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1.
Foods ; 13(17)2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39272457

RESUMO

Acrylamide (AA) is a contaminant resulting from the Maillard reaction and classified by the International Agency for Research on Cancer (IARC) as a probable carcinogen in Group 2A, with proven neurotoxic effects on humans. European Union (EU) Regulation No. 2017/2158 is currently in force, which establishes measures meant to reduce AA levels in food and sets reference values, but not legal limits, equal to 40 and 150 µg/kg AA in processed cereal-based foods intended for infants and young children and in biscuits and rusks, respectively. For this reason, sixty-two baby foods were analyzed using ultra-high performance liquid chromatography with diode array detector and quadrupole time-of-flight mass spectrometry (UHPLC-DAD-Q-TOF/MS) to check whether industries were complying with these values, even though AA control is not legally mandatory. In total, 14.5% of the samples exceeded the reference values; these were homogenized chicken products (211.84 ± 16.53, 154.32 ± 12.71, 194.88 ± 7.40 µg/kg), three biscuits (276.36 ± 0.03, 242.06 ± 0.78, 234.78 ± 4.53 µg/kg), a wheat semolina (46.07 ± 0.23 µg/kg), a homogenized product with plaice and potatoes (45.52 ± 0.28 µg/kg), and a children's snack with milk and cocoa (40.95 ± 0.32 µg/kg). Subsequently, the daily intake of AA was estimated, considering the worst-case scenario, as provided by the consumption of homogenized chicken products and biscuits. The results are associated with margins of exposure (MOEs) that are not concerning for neurotoxic effects but are alarming for the probable carcinogenic effects of AA.

2.
Foods ; 12(15)2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37569227

RESUMO

The quality of commercially available extra-virgin olive oils (VOOs) of different chemical compositions was evaluated as a function of storage (12 months), simulating market storage conditions, to find reliable and early markers of the virgin olive oil (VOOs) quality status in the market. By applying a D-optimal design using the Most Descriptive Compound (MDC) algorithm, 20 virgin olive oils were selected. The initial concentrations of oleic acid, hydrophilic phenols, and α-tocopherol in the 20 VOOs ranged from 58.2 to 80.5%, 186.7 to 1003.2 mg/kg, and 170.7-300.6 mg/kg, respectively. K270, ∆K, (E, E)-2.4-decadienal and (E)-2-decenal, and the oxidative form of the oleuropein aglycon (3,4-DHPEA-EA-OX) reflected the VOO quality status well, with 3,4-DHPEA-EA-OX being the most relevant and quick index for simple monitoring of the "extra-virgin" commercial shelf-life category. Its HPLC-DAD evaluation is easy because of the different wavelength absorbances of the oxidized and non-oxidized form (3,4-DHPEA-EA), respectively, at 347 and 278 nm.

3.
Foods ; 11(19)2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36230110

RESUMO

The crushing system is crucial in the virgin olive oil (VOO) mechanical extraction process. The use of different crusher machines can highly influence the quality of the final product, mainly due to the phenolic and volatile content responsible for VOO sensory and health properties. An experimental investigation was conducted to evaluate the effect of the geometric features of a new model of crusher machine for olives. The crusher machine consists of interchangeable rotors: a rotor with hammers and a rotor with knives. The evaluation was carried out with the same fixed grid in stainless steel with 6 mm diameter circular holes. An evaluation was carried out on the impact of the crusher tools on the pit particle size and on the distribution of energy and temperature. The performance of the plant was also assessed in terms of process efficiency and olive oil quality. The results showed that the specific energy released by the tool per unit of product, calculated through both energy conservation and comminution theory, is about 25-27% higher in the case of hammers. Since the impact energy is mainly dissipated in the product as heat, the temperature reached during milling operations with the hammer crusher was also higher by the same percentage with respect to the knife crusher. This has important consequences on the quality of the product: the new knife rotor used in the crushing phase produced an improvement in VOO quality, relating mainly to sensory attributes and the health-enhancing properties of the final product. The ability of the crusher to break cell walls and vacuoles, thus releasing the oil contained therein, is comparable for the two different rotors.

4.
Foods ; 10(11)2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34829165

RESUMO

The development of innovative technologies in the mechanical extraction process of extra virgin olive oil can improve its quality standards through the modulation of physical, chemical and biochemical processes. Extra virgin olive oil quality and varietal differentiation are influenced by many factors, particularly the extraction. The use of ultrasound technology in the extraction process does not affect the quality, the composition, and the thermal properties of the oil, facilitating its separation from solids, and it allows the release of active compounds from the olive paste, with a positive influence on the phenolic content. In this study, the impact of ultrasound technologies was evaluated on merceological parameters, quality profile, and organoleptic features of extra virgin olive oils extracted from whole and destoned olives of the three main Italian cultivars (i.e., Peranzana, Canino, and Coratina). The parameters analyzed were influenced by both genotype and treatment, in particular, sonication did not lead to significant changes in the nutraceutical profile of the oils. The de-stoned olives were able to determine a great improvement of oil quality both for phenolic and volatile composition with a significant enhancement of health and sensory properties of the product.

5.
Antioxidants (Basel) ; 10(9)2021 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-34573013

RESUMO

We undertook a qualitative and quantitative assessment of the bioactive compounds, volatile substances, sensory profile, and antioxidant activity of eight different commercial pomegranate juices (PJs) differing by cultivation area, processing (from concentrate (CPJ) or not (NCPJ)), and microbial stabilization. Punicalins were the main ellagitannins, whereas the predominant anthocyanin was cyanidin 3,5-diglucoside, followed by cyanidin 3-glucoside. Total phenols, tannins, hydrolyzable tannins, and anthocyanins in the investigated juices ranged from 1379.9 to 3748.8 mg gallic acid equivalent (GAE)/L, 394.8 to 895.2 mg GAE/L, 150.8 to 2374.2 mg ellagic acid/L, and 0 to 281 mg cyanidin 3-glucoside/L, respectively. Antioxidant activity, determined by DPPH•, FRAP, and ABTS, was positively correlated with the total phenolic compounds and hydrolyzable tannins. Alcohols, acids, and furans were the volatile groups that best described the differences between juices. The most abundant volatile compound was 3-Furfural (8.6-879.9 µg/L) in those juices subjected to the concentration process and to high-temperature short-time (HTST) treatment, whereas it was not present in juice subjected to high-pressure processing (HPP). Processing also affected the juices' sensory attributes: NCPJs were characterized by 'red-purple', 'pomegranate fruit', 'fresh fruit', and 'overall intensity' notes, while in CPJs these notes were not revealed or were masked by those related to heat treatment. Our results provide useful information on the importance of extraction methods and on the overall quality of PJ for the food industry.

6.
Foods ; 10(7)2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34359448

RESUMO

The malaxation step, one of the most important phases of the virgin olive oil (VOO) mechanical extraction process involved in the development of the main quality characteristics of the final product, was carried out at a low temperature (18 °C). The rapid control of malaxer temperature was handled with the same chiller as that of the heat exchanger used in a semi-industrial extraction plant. Low temperature was used during the full olive paste kneading process and also for half of this process, which showed that there was a significant impact on the phenolic and volatile contents of VOO. Trials were conducted on three different cultivars (Canino, Moraiolo and Peranzana), and their phenolic and volatile concentrations showed different quantitative and qualitative effects due to the prolonged use of low temperature after the crushing phase, as a function of the different genetic origins of the olives. The process of phenolic compound solubilization into the oily phase was negatively influenced by the use of low temperature during the entire malaxation period for all the cultivars, whereas the volatile fraction showed an improvement in VOO flavor mainly due to the oil extracted from Canino olives.

7.
Food Chem ; 351: 129297, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33647692

RESUMO

Green glass (GG), ultraviolet grade absorbing glass (UVAGG), and multilayer (plastic-coated paperboard aluminium foil) (MLP) packagings were used for storing two commercially extra virgin olive oils (EVOOs) with different phenolic and volatile compound contents to evaluate their effect on oil quality evolution over 10 months of light exposure. Quality parameters such as free acidity, peroxide value, spectrophotometric indices, antioxidant and volatile compositions as well as sensory characteristics were evaluated; packaging material type and initial antioxidant composition significantly influenced EVOOs' resistance to oxidation, and consequently their quality. Compared with GG or UVAGG, MLP provided superior protection against oxidation; oils stored in MLP containers retained their characteristics within the regulatory limits and contained more antioxidants and fewer 'rancid' defect and related volatile compounds.


Assuntos
Armazenamento de Alimentos , Luz/efeitos adversos , Azeite de Oliva/análise , Polifenóis/análise , Compostos Orgânicos Voláteis/análise , Antioxidantes/análise , Oxirredução , Tempo
8.
Food Chem ; 342: 128369, 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33143966

RESUMO

High vacuum technology has been incorporated into a new assisted extraction system applied to virgin olive oil (VOO) processing, which was tested at a lab-scale pilot plant to evaluate its impact on the physicochemical properties of the olive paste and oil. The vacuum system induced changes in the mechanical and structural properties of the olive cells, improving the coalescence of the oil droplets due to substantial cellular and intracellular mass transfer during the process, as shown by cryo-scanning electron microscopy (Cryo-SEM) analysis. The effects on the quality characteristics of VOOs extracted from three cultivars at different malaxation temperatures were evaluated. A significant increase in the phenolic content, from 25.2% to 48.6%, was observed. The content of volatile compounds responsible for the VOO flavor decreased as a function of malaxation temperature. The reduction of some volatile molecules related to the VOO off-flavor (ethanol, ethyl acetate and acetic acid) was also shown.


Assuntos
Manipulação de Alimentos/métodos , Azeite de Oliva/química , Fenóis/análise , Compostos Orgânicos Voláteis/análise , Microscopia Crioeletrônica , Cromatografia Gasosa-Espectrometria de Massas , Olea/química , Olea/metabolismo , Fenóis/isolamento & purificação , Temperatura , Vácuo , Compostos Orgânicos Voláteis/isolamento & purificação
9.
Food Chem ; 311: 126044, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31869643

RESUMO

The quality evolution of 14 extra-virgin olive oils (EVOOs), with different initial polyphenol and oleic acid (64.6-77.7%) levels, was determined during real-time storage in dark conditions at room temperature for 22 months. EVOOs with low (<20-200 mg/kg), medium (450-700 mg/kg), and high polyphenolic levels (750-1400 mg/kg) were used. We found high correlations among peroxide values, K232, K270, and storage time. Oleuropein derivatives decreased by 98%, 89%, and 85% in EVOOs with low, medium, and high polyphenolic levels, respectively, with the highest depletion occurring in those with the lowest initial concentrations. Besides having higher α-tocopherol protection from oxidative phenomena, EVOOs with the highest phenolic fractions showed lower head space accumulations of off-flavour volatile substances and thus demonstrated the best retention of sensory and health benefits. We propose that the shelf life of EVOOs can be determined from their initial levels of oleuropein derivatives.


Assuntos
Armazenamento de Alimentos , Iridoides/análise , Ácido Oleico/análise , Azeite de Oliva/química , Polifenóis/análise , alfa-Tocoferol/análise , Escuridão , Glucosídeos Iridoides , Oxirredução , Paladar , Fatores de Tempo
10.
Front Nutr ; 6: 134, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31555654

RESUMO

The main operators of the olive oil sector are continuously involved in the development of the olive oil mechanical extraction process with the common aim of increasing both the quality and the oil extraction yield coupled with the potential enhancement of the working efficiency of the olive mill. The pulsed electric field (PEF) is a recently studied technological innovation for the improvement of olive oil extraction technology. The impact of the PEF on the diffusion of oil and microconstituents, determined by the disruption effects on olive cell tissues carried out by the non-thermal method, was evaluated. A PEF can increase the permeability and breaking of the cell membranes with a consequent positive result on oil extractability and quality, mainly related to the compounds involved in the health and sensory properties of extra virgin olive oil. The PEF was tested on three Italian olive cultivars (Carolea, Coratina, and Ottobratica). The results showed a positive impact of the new technology on the oil yield, with an increase ranging from 2.3 to 6%, and on the concentration of hydrophilic phenols, with an increase ranging from 3.2 to 14.3%, with respect to the control tests. The data of the main compounds related to the health and sensory notes also showed high variability as a consequence of the genetic origins of the olive cultivars.

11.
Molecules ; 24(18)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31500173

RESUMO

Olive paste (OP) is a novel by-product of olive mill industry composed of water, olive pulp, and skin. Due to its richness in bioactive compounds, OP exploitation for human consumption has recently been proposed. Starter driven fermented OP is characterized by a well-balanced lipid profile, rich in mono and polyunsaturated fatty acids, and a very good oxidative stability due to the high concentration of fat-soluble antioxidants. These characteristics make OP particularly suitable as a functional ingredient for food/feed industry, as well as for the formulation of nutraceutical products. New types of taralli were produced by adding 20% of fermented OP from black olives (cv Cellina di Nardò and Leccino) to the dough. The levels of bioactive compounds (polyphenols, triterpenic acids, tocochromanols, and carotenoids), as well as the fatty acid profile, were monitored during 180 days of storage and compared with control taralli produced with the same flour without OP supplementation. Taralli enriched with fermented OP showed significantly higher levels of bioactive compounds than conventional ones. Furthermore, enriched taralli maintained a low amount of saturated fatty acids and high levels of polyphenols, triterpenic acids, tocochromanols, and carotenoids, compared to the initial value, up to about 90 days in the usual conditions of retailer shelves.


Assuntos
Antioxidantes/farmacologia , Pão/análise , Olea/química , Compostos Fitoquímicos/química , Antioxidantes/química , Fermentação , Indústria de Processamento de Alimentos , Humanos , Itália , Azeite de Oliva/química , Azeite de Oliva/farmacologia , Oxirredução/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Polifenóis/química , Polifenóis/farmacologia
12.
Food Chem ; 289: 7-15, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30955668

RESUMO

Ultrasound-assisted extraction is an innovative technique applied to the extraction process for virgin olive oil (VOO), which is generally employed to increase plant efficiency and improve product quality. A high-power ultrasound (US) device was introduced at an industrial plant that can process at 2 tons/h to evaluate the technique's physicochemical impact on quality parameters of VOO that was caused by an intensive mass transfer induced by acoustic cavitation process and shockwaves. The impact on oil yield was also evaluated with respect to the ripening stage and malaxation time. No significant effects on the legal and commercial parameters of VOO (including quality indices, sterols, triterpene dialcohols, waxes and diacylglycerols) were found for olives at medium-early ripening stage. Significant physical changes, increased extraction yield (22.7%), enhanced phenol content (10.1%) were observed in US-VOO compared to control (C) oil extracted with a traditional process at an early maturity index.


Assuntos
Manipulação de Alimentos/métodos , Olea/metabolismo , Azeite de Oliva/isolamento & purificação , Olea/química , Azeite de Oliva/química , Fenóis/análise , Fenóis/química , Pressão , Sonicação , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
13.
Int J Food Microbiol ; 295: 49-53, 2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-30802684

RESUMO

This study aimed to evaluate a polyphenol extract from olive oil by-product, to improve the preservation of "Fior di latte" cheese during storage. Nine batches of "Fior di latte" cheese were manufactured in a local dairy production plant: three batches treated with 250 µg/mL of phenols from olive oil by-products in the governing liquid; three batches treated with 500 µg/mL of phenols in the governing liquid, and three untreated batches as the control group. The phenols effectively retarded the growth of Pseudomonas fluorescens and Enterobacteriaceae, acting mainly on the lag phase of the microorganisms, resulting in the prolongation of the time needed to reach the acceptable microbial limit. The delay in the growth of the spoilage bacteria was considered to indirectly influence the sensorial acceptability threshold, recorded through survival analysis. The combination of the two above-mentioned factors promotes the extension of "Fior di latte" cheese shelf life. by >2 and 4 days, for PA and PB respectively.


Assuntos
Anti-Infecciosos/farmacologia , Queijo/microbiologia , Enterobacteriaceae/efeitos dos fármacos , Microbiologia de Alimentos/métodos , Conservação de Alimentos/métodos , Azeite de Oliva/química , Pseudomonas fluorescens/efeitos dos fármacos , Anti-Infecciosos/química , Contagem de Colônia Microbiana
14.
Food Chem ; 279: 426-434, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30611510

RESUMO

The aim of this work was to evaluate the effects of a phenolic extract from olive mill waste water on the stabilization of refined olive oil and on French fry quality during the frying process. Frozen, pre-fried potatoes were fried at 180 °C for 8 min in refined olive oil enriched by different concentrations of a phenolic extract, while oil enriched by a common synthetic antioxidant (butylated hydroxytoluene) was used for comparison. The whole frying process took six hours. The phenolic extract has revealed as a very promising oil stabilizing agent during frying, playing an important role (dose-dependent) in preserving the antioxidants both in oil and in food, in reducing the formation of unwanted compounds (acrolein and hexanal), and in contrasting the acrylamide production. These results clearly show that the phenolic extract can be used as a source of natural antioxidants to replace (or avoid) synthetic additives in foods or beverages.


Assuntos
Antioxidantes/química , Aditivos Alimentares/química , Manipulação de Alimentos/métodos , Fenóis/química , Extratos Vegetais/química , Acrilamida/química , Hidroxitolueno Butilado/química , Azeite de Oliva/química , Oxirredução , Fenóis/análise , Solanum tuberosum/química , Compostos Orgânicos Voláteis/química , alfa-Tocoferol/química
15.
Food Chem Toxicol ; 122: 234-241, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30321573

RESUMO

In this study we investigated the genotoxic potential of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, (PhIP); 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline, (IQ); 2-amino-3,8-dimethyl-imidazo[4,5-f]quinoxaline, (MeIQx) and 2-amino-3,4,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (DiMeIQx) on human freshly isolated peripheral blood mononuclear cells (PBMC) by the comet assay. The preventive ability of three different phenolic extracts derived from olive (O-PE), virgin olive oil (OO-PE) and olive leaf (OL-PE) on PhIP induced DNA damage was also investigated. PhIP and IQ induced a significant DNA damage at the lowest concentration tested (100 µM), while the genotoxic effect of MeIQx and DiMeIQx become apparent only in the presence of DNA repair inhibitors Cytosine b-D-arabinofuranoside and Hydroxyurea (AraC/HU). The inclusion of metabolic activation (S9-mix) in the culture medium increased the genotoxicity of all HCAs tested. All three phenolic extracts showed an evident DNA damage preventive activity in a very low concentration range (0.1-1.0 µM of phenols) which could be easily reached in human tissues "in vivo" under a regular intake of virgin olive oil. These data further support the observation that consumption of olive and virgin olive oil may prevent the initiation step of carcinogenesis. The leaf waste could be an economic and simple source of phenolic compounds to be used as food additives or supplements.


Assuntos
Aminas/toxicidade , Antimutagênicos/farmacologia , Compostos Heterocíclicos/toxicidade , Leucócitos Mononucleares/efeitos dos fármacos , Mutagênicos/toxicidade , Olea/química , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Ativação Metabólica , Aminas/farmacocinética , Ensaio Cometa , Dano ao DNA , Compostos Heterocíclicos/farmacocinética , Humanos , Mutagênicos/farmacocinética , Fenóis/isolamento & purificação , Folhas de Planta/química , Óleos de Plantas/química
16.
Food Chem ; 229: 726-733, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28372237

RESUMO

The influence of light exposure on the quality of commercially available extra-virgin olive oils (EVOOs) of different chemical composition was studied as a function of storage (11weeks) under conditions simulating market storage. By mildly stripping the polyphenols from oil 'A', with high levels of polyphenols and oleic acid, and oil 'B', exhibiting a medium level of polyphenols and a low level of oleic acid, 'C' and 'D' EVOOs were obtained. Ten EVOOs were produced as mixtures of these four oils. The initial concentrations of oleic acid and polyphenols in the 14 oils ranged from 64.5 to 77.7% and 18.1 to 1476.7mg/kg, respectively. The extinction coefficient K270 well reflected the EVOO product quality. EVOOs richer in oleuropein derivatives showed superior oxidative stability, which resulted in lower off-flavour volatile compound production and α-tocopherol and polyphenols losses, and thus, higher EVOO sensory and health benefits.


Assuntos
Armazenamento de Alimentos/métodos , Iluminação/efeitos adversos , Iluminação/métodos , Azeite de Oliva/química , Armazenamento de Alimentos/normas , Glucosídeos Iridoides , Iridoides/análise , Iridoides/química , Iluminação/normas , Ácido Oleico/análise , Ácido Oleico/química , Azeite de Oliva/análise , Oxirredução , Polifenóis/análise , Polifenóis/química , Fatores de Tempo , alfa-Tocoferol
17.
J Agric Food Chem ; 63(26): 6066-74, 2015 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-26072976

RESUMO

The concentration of phenolic and volatile compounds in virgin olive oil (VOO) is closely related to the different operative conditions applied to the mechanical extraction process of the olive oil. However, the great qualitative and quantitative variability of these compounds indicates an important role played by genetic and agronomic aspects. A heat exchanger was placed in front of a traditional, covered malaxer to study the impact of flash thermal conditioning (FTC) of olive paste on the quality of VOO, which is highly influenced by phenolic release and aroma generation. The VOO flash thermal conditioning of five major Italian cultivars showed a higher concentration of phenols (range of increase percentage, 9.9-37.3%) compared to the control trials, whereas the FTC treatment featured a differentiated impact on the volatile fractions, associated with the genetic origins of the olives.


Assuntos
Olea/química , Azeite de Oliva/química , Fenóis/química , Compostos Orgânicos Voláteis/química , Manipulação de Alimentos , Frutas/química , Temperatura Alta , Fenômenos Mecânicos , Azeite de Oliva/isolamento & purificação
18.
J Agric Food Chem ; 62(17): 3813-22, 2014 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-24697604

RESUMO

Response surface modeling (RSM) was used to optimize temperature and oxygen concentration during malaxation for obtaining high quality extra virgin olive oils (EVOOs). With this aim, those chemical variables closely related to EVOO quality, such as the phenolic and the volatile compounds, have been previously analyzed and selected. It is widely known that the presence of these substances in EVOOs is highly dependent on genetic, agronomic, and technological aspects. Based on these data, the two parameters were optimized during malaxation of olive pastes of four important Italian cultivars using some phenols and volatile compounds as markers; the optimal temperatures and oxygen levels, obtained by RSM, were as follows for each cultivar: 33.5 °C and 54 kPa of oxygen (Peranzana), 32 °C and 21.3 kPa (Ogliarola), 25 °C and 21.3 kPa (Coratina), and 33 °C and 21.3 kPa (Itrana). These results indicate the necessity to optimize these malaxing parameters for other olive cultivars.


Assuntos
Manipulação de Alimentos/métodos , Frutas/química , Olea/química , Oxigênio/análise , Óleos de Plantas/isolamento & purificação , Itália , Azeite de Oliva , Óleos de Plantas/análise , Temperatura
19.
J Agric Food Chem ; 61(20): 4953-60, 2013 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-23590117

RESUMO

The quality of virgin olive oil (VOO) is strictly related to the concentrations of phenolic and volatile compounds, which are strongly affected by the operative conditions of the VOO mechanical extraction process. The aim of this work is to study the impact of a new technology such as flash thermal conditioning (FTC) on olive paste structural modification and on VOO quality. The evaluation of olive paste structure modification by cryo-scanning electron microscopy (cryo-SEM) showed that the application of FTC after crushing produces significant differences in terms of the breaking of the parenchyma cells and aggregation of oil droplets in comparison to the crushed pastes. The virgin olive oil flash thermal conditioning (VOO-FTC) featured a higher concentration of volatile compounds compared to that in the control, particularly of all saturated and unsaturated aldehydes and esters, whereas the phenolic concentration was higher in VOO obtained from the traditional process (VOO-C).


Assuntos
Manipulação de Alimentos/métodos , Qualidade dos Alimentos , Frutas/química , Temperatura Alta , Olea/química , Óleos de Plantas/química , Técnica de Fratura por Congelamento , Frutas/ultraestrutura , Microscopia Eletrônica de Varredura , Azeite de Oliva , Fenóis/análise , Compostos Orgânicos Voláteis/análise
20.
Food Chem ; 138(2-3): 1381-91, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23411258

RESUMO

Secoiridoid derivatives are the most important antioxidants of virgin olive oil (VOO), and their oxidation products could be used as molecular markers of VOO freshness to define the VOO autoxidation state. The aim of this research was to characterise the dialdehydic form of decarboxymethyl elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) oxidation products to find analytical indicators that could be used as early evaluation index of the VOO autoxidation state. 3,4-DHPEA-EDA was oxidised by enzymatic and Fenton reactions. Terpenic structure oxidation products accumulated in VOO during the autoxidation process, thus they may be used as early evaluation index of the VOO autoxidation state before fatty acids oxidation.


Assuntos
Fenóis/química , Óleos de Plantas/química , Piranos/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Estrutura Molecular , Azeite de Oliva , Oxirredução
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