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Olive oil flavouring with aromatic plants and spices is a traditional practice in Mediterranean gastronomy. The aim of this work was to compare the influence of two different flavouring techniques (infusion of spices into the oil vs. combined malaxation of olives paste and spices) on chemical and sensory quality of flavoured olive oil. In particular, oxidative and hydrolytic degradation (by routine and non-conventional analyses), phenolic profiles (by HPLC), volatile compounds (by SPME-GC/MS), antioxidant activity, and sensory properties (by a trained panel and by consumers) of the oils were evaluated. The obtained results evidenced that the malaxation method was more effective in extracting the phenolic compounds, with a significantly lower level of hydrolysis of secoiridoids. As a consequence, antioxidant activity was significantly lower in the oils obtained by infusion, which were characterized by a higher extent of the oxidative degradation. The volatile compounds were not significantly influenced by changing the flavouring method, apart for sulfur compounds that were more abundant in the oils obtained by the combined malaxation method. From a sensory point of view, more intense bitter and pungent tastes were perceived when the infusion method was adopted.

One sample of lampante olive oil, neutralised and bleached by a laboratory-scale refining plant, was deodorised at the two most frequently adopted temperatures in olive oil refining (220°C and 230°C). The samples of deodorised oil were subjected to oven test at 60°C for 25 days. Aliquots of the oils were sampled at fixed times for analytical determinations, and the oxidative stability was evaluated by measuring the time needed to reach the peroxide value of 20 meq O2/kg. The sample that showed the highest oxidative stability was the oil deodorised at the highest temperature. This oil presented a higher level of TAG oligopolymers (TAGP) and lower amounts of oxidised TAGs (ox-TAG) respect to the oil deodorised at lower temperature. These findings could be explained by the greater pro-oxidant effect of ox-TAG respect to TAGP. Practical applications: The results of this paper can help to choose the right deodorisation temperature for an oil. In fact, increasing the deodorisation temperature – other parameters being equal – leads to an increase in the oxidative stability of the refined oil. Therefore it could be an option when refining oils with potentially low stability. Nevertheless, it should be preferred submitting to refining slightly oxidized oils, with lower deodorisation temperatures, in order to obtain oils with low amounts of both ox-TAG and TAGP. Effect of different deodorisation temperatures on the oxidative stability of an olive oil.

The aim of this work was to determine the effect of natural-style processing, by using three different cultivars, on the oxidative and hydrolytic degradation of the lipid fraction of table olives. Samplings were made at harvest and after 4 and 8 months of processing. The Italian table olive cultivars Bella di Cerignola, Termite di Bitetto, and Peranzana, diffused in the Apulia region, were considered. During processing, the total phenols content of the lipid fraction decreased from 381–417 mg/kg oil to 106–125 mg/kg oil, depending on the cultivar. The level of primary oxidation at the end of processing was relatively low, as compared to high quality lipids such as extra virgin olive oil: peroxide value and oxidized triacylglycerols accounted for 11.7–13.1 meq O 2 /kg oil and 3.3–7.1 g/kg respectively, depending on the cultivar. A very modest secondary oxidation occurred, as shown by final amounts of triacylglycerol oligopolymers ranging from 0.6 to 0.9 g/kg. On the contrary, a relevant hydrolytic degradation was observed, with free fatty acids accounting for 2.04–2.25 g/100 g oleic acid and diacylglycerols in the range 45.4–48.0 g/kg, at the end of processing. The polar compounds, mainly represented by diacylglycerols, reached values in the ranges 41.1–55.9 g/kg after 4 months and 58.0–62.0 g/kg after 8 months.

An experimental investigation was carried out with the aim to assess the influence of the chemical characteristics of the extra virgin olive oil used in dough formulation of bakery products on the evolution of hydrolytic and oxidative lipid fraction degradation, by means of the determinations of free fatty acids, peroxide value, specific absorption at 232 and 270nm, as well as volatile and polar compounds. At this purpose, three different monovarietal extra virgin olive oils, cultivars Bosana, Coratina and Ogliarola barese (named Ogliarola), having different chemical composition, were tested and used in the taralli production recipes. The obtained data showed that oxidized triacylglycerols significantly increased during storage irrespective of the oils used in dough formulation, whereas peroxide value, K232 and polar compounds significantly increased only in taralli prepared with Bosana oil; all others parameters did not show significant differences. In any case, a different lipid degradation was observed in function of the utilized oils. In particular, when Coratina oil was used, a significant lesser oxidative degradation was observed, probably due to both the higher content of antioxidants (total phenols and carotenoids) and the lower content of substances characterized by pro-oxidant activity (oxidized triacylglycerols and diacylglycerols) than those of Bosana and Ogliarola oils. The results of the volatile compounds confirm the more susceptibility to oxidation of taralli made with Bosana oil. The research assessed the importance of the chemical composition of extra virgin olive oil used in the ingredient formulation of taralli. © 2013 Elsevier Ltd.

The literature contains several papers dealing with the volatile constituents contributing to the aroma of fresh and processed tomatoes. Along with the traditional tomato-based products, tomato-based pâtes, characterized by complex ingredient formulations, are commonly consumed as a seasoning for pasta, and as a dressing for meats, salads, and sandwiches. To the best of our knowledge, no investigations have been published on the influence of thermal stabilization treatments on the composition of volatile compounds in tomato-based pâtes. To this aim, thermally stabilized and not stabilized tomato-based pâtes were subjected to the analysis of volatile compounds. The results obtained highlighted the influence of the thermal stabilization process on the evolution of volatile composition tomato-based pâtes. In particular, the terpenic compounds showed significant decreases after the thermal stabilization process treatment, due to their degradation and oxidation favored by high temperatures. The thermal stabilization caused, moreover, an increase in volatile compounds deriving from lipid oxidation and Maillard reaction, characterized by low-sensory thresholds, and from the thermal degradation of carotenoids and fresh tomato-derived compounds.

In this work, differential scanning calorimetry (DSC) was for the first time applied to evaluate cooling and heating curves and related thermal properties of olive oil during refining process steps starting from two series of samples at different initial peroxide values (low, 15meqO2/kg and high, 30meqO2/kg). Thermal properties were statistically correlated by means of principal component analysis (PCA) to those substance classes (products deriving from oxidation, polymerization and hydrolysis of triacylglycerols (TAG)) that could exert adverse effects on consumer health and a negative contribution to the shelf-life of the refined oil. A concomitant significant increase of K270 and polymerized TAG, as a general decrease of oxidation level was exhibited by oils during bleaching. Crystallization significantly shifted towards lower temperatures as well as onset temperature of heating, enlarging transition range, starting from bleaching and at both oxidation levels. PCA was performed to tentatively discriminate among samples according to different refining steps and/or initial level of oxidation correlating thermal properties and chemical results. The first principal component clearly clustered samples according to different refining steps and this differentiation was possible on the basis of the relation of thermal parameters with polymerized TAG conjugated dienes and trienes (K232 and K270, respectively). This preliminary goal should lead to deepen the study of DSC application in the evaluation of the quality of olive and other vegetable oils during refining. Practical applications: DSC is a thermal technique that nowadays covers a large set of applications in lipid technology due to its indisputable advantages as it does not require sample preparation and use of solvents, resulting in a reduced environmental impact. The preliminary findings of this study promote the application of the technique in the evaluation of olive oil quality during refining steps in relation with molecular species formed as polymerized TAG and conjugated trienes discriminating crude and neutralized samples to bleached and deodorized oils. DSC could be also applied on other vegetable oils where refining process is more frequently applied. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Burrata is an Italian fresh ‘pasta filata’ cheese made from cow's milk and cream that is rapidly spreading in Europe. It has very high caloric content, and a technological protocol was developed for producing a reduced-fat type and fortifying it with polyunsaturated fatty acids (PUFA) of vegetable origin. A satisfactory reduced-fat prototype was obtained by using a 14% fat cream, which was specifically developed by diluting double cream with a suspension of carob seed flour. The composition of the new cheese changed with respect to the control, but the sensory characteristics were not impaired. Moisture increased from 62·6 to 68·4%, fat on dry matter decreased from 59·1 to 34·7%, and the caloric content decreased from 1060·8 to 718 J/100 g. Proteolysis and lipolysis were not affected by the technological modifications: after 7 d storage, the electrophoretic pattern of caseins and the free fatty acids profile of experimental and control cheeses were not significantly different. Fortification of reduced-fat Burrata with PUFA was obtained by using two commercial formulates available at a compatible price with the current economic values of the cheese. The two formulates derived from flaxseeds and Carthamus tinctorius oil and allowed enrichment in C18 :3 : n3 (α-linolenic acid, ALA), and 9cis,11trans- and 10trans,12cis- conjugated linoleic acid (CLA), respectively. Fortification was easy to perform under a technical point of view, but the negative sensory impact limited fortification at a maximum of 7·0 mg g-1 fat ALA and 6·8 g-1 fat CLA.

An experimental investigation was carried out to assess the fatty acid composition and the degradation level of the covering oil present in canned fish. The most commonly marketed canned fish types were considered (tuna, sardines, anchovies, mackerels), as well as different kinds of covering oil: extra virgin olive oil, olive oil, refined seed oil. A total of 68 samples were analyzed. Two-way analysis of variance, followed by Fisher's Least Significant Difference test for multiple comparisons, and principal component analysis were carried out to compare the effect of both type of oil used and kind of fish on oil quality. The obtained results showed the lowest extent of both hydrolytic and oxidative degradation in samples containing extra virgin olive oil. In particular, the contents of triacylglycerol oligopolymers, imputable to secondary oxidative degradation, were equal to 0.17%, 0.50% and 0.74% for extra virgin olive oil, olive oil and refined seed oil, respectively. Olive oil showed significantly higher hydrolytic degradation, with diacylglycerols equal to 3.37%, but lower oxidative degradation and trans isomers content than refined seed oil. Finally, the type of fish did not seem to influence the extent of oxidative and hydrolytic degradation, with the only exception of sardines’ covering oil. This oil, characterized by the highest polyunsaturated fatty acid content, showed the highest values of oxidized triacylglycerols (1.32%) and specific absorption at 232 ( K 232 , 4.030), indices of primary oxidative degradation.

An investigation was carried out to evaluate the use of High Performance Size-Exclusion Chromatography (HPSEC) of polar compounds of refined, mild deodorized, extra virgin olive oils as well as of their blends, in attempting to reveal significant differences in the amounts of the substance classes constituting polar compounds among these oils. Two sets of blends were prepared by mixing an extra virgin olive oil with both refined and mild deodorized olive oils in increasing amounts. The obtained data highlighted that the triacylglycerol oligopolymers were absent or present in traces in the extra virgin olive oil, while their mean amount was equal to 0.04. g/100. g and 0.72. g/100. g in mild deodorized and refined olive oils, respectively. Oxidized triacylglycerols and diacylglycerols were more abundant in mild deodorized oil and refined oil than in extra virgin olive oil. The Factorial Discriminant Analysis of the data showed that the HPSEC analysis could reveal the presence of refined/mild deodorized oils in extra virgin olive oils. In particular, the classification functions obtained allowed designation of mixtures containing at least 30. g/100. g of mild deodorized oil and all those containing refined olive oil as deodorized oil, therefore as oils subjected to at least a mild refining treatment. © 2011 Elsevier Ltd.

An extra virgin olive oil was used as seasoning for three different types of focaccia produced on an industrial scale. This oil and samples of the oil extracted from the focaccias after baking were submitted to routine analyses and to silica gel column chromatography to separate polar compounds. These were then subjected to high performance size-exclusion chromatographic (HPSEC) analysis and it allowed to determine oxidative and hydrolytic degradation products. The results were compared with those obtained from artisan focaccias, seasoned with the same oil and toppings, by statistical analyses. The different technologies and the toppings employed directed in different ways the oxidative and hydrolytic processes in the oil. Copyright © Taylor & Francis Group, LLC.

BACKGROUND: Various studies have shown the ability of volatile compounds to influence the quality of charcuterie products because of their effect on sensorial properties. To the best of our knowledge, there are no data in the scientific literature concerning the evolution of volatile compounds of vacuum-packed ripened sausages over time. The aim of this work was to evaluate the evolution of volatile compounds in vacuum-packed ripened sausages over time, considering that this kind of packaging is the most commonly used to prolong the shelf-life of these products. RESULTS: Sixty-nine volatile compounds were identified. Those derived from spices represented the prevailing compounds at the beginning of storage and significantly decreased (P < 0.001) during 5 months of storage, as a result of the well-known antioxidant activity. Conversely, compounds derived from the autoxidation of lipids, which are among those chiefly responsible of sensorial properties of meat products, significantly increased (P < 0.001). CONCLUSION: The research demonstrated that vacuum packaging influenced the evolution of volatile compounds during storage of ripened sausages. In particular, the increase of volatile compounds derived from autoxidation of the lipid fraction indicated that oxidative processes involved the fatty fraction of ripened sausages also in the scarcity of oxygen. Copyright © 2011 Society of Chemical Industry

An experimental investigation was carried out to study the evolution of the volatile compounds of ripened sausages as a function of both storage time (time) and composition of packaging atmosphere (MAP). Ripened sausages, prepared at an industrial plant, were packed applying three different atmosphere compositions and were stored for three months. The obtained data evinced that the evolution of the volatile compounds was significantly related to the variable time more than to the variable MAP. The main volatile compounds were those derived from spices. Among them, Δ3-carene was the most abundant and a significant decrease was observed during storage (p

Several studies have investigated the interaction of free fatty acids with the oxidative phenomena involving oils during processing and storage. Nevertheless, the available information is insufficient and, in some cases, contradictory.The aim of this work was to throw light upon this matter, by evaluating - by means of different analytical approaches - the effect of adding increasing amounts of free fatty acids (0.25%, 0.5%, 1%, 3%) on the oxidative processes occurring in purified olive oil during oxidation at 60°C.The results obtained showed that oxidized forms of triglycerides and polar oligopolymers of triglycerides increased during oxidation. Low amounts of added FFA caused a further increase of the levels of oxidized triglycerides and triglyceride oligopolymers - pointing out a pro-oxidant activity - while higher doses of added free fatty acids lead to lower amounts of oxidized forms of triglycerides respect to the purified oil. This could be due to an increase in peroxide decomposition exerted by free fatty acids when present in higher amounts. © 2010 Elsevier Ltd.

Sensory analysis and determination of analytical indices to evaluate the oxidative degradation of the liquid medium were used to assess the overall quality of tuna canned in different types of oil. Moreover, the relationships between the quality of the liquid medium and the quality of raw material were studied. The results pointed out that quality of the raw material changed as related to the types of oil used. In particular, the tuna in extra virgin olive oil showed significant higher scores for the descriptors related to the quality of raw materials and lower values for the indices that evinced the degradation of liquid medium.

BACKGROUND: There is little information in the scientific literature on the degradation of the fatty fraction of biscuits during storage. Thus two trials were performed utilizing two different kinds of margarine for a better evaluation of the phenomenon. RESULTS: Covariance analysis of the data evidenced a significant increase of the oxidized triacylglycerols (P < 0.001), together with a significant decrease (P < 0.001) in the amount of monounsaturated and polyunsaturated fatty acids. On the other hand, the level of hydrolytic degradation did not show significant variation. CONCLUSION: Principal components analysis ascertained that about 60% of the variance of the data could be attributed to the quality of the margarine, while about 30% was ascribable to the increase of oxidative degradation induced by storage. Copyright © 2009 Society of Chemical Industry

Four different types of "focaccia" (Italian flat bread) prepared with the same dough and the same extra virgin olive oil but with different seasonings, were analyzed. Lipids were extracted from each sample using the Folch method. The indices commonly used to assess oil quality, the amounts of trans fatty acids and compounds of triglyceride polymerization, oxidation and hydrolysis, were determined in all the samples to better assess the degree of oxidation and hydrolysis of the oils. The findings showed that, once baked, the oil sampled from the different types of focaccias could not be included in the virgin category. The level of oxidation of the baked samples was greater than that in the uncooked oil. However the results obtained showed that the level of degradation of the extracted oils was lower than that found in edible refined oils and it seemed to be influenced by the topping used to flavour the focaccias. © 2007 Elsevier Ltd. All rights reserved.

Summary The present study demonstrates the use of fluorescence spectroscopy for monitoring changes in virgin olive oil during storage. Total luminescence and synchronous scanning fluorescence spectroscopy techniques were tested with the purpose to check their ability to monitor changes occurring in olive oil during storage in different conditions: in clear and green glass bottles exposed to light, and in darkness. Total luminescence spectra of the initial oil samples in n-hexane solutions exhibited intense peaks, one with a maximum appearing at 320 nm in emission and 290 nm in excitation, attributed to tocopherols, and another appearing at 670 nm in emission and 405 nm in excitation, belonging to the pigments of the chlorophyll group. The intensity of these emissions decreased during storage depending on the storage conditions. Additional bands appeared in oils exposed to light in the intermediate range of excitation and emission wavelengths, arising from unidentified compounds. Bands attributed to tocopherols, chlorophylls and those tentatively ascribed to phenolic compounds were observed in the synchronous scanning fluorescence spectra, allowing monitoring of the storage effects on these constituents and their quantitative assessment after appropriate calibration. The results presented confirm the capability of the fluorescence techniques to monitor the quality of oil products.

Extra-virgin olive oils used in the production of flavoured oils can derive from a single cultivar or can be a blend of two or more mono-varietal oils. In order to investigate the effects of the characteristics of the oil blends on the quality of the deriving flavoured oils, three mono-cultivar extra-virgin olive oils (Coratina, Peranzana, Ogliarola) were used to produce three blends, which were successively flavoured by infusion. From each blend, three types of flavoured olive oils were produced: basil, chilli pepper, and garlic + chilli pepper. Mono-varietal extra-virgin olive oils, blends, and flavoured oils were submitted for routine analyses and for determination of polar compounds, phenolic profile, antioxidant activity, and volatile profiles. The panel and consumer tests were also carried out on the flavoured oils. Along with the undoubted influence of the flavouring agents, the quality parameters of each blend changed and their changes greatly depend on the starting blend. The parameters mostly affected by oil blend were: acidity, K232, peroxide values, diacylglycerols, polar compounds, total phenolics, antioxidant activity, and phenolics such as p-coumaric acid, tyrosol acetate, vanillic acid, tyrosol, hydroxytyrosol, hydroxytyrosol acetate, dialdehydic form of elenolic acid linked to tyrosol, and ligstroside aglycone, oleuropein aglycone. The effects of oil blending were rather limited on volatile profiles and sensory characteristics.

High performance size exclusion chromatography analysis (HPSEC) of polar compounds extracted from the lipid fraction of biscuits was able to separate and quantify the different classes of substances formed by to both oxidation (triglyceride oligopolymers and oxidized triglycerides) and hydrolysis (diglycerides) of triglycerides, providing a reliable measure of the quality of edible fats. Mean values in 42 samples were 0.61%, 0.89%, and 4.69% for triglyceride oligopolymers, oxidized triglycerides, and diglycerides, respectively. These results indicated a considerably high extent of hydrolytic and oxidative degradation of the biscuits’ lipid fraction.

Olives (Olea europaea cv. Coratina) used for oil production were stored for 30 days at three different temperatures and under different atmospheres (ambient temperature, 5 °C with a flux of humidified air, 5 °C with a flux of 3%O2 + 5%CO2). The olives were kept in jars used for fruit storage, each with a capacity for 1.5 kg of olives. Conventional analyses (acidity, peroxide value, specific extinction coefficient at 232 nm and 270 nm) and non conventional (polar compounds) analyses were carried out in order to measure the hydrolytic and oxidative degradation of the oils obtained from the olives. Storage at 5 °C, both under a flow of humidified air and a flow of 3%O2 + 5%CO2, produced oils that maintained their initial chemical qualities until the end of the experimentation; whereas storage of olives at room temperature led to their deterioration after 15 days of storage.

The hydrolytic and oxidative degradation of olive oil and extra-virgin olive oil, used as covering liquids in canned dried tomatoes, was studied during storage by means of conventional (acidity, peroxide value, p-anisidine value) and non conventional (polar compounds) analyses. The effects of the addition of spices were also considered. The hydrolysis and oxidation of olive oil increased faster and was higher than that of extra-virgin olive oil in terms of absolute values but some other indices, such as percentage of oligopolymers and percentage of oxidized triglycerides, increased faster in extra-virgin olive oil than in olive oil. The antioxidant effect given by a higher concentration of polyphenols in the extra-virgin olive oil was shown by a reduced amount of secondary oxidation. However, olive oil and extra-virgin olive oils showed similar behaviour in terms of peroxide formation.

The effects of adding mixtures of herbs such as garlic, laurel, and marjoram on selected chemical indices of olive oil from canned dried tomatoes were studied for various storage periods of up to 1 yr. Conventional analytical indices measured included acidity, PV, and p-anisidine value. Flavored samples showed kinetic constant values that were significantly (P=0.001) higher than unflavored ones, whereas oligopolymer and oxidized TG and DG contents were similar to or slightly higher than in the unflavored samples compared with those with herbs. The addition of the mixture of herbs slowed polymerization reactions but did not inhibit TG oxidation. Discrepancies between the results obtained by conventional analyses and high-performance size-exclusion chromatography indicated that the former approaches were insufficient to determine oxidative degradation of oil as a result of interferences from compounds in the food matrix.

An experimental investigation was carried out to study the influence that exposure to light has on the quality of extra virgin oil during a 12-month storage period by comparing it with the quality of extra virgin oil stored in the dark. The results showed that the oils stored in the light had significantly lower tocopherol, carotenoid and chlorophyll contents than did the same oils kept in the dark. Moreover, the oils stored in the dark mainly contained primary oxidation products, while the oils kept in the light contained secondary oxidation products as confirmed by the K270 values which exceeded the legal limits even after purification by means of alumina. Overall, the results obtained showed that the shelf life of the oils exposed to light is shorter than that of oils kept in the dark, and that after only 2 months of exposure to light the oils examined could no longer be considered as extra virgin.

Forty olive oil samples (refined olive oil plus virgin olive oil) were tested to check the possibility of using recent non-conventional analytical parameters to assess quality. The routine analyses prescribed by the EEC Reg. No 2568/91 and subsequent extensions were carried out on all samples. The analytical techniques used included silica gel column chromatography for the separation of polar compounds from oil, and their subsequent high performance size-exclusion chromatography (HPSEC) analysis to quantify the oxidation, polymerisation and hydrolysis product classes. Based on the results obtained, it seems logical to use the percent oligopolymer content to measure the level of oxidation in commercial class olive oil. The diglyceride level can provide information about the extent of hydrolytic degradation.

The evolution of oxidized triglycerides (ox-TG) during industrial refining was studied in soybean, sunflower, peanut, and corn oils. The analytical techniques used were silica gel column chromatography and high-performance size exclusion chromatography. The decrease in ox-TG during refining (42.3% on average) was accompanied by an increase in triglyceride oligopolymers (TGP). The inverse correlation between the two lipid groups suggests that the decrease in ox-TG during refining was due in part to the occurrence of polymerization reactions. An inverse correlation was also found between the percentage sum of ox-TG + TGP and percent TGP, indicating that a part of the ox-TG also underwent degradation or transformation reactions. On average, almost 58% of the ox-TG remained unchanged during refining and, of the rest, about half was involved in polymerization reactions and half in degradation or transformation reactions.

An experimental investigation was carried out to evaluate the quality of virgin olive oils obtained when either a hammer-crusher or a disk-crusher were used for the olive paste preparation; the effect of the temperature rise caused by rapid olive crushing was also assessed. Oxidative degradation in the oils obtained from hammer-crushed olives was significantly higher than in those obtained from disk-crushed olives as shown by the levels of oxidised triacylglycerols and the results of the oven test. A significant inverse correlation (p

Summary An experimental investigation ascertained the variation of the contents of saturated, unsaturated and polyenoic fatty acids, as well as of the trans-isomers of unsaturated fatty acids, in different vegetable oils (virgin olive oil, refined sunflower, refined peanut) submitted to either conventional or microwave heating. The results obtained showed that heat treatment causes a worsening of the nutritional quality of the fatty fraction. As a consequence, the contents of unsaturated and polyenoic fatty acids decreased, with greater variations in the oils heated by microwave than by a conventional oven, while the saturated fatty acid contents did not change substantially. The heat treatments also caused an increase in the trans-isomers of unsaturated fatty acids and this was more evident after microwave treatment.

Three major virgin olive oil varieties (Dritta, Leccino, and Coratina) extracted by a modern centrifugation system aided with a new plant enzyme preparation (having prevalently pectolytic activity) were characterized. These oils showed a clearly enhanced quality standard, owing to higher levels of some important minor components (phenolics, volatiles, tocopherols, carotenes, and chlorophylls) and to frequently lower concentrations of oxidized triglycerides and diglycerides. The oils were therefore characterized by lower susceptibility to oxidation and longer shelf life, and their flavor, aroma, and color features appeared to be significantly improved. The saponifiable fraction was practically not affected as the enzymatic effects involved only the membranes of the oil droplets, where the nonglyceridic compounds are essentially located.

An experimental investigation was carried out to assess the oxidative and hydrolytic quality of the lipid fraction of bouillon cubes. Besides the routine analyses prescribed by EC regulations, determinations of fatty acid composition and unsaturated fatty acid trans isomers were also performed. From the lipid fraction extracted from each cube, polar compounds were separated by silica gel column chromatography and then submitted to HPSEC (high-performance size exclusion chromatography) analysis to determine the classes of substances deriving from oxidation, polymerisation and hydrolysis of triglycerides. The data obtained showed that the determination of trans isomers and the subsequent HPSEC analysis of polar compounds enable one to ascertain the actual degradation of the lipid fraction of such food preparations. The degree of degradation of the lipid fraction of bouillon cubes was similar to that normally found in olive-pomace oil, which is the poorest olive oil commercial class. Finally, the contents of trans isomers and triglyceride oligopolymers are shown to be significantly higher in hydrogenated than in non-hydrogenated vegetable fats.

An experimental trial was carried out to evaluate, by means of determination of polar compounds and their subsequent HPSEC analysis, the influence of the hammer-crusher temperature during the olive paste preparation prior to oil extraction. Olives of Cima di Bitonto cultivar were processed utilising a laboratory-scale hammer-crusher conditioned at three different temperatures (12, 16 and 20 °C). The analytical results showed that the quality of the extracted oils was negatively influenced by increasing the crushing temperature. The oils obtained at higher crusher temperatures were more susceptible to oxidation than the oils obtained with crusher conditioned at lower temperatures. The HPSEC analysis of polar compounds was found to be useful to evaluate the oxidative and hydrolytic degradation levels of virgin olive oils also after slight thermal raising.

An experimental investigation was performed to characterise the fat fraction of bouillon cubes. Besides the routine analyses, the analytical methods used were: silica-gel column chromatography to separate polar compounds, high performance size-exclusion chromatography (HPSEC) for the qualitative and quantitative determination of the single classes of substances constituting the polar compounds, and gas chromatography to determine the acid composition and the trans isomers of unsaturated fatty acids. The fats blended into the bouillon preparations were highly variable and were mainly made up of refined vegetable oils that had undergone hardening, by hydrogenation in most cases. Determination of the free fatty acids and of the peroxide values yielded figures that in some cases exceeded the limits set for the commercialisation of refined vegetable oils. Compared to the routine analyses, the HPSEC analysis of the polar compounds provided a better evaluation of the level of degradation of the fat extracted from the bouillon formulations. The levels of oxidative and hydrolytic degradation were rather high, and similar to those reported for poor quality oils. Analyses of the trans isomers of oleic acid yielded particularly high values (even over 20%) and differentiated the cubes on the basis of the type of fat added.

A comparative study was performed to evaluate the effects that microwave (12 and 15 min at 1,100 W) and conventional heating (36 and 45 min at 230 °C) have on olive oil (refined+virgin). The extent of the oxidative and hydrolytic degradation of the differently heated oils was evaluated by high performance size-exclusion chromatographic analysis of their polar compounds. The experimental results showed a great degradation of the oils with values of polar compounds higher than 26% at the most intense treatment. Significantly higher amounts of polar compounds, of triglyceride oligopolymers – known to have adverse effects on human health – and of oxidised triglycerides were found in microwaved than in conventionally heated oils, indicating a higher extent of oxidative degradation.

The production process for making Cacioricotta, the most common goat cheese of Apulia, was modified to improve both its yield and organoleptic characteristics. The changes made to the traditional cheese-making process consisted in reducing the amounts of rennet to be added from 100 to 40 ml/q (q=quintal=100 kg) and in introducing a mesophilic starter mixed with the conventional thermophilic starter. The traditional cheese was compared to the modified product by means of routine analyses and measurements of the cheese yields and determination of free aminoacids and free fatty acids. The analytical techniques utilized were high pressure liquid chromatography (HPLC) and gas chromatography (GC). Both the cheeses had the same level of proteolysis while lipolysis was significantly lower (p

The effect of heat treatment (70, 80 and 95°C, for 1, 3 and 10 min) on the rennet clotting time (RCT) has been evaluated in cow milk ( Bruna Italiana ) and in the milks of five goat breeds ( Saanen , Camosciata , Ionica , Garganica and Maltese ). The RCT of raw cow milk ranked at an intermediate level compared to that of raw milk of goat breeds examined. With respect to the raw milks, the RCTs of cow milk became progressively longer as a function of both heating temperature and time, while all the goat milks' RCTs decreased. Significant ( P Camosciata , Ionica , Garganica and Maltese goat milks even after mild heating (to 70°C for 1 min), while significant ( P Saanen goat milk only with intense heating (95°C for 1, 3 and 10 min).

This paper proposes an analytical method to evaluate the classes of products of polymerization, oxidation and hydrolysis as well as the polar compounds present in refined edible oils in a more reliable fashion. The polar compounds of a marketed refined peanut oil were analyzed by preparative gel permeation chromatography and the classes of substances corresponding to single chromatogram peaks were collected by means of a fraction collector, purified and used as standards for high-performance size-exclusion chromatographic analysis. The linearity of detector response, the precision and accuracy of the method for each class of compounds and for polar compounds were assessed. Another aim was to verify whether this method may be applied to other refined peanut oils and to edible vegetable oils in general, even of different botanical origin, using the standards that had already been prepared for that particular peanut oil. The results obtained showed that this was possible and the analytical method developed can be extended to the most common edible vegetable oils.

An experimental investigation was carried out on olive oils of the Ogliarola Salentina and Coratina cultivars to assess the influence of the two different olive grinding techniques and kneading process on the quality of the oils. The experimental data obtained showed that resistance to oxidation, total phenols and phenolic compounds analysed for HPLC were higher in the Coratina oils than in the Ogliarola oils. The use of hammer-crushers plus kneader rather than stone mills plus kneader always produced significant increases in the total phenols. Resistance to oxidation was assessed by the Rancimat method and showed a significant correlation with the amounts of total phenols and of an unidentified substance (peak I) which was conspicuously present amongst the substances evaluated for HPLC.

The aim of this investigation was to trace the fate of oxidation levels in crude olive-pomace oil during refining. Seven series of samples were examined. Each series comprised samples of the unprocessed crude oil and of the same oil collected after each step of the refining process. The analyses were performed by means of silica gel column chromatography and high-performance size-exclusion chromatography. The data obtained showed that triglyceride oligopolymers increased during refining, especially during bleaching and deodorization, and that the levels of these compounds were on average ∼4-fold greater in the refined oils than in the crude oils. Conversely, oxidized triglycerides decreased by an average of 49% as the oil was processed into a refined oil. When the percent values of oxidized triglycerides were plotted against the percent values of oligopolymers, a linear trend of the experimental data was depicted for all the series examined. The regression lines computed revealed correlation between the two classes. This indicated that one of the reasons oxidized triglycerides decreased during olive-pomace oil refining was related to the occurrence of polymerization reactions. It was finally suggested that the content of oligopolymers triglycerides may be usefully employed as a reliable analytical index for estimating the level of oxidation of a freshly refined oil.

The combined effect of natural antioxidants and packaging materials on the quality decay of breakfast cereals during storage was evaluated. Corn flakes were produced on industrial scale, using different packages and adding natural tocopherols to the ingredients, and stored for 1 year. The samples were then submitted to sensory analysis and HS-solid phase microextraction/gas chromatography/mass spectrometry (SPME/GC/MS) analysis. The packaging had a significant influence on the sensory profile of the aged product: metallized polypropylene gave the highest levels of oxidation compounds and sensory defects. The sensory profile was improved using polypropylene and especially high-density polyethylene. Natural tocopherols reduced the sensory decay of the flakes and the oxidative evolution of the volatile profile. They gave the most remarkable improvement in polypropylene (either metallized or not) packs. Polypropylene showed a barrier effect on the scalping of volatiles outside of the pack. This led to higher levels of oxidation volatiles and faster rates of the further oxidative processes involving the volatiles. © The Author(s) 2013.

The effect of drying temperatures on the profile of volatile compounds of pasta was studied. The solid phase microextraction coupled with gas chromatography/mass spectrometry allowed to identify 72 volatile compounds in the samples of not-dried, low-temperature-dried (LT-dried), high-temperature-dried (HT-dried), and wrongly very-high-temperature-dried (WVHT-dried) pastas. The samples of not-dried pasta contained alcohols, aldehydes, short-chain ketones, esters, furans, and some sulfur compounds. In the LT-dried pasta, the volatile aldehydes derived from lipid oxidation were more abundant than in HT-dried pasta. HT-dried pasta showed higher levels of furan and furan derivatives (especially 2-furanmethanol), derived from the Maillard reaction, than LT-dried pasta (p < 0.05). Pyrazines arose from WVHT treatment. Significant differences were observed also for the color indices when comparing pasta subjected to LT and HT drying (p < 0.001). Several volatile Maillard reaction products were significantly correlated (p < 0.05 and p < 0.01) to a* and 100 - L*. The ratio aldehydes/furans allowed distinguishing in a significant way the treatments, independently from the lot characteristics. © 2013 Springer Science+Business Media New York.

The influence of the storage time on the levels of thermo-oxidation compounds of extra virgin olive oil (EVOO) during frying was evaluated. To this aim, two extra virgin olive oils (cv Bosana, EVOO1 and cv Semidana, EVOO2) fresh and after storage, were used, for deep-frying of potatoes. EVOO stored for a longer time led to a significant increase of the TAGP and ox-TAG content in both the residual fried oils and the oil extracted from potato chips, with respect to the levels observed when frying was performed with oils stored for a shorter time.

The aim of this work was to develop a DNA microsatellite-based method of analysis to allow traceability of the three Italian Protected Designation of Origin (PDO) table olives in comparison with fruits of another seven highly diffused table olive cultivars. The analyses were carried out by using 16 primer pairs, with a mean of five different alleles detected per primer set, and power of discrimination from 0.56 to 0.90. Allelic error rates in the range of 0-3.8% were observed. By combining data from the most reliable and highly informative microsatellites (DCA3, DCA16, DCA17, DCA18, UDO-043, and GAPU101), it was possible to identify the PDO fruits over the panel of 10 cultivars, with the probability of a chance match between different cultivars as low as 10(-9) and with 0.5% error rate. The amplification profile is independent of environmental and processing conditions and is helpful to verify the authenticity of PDO samples.

An experimental investigation was carried out with the aim to investigate on the isomerisation of 1,2-diacylglycerols to 1,3-diacylglycerols as a function of the storage conditions, as well as to identify indices useful to evaluate the freshness of the oils. Two oils derived from two different cultivars (Coratina and Ogliarola barese) were stored for two years as follows: in bottles at dark; in clear glass bottles at light; in green glass bottles at light; in bottles at dark, the latter subjected to repeated opening and samplings to simulate domestic use. The obtained results evinced that during the storage period a significant increase in the 1,3-isomers was observed due to an isomerisation from the 1,2 to the 1,3 isomeric form, consequently the 1,3/1,2 ratio increased in both oils. The covariance analysis of the data showed that the isomerisation of diacylglycerols, taking place during time, was affected by the type of oil, probably due to the different initial hydrolysis level, but was not affected by the storage conditions. Among the parameters considered, the total diacylglycerols/1,3-diacylglycerols ratio could be used as freshness index of extra virgin olive oil, since it is not affected by either oil or storage conditions. © 2012 Elsevier Ltd. All rights reserved.

Summary: The lipid fraction of bakery products undergoes a significant degradation during baking, with an increase in undesirable oxidised substances, that can act as catalysts for further oxidative reactions during storage reducing the product shelf life. The use of extra virgin olive oil in bakery products rich in fat in place of refined oils was studied, assessing the evolution of the oxidative and hydrolytic degradation during storage. Two-way analysis of variance, followed by Tukey's HSD test for multiple comparisons, covariance and principal component analyses were carried out to compare the effect of the type of oils. The data obtained showed that the evolution of the oxidation levels in the analysed samples during storage was related to the type of oil used in the production process. Particularly, the use of extra virgin olive oil led to significantly lower values of hydroperoxides, ultraviolet absorption constants, triacylglycerol oligopolymers and oxidised triacylglycerols. © 2012 The Authors. International Journal of Food Science and Technology © 2012 Institute of Food Science and Technology.

An experimental investigation was carried out to evaluate the quality of taralli as a function of the type of oil used in their dough formulation. To this end, 4 types of oil (extra virgin olive oil, olive oil, olive-pomace oil, and refined palm oil) were utilized to prepare taralli to investigate on the lipid fraction degradation and evaluate the taralli acceptability by consumers. The data obtained pointed out that taralli manufactured with extra virgin olive oil were significantly more appreciated than those made with refined oils due to their visual appearance and odor. Moreover, with respect to the other kinds of oil, the use of extra virgin olive oil led to significantly lower values (P < 0.05) of specific absorption at 232 and 270 nm (K(232) and K(270) , respectively) and of triacylglycerol oligopolymers. It also proved to present a much lower content in oxidized triacylglycerols and diacylglycerols than olive-pomace oil and refined palm oil, respectively. Furthermore, trans fatty acid isomers were absent in taralli made with extra virgin olive oil but were constantly present in those produced with refined oils.

The refining process is essential to make edible both lampante olive oils and solvent-extracted vegetable oils. The aim of this work was to evaluate the influence of the crude oil oxidation level and of the standard refining process on the amount of oxidized triacylglycerols (ox-TAG) and triacylglycerol oligopolymers (TAGP) in the corresponding refined oil. A virgin olive oil was let to progressively autoxidize at room temperature and was used at different oxidation levels in the experimental trials. Samples were submitted to the same refining process, utilizing a laboratory-scale pilot plant. The results obtained showed that the steps of the refining process caused the increase of oligomeric oxidation products in the refined oil respect to the corresponding raw oil. In this study the oxidative degradation in the crude oil resulted to be correlated to the final amounts of ox-TAG and TAGP. These findings point out that the final levels of oxidation products in refined oils depend both on the adopted standard refining steps and on the oxidative level of the crude oils. In particular, being ox-TAG highly pro-oxidant substances, the oxidative status of the crude oil can severely affect the shelf-life of the refined oil. © 2011 Elsevier Ltd.

An experimental investigation was carried out with the aim to evaluate the pro-oxidant activity of oxidized triacylglycerols and compare it with that observed for polar triacylglycerol oligopolymers. The research on these classes of substances, that form during processing and storage of fats and oils, has a great concern with the study of the effect of heat in technologic processes, such as vegetable oils refining, frying and cooking. Oxidized triacylglycerols and polar triacylglycerol oligopolymers, obtained in purity by preparative gel permeation chromatography, were added in amounts of 0.25-1 g/100 g both to a purified and an unpurified olive oil. Regarding the oxidized triacylglycerols, the accelerated oxidation tests showed that the induction times of both oils significantly decreased at increasing concentrations of these compounds, demonstrating their pro-oxidant effect. Moreover, the data showed that the pro-oxidant activity of oxidized triacylglycerols was greater than that of polar triacylglycerol oligopolymers. © 2010 Elsevier Ltd.

Publisher Summary Focaccia is a typical bakery product of many Italian regions, and it shows variants depending on the productive area. Today, focaccia is largely appreciated for its sensory properties and has its own market. It is usually consumed, still hot, as a “street food,” immediately after its production. Focaccia is made of a few simple ingredients—flour, water, fatty substances (oil or lard), yeast, and salt—but a myriad of nuanced differences are obtainable by topping it, prior to cooking, with fresh tomato, onions, potatoes, olives, cheese, etc. or flavoring it with herbs (rosemary, sage, oregano, etc.). Durum wheat, re-milled semolina is used in the production of some types of focaccia. Olive oil, notably extra-virgin olive oil, is an essential ingredient in many types of focaccia. Focaccia usually appears as a circular flat bread, single layered, oily, and variously topped. The productive steps of the various focaccia types are: mixing, kneading, leavening, flattening, proofing, and baking. In the past, only a sourdough-based prolonged productive process was performed; however, today, fresh compress baker's yeast is used in the majority of bakeries to prepare focaccia.

Various studies have shown the ability of volatile compounds to influence the quality of charcuterie products because of their effect on sensorial properties. To the best of our knowledge, there are no data in the scientific literature concerning the evolution of volatile compounds of vacuum-packed ripened sausages over time. The aim of this work was to evaluate the evolution of volatile compounds in vacuum-packed ripened sausages over time, considering that this kind of packaging is the most commonly used to prolong the shelf-life of these products.Sixty-nine volatile compounds were identified. Those derived from spices represented the prevailing compounds at the beginning of storage and significantly decreased (P0.001) during 5 months of storage, as a result of the well-known antioxidant activity. Conversely, compounds derived from the autoxidation of lipids, which are among those chiefly responsible of sensorial properties of meat products, significantly increased (P0.001).The research demonstrated that vacuum packaging influenced the evolution of volatile compounds during storage of ripened sausages. In particular, the increase of volatile compounds derived from autoxidation of the lipid fraction indicated that oxidative processes involved the fatty fraction of ripened sausages also in the scarcity of oxygen.