in 2004–2005 using two 24-h recall questionnaires to assess diet. The results were compared with the acceptable daily intake (ADI) proposed by the Joint Expert Committee on Food Additives (JECFA). The mean dietary exposure to sulphites was 0.08 mg kg^?1 bw day^?1, only 11% of the ADI in the overall group of children (4–18 years old), but the acceptable intake was exceeded by 4% of 4–6 year olds. For the adults (35–65 years old), the mean dietary exposure was 0.31 mg kg^?1 bw day^?1, 45% of the ADI, but the acceptable intake was exceeded in 14.6% of cases. The major contributing foods were minced meat and other meat products for children and wine for adults.     

Retention and distribution of natural antioxidants (α-tocopherol, polyphenols and terpenic acids) after shallow frying of vegetables in virgin olive oil

Potatoes, green peppers, zucchinis and eggplants were shallow fried in virgin olive oil (VOO) according to the Mediterranean traditional culinary practice. Zucchinis and eggplants were also blanketed with wheat flour or batter prior to frying. Polyphenols and hydroxy pentacyclic triterpene acids (HPTAs) were determined by GC/MS, while α-tocopherol was determined by high-performance liquid chromatography. Among 12 polyphenols determined, tyrosol predominated in frying oils and zucchini samples, while chlorogenic acid was the major phenolic species in the other vegetable samples. The triterpene acids maslinic, oleanolic and ursolic were determined in frying oils and fried vegetables, while α-tocopherol was present in all samples. Besides water loss and oil absorption, shallow frying resulted in partial loss of all the antioxidants studied in frying oils and enrichment of fried vegetables with olive oil antioxidants, which was in some extent affected by the type of vegetable fried and the culinary practice followed. The overall retention of the antioxidants in oil and food ranged from 32% to 64% for α-tocopherol, 25% to 70% for polyphenols and 35% to 83% for HPTA. It appears that vegetables fried in VOO provide an additional intake of α-tocopherol, terpenic acids and polyphenols as tyrosol and chlorogenic acid.     

Direct analysis of glucuronidated metabolites of main olive oil phenols in human urine after dietary consumption of virgin olive oil

In the present study we report on a UPLC-MRM validated method for the simultaneous direct analysis of main glucuronidated metabolites of olive oil phenols: tyrosol, hydroxytyrosol and its O-methyl metabolite homovanillyl alcohol in human urine after dietary olive oil ingestion. The developed method was linear within the concentration range 20–2000 ng/mL with adequate recovery of analytes (>86%). Intra- and inter-day precision and accuracy were according to standard requirements for method validation criteria. Using the developed method, urinary concentrations and excretion rates of glucuronides of olive oil phenols were successfully estimated in an intervention study with 11 healthy volunteers supplemented with a dietary dose of virgin olive oil (VOO) (50 mL). Therefore, about 13% of the consumed olive oil polyphenols were recovered in 24-h urine, where 75% of them were in the form of glucuronides (3′- and 4′-O-hydroxytyrosol glucuronides, 4′-O-glucuronides of tyrosol and homovanillyl alcohol) and 25% as free compounds.     

Health-promoting properties of oleocanthal and oleacein: Two secoiridoids from extra-virgin olive oil

Abstract

Extra virgin olive oil (EVOO) polyphenols, including the secoiridoids oleocanthal (OLC) and oleacein (OLE), are attracting attention because of their beneficial effects on health. Data on OLC and OLE bioavailability are scarce, as most research on EVOO polyphenols has concentrated on hydroxytyrosol, tyrosol, and oleuropein. Consequently, relevant goals for future research are the elucidation of OLC and OLE bioavailability and finding evidence for their beneficial effects through pre-clinical and clinical studies. The aim of this review is to shed light on OLC and OLE, focusing on their precursors in the olive fruit and the impact of agronomic and processing factors on their presence in EVOO. Also discussed are their bioavailability and absorption, and finally, their bioactivity and health-promoting properties.     

Migrated phthalate levels into edible oils

The determination of phthalates in edible oils (virgin olive oil, olive oil, canola oil, hazelnut oil, sunflower oil, corn oil) sold in Turkish markets was carried out using gas chromatography–mass spectrometry. Mean phthalate concentrations were between 0.102 and 3.863 mg L^?1 in virgin olive oil; 0.172 and 6.486 mg L^?1 in olive oil; 0.501 and 3.651 mg L^?1 in hazelnut oil; 0.457 and 3.415 mg L^?1 in canola oil; 2.227 and 6.673 mg L^?1 in sunflower oil; and 1.585 and 6.248 mg L^?1 in corn oil. Furthermore, the influence of the types of oil and container to the phthalate migration was investigated. The highest phthalate levels were measured in sunflower oil. The lowest phthalate levels were determined in virgin olive oil and hazelnut oil. The highest phthalate levels were determined in oil samples contained in polyethylene terephthalate.     

Assessment of caffeine intake in the Korean population

An improved method for the analysis of caffeine in foods by HPLC was validated by measuring several analytical parameters. The caffeine contents of 1202 products available from Korean markets were analysed. A consumption study was conducted by using data from the Korea National Health and Nutrition Examination Survey (KNHANES), 2010–12, to estimate the caffeine intakes of the Korean population. The mean intakes of caffeine from all sources in the general population and consumers were 67.8 and 102.6 mg day^?1 for all age groups, respectively. The 95th percentile intakes of the general population and consumers were 250.7 and 313.7 mg day^?1, respectively. In those aged 30–49 years, the caffeine intakes of the general population and consumers were highest at 25.5% (101.8 mg kg^?1 day^?1) and 36.6% (0.9 mg kg^?1 day^?1), respectively, compared with the maximum recommended daily intake (400 mg day^?1) for adults. In the general population, the main contributors to the total caffeine intake were carbonated beverage for the younger age groups and coffee for the adults. These data provide a current perspective on caffeine intake in the Korean population.     

Assessment of the dietary intake of propylene glycol in the Korean population

An improved method for the analysis of propylene glycol (PG) in foods using a gas chromatography-flame ionisation detector (GC-FID), with confirmation by GC-MS, was validated by measuring several analytical parameters. The PG concentrations in 1073 products available in Korean markets were determined. PG was detected in 74.1% of the samples, in a concentration range from the limit of detection (n.d., 0.39 μg ml^?1) to 12,819.9 mg kg^?1. The Korea National Health and Nutrition Examination Survey (KNHANES) 2011–2013 reported the mean intake levels of PG from all sources by the general population and consumers were 26.3 mg day^?1 (0.52 mg kg^?1 day^?1) and 34.3 mg day^?1 (0.67 mg kg^?1 day^?1), respectively. The 95th percentile intake levels of the general population and consumers were 123.6 mg day^?1 (2.39 mg kg^?1 day^?1) and 146.3 mg day^?1 (2.86 mg kg^?1 day^?1), respectively. In all groups of the general population, breads were the main contributors to the total PG intake. These reports provide a current perspective on the daily intake of PG in the Korean population.     

Healthy Virgin Olive Oil: A Matter of Bitterness

Virgin olive oil (VOO) is the pillar fat of Mediterranean diet. It is made from olive fruits and obtained by squeezing olives without any solvent extraction. Respect to the seed oils, an unique polar polyphenol-rich fraction gives VOO a bitter and pungent taste.

The recent substantiation by European Food Safety Authority (EFSA) of a health claim for VOO polyphenols may represent an efficient stimulus to get the maximum health benefit from one of the most valuable traditional product of Mediterranean countries educating consumers to the relationship between the VOO bitterness and its health effect.

Agronomical practices and new processing technology to avoid phenolic oxidation and hydrolysis and to enhance the aromatic components of the VOO have been developed and they can be used to modulate taste and flavor to diversify the products on the market. VOOs having high concentration of phenol compounds are bitter and pungent therefore many people do not consume them, thus loosing the health benefits related to their intake.

In this paper, the chemist's and nutritionist's point of view has been considered to address possible strategies to overcome the existing gap between the quality perceived by consumer and that established by expert tasters. Educational campaigns emphasizing the bitter-health link for olive oils should be developed.     

Quantitative risk assessment on the dietary exposure of Finnish children and adults to nitrite

Nitrite intake from the consumption of cured meat and tap water was estimated for Finnish children of 1, 3 and 6 years as well as Finnish adults of 25–74 years. Nitrite content in the foods was measured by capillary electrophoresis, and was then used together with individual food consumption data from the FINDIET 2007 and DIPP studies in a stochastic exposure assessment by a Monte Carlo Risk Assessment (MCRA) program. Nitrite intake from additive sources and tap water was assessed, and more than every 10th child between the ages 3 and 6 years was estimated to have a nitrite intake exceeding the acceptable daily intake (ADI) of nitrite. The high exposure levels were caused by frequent consumption of large portions of sausages, up to 350 g day^–1 or 750 g in 3 days, among the children. Median nitrite intake from cured meat was 0.016, 0.040, 0.033 and 0.005 mg kg^–1 body weight day^–1 for children of 1, 3 and 6 years and adults, respectively. Bayesian estimation was employed to determine safe consumption levels of sausages and cold cuts for children, and these results gave rise to new national food consumption advice.     

New genotypes of table olives: profile of bioactive compounds

New table olive genotypes (48) coming from a cross‐breeding programme were evaluated. Most of the fruit traits covered a wide range of variability on the set of genotypes, fruit weight (1.1–9.7 g), pulp‐to‐pit ratio (1.7–10.0), fruit shape (1.0–1.6) and oil content (1.3–15.2%). This is the first time that healthy compounds such as triterpenic acids and phenolic compounds have also been evaluated in olive progenies. Genotypes were stored for 2 months in sterilised brine (5% NaCl and 0.5% acetic acid). A high amount of maslinic (685.0–1394.2 mg kg^?1 olive flesh) and oleanolic acids (275.3–817.9 mg kg^?1 olive flesh) was found in the flesh of olives stored. The main oleosidic and phenolic compounds evaluated in brines were hydroxytyrosol (1.9–8.4 mmol L^?1), hydroxytyrosol glucosides (0.4–19.8 mmol L^?1), oleuropein (0.0–4.7 mmol L^?1) and the antimicrobial compounds, dialdehydic form of decarboxymethyl elenolic acid linked to hydroxytyrosol (0.0–3.4 mmol L^?1) and decarboxymethyl elenolic acid (0.0–1.7 mmol L^?1), the latter two being observed in only ten genotypes. The wide range of variation observed for most compounds indicates that the contents of these healthy compounds may be used as selection criteria in table olive breeding programmes.     

High vacuum applied during malaxation in oil industrial plant: Influence on virgin olive oil extractability and quality

Vacuum technology was applied for the first time at industrial scale to the mechanical extraction processes of virgin olive oil (VOO). The study was carried out using an industrial plant with a working capacity of 4 tons of olives. The use of high vacuum conditions during the malaxation process induced an intense mass transfer into the olive paste that improved the coalescence phenomena of oil droplets with a significant increase in oil extractability for four different cultivars (Arbequina, Arbosana, Koroneiki and Picual). The evaluation of the quality characteristics of the Picual VOO showed an enhancement in the hydrophilic phenol fraction mainly related to the oleacein content. The low temperature set during the vacuum treatment (16 ± 1 °C for 30 min of malaxation) limited the stripping process of the main aldehydes, alcohols and esters. In contrast, other negative volatile compounds related to off-flavoured VOO (ethanol, 3-methyl-1-butanol, ethyl acetate and acetic acid) were significantly reduced.     

橄榄多酚的化学组成、药理作用及提取技术研究进展

橄榄多酚是从橄榄果实和橄榄叶中提取的酚类抗氧化物质的总称,富含没食子酸、香豆酸、酪醇、羟基酪醇和橄榄苦苷等多种生物活性成分。橄榄多酚具有抗氧化、消炎抗菌、降糖降脂、防治心血管疾病等多种药理作用,在医药、保健品和化妆品等领域具有良好的开发应用前景。综述了橄榄多酚的主要来源、化学组成、药理作用和主要提取技术,展望了橄榄多酚的研究和开发前景,旨在为橄榄特色资源及橄榄多酚的综合开发利用提供参考。     

Consumer exposures to anthocyanins from colour additives,colouring foodstuffs and from natural occurrence in foods

Anthocyanins are responsible for the red/blue colour of grapes, currants, and other fruits and vegetables. They may also be extracted for use as colour additives (E163) or concentrated for use as colouring foods. Consumer exposures have been assessed using data on natural occurrence, use levels and frequencies from food manufacturers and European food consumption data. Intakes from natural occurrence can be up to 4 mg kg bw^?1 day^?1 at the mean and up to 17 mg kg bw^?1 day^?1 for children who are high level consumers of red/black berries and small fruits. High-level intakes for children from food colour and colouring food applications lie in the range 0.3–6.3 mg kg bw^?1 day^?1 and for adults at 0.6–2.8 mg kg bw^?1 day^?1. Exposures from food colour use and colouring foods separately or combined are therefore lower than those from natural occurrence in foods.     

Phenolic compounds in olive oil and olive pomace from Cilento (Campania,Italy) and their antioxidant activity

Virgin olive oil (VOO) has nutritional and sensory characteristics that make it unique and a basic component of the Mediterranean diet. Its importance is mainly attributed to its richness in polyphenols, which act as natural antioxidants and may contribute to the prevention of several human diseases. In this paper we report the determination and quantification of oleocanthal, one of the main substances responsible for the bitter taste of olive oil, together with a quali-quantitative analysis by HPLC analytical methods of phenolics from Cilento VOO and olive oil pomace. The total phenolic content was also determined and the in vitro antioxidant and free-radical scavenging activities by DPPH test was evaluated. A superoxide anion enzymatic assay was also carried out and the results were confirmed by the inhibition of xanthine oxidase activity assay. The possible protective role played by VOO secoiridoids on injurious effects of reactive oxygen metabolites on the intestinal epithelium, using Caco-2 human cell line, was investigated.     

Use crude olive leaf juice as a natural antioxidant for the stability of sunflower oil during heating

Olive leaves (Kronakii cultivar) were obtained from the annual pruning of olive trees and pressed to obtain a crude juice. Aliquots from the concentrated crude olive leaf juice, representing 400, 800, 1600 and 2400 ppm as polyphenols, were added to sunflower oil. Samples of sunflower oil mixed with olive leaf juice were heated intermittently at 180 ± 5 °C for 5 h day^?1 and the heating process was repeated for five consecutive days. A control experiment was performed where butylated hydroxyl toluene (BHT) at 200 ppm was added to sunflower oil prior to intermittent heating in order to compare the antioxidant efficiency between the natural polyphenolics of olive leaf juice and synthetic antioxidant BHT. Some physical and chemical constants for the unheated and heated sunflower oil were determined. The data indicate that the addition of olive leaf juice to sunflower oil heated at 180 °C induced remarkable antioxidant activity and at 800 ppm level was superior to that of BHT in increasing sunflower oil stability.     

Evaluation of table olive by‐product as a source of natural antioxidants

The main by‐product from the table olive canning industry is the stone with some residual olive flesh. The purpose of this study was to evaluate the composition – phenolic compounds (hydroxytyrosol, tyrosol and oleuropein) and tocopherol – and the antioxidant activity in different fractions (flesh, stone and seed) from the table olive by‐product and the whole by‐product. The highest amounts of phenolic compounds (1710.0 ± 33.8 mg kg^?1) as well as the highest antioxidant activity (8226.9 ± 9.9 hydroxytyrosol equivalents mg kg^?1) were obtained in the seed. The highest amounts of hydroxytyrosol (854.8 ± 66.0 mg kg^?1) and tyrosol (423.6 ± 56.9 mg kg^?1) were found in the whole by‐product from the pepper stuffed olives, while the stone without seed had the maximum oleuropein content (750.2 ± 85.3 mg kg^?1). α‐Tocopherol values were between 79.8 ± 20.8 mg kg^?1 in the seed of the olive stone and 6.2 ± 1.2 mg kg^?1 in the whole by‐product from the anchovy‐stuffed olives. In light of the results obtained, it would seem possible to use table olive by‐product as a source of natural antioxidants in foods, cosmetics or pharmaceutical products, thus contributing to diminishing the environmental impact of table olive by‐product and to its revalorisation.     

Olive Oil Phenolics Prevent Oxysterol‐Induced Proinflammatory Cytokine Secretion and Reactive Oxygen Species Production in Human Peripheral Blood Mononuclear Cells,Through Modulation of p38 and JNK Pathways

1 Scope

The aim of the present study was to investigate the ability of extra virgin olive oil (EVOO) polyphenols to counteract the proinflammatory effects induced by dietary and endogenous oxysterols in ex vivo immune cells.

2 Methods and results

Peripheral blood mononuclear cells (PBMCs), separated from the whole blood of healthy donors, were utilized and were stimulated with an oxysterols mixture, in the presence of physiologically relevant concentrations of the EVOO polyphenols, hydroxytyrosol, tyrosol, and homovanillic alcohol. Oxysterols significantly increased the production of proinflammatory cytokines, interleukin‐1β, regulated on activation, normal T‐cell expressed and secreted and macrophage migration inhibitory factor in ex vivo cultured PBMCs. Increased levels of reactive oxygen species (ROS) were also detected along with increased phosphorylation of the p38 and JNK. All phenolic compounds significantly reduced cytokine secretion induced by the oxysterols and inhibited ROS production and mitogen activated protein kinase phosphorylation.

3 Conclusions

These results suggest that extra virgin olive oil polyphenols modulate the immune response induced by dietary and endogenous cholesterol oxidation products in human immune cells and may hold benefit in controlling chronic immune and/or inflammatory processes.     

HPLC–ESI-MS investigation of tyrosol and hydroxytyrosol oxidation products in virgin olive oil

The aim of this research is the characterisation of the oxidation products of several hydrophilic phenols of virgin olive oil (VOO), such as hydroxytyrosol (3,4-DHPEA) and tyrosol (p-HPEA) and, their identification in the product during storage. This work is aimed at finding analytical indicators that can be used both as molecular markers of VOO “freshness” and for the evaluation of the shelf life of the product itself. Two oxidation systems were examined for the oxidation of p-HPEA and 3,4-DHPEA: enzymatic oxidation and Fenton oxidation. Reaction products were different for the two systems and were identified as quinones, dimers, and acids. During the autoxidation process, Fenton reaction oxidation products, but not enzymatic oxidation products, were found in VOO.     

Influence of Eriophyid mites (Aculus olearius Castagnoli and Aceria oleae (Nalepa) (Acarina: Eriophyidae)) on some physical and chemical characteristics of Ayvalık variety olive fruit

BACKGROUND: Aculus olearius Castagnoli is a recently recorded species that damages olive fruits in the Mediterranean basin of Turkey. Thus, the effects of Eriophyid mites (Aculus olearius Castagnoli and Aceria oleae (Nalepa) (Acarina: Eriophyidae) on the olive fruits from Ayval?k variety in southern Turkey were studied for the first time in terms of some physical parameters and chemical constituents including some individual phenolics. RESULTS: The Eriophyid damaged fruits had higher L* values (lighter colour) and tyrosol level (37.53 mg kg^?1) than the undamaged fruits (28.51 mg kg^?1) in August. In contrast, Eriophyid damaged fruits were darker in colour and had lower levels (25.77 mg kg^?1) of tyrosol than those of undamaged fruits (79.14 mg kg^?1) in October. Eriophyid damaged samples had higher values of vanillic acid than the undamaged samples. An increase in the average concentrations of hydroxytyrosol and p‐coumaric acid was observed in the fruits harvested in August, whilst the oleuropein content decreased. CONCLUSION: The harvest in October can be recommended regarding the higher dimensional values, total oil, dry matter and oleuropein contents. But the interaction between harvest time and Eriophyid damage was found effective in terms of tyrosol content and skin colour; as tyrosol values were lower in the fruits harvested in October and the fruits were darker. The resistance of undamaged fruits against Eriophyid damage can be linked to high tyrosol content of these fruits. Copyright © 2010 Society of Chemical Industry