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Study of different kinds of “Pesto Genovese” by the analysis of their volatile fraction and chemometric methods
Abstract
The volatile fraction of different kinds of Pestogenovese, a typical Italian basil-based pasta sauce, was analysed by Headspace Sorptive Extraction (HSSE)-Gas Chromatography–Mass Spectrometry (GC–MS) coupled with chemometric methods. Three kinds of commercial samples were considered: (a) non heat-processed shop manufactured, (b) heat-processed industrial and (c) non heat-processed industrial samples. The category of heat-processed samples was easily discriminated by the amounts of the terpene hydrocarbon α-terpinene. In order to distinguish the three categories, multivariate statistical analysis was then performed. Good prediction results were obtained by the combination of Linear Discriminant Analysis (LDA) and Stepwise LDA (STEPLDA): the percentage of correct predictions was 92 for food industry manufactured non heat-processed samples and 100 both for shop manufactured, non heat-processed samples, and for food industry manufactured, heat-processed samples.
... SBSE coating is stable, but the analytes transfer was required from plant matrix to achieve efficient extraction. In previous study, SBSE is a good tool for the analysis of volatile composition (alcohols [74][75][76][77][78][79][80][81][82][83]54,86], aldehydes [74][75][76][77][78][79][80][81][82]84,54], ketones [74][75][76][77][78], acids [74][75][76]81], terpenes [74][75][76][77][78][79]82,54], norisoprenoids [74][75][76][77][78]82,83], esters [77][78][79][80][81][82]54,86], phenols and lactone [84,85]). The main samples are fruit matrices such as raspberry [79,80], grape [81][82][83][84][85], pomegranate [54], melons [86], peaches [77], apple [74], and blackberries [75]. ...
... SBSE coating is stable, but the analytes transfer was required from plant matrix to achieve efficient extraction. In previous study, SBSE is a good tool for the analysis of volatile composition (alcohols [74][75][76][77][78][79][80][81][82][83]54,86], aldehydes [74][75][76][77][78][79][80][81][82]84,54], ketones [74][75][76][77][78], acids [74][75][76]81], terpenes [74][75][76][77][78][79]82,54], norisoprenoids [74][75][76][77][78]82,83], esters [77][78][79][80][81][82]54,86], phenols and lactone [84,85]). The main samples are fruit matrices such as raspberry [79,80], grape [81][82][83][84][85], pomegranate [54], melons [86], peaches [77], apple [74], and blackberries [75]. ...
... SBSE coating is stable, but the analytes transfer was required from plant matrix to achieve efficient extraction. In previous study, SBSE is a good tool for the analysis of volatile composition (alcohols [74][75][76][77][78][79][80][81][82][83]54,86], aldehydes [74][75][76][77][78][79][80][81][82]84,54], ketones [74][75][76][77][78], acids [74][75][76]81], terpenes [74][75][76][77][78][79]82,54], norisoprenoids [74][75][76][77][78]82,83], esters [77][78][79][80][81][82]54,86], phenols and lactone [84,85]). The main samples are fruit matrices such as raspberry [79,80], grape [81][82][83][84][85], pomegranate [54], melons [86], peaches [77], apple [74], and blackberries [75]. ...
... [3] Basil is also the main ingredient of the pasta sauce 'Pesto alla Genovese'. [4] The ingredients of this sauce, besides basil, include cheese (Parmesan, Romano or both), extra-virgin olive oil, pine nuts and/or walnuts and garlic. [5] The unique flavour of this sauce stems from a balanced contribution of these ingredients and the aroma and taste of the basil. ...
... [5] The unique flavour of this sauce stems from a balanced contribution of these ingredients and the aroma and taste of the basil. [4] The flavour and taste of basil are attributed to terpenes and terpenoids, [6] two large classes of chemicals containing many hundreds of distinct compounds. Terpenes are synthesised from isoprene (2-methyl-1,3-butadiene), having the formula (C 5 H 8 ) n , with n = 2 giving the monoterpenes, n = 3 the sequiterpenes, n = 4 the diterpenes, etc. [7] In turn, the terpenoids, also known as isoterpenes, are oxygenated derivatives of terpenes. ...
... [13] In addition, for methyl cinnamate, the m/z 163 product ion is shared by a hydrated product ion of the reaction with diallyl disulphide. [13] The latter compound is found in garlic, commonly used in foodstuffs along with basil, [4,5] and hence is likely to interfere with methyl cinnamate quantification. Thus, the H 3 O + precursor ion is not the best choice for the analysis of basil headspace, leaving NO + and O 2 + • as possible precursors. ...
Basil (Ocimum basilicum) is an important flavourant plant which constitutes the major ingredient of the pasta sauce 'Pesto alla Genovese'. The characteristic smell of basil stems mainly from a handful of terpenoids (methyl cinnamate, eucalyptol, linalool and estragole), the concentration of which varies according to basil cultivars. The simple and rapid analysis of the terpenoid constituents of basil would be useful as a means to optimise harvesting times and to act as a quality control process for basil-containing foodstuffs. Classical analytical techniques such as gas chromatography/mass spectrometry (GC/MS) are, however, slow, technically demanding and therefore less suitable for routine analysis. A new chemical ionisation technique which allows real-time quantification of traces gases, Selected Ion Flow Tube Mass Spectrometry (SIFT-MS), was therefore utilised to determine its usefulness for the assay of terpenoid concentrations in basil and pesto sauce headspace. Trace gas analysis was performed using the NO(+) precursor ion which minimised interference from other compounds. Character-impacting compound concentration was measured in basil headspace with good reproducibility and statistically significant differences were observed between cultivars. Quantification of linalool in pesto sauce headspace proved more difficult due to the presence of interfering compounds. This was resolved by careful selection of reaction product ions which allowed us to detect differences between various commercial brands of pesto. We conclude that SIFT-MS may be a valid tool for the fast and reproducible analysis of flavourant terpenoids in basil and basil-derived foodstuffs.
... Pesto is a typical Italian basil-based pasta sauce (Mitić-culafić et al., 2014; Zunin et al., 2009;Masino et al., 2008) which has recently met with the favor of the international market particularly in North America (Zunin et al., 2009;Fabiano et al., 2000). The pesto sauce is the second most popular pasta sauce after tomato sauce (Masino et al., 2008). ...
... Pesto is a typical Italian basil-based pasta sauce (Mitić-culafić et al., 2014; Zunin et al., 2009;Masino et al., 2008) which has recently met with the favor of the international market particularly in North America (Zunin et al., 2009;Fabiano et al., 2000). The pesto sauce is the second most popular pasta sauce after tomato sauce (Masino et al., 2008). ...
One of the major problems for pesto sauce type products is the tendency of oil to cream, causing their alteration and decreasing consumer’s acceptability. In this study, colloidal and oxidative stability of pesto samples with (0.5-1.2%) of beeswax was evaluated during storage at 4, 20 and 40°C. The rheological behavior and color analysis was evaluated at the same temperatures. Sensory evaluation by using a hedonic test was also perfomed. Increasing the samples beeswax content increased the pesto colloidal stability. The samples with 0.8-1.2% have the highest stability and overall performed well on sensory analysis. The peroxide values of samples increased significantly (p
... Furthermore, aromatic compounds extracted from sweet basil are used in cosmetics and natural fragrances [3] and drunk as basil tea [1]. Genova is popular for its use in pasta sauces [7] and contains high levels of polyphenol components, such as rosmarinic acid, a caffeic acid derivative, chicoric acid, and caffeic acid, with particularly high rosmarinic acid content [8,9]. Rosmarinic acid exhibits antioxidant, anti-inflammatory, and neuroprotective properties [9] and is abundant in sweet basil and other plants of the Lamiaceae family, such as egoma and lemon balm [10,11]. ...
This study has developed a production method for high-quality Genova tea with excellent antioxidant properties. The antioxidant properties of each part of the Genova basil plant (i.e., leaves, flowers, and stems) were determined; the leaves and flowers showed higher antioxidant values. We also investigated the effects of steaming time and drying temperature on the antioxidant composition and properties, color, and aroma using leaves with good yield potential and high antioxidant properties. The color showed excellent green color retention with freeze- and machine-drying at 40 °C without steam-heat treatment. Steaming for 2 min was effective in maintaining high values of total polyphenol content, antioxidant properties (1,1-diphenyl-2-picrylhydrazine and hydrophilic oxygen radical adsorption capacity), rosmarinic acid, and chicoric acid, and a drying temperature of ≤40 °C was recommended. Freeze-drying without steaming was the best method to retain all three of Genova’s main aroma components, Linalool, trans-alpha-bergamotene, and 2-methoxy-3-(2-propenyl)-phenol. The method developed in this study can improve the quality of dried Genova products and be applied in the food industry, cosmetics, and pharmaceutical industries.
... Moreover, the mild preservation technology of modified atmosphere packaging combined with refrigeration was tested to reduce the high impact of the heating process on the organoleptic properties with the purpose to extend the pesto shelf life [6]. A great variety of pesto sauces exist in the market, with various recipes and applied stabilization (acidification, pasteurization, water activity reduction [7]), while the consumption of no-heated pesto is reserved for homemade recipes [8]. This type of sauce is not very stable and is sensitive to modification related to environmental conditions and food processing. ...
A natural antioxidant extract obtained from oil mill wastewater was used for the formulation of basil pesto sauce, with the aim to improve quality and stability during storage. The antioxidant extract was added to traditional ingredients (basil, cheese, oil, etc.) and after preparation, packaging, and thermal treatment it was submitted to storage (monitored for 90 days). Fresh samples were stored at 4 °C and pasteurized samples were stored at room temperature. The effect of natural antioxidant addition on basil pesto sauce was evaluated for the main qualitative attributes, such as: physicochemical, microbiological, and antioxidant parameters. The principal results showed that the addition of a natural phenolic extract led to an evident reduction in pH, attaining food safety values under pH 4. The high oxidative stability observed in the basil pesto sauces fortified with the phenolic extract suggests that the incorporation of phenolic compounds delays the propagation phase of lipid oxidation.
... Pesto is a typical Italian basil-based pasta sauce, which is common on the international market [1]. It is the second most popular condiment for pasta after tomato sauce [2], and it is widely used all over the world for the preparation of many dishes. ...
Basil-based semi-finished products, which are mainly used as an intermediate to produce the typical pesto sauce, are prepared and exported all over the world. Color is a fundamental organoleptic requirement for the acceptability of these semi-finished products by the manufacturers of the pesto sauce. Some alternative formulations, which adjust the typical industrial recipe by both changing the preservative agent (ascorbic acid, citric acid, or a mixture of both) and introducing a preliminary thermic treatment (blast chilling), were evaluated. In this work, a fast and non-destructive spectrophotometric analysis, to monitor the color variations in these food products during their shelf-life, was proposed. The raw diffuse reflectance spectra (380-900 nm) obtained by a UV-visible spectrophotometer, endowed with an integrating sphere, together with the CIELab parameters (L*, a*, b*) automatically obtained from these, were considered, and elaborated using multivariate statistical analysis (principal component analysis). From this preliminary study, blast chilling, together with the use of ascorbic acid, proved to be the best solution to better preserve the color of these products during their shelf-life.
... Traditional pesto originated from Liguria, a North Italian region that along a wide tract of the Mediterranean coast [3]. Other traditional ingredients are cheese, and/or walnuts and garlic [4]. Offering new and modified products is in line with the growing demand for healthy products . ...
Abstract
Some rheological characteristic s (cohesiveness, consistency, firmness, viscosity) and the color of modified pesto sauces were evaluated in the present stu dy. The applied production technology revealed that the traditional pesto recipe could be altered by using nutritional plant leaves. For the purposes of the study A. ursunum, A. bulgaricum, C. balsamita, P. oleracea, and M. officinal is leaves were chosen.
Keywords: pesto, color, rheology, conventional grass plants
... Traditional pesto originated from Liguria, a North Italian region that along a wide tract of the Mediterranean coast [3]. Other traditional ingredients are cheese, and/or walnuts and garlic [4]. Offering new and modified products is in line with the growing demand for healthy products . ...
... Only raw pesto preserves the composition of its ingredients. In contrast, food industries manufacture pesto by applying thermal treatment to the raw ingredients, while mild preservation techniques like moderate atmosphere packaging or refrigeration are only used for small and local producers (Zunin, Salvadeo, Boggia, & Lanteri, 2009). The other three samples of Genovese pesto analysed were heat-processed to preserve their quality for longer, which may have caused losses in the volatile fraction that contained estragole and methyl eugenol. ...
Citation: Ciriello, M.; Cirillo, V.; Formisano, L.; De Pascale, S.; Romano, R.; Fusco, G.M.; Nicastro, R.; Carillo, P.; Kyriacou, M.C.; Soteriou, G.A.; et al. Salt-Induced Stress Impacts the Phytochemical Composition and Aromatic Profile of Three Types of Basil in a Genotype-Dependent Mode. Plants 2023, 12, 2167. https:// Abstract: Basil (Ocimum basilicum L.) is among the most widely used aromatic plants of Lamiaceae, often grown in areas where salinity is an adverse factor. Most studies on the effect of salinity on basil focused on the influence of salt stress on productive traits, while few reported on how it affects the phytochemical composition and the aroma profile. Three basil cultivars (Dark Opal, Italiano Classico, and Purple Ruffles) were grown hydroponically for 34 days with two nutrient solutions that differed in NaCl concentration [no NaCl (Control) and 60 mM NaCl]. Yield, secondary metabolite concentration (β-carotene and lutein), antioxidant activity [1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reduction antioxidant power (FRAP)], and aroma profile based on composition of volatile organic compounds (VOCs) were appraised in response to salinity applications. Salt stress significantly reduced fresh yield in Italiano Classico and Dark Opal by 43.34 and 31.69%, respectively, while no effect was observed in Purple Ruffles. Furthermore, the salt-stress treatment increased β-carotene and lutein concentrations, DPPH, and FRAP activities, and the total nitrogen content of the latter cultivar. CG-MS analysis revealed significant differences in VOCs composition of the basil cultivars, with Italiano Classico and Dark Opal characterized by the predominance of linalool (average 37.52%), which, however, was negatively affected by salinity. In Purple Ruffles, the predominant VOC compound, estragole (79.50%), was not affected by the deleterious effects of NaCl-induced stress.
The purpose of this study was to determine the optimal mixing ratio of olive oil, parmesan cheese, and nuts for preparation of pesto with spinach. Based on a surface response methodology (RSM), the independent variables were olive oil (100~300 g), parmesan cheese (25~75 g) and nuts (12~36 g). The dependent variables were physico-chemical properties as pH, color values (L, a, and b values), viscosity and sensory evaluation. pH decreased with increasing parmesan cheese levels. The L value decreased and the a and b values increased with increasing olive oil levels. Viscosity was negatively correlated with olive oil levels but positively correlated with the amounts of parmesan cheese and nuts. The addition of oil exerted a positive effect on gloss, and oily taste. In the sensory evaluation, the values of appearance, color, flavor, taste and overall acceptance were in the range of 4.4~7.2, 3.7~7.4, 4.4~7.1, 3.9~7.3 and 3.5~7.6, respectively. The sensory evaluation results showed significant values in appearance (p
Starting from a registered patent, the aim of the present study was to improve the osmotic dehydration (OD) process of Protected Designation of Origin Genovese basil leaves by composite experimental design. The contemporary optimization of both process variables and mixture composition allowed enhancing the quality of the dried product. A tentative substitution in the OD brine of the polyalcohol sorbitol with the novel food trehalose was also performed. Sensorial techniques and headspace analysis were applied to monitor changes in appearance, texture, flavor and color. The best appearance and aroma of dried leaves were obtained at 67.5C with a dipping time of 55 s in a brine containing 65% water, 20% sorbitol and 15% NaCl. Using trehalose did not lead to a significant improvement of the quality of the final product. This experimental approach could be successfully used, also on industrial scale, for the optimization of similar OD processes.
The paper shows the optimization of an osmotic dehydration (OD) process by composite design in order to simultaneously optimize both the process variables and the brine composition. This experimental approach can be successfully used, also on industrial scale, for the optimization of similar OD processes, with the aim to enhance the quality of the dried food and to limit their changes in appearance, texture, flavor and color.
Treatments of autoclaving, high temperature aging (aged-black garlic), crushing, and roasting at 100, 150, and 200°C were
applied to alter the volatile profiles of garlic (Allium sativum L.). Headspace volatiles in samples were analyzed by a solid phase microextraction (SPME)-GC/MS. Total peak areas of crushed-raw
garlic were the highest and those of aged-black garlic clove were the lowest. Crushing effects were clearly observed in raw
garlic, aged-black garlic, and roasted garlic at 200°C for 60 min. Sulfur-containing volatiles including diallyl disulfide
and diallyl trisulfide were major volatiles. Generally, peak areas of diallyl disulfide decreased when garlic received autoclaving
and roasting treatment while diallyl trisulfide and allyl methyl trisulfide increased during heat treatment compared to raw
garlic. Roasting at 200°C for 60 min caused the formation of pyrazines greatly in garlic. Principal component analysis (PCA)
for the volatile profiles by SPME-GC/MS could discriminate types of processed garlic successfully.
Keywordsgarlic–headspace volatiles–processing effect–solid phase microextraction
Static headspace sorptive extraction using polyurethane foams (HSSE(PU)) followed by gas chromatography coupled to mass spectrometry is proposed for volatile analysis. The application of this novel analytical approach to characterize the volatiles profile from roasted coffee samples, selected as model system, revealed remarkable advantages under convenient experimental conditions. The comparison of HSSE(PU) with other well-established procedures, such as headspace sorptive extraction using polydimethylsiloxane (HSSE(PDMS)) and headspace solid phase microextraction using carboxen/polydimethylsiloxane fibers (HS-SPME(CAR/PDMS)), showed that the former presented much higher capacity, sensitivity and even selectivity, where larger abundance and number of roasted coffee volatile compounds (e.g. furans, pyrazines, ketones, acids and pyrroles) could be achieved, under similar experimental conditions. The data presented herein proved, for the first time, that PU foams present great performance for static headspace sorption-based procedures, showing to be an alternative polymeric phase for volatile analysis.
Aussagekräftige Methoden zur Authentizitätsbewertung sind unerlässlich, um so-wohl einen fairen Handel als auch das Vertrauen der Verbraucher in die Qualität von Lebensmitteln zu gewährleisten. Das Ziel dieser Arbeit war es, anhand der Parameter 'Enantioselektivität' und 'Iso-topendiskriminierung' Methoden zur Authentizitätskontrolle von Schaumweinen und Erdbeeren, beides Produkte mit einem vergleichsweise hohen Handelswert, zur Verfügung zu stellen. Um unmittelbare Anwendbarkeit in der Praxis zu ermög-lichen, sollten dabei Untersuchungsmethoden zur Anwendung kommen, wie sie in Speziallaboratorien der Lebensmittelkontrolle gängig sind. Die Methoden der Wahl waren Gaschromatographie-Massenspektrometrie (HRGC-MS), Multidimensionale Gaschromatographie an achiraler/chiraler Phase (enantio-MDGC-MS) und Isoto-penverhältnismassenspektrometrie (IRMS), letztere sowohl in der Anwendung mittels Elementaranalysatoren (EA) als auch in der Kopplung mit der Gaschroma-tographie (HRGC-IRMS). Zur Echtheitsprüfung von Schaumweinen wurde 1,2-Propandiol als mögliche neue Markerkomponente ausgewählt und eine Methode zu dessen Extraktion und Enantiomerenanalytik erarbeitet. Die erzielten Ergebnisse zeigten, dass weder der Gehalt noch das Enantiomerenverhältnis für sich alleine eine Aussage über Her-kunft oder Produktionsmethode ermöglichen. Eine Kombination beider Parameter kann jedoch als Ausgangspunkt für die Authentifizierung von Schaumweinen die-nen. Die Untersuchung von Erdbeer-Aromaprofilen mittels HRGC-MS ergab, dass die Aromastoffzusammensetzung von Erdbeeren maßgebend von der jeweiligen Erd-beersorte beinflusst wird. Es zeigte sich, dass alle Erdbeer-Aromaprofile einem von zwei möglichen Aromaprofiltypen von Kulturerdbeeren zuzuordnen sind. Im Hinblick auf eine Authentizitätsbewertung anhand von Aromastoffprofilen ermög-licht dies den Nachweis einer höheren Menge von nicht aus der Erdbeerfrucht stammendem Aroma zu Erdbeerprodukten. Ein wesentlicher Ansatz zur Überprüfung der Authentizität von Erdbeeraromastof-fen war die Messung des Stabilisotopenverhältnisses von 4-Hydroxy-2,5-dimethyl-3(2H)-furanon (Furaneol®), welcher als "Schlüsselaromastoff" bei Erdbeeren (und Ananas) gilt. Die Ergebnisse zeigten, dass lediglich das Sauerstoffstabilisotopen-verhältnis 18O/16O als Grundlage für eine aussagekräftige Methode dienen kann. IV Eine Unterscheidung von natürlichem Erdbeeraroma aus Erdbeerfrüchten und aus anderen natürlichen Materialien ließ sich hierbei nicht erreichen, jedoch war die synthetische Herkunft einddeutig identifizierbar. Der Einsatz geplanter Multiele-mentanalytik scheiterte an unzureichender Reproduzierbarkeit sowohl bei 2H/1H-, als auch bei 13C/12C-Analysen, wobei die Ursache bei erstgenannten in Aus-tauschreaktionen liegt. Reliable authenticity control methods are of key importance both to ensure honest trading standards and consumers' trust in food quality. The aim of this study was to provide methods for checking the authenticity of strawberries and sparkling wine, both products with a high trade value, using the parameters 'enantioselectivity' and 'isotope discrimination'. To ensure that the methods are easily applicable in food control they should be feasible on appara-tuses that form part of the established equipment of a specialised food control laboratory. The chosen methods were gas-chromatography coupled with mass spectrometry (HRGC-MS), multi-dimensional gas chromatography (achiral/chiral phase, enantio-MDGC-MS) and isotope ratio mass spectrometry, the latter cou-pled with both elemental analysis (EA-IRMS) and gas chromatography (GC-IRMS). For the authentification of sparkling wine, 1,2-propanediol was evaluated as a po-tential new marker compound, and a method for its extraction and gas chromato-graphic analysis was developed. The results showed that neither the content nor the enantiomeric excess of said compound taken alone could provide sufficient information to identify the product in terms of its geographic origin or production process. However, a combination of both parameters is a promising starting point for the authentication of sparkling wines. Further, the study of the aroma profiles of strawberries, measured by HRGC-MS, showed that the flavour profiles of strawberries are decisivly influenced by the strawberry variety. The results demonstrated that the aroma profiles could be classified into one of two groups of strawberry aroma profiles of cultivated straw-berries. This in consequence made it possible to use deviations from these known aroma profiles of strawberry flavour as an indication for an adulteration of straw-berry products with flavorings derived form sources other than strawberry fruits. An important approach to the authentification of strawberries was the measure-ment of the ratio of stable isotopes in 4-Hydroxy-2,5-dimethyl-3(2H)-furanone (Furaneol®), this being considered to be a key component in the flavour of straw-berries (and ananas). The results showed that the stable isotope ratios of oxygen, 18O/16O, alone can be used as a basis in a reliable method. Further, it was demon-strated that by this approach no distinction between natural strawberry flavor from VI the named fruit or other biological sources could be achieved. However, Furaneol® of synthetic origin could be clearly identified. The application of multielement analysis failed due to insufficient reproducibility of both 2H/1H and 13C/12C analysis, whereas the reason for the fromer are exchange reactions.
Static headspace (SHS), headspace solid phase microextraction (HS-SPME), headspace sorptive extraction (HSSE), and direct thermal desorption (DTD) were applied to the analysis of four French virgin olive oils from Corsica. More than 60 compounds were isolated and characterized by GC-RI and GC-MS. SHS was not suited to the characterization of olive oil volatile compounds because of low sensitivity. The SPME and HSSE techniques were successfully applied to olive oil headspace analysis. Both methods allow the characterization of volatile compounds (mainly C(6) aldehydes and alcohols), which contribute significantly to the "green" flavor note of virgin olive oils. The PDMS stir bar showed a higher concentration capacity than a DVB/CAR/PDMS SPME fiber due to the higher volume of polymeric coating. DTD was a very good tool for extracting volatile and especially semivolatile compounds, such as sesquiterpenes, but requires a significant investment like that for HSSE. Finally, SPME may be a more appropriate technique for routine quality control due to its operational simplicity, repeatability, and low cost.
This paper describes the development and application of a new analytical method for the analysis of the volatile fractions of pesto, a typical Italian basil-based pasta sauce, and its ingredients. The extraction of the volatile fraction was realized by headspace sorptive extraction (HSSE) and the extracted volatiles were then thermodesorbed, cryoconcentrated in a cooled injector and analysed by gas chromatography-mass spectrometry.This study shows that despite the great variability detected in the composition of the volatile fractions of several samples of “Pesto Genovese”, the ingredients traditionally used in pesto preparation (basil, pine nuts, walnuts, cheese, extra-virgin olive oil and garlic) give a significant and distinctive contribution to the pesto volatile fraction. Thus, the HSSE analysis of “Pesto Genovese” could be very useful for a careful control of the composition of this valuable niche product.
This paper describes an approach for the colour-based classification of RGB images, taken with a common digital CCD camera on inhomogeneous food matrices. The aim was that of elaborating a feature selection/classification method independent of the specific food matrix that is analysed, in the sense that the variables that are the most relevant ones for the classification of the analysed samples are selected in a blind way, with no a priori assumptions on the basis of the nature of the considered food matrix. A one-dimensional signal describing the colour content of each acquired digital image, which we have called colourgram, is created as the contiguous sequence of the frequency distribution curves of the three red, green and blue colours values, of related parameters (also including hue, saturation and intensity) and of the scores values deriving from the PCA analysis of the unfolded 3D image array, together with the corresponding loadings values and eigenvalues. Once a sufficient number of digital images has been acquired, the corresponding colourgrams are then analysed by means of a feature selection/classification algorithm based on the wavelet transform, wavelet packet transform for efficient pattern recognition (WPTER). This approach was tested on a series of samples of “pesto”, a typical Italian vegetable pasta sauce, which presents high colour variability, mainly due to technological variables (raw materials, processes) and to the degradation of chlorophylls during storage. Good classification results (100% of correctly classified objects with very parsimonious models) have been obtained, also in comparison with the visual evaluation results of a panel test.
The theory and practice of a novel approach for sample enrichment, namely the application of stir bars coated with the sorbent polydimethylsiloxane (PDMS) and referred to as stir bar sorptive extraction (SBSE) are presented. Stir bars with a length of 10 and 40 mm coated with 55 and 219 μL of PDMS liquid phase, respectively were applied. The 10-mm stir bars are best suited for stirring sample volumes from 10 up to 50 mL whereas 40-mm stir bars are more ideal for sample volumes up to 250 mL. Depending on sample volume and the stirring speed, typical stirring times for equilibration are between 30 and 60 min. The performance of SBSE is illustrated with the analysis of volatile and semivolatile micropollutants from aqueous samples. Detection limits using mass selective detection are in the low ng/L range for a wide selection of analytes from the EPA priority pollutant lists including analytes ranging in volatility from 1,1,1-trichloroethane to chrysene. For the extraction of selected compounds from 200-mL samples, detection limits below 0.1 ng/L are reached in the selected ion monitoring mode. A comparison between SBSE and solid-phase microextraction is made. ©1999 John Wiley & Sons, Inc. J Micro Sep 11: 737–747, 1999
A new sampling technique, Headspace Sorptive Extraction (HSSE), is here applied for the first time to the headspace sampling of medicinal and aromatic plants. The analyte partition coefficient between HSSE-PDMS stir bar and sample headspace (K1), the concentration factor (CF), the reproducibility, and the minimum recoverable amount were determined by analyzing standard solution of high volatility C5–C7 compounds with different polarities and structures (cyclohexane, propyl acetate, hexanal, 1-hexen-3-ol, isoamyl acetate, and 2-heptanol). Four aromatic and medicinal plants, viz. rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.), thyme (Thymus vulgaris L.), and valerian (Valeriana officinalis L.) were analyzed by HSSE-GC with PDMS stir bars, and their concentration capacity was compared with those of S-HS and HS-SPME with different fibers. HSSE showed very high concentration capability with both standard and real sample components.
Summary This study was intended to extend, by optimizing modified atmosphere packaging (MAP), the shelf-life of the Italian vegetable sauce used for spaghetti and known as ‘pesto’. A mathematical model was developed in order to predict gas composition inside the polymeric package (CO2 concentration). Predictions of equilibration time and equilibrium gas composition showed moderately good agreement with experimental data. A useful extension of pesto shelf-life, up to 120 days, was achieved by adopting a target atmosphere containing, at steady-state, 10% CO2 and 90% N2 at 5 °C. Microbial growth was inhibited by the CO2 levels, but was not accompanied by significant changes in odour and colour.
A new approach for sorptive enrichment of analytes from the headspace of aqueous or solid samples, referred to as headspace sorptive extraction (HSSE) is described. The technique implies the sorption of volatile and semivolatile compounds into a large amount of polydimethylsiloxane (ca. 50 mg) placed on a glass rod support. The polydimethylsiloxane (PDMS) coated rod is fixed in the head of a closed vial or erlenmeyer and the sample is equilibrated for 30–60 min. The PDMS coated glass bar is then thermally desorbed on-line with capillary gas chromatography–mass spectroscopy (GC–MS). Using a large amount of sorptive phase highly volatile compounds can be efficiently enriched and compared to solid phase microextraction on a 100 μm PDMS fiber where a significant increase in sensitivity is achieved. Limits of detection are in the ng L−1 (ppt) range. The potential of HSSE is illustrated with the analysis of some food samples. © 2001 John Wiley & Sons, Inc. J Micro Sep 12: 577–584, 2000
In this review a new approach to the food aroma analysis using various instrumental techniques is described. In the last decade extensive studies have been performed concerning aroma profiles (called in this article ‘aromagrams’) of food products and beverages. Aromagram is characteristic or even individual fingerprint of the odour, obtained usually by chromatographic methods or electronic nose. Basing on the fact that each product has its own unique pattern of volatile components, it is possible to get desired information about organoleptic quality and health safety of the product by qualitative and quantitative comparison of aromagrams of different foodstuffs. Appearance of aromagrams and their usefulness depend on the assay method, particularly on the extraction step. The paper reviews the methods developed to analyse volatiles in food products basing upon their aroma profiles.
A method for the determination of trace amounts of off-flavor compounds including 2-methylisoborneol, geosmin and 2,4,6-trichloroanisole in drinking water was developed using the stir bar sorptive extraction technique followed by thermal desorption-GC-MS analysis. The extraction conditions such as extraction mode, salt addition, extraction temperature, sample volume and extraction time were examined. Water samples (20, 40 and 60 ml) were extracted for 60-240 min at room temperature (25 degrees C) using stir bars with a length of 10 mm and coated with a 500 microm layer of polydimethylsiloxane. The extract was analyzed by thermal desorption-GC-MS in the selected ion monitoring mode. The method showed good linearity over the concentration range from 0.1 or 0.2 or 0.5 to 100 ng l(-1) for all the target analytes, and the correlation coefficients were greater than 0.9987. The detection limits ranged from 0.022 to 0.16 ng l(-1). The recoveries (89-109%) and precision (RSD: 0.80-3.7%) of the method were examined by analyzing raw water and tap water samples fortified at the 1 ng l(-1) level. The method was successfully applied to low-level samples (raw water and tap water).
Headspace sorptive extraction (HSSE) and stir bar sorptive extraction (SBSE), two recently introduced solventless enrichment techniques, have been applied to the analysis of the headspace of Arabica roasted coffee and of the headspace of the brew and of the brew itself. In both HSSE and SBSE enrichment is performed on a thick film of poly(dimethylsiloxane) (PDMS) coated onto a magnet incorporated in a glass jacket. Sampling is done by placing the PDMS stir bar in the headspace (gas phase extraction or HSSE) or by immersing it in the liquid (liquid phase extraction or SBSE). The stir bar is then thermally desorbed on-line with capillary GC-MS. The performance of HSSE and SBSE have been compared through the determination of the recoveries and relative abundances of 16 components of the coffee volatile fraction to classical static headspace (S-HS) and to headspace and in-sample solid phase microextraction (HS-SPME and IS-SPME, respectively) applying the fibers PDMS 100 microm, Carbowax/divinylbenzene 65 microm (CW/DVB), Carboxen/PDMS 75 microm(CAR/PDMS), polyacrylate 85 microm(PA), PDMS/divinylbenzene 65 microm(PDMS/DVB), and Carboxen/divinylbenzene/PDMS 50-30 microm(CAR/PDMS/DVB). In all cases, HSSE and SBSE gave higher recoveries, and this is entirely due to the high amount of PDMS applied.
This study aimed at evaluating if the volatile terpenoid hydrocarbons of extravirgin olive oils from West Liguria, a North Italy region, could trace their geographical origin. If terpenoid hydrocarbons were individually considered, three compounds, i.e. alpha-copaene, alpha-muurolene and alpha-farnesene, allowed building a simple decision tree and discriminating oils produced in West Liguria from oils produced in other Mediterranean regions. Moreover, the multivariate analysis allowed building West Liguria class-models with high predictive ability, confirming the fundamental role of the volatile terpenoid hydrocarbons for the geographical characterisation of West Liguria oils.
Aspetti microbiologici del pesto ligure. Industria Conserve
- E Vicini
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Vicini, E., & Previdi, P. (1992). Aspetti microbiologici del pesto ligure. Industria
Conserve, 67, 426–429.
An extandable package of programs for explorative data analysis, classification and regression analysis, Department of Chemistry and Technology of Food and Drugs
- M Forina
- S Lanteri
- C Armanino
- C Casolino
- M Casale
- V-Parvus
Aspetti microbiologici del pesto ligure
- Vicini