Volatile Constituents of Jambolan (Syzygium cumini L.) Fruits at Three Maturation Stages and Optimization of HS-SPME GC-MS Method Using a Central Composite Design

Application of Sorbent-Based Extraction Techniques in Food Analysis

This review presents an outline of the application of the most popular sorbent-based methods in food analysis. Solid-phase extraction (SPE) is discussed based on the analyses of lipids, mycotoxins, pesticide residues, processing contaminants and flavor compounds, whereas solid-phase microextraction (SPME) is discussed having volatile and flavor compounds but also processing contaminants in mind. Apart from these two most popular methods, other techniques, such as stir bar sorptive extraction (SBSE), molecularly imprinted polymers (MIPs), high-capacity sorbent extraction (HCSE), and needle-trap devices (NTD), are outlined. Additionally, novel forms of sorbent-based extraction methods such as thin-film solid-phase microextraction (TF-SPME) are presented. The utility and challenges related to these techniques are discussed in this review. Finally, the directions and need for future studies are addressed.

Comparative Study of Essential Oils from Different Organs of Syzygium cumini (Pamposia) Based on GC/MS Chemical Profiling and In Vitro Antiaging Activity

Syzygium cumini L. is an evergreen tree belonging to family Myrtaceae, employed for different traditional uses like diabetes, inflammation, and fever. The current study aimed to compare the chemical compositions of the essential oils (EOs) isolated from different organs of Syzygium cumini (leaves (Scl), fruits (Scf), seeds (Scs), and bark (Scb)) using a GC/MS analysis. Also, a chemometric analysis was applied to explore the main similarities and differences among different organs using a Principal Component Analysis (PCA) and a hierarchal cluster analysis (HCA). Furthermore, in vitro antiaging activities were investigated via anti-collagenase, anti-elastase, and anti-hyaluronidase assays. The GC-MS analysis revealed 82 compounds representing 92.13%, 99.42%, 100%, and 92.97% in Scl, Scf, Scs, and Scb, respectively. The predominant components were α-pinene, β-pinene, (E)-β-caryophyllene, α-caryophyllene, caryophyllene oxide, and α-humulene epoxide II with variable percentages. All EOs were positioned on positive PC1, except for Scs, which was positioned on the negative side in a separate quadrant. The HCA dendrogram displayed the closeness of Scl and Scb, which was not clearly recognized in the PCA score plot. Moreover, the Scs oils were totally discriminated from other parts. The Scl and Scs oils showed superior anti-collagenase, anti-elastase, and anti-hyaluronidase activities. Thus, S. cumini oils should be considered for cosmetic preparations to retard skin aging manifestations.

Extraction and purification of α-pinene; a comprehensive review

Extensive use of α-pinene in cosmetics, and medicine, especially for its antioxidant/antibacterial, and anti-cancer properties, and also as a flavoring agent, has made it a versatile product. α-Pinene (one of the two pinene isomers) is the most abundant terpene in nature. When extracting α-pinene from plants and, to a lesser extent, fruits, given that its purity is essential, purification methods should also be used as described in this study. Also, an attempt has been made to describe the extraction techniques of α-pinene, carried out by conventional and novel methods. Some disadvantages of conventional methods (such as hydrodistillation or solvent extraction) are being time consuming, low capacity per batch and being labor intensive and the requirement of trained operators. Most novel methods, such as supercritical fluid extraction and microwave-assisted extraction, can reduce the extraction time, cost, and energy compared to conventional methods, and, in fact, the extraction and preservation efficiency of α-pinene in these methods is higher than conventional methods. Although the above-mentioned extraction methods are effective, they still require rather long extraction times. In fact, advanced methods such as green and solvent-free ultrasonic-microwave-assisted extraction are much more efficient than microwave-assisted extraction and ultrasound-assisted extraction because the extraction efficiency and separation of α-pinene in these methods are higher; furthermore, no solvent consumption and maximum extraction efficiency are some crucial advantages of these techniques. However, the application of some novel methods, such as ultrasound-assisted extraction, in industry scale is still problematic because of their intricate design data.

Volatiles Accumulation during Young Pomelo (Citrus maxima (Burm.) Merr.) Fruits Development

As widely planted fruits with high nutritional and medical values, pomelos are managed systematically to achieve the largest economic benefits. But the annual shedding of young pomelos, which could be applied as feedstocks for essential oil extraction with their abundant volatiles, leads to a waste of source. The present study selected two commonly planted pomelo (Citrus maxima (Burm.) Merr.) varieties in Southern China, to investigate the volatile profiles during young pomelo fruits development. Combing transcriptomic analysis, this study aimed at identifying the prominent volatile components in young pomelo fruits in order to preferably extract profitable volatiles, as well, increasing the knowledge concerning regulatory roles of transcription factors (TFs) on volatiles accumulation in young pomelos. Totally 29 volatiles were identified, including 14 monoterpenoids and 13 sesquiterpenoids. Diprene was the principal component with the highest amount. Volatiles were generally decreased during fruits development but preferable stages were figured out for volatile collections. 12 and 17 TFs were related to developing time while ERF003 and MYC2 were highly correlated to monoterpenoids. These findings put forward the comprehensive usages of young pomelos and enriched the regulatory roles of TFs on both fruit development and volatiles metabolism.

Characterization of odor-active volatile compounds of jambolan [Syzgium cumini (L.) Skeels] wine

Volatile constituents in jambolan [Syzgium cumini (L.) Skeels] wine were isolated by headspace-solid phase microextraction (HS-SPME) and analyzed by gas chromatography-flame ionization detector (GC-FID), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). The composition of the jambolan wine included 52 esters, 20 terpenes, 13 alcohols, 12 acids, 11 aldehydes, 4 ketones, 4 oxides, and 5 miscellaneous compounds. Aroma extract dilution analysis and odor activity units were used for the determination of odor-active compounds. A total of 19 odor-active compounds were found as odor-active volatiles, from which (E)-β-ionone, phenylacetaldehyde, ethyl acetate, ethyl hexanoate, and ethyl benzoate were the most important. The similar results of the GC-O and OAV approaches suggests that HS-SPME-GC-O could be used as a fast and simple tool to quality control of the jambolan wine aroma.

Anatomical Investigation and GC/MS Analysis of 'Coco de Mer', Lodoicea maldivica (Arecaceae)

Lodoicea maldivica (J.F.Gmel.) Pers. (Arecaceae), 'Coco de Mer', is a palm, growing as endemic in the Seychelles islands. Its fruit weighs up to 20 kg and is characterized by a fleshy and fibrous envelope surrounding the nutlike portion. The present work combines a morpho-anatomical and a phytochemical analysis of the fruit exocarp and mesocarp. The exocarp is composed by a layer of palisade cells. The mesocarp is characterized by vascular bundles and by sclereids. In the aerenchyma, the internal zone of the mesocarp, cells aggregates were positive to phenols, while idioblasts were positive to terpenes. We performed a GC/MS analysis with a semi-quantitative relative amount calculation of the recorded compounds. The GC/MS essential oil profile revealed the dominance of acyclic sesquiterpenoids (53.95 %), followed by bicyclic sesquiterpenoids (31.69 %), monoterpenes (11.89 %) and monocyclic sesquiterpenoids (2.44 %). The terpenes detected in higher amounts, β-caryophyllene and bicyclogermacrene, are known for activity against insect larvae, but have been proposed as antiviral candidates against SARS-CoV-2. The third compound in amount, aromadendrene, is active against bacteria and, again, known to possess insecticidal properties.

Volatile Compounds and Physicochemical Quality of Four Jabuticabas (Plinia sp.)

The jabuticaba is a native Brazilian fruit that has aroused worldwide interest in terms of its nutritional composition and biological activity. However, research on the profile of volatile compounds (VOCs) emitted by these fruits is rare. This study presents the first identification of VOCs from four jabuticaba species. The aim of the study was to characterize the aromatic profile of the following species: ‘Sabará’ (Plinia jaboticaba), ‘Escarlate’ (Plinia phitrantha × Plinia cauliflora), ‘Otto Andersen’ (Plinia cauliflora), and ‘Esalq’ (Plinia phitrantha). The analysis was performed by headspace solid-phase microextraction combined with gas chromatography/mass spectrometry (SPME-GC-MS). Multivariate analysis techniques applying the partial least squares-discriminant analysis (PLS-DA) and heatmap were used to compare the results. Fruit quality parameters were determined in terms of fresh mass (g), skin color, soluble solids, and titratable acidity. A total of 117 VOCs was identified including terpenoids, esters, alcohols, aldehydes, alkanes, ketones, and carboxylic acids, with 36 VOCs common to all four species. Terpenes were the majority for all jabuticabas with smaller contributions from other volatile classes, especially β-cubebene, β-elemene, and D-limonene for the ‘Otto Andersen’ jabuticaba.

Physicochemical, microbial, and aroma characteristics of Chinese pickled red peppers (Capsicum annuum) with and without biofilm

Biofilm formation in the production of fermented vegetable might impact its quality and safety. In this study, physicochemical and microbial properties, volatile and aroma-active compounds between PRPs without biofilm (NPRP) and with biofilm (FPRP) were investigated by gas chromatography-mass spectrometry, gas chromatography-olfactometry, aroma extract dilution analysis, and spiking tests. The pH and titratable acidity were 3.66 ± 0.00 and 0.47 ± 0.08 g/100 g lactic acid in NPRP and 3.48 ± 0.01 and 0.87 ± 0.10 g/100 g lactic acid in FPRP, respectively. The nitrite level of the two PRPs was 1.87–1.92 mg kg⁻¹, which was below the limited value (20 mg kg⁻¹) of fermented vegetables regulated by the GB2760-2017. FPRP had relatively higher microbial and yeast numbers than NPRP, three common pathogens, namely, Salmonella spp., Staphylococcus aureus, and Shigella spp. were not detected. A total of 70 and 151 aroma compounds were detected in NPRP and FPRP, respectively, including 13 classes of compounds. The dominant aroma attributes of FPRP were sour, floral, mushroom-like, green, and smoky, while NPRP exhibits a mushroom-like flavor. Acetic acid, ethanol, α-terpineol, (E)-2-nonenal, 2-heptanol, phenylethyl alcohol, and linalool were potent key aroma-active compounds in NPRP and FPRP. Results of spiking tests showed that the addition of each substance not only increased its own odour, but also had significant effects on other smells. FPRP displayed richer varieties and contents of aroma profile than NPRP. However, some compounds, such as 4-ethylguaiacol and 4-vinylguaiacol, which were only detected in FPRP, had negative roles on the aroma attributes.

The aroma profile of PRPs was evaluated by GC-MS, GC-O, AEDA, OVA and spiking test. Biofilm can improve the variety and contents of aroma.