Analysis of roasted and unroasted Pistacia terebinthus volatiles using direct thermal desorption-GCxGC-TOF/MS

A novel headspace solid-phase microextraction arrow method employing comprehensive two-dimensional gas chromatography-mass spectrometry combined with chemometric tools for the investigation of wine aging

BACKGROUND

Omics is used as an analytical tool to investigate wine authenticity issues. Aging authentication ensures that the wine has undergone the necessary maturation and developed its desired organoleptic characteristics. Considering that aged wines constitute valuable commodities, the development of advanced omics techniques that guarantee aging authenticity and prevent fraud is essential.

RESULTS

Α solid phase microextraction Arrow method combined with comprehensive two-dimensional gas chromatography-mass spectrometry was developed to identify volatiles in red wines and investigate how aging affects their volatile fingerprint. The method was optimized by examining the critical parameters that affect the solid phase microextraction Arrow extraction (stirring rate, extraction time) process. Under optimized conditions, extraction took place within 45 min under stirring at 1000 rpm. In all, 24 monovarietal red wine samples belonging to the Xinomavro variety from Naoussa (Imathia regional unit of Macedonia, Greece) produced during four different vintage years (1998, 2005, 2008 and 2015) were analyzed. Overall, 237 volatile compounds were tentatively identified and were treated with chemometric tools. Four major groups, one for each vintage year were revealed using the Hierarchical Clustering Analysis. The first two Principal Components of Principal Component Analysis explained 86.1% of the total variance, showing appropriate grouping of the wine samples produced in the same crop year. A two-way orthogonal partial least square - discriminant analysis model was developed and successfully classified all the samples to the proper class according to the vintage age, establishing 17 volatile markers as the most important features responsible for the classification, with an explained total variance of 88.5%. The developed prediction model was validated and the analyzed samples were classified with 100% accuracy according to the vintage age, based on their volatile fingerprint.

SIGNIFICANCE

The developed methodology in combination with chemometric techniques allows to trace back and confirm the vintage year, and is proposed as a novel authenticity tool which opens completely new and hitherto unexplored possibilities for wine authenticity testing and confirmation.

Effect of Encapsulation Techniques on Aroma Retention of Pistacia terebinthus L. Fruit Oil: Spray Drying, Spray Freeze Drying, and Freeze Drying

The primary aim of this investigation was to assess the impact of varying the ratio of gum arabic to maltodextrin and employing diverse encapsulation techniques on the properties of the powdered substance and the capacity to retain the aromatic attributes of terebinth fruit oil. Distinct ratios of gum arabic to maltodextrin (75:25, 50:50, and 25:75) were employed to fabricate oil-in-water emulsions. The utmost stability of the emulsion was realized at a gum arabic to maltodextrin ratio of 75:25, characterized by a minimal creaming index and an even and small-scale dispersion. The encapsulation techniques employed included spray drying (SD), spray freeze-drying (SFD), and freeze-drying (FD). These methodologies were compared based on encapsulation efficiency, desiccation yield, powder attributes, and the capacity to retain aroma. The encapsulation efficiencies were notably higher (>90%) in SD, particularly with the application of an ultrasonic nozzle and a two-fluidized nozzle (2FN), in contrast to those obtained through SFD and FD. Notably, SD employing an ultrasonic nozzle exhibited superior preservation of volatiles (73.19%) compared to FD (24.45%), SD-2FN (62.34%), and SFD (14.23%). Among the various components, α-pinene and linalool stood out with near-perfect retention rates, close to 100%.

Study of volatile compounds in Greek pistachio (Pistacia vera L. 'Aegina' cultivar) oils using Soxhlet and ultrasound assisted extraction

Headspace solid-phase microextraction followed by gas chromatography-mass spectrometry (HS-SPME/GC-MS) represents the most used solvent-free methodology for the characterization of the complex and heterogeneous mix of volatile compounds. The present study investigates the differences in volatile profile of pistachio oils 'Aegina' cultivar extracted with two different techniques, ultrasound assisted extraction (UAE) and Soxhlet. Differences were observed both in the pistachio oil yield and the composition of the volatile compounds among these two groups of samples, which were significantly influenced due to the different thermal conditions. In terms of pistachio oil yield, the Soxhlet extraction technique was proven more efficient (52.5-68.2% w/w) than the UAE type (28.2-42.6% w/w). A total of 34 and 30 volatile compounds were identified for UAE and Soxhlet, respectively. The main ones associated with UAE were α-pinene, octane and decane, while the volatiles formed as a consequence of Soxhlet extraction were decane, nonanal and (E)-2-decenal. Terpenes' concentrations were found decreased in Soxhlet's samples, but hydrocarbons and aldehydes were significantly increased in these samples. Numerous studies concluded in common results. However, this article is the first to explore the influence of different extraction types on the volatile profile of the unique flavour and odor pistachio oil 'Aegina' cultivar.

Group-type quantitative analysis of flavor compounds in ripening avocados

Avocados are a superfood gaining popularity in people's diet. Profiling and quantifying the volatiles associated with flavor can further the understanding of the fruit. However, this is challenging due to the relatively low abundances of volatile compounds. The complex mixtures inherent to avocado flavor can result in co-elutions using classical chromatographic techniques. To overcome these challenges, solid phase microextraction was used to extract and pre-concentrate volatiles, then separated and quantified using two-dimensional gas chromatography with a flame ionization detector. This technique enhances separation power and produces well-ordered chromatograms, allowing for templated groupings of compounds of similar chemical composition into regions. Using the flame ionization detector, an average response factor was determined and used for quantification of these templated group-type regions, as well as individual compounds. This group-type quantification improved overall precision of compound classes in 50 avocados by at least a factor of 2, when compared to that of the individual components. Overall, the abundance of associated flavor groups such as terpenes and alcohols decreased, whereas aldehyde groups remained constant throughout ripening. The combination of solid phase microextraction with two-dimensional gas chromatography and group-type quantification allows for an overall better understanding of the volatiles associated with flavor of avocados. This article is protected by copyright. All rights reserved.

Two-Dimensional Gas Chromatographic and Mass Spectrometric Characterization of Lipid-Rich Biological Matrices-Application to Human Cerumen (Earwax)

Earwax is a readily accessible biological matrix that has the potential to be used in disease diagnostics. However, its semisolid nature and high chemical complexity have hampered efforts to investigate its potential to reveal disease markers. This is because more conventional methods of analysis such as gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry yield unsatisfactory results due to the presence of many nonvolatile and/or coeluting compounds, which in some cases have very similar mass spectrometric profiles. In addition, these routine methods often require the sample to be saponified, which dramatically increases the complexity of the analysis and makes it difficult to determine which compounds are actually present versus those that are produced by saponification. In this study, two-dimensional GC mass spectrometry (GC × GC-MS) was successfully applied for the characterization of the chemical components of earwax from healthy donors using nonpolar (primary) and midpolar (secondary) columns without saponification. Over 35 of the compounds that were identified are reported for the first time to be detected in unsaponified earwax. The resulting GC × GC-MS contour plots revealed visually recognizable compound class clusters of previously reported groups including alkanes, alkenes, fatty acids, esters, triglycerides, and cholesterol esters, as well as cholesterol and squalene. The application of GC × GC-MS revealed results that provide a foundation upon which future studies aimed at comparing healthy donor earwax to that from individuals exhibiting various disease states can be accomplished.

An overview of conventional and emerging techniques of roasting: Effect on food bioactive signatures

Roasting is a food processingtechnique that employs the principle of heating to cook the product evenly and enhance the digestibility, palatability and sensory aspects of foods with desirable structural modifications of the food matrix. With the burgeoning demand for fortified roasted products along with the concern for food hygiene and the effects of harmful compounds, novel roasting techniques, and equipment to overcome the limitations of conventional operations are indispensable. Roasting techniques employing microwave, infrared hot-air, superheated steam, Revtech roaster, and Forced Convection Continuous Tumble (FCCT) roasting have been figuratively emerging to prominence for effectively roasting different foods without compromising the nutritional quality. The present review critically appraises various conventional and emerging roasting techniques, their advantages and limitations, and their effect on different food matrix components, functional properties, structural attributes, and sensory aspects for a wide range of products. It was seen that thermal processing at high temperatures for increased durations affected both the physicochemical and structural properties of food. Nevertheless, novel techniques caused minimum destructive impacts as compared to the traditional processes. However, further studies applying novel roasting techniques with a wide range of operating conditions on different types of products are crucial to establish the potential of these techniques in obtaining safe, quality foods.

A histopathological, immunohistochemical and biochemical investigation of the antidiabetic effects of the Pistacia terebinthus in diabetic rats

We investigated the antidiabetic activity of Pistacia terebinthus (PT) extracts in streptozotocin (STZ) induced diabetic rats. We used 40 Wistar albino male rats divided into five groups: control (C), diabetes (DM), diabetes + acarbose (DM + AC), diabetes + PT (DM + PT) and PT. DM was established by intraperitoneal injection of STZ. Immunohistochemistry revealed that STZ reduced insulin immunoreactivity in the pancreas of the diabetic rats. To the contrary, insulin immunoreactivity in the pancreatic β cells of PT treated diabetic rats was increased significantly. Decreased levels of blood glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), glucose, total triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL) and low density lipoprotein (LDL) were found in the PT supplemented diabetic group. Also, malondialdehyde (MDA) and antioxidant defense system enzyme levels were normalized in the DM + PT group. PT exhibited a protective effect on liver, kidney and pancreas that had been damaged by STZ induced DM.

Influence of cultivar and technological conditions on the volatile profile of virgin pistachio oils

The main aim of this work was to characterize the volatile profile of virgin pistachio oils produced from eight cultivars (Aegina, Avdat, Kastel, Kerman, Larnaka, Mateur, Napoletana and Sirora), under different technological conditions (temperature, roasting, use of whole nuts, screw speed and nozzle diameter), and compare it with those of commercial pistachio oils. Terpenes (15.57-41.05 mg/kg), accounting for ~97% of total volatiles, were associated with appreciated sensory properties, with α-pinene as the main volatile (14.47-37.09 mg/kg). Other terpene compounds such as limonene (0.11-3.58 mg/kg), terpinolene (0.00-1.61 mg/kg), β-pinene (0.12-1.20 mg/kg) and α-terpineol (0.00-1.17 mg/kg) were quantified at lower concentrations. Acids, alcohols, aldehydes, esters and hydrocarbons only summed to ~3% of the total volatile compounds. The volatiles content greatly depended on the pistachio cultivar employed. The influence of extraction conditions was also very relevant; in particular, terpenes doubled (28.38-53.84 mg/kg) using whole pistachios for oil extraction, also being incremented by mild processing conditions. On the contrary, higher temperature or roasting decreased the terpene content (~50-25% respectively), and pyrazines appeared (up to 3.12 mg/kg).

Two-Dimensional Gas Chromatography Coupled With Mass Spectrometry in Food Analysis

The development of instrumental analytical techniques provided the opportunity for in-depth characterization of many food matrices. In particular, the use of gas chromatography coupled with mass spectrometry gives impressive results in terms of quality and authenticity testing, conducting food freshness evaluations and contamination assessments. A new variant of gas chromatography, namely two-dimensional gas chromatography (GC × GC), and various versions of mass spectrometry have been developed since last 15 years, and they still remain at the time of their renaissance. The present critical review is focused on the use of GC × GC coupled with mass spectrometry for qualitative and quantitative reasons in food analysis. It is explained how powerful analytical tool is above-mentioned technical solution. Special attention is devoted to the issues related to the development of this technique during last years in terms of key construction elements, such as modulators and MS detectors. Finally, the critical discussion on many various aspects including advantages and more important disadvantages, caused probable moderate interest of this solution, in food analytics is concerned.

Characterization of the Aroma-Active, Phenolic, and Lipid Profiles of the Pistachio (Pistacia vera L.) Nut as Affected by the Single and Double Roasting Process

The pistachio (Pistacia vera L.) nut is one of the most widely consumed edible nuts in the world. However, it is the roasting process that makes the pistachio commercially viable and valuable as it serves as the key step to improving the nut's hallmark sensory characteristics including flavor, color, and texture. Consequently, the present study explores the effects of the single-roasting and double-roasting process on the pistachio's chemical composition, specifically aroma-active compounds, polyphenols, and lipids. Results showed the total polyphenol content of increased with the roasting treatment; however, not all phenolic compounds demonstrated this behavior. With regard to the aroma and aroma-active compounds, the results indicated that roasting process results in the development of characteristics and pleasant aroma of pistachio samples due to the Maillard reaction. With regard to lipids, the pistachio roasting treatment reduced the concentration of CN38 diacylglycerides while increasing the amount of elaidic acid.

Pistacia Terebinthus Coffee Protects against Thioacetamide-Induced Liver Injury in Rats

Aim/background: Pistacia terebinthus is used as a coffee substitute in the East and Southern Anatolia regions of Turkey. It contains unsaturated fatty acids, tocopherols, polyphenols and carotenoids. P. terebinthus has anti-inflammatory and potential antioxidant activity. In this study we evaluated the protective effects of P. terebinthus coffee (PTC) on thioacetamide (TAA)-induced liver injury in rats. Materials and methods: Twenty-eight male Sprague-Dawley rats were equally randomized into four groups. Chronic liver injury was induced with TAA (100 mg/kg i.p. three times weekly). The first group of rats served as control and received only tap water (G1), and the remaining groups of rats received PTC, p.o (G2); TAA (G3); TAA plus PTC, p.o (G4), respectively. Results: After 8 weeks, PTC intake significantly reduced fibrosis/inflammation scores (p < 0.05) in the livers of TAA-treated group. Compared to control group, PTC intake reduced transforming growth factor beta (TGF-β) concentrations in the liver (p < 0.05). Compared to the TAA group, TGF-β, nuclear factor kappa B (NF)-κB (p < 0.05), tumor necrosis factor alpha (TNF-α) concentrations in the liver tissue were reduced by PTC intake. Discussion and conclusion: PTC intake provided beneficial effects against TAA-induced liver injury in rats. PTC probably suppresses the proinflammatory cytokines through NF-κB signaling pathway.

Processing of a novel powdered herbal coffee (Pistacia Terebinthus L. Fruits Coffee) and its sensorial properties

In this study, the effects of roasting method, grinding and reduction in oil content on the characteristics of Pistacia terebinthus fruit coffee were investigated. Pistacia terebinthus fruit was roasted by microwave, pan and combined (microwave and convection) methods. The degree of roasting was determined by L*, a*, b* color values. The roasting times were 1,500, 1,900 and 1,620 s for microwave, pan and combined roasting methods, respectively. Cold press was used to reduce the oil content both prior to roasting and after the roasting. The oil content was reduced to around 21.5 % in all roasting methods to approach to that of coffee beans. Powdered Pistacia terebinthus fruit coffee brews were compared with each other and Turkish coffee in terms of aroma, flavor, acidity aftertaste, and overall acceptability. Sensorial analysis results showed that coffee brews prepared by pressing after the roasting process were better than those pressing prior to roasting.

Five Pistacia species (P. vera, P. atlantica, P. terebinthus, P. khinjuk, and P. lentiscus): a review of their traditional uses, phytochemistry, and pharmacology

Pistacia, a genus of flowering plants from the family Anacardiaceae, contains about twenty species, among them five are more popular including P. vera, P. atlantica, P. terebinthus, P. khinjuk, and P. lentiscus. Different parts of these species have been used in traditional medicine for various purposes like tonic, aphrodisiac, antiseptic, antihypertensive and management of dental, gastrointestinal, liver, urinary tract, and respiratory tract disorders. Scientific findings also revealed the wide pharmacological activities from various parts of these species, such as antioxidant, antimicrobial, antiviral, anticholinesterase, anti-inflammatory, antinociceptive, antidiabetic, antitumor, antihyperlipidemic, antiatherosclerotic, and hepatoprotective activities and also their beneficial effects in gastrointestinal disorders. Various types of phytochemical constituents like terpenoids, phenolic compounds, fatty acids, and sterols have also been isolated and identified from different parts of Pistacia species. The present review summarizes comprehensive information concerning ethnomedicinal uses, phytochemistry, and pharmacological activities of the five mentioned Pistacia species.