Determination of low molecular weight volatiles in Ficus carica using HS-SPME and GC/FID

Formulation of goat's milk yogurt with fig powder: Aromatic profile, physicochemical and microbiological characteristics

Fig (Ficus carica L.) is an excellent source of sugars, dietary fibers, minerals, vitamins, organic acids and phytochemicals. The aim of the present work was to investigate the effect of fig powder supplement, as a natural sweetener and flavoring agent, on the physicochemical, microbiological and sensory characteristics of goat's milk yogurt. It aimed also to determine antioxidant capacity and volatile profile using gas chromatography/mass spectrometry (GC/MS) analysis. Pyrolysis-GC/MS (Py-GC/MS) was also used for the characterization of fig powder. Fig powder exhibited an important antioxidant activity against DPPH^. Radical (IC₅₀ = 1.92 ± 0.05 mg per mL). Volatile compounds, from several classes (acids, alcohols, aldehydes, esters, triterpenoids and others) were identified in fig powder. Py-GC/MS data revealed that degradation of fig powder macromolecules leaded to the formation of several aromatic and volatile compounds such as fatty acids, ketones, aromatic phenols, lactones among others. The addition of fig powder increased significantly (p < 0.05) the titrable acidity, the total solids, the carbohydrate content, and the total lactic acid bacteria count of yogurts. Likewise, fig powder supplement improved yogurt taste, texture and aroma and covered the unpleasant flavor of goat's milk. Thus, fig powder is a natural sweetener and flavoring agent that can be used to formulate a new stirred goat's yogurt of good quality.

Evaluation of the Physicochemical and Sensory Characteristics of Different Fig Cultivars for the Fresh Fruit Market

Physicochemical and sensory properties of nine fig cultivars: 'San Antonio' (SA), 'Blanca Bétera' (BB), 'Brown Turkey' (BT), 'Tres Voltas L'Any' (TV), 'Banane' (BN), 'Cuello Dama Blanco' (CDB), 'Cuello Dama Negro' (CDN), 'Colar Elche' (CE), and 'De Rey' (DR), were compared at three different ripening stages. Weight, size, titratable acidity, pH, skin and flesh colours, firmness, maturation index (MI), and volatile compounds were determined in samples from two consecutive seasons, in addition to both descriptive and hedonic sensory analysis. The mechanical behaviour of figs determined by firmness analysis and colour changes in both skin and flesh was the most important trait for the discrimination of ripening stages. Notable differences among cultivars were found in most of the parameters studied, in particular the inter-cultivar differences highlighted for MI, pH, acidity, and skin colour analyses, followed by volatile compounds. Principal component analysis (PCA) indicated that MI, pH, colour parameters of flesh (h and L*), and terpenes were the best physicochemical indices to determine overall acceptability which is highly correlated with the sensory attributes flesh colour and fruit flavour. The results suggested that CDN and SA showed huge consumer acceptability among the fig cultivars studied.

Quantitation of endogenous amount of ethanol, methanol and acetaldehyde in ripe fruits of different Spanish olive varieties

BACKGROUND

The use of healthy olives and their good management along the production process are necessary to obtain the best quality virgin olive oils. One parameter related to the health of the olives is the content of fatty acid alkyl esters. Because these come from the esterification of C16 and C18 free fatty acids with short chain alcohols, the control of methanol, ethanol and acetaldehyde (precursor of ethanol) and their origin (endogenous or from fermentation) is essential. The present study reports the endogenous amount of these compounds in some of the main Spanish olive varieties. For their analyses, headspace solid phase micro-extraction was applied and, to ensure quantitation reliability, the matrix-matched technique was used to build the calibration lines.

RESULTS

For healthy and mature olives, the contents of ethanol and methanol are much higher and vary within a wider range than those corresponding to acetaldehyde. Because olives were not directly analyzed but previously homogenized, there was no correlation between the olive size parameters and the contents of the compounds investigated. However, these contents are characteristic of each variety. When comparing healthy and unhealthy olives, significant differences were only observed for ethanol contents.

CONCLUSION

Higher contents of short alcohols are not only the result of an unhealthy or poor state of the fruits, but also the variety. Therefore, because these alcohols are precursors of fatty acid alkyl esters, the maximum permissible content of the latter should not be set at a single value for all olive varieties. © 2020 Society of Chemical Industry.

Nutritional, chemical and bioactive profiles of different parts of a Portuguese common fig (Ficus carica L.) variety

This study aims to give an unprecedented contribution on the chemical composition and bioactivities of the most produced and appreciated Portuguese fig variety ("Pingo de Mel") with the view of expanding the knowledge on its potentialities. An advanced characterization of its peel and pulp parts was carried out. Four free sugars (glucose, fructose, trehalose and sucrose), 5 organic acids (oxalic, quinic, malic, citric, and succinic acids), tocopherols in all their 4 forms, besides 23 fatty acids were detected in the samples. Fifteen different phenolic components were found in the peel hydroethanolic extract; whereas 12 were detected in the pulp hydroethanolic extract. Quercetin-3-O-rutinoside (rutin) was the major constituent of the peel, accounting for 33.8% of its phenolic content, followed by 5-O-caffeoylquinic acid and vanillic acid malonyl di-deoxyhexoside. Caffeic acid derivatives, such as caffeic acid hexosides, were the major components of pulp, followed by vanillic acid derivatives and O-caffeoylquinic acid. Both extracts displayed promising antioxidant capacities in all methods used, namely the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging, the reducing power, the inhibition of β-carotene bleaching assays, the thiobarbituric acid reactive substances assay and the oxidative haemolysis inhibition assay; however, the peel presented significantly lower IC₅₀ values than pulp. The extracts showed practically identical antibacterial capacities, being effective against methicillin-sensitive Staphylococcus aureus (MICs = 2.5 mg/mL), besides methicillin-resistant S. aureus, Escherichia coli and Morganella morganii (MICs = 5 mg/mL). The obtained results evidence that the fig peel is superior to the corresponding pulp as it relates to nutritional and phenolic profiles as well as bioactivities, endorsing the urgency in valorising and exploiting this usually discarded industrial by-product.

Comprehensive two-dimensional gas chromatography-mass spectrometry combined with multivariate data analysis for pattern recognition in Ecuadorian spirits

The current methodology used in quality control of Ecuadorian beverages such as Pájaro azúl, Puro and Pata de vaca is carried out by using conventional gas chromatography; however, it does not allow the fingerprinting of these Ecuadorian spirit beverages and their possible cases of adulteration. In order to overcome this drawback, comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC-MS) was combined with multivariate data analysis, revealing that compounds like citronellal, citronellol, geraniol, methyl anthranilate, (-)-trans-α-bergamotene, (-)-cis-α-bergamotene and D-limonene can be considered key elements for pattern recognition of these traditional beverages and product adulteration cases. Thus, the two-dimensional chromatographic fingerprints obtained by GC × GC-MS coupled with chemometric analysis, using Principal Component Analysis and Fisher-ratio can be considered as a potential strategy for adulteration recognition, and it may used as a quality assurance system for Ecuadorian traditional spirits.

Volatile profile of Greek dried white figs (Ficus carica L.) and investigation of the role of β-damascenone in aroma formation in fig liquors

BACKGROUND

During an investigation of the chemical profile of Greek figs (Ficus carica L.), several aqueous ethanol extracts (liquors) were prepared from dried Smyrna fig varieties cultivated in the two major fig-producing geographical areas in Greece: Peloponnese and Evia Island. The distinctive aroma observed among the prepared fig liquors led to the investigation of the odor profile of the different fig cultivars through HS-SPME coupled with GC/MS analysis, with focus on the factors that affect it before and during the preparation of the respective liquors.

RESULTS

Significant variation in volatiles was noticed among all fig cultivars, as also between each fig cultivar pulp and the respective liquor. The observed diversity was a result of chemical reactions taking place in the ethanol matrix during the preparation of the liquor. The 'key' odor compound of dried fig aroma was found to be β-damascenone. Owing to its low detection threshold and minute quantity in fig cultivars, the presence of β-damascenone was furthermore confirmed through GC/MS/MS and GC/TOF-MS. β-Damascenone was identified in variable quantities among fig varieties and their liquors, predominating in Kalamon fig cultivar of Peloponnese region, while its amount was found to be dependent on the postharvest storage time and preservation process of dried figs.

CONCLUSION

Each of the studied fig cultivars and liquors showed a unique aroma profile, and the obtained results were used for the preparation of the first dried fig liqueur for potential commercial use with the highest content of β-damascenone. © 2017 Society of Chemical Industry.

Analysis of Volatile Compounds by Advanced Analytical Techniques and Multivariate Chemometrics

Smelling is one of the five senses, which plays an important role in our everyday lives. Volatile compounds are, for example, characteristics of food where some of them can be perceivable by humans because of their aroma. They have a great influence on the decision making of consumers when they choose to use a product or not. In the case where a product has an offensive and strong aroma, many consumers might not appreciate it. On the contrary, soft and fresh natural aromas definitely increase the acceptance of a given product. These properties can drastically influence the economy; thus, it has been of great importance to manufacturers that the aroma of their food product is characterized by analytical means to provide a basis for further optimization processes. A lot of research has been devoted to this domain in order to link the quality of, e.g., a food to its aroma. By knowing the aromatic profile of a food, one can understand the nature of a given product leading to developing new products, which are more acceptable by consumers. There are two ways to analyze volatiles: one is to use human senses and/or sensory instruments, and the other is based on advanced analytical techniques. This work focuses on the latter. Although requirements are simple, low-cost technology is an attractive research target in this domain; most of the data are generated with very high-resolution analytical instruments. Such data gathered based on different analytical instruments normally have broad, overlapping sensitivity profiles and require substantial data analysis. In this review, we have addressed not only the question of the application of chemometrics for aroma analysis but also of the use of different analytical instruments in this field, highlighting the research needed for future focus.

In vitro antimicrobial and anti-proliferative activities of plant extracts from Spathodea campanulata, Ficus bubu, and Carica papaya

CONTEXT

African medicinal plants represent a prominent source of new active substances. In this context, three plants were selected for biological investigations based on their traditional uses.

OBJECTIVE

The antimicrobial and anti-proliferative features of three plants used for medicinal purpose were evaluated.

MATERIALS AND METHODS

The antimicrobial activities of methanol extracts of Ficus bubu Warb. (Moraceae) stem bark and leaves, of Spathodea campanulata P. Beauv. (Bignoniaceae) flowers, as well as those of Carica papaya Linn. (Caricaceae) latex, were determined using the microbroth dilution method against a set of bacteria and fungi pathogens including: Enterococcus faecalis, Staphylococcus aureus, S. saprophyticus, S. epidermididis, Escherichia coli, Klebsiella pneumonia, Salmonella typhimurium, Candida albicans, and Trichophyton rubrum. The tested concentrations of extracts ranged from 2500.0 to 2.4 μg/mL and MIC values were evaluated after 24 h incubation at 37 °C. Subsequently, MTT assay was used to estimate anti-proliferative activity of these methanol extracts and of F. bubu latex on three human cancer cell lines (U373 glioblastoma, A549 NSCLC, and SKMEL-28 melanoma).

RESULTS

The methanol extract of F. bubu stem bark exhibited the highest antimicrobial activity against C. albicans with a MIC value of 9.8 μg/mL, while the F. bubu latex and the methanol extract of F. bubu leaves induced significant anti-proliferative activity against lung (IC50 values of 10 and 14 μg/mL, respectively) and glioma (IC50 values of 13 and 16 μg/mL, respectively) cancer cells.

CONCLUSION

These results indicate that effective drugs could be derived from the three studied plants.

Characterisation of volatiles in dried white varieties figs (Ficus carica L.)

The aromatic profile of volatiles in dried figs varieties Bružetka Bijela and Zimnica were characterised by headspace solid-phase (HS-SPME) procedure with gas chromatography-mass spectrometry analysis (GC-MS). The volatile compounds were distributed by distinct chemical classes, including alcohols, aldehydes, esters, terpenic compounds, and other compounds. The figs were dried in a pilot plant cabinet dryer. Prior to drying process, figs were pre-treated by sulphur dioxide, immersed in solution of citric acid and ascorbic acid, respectively. Several mathematical thin-layer drying models, available in the literature, were fitted to experimental data of figs, implementing non-linear regression analysis techniques. The results showed that pre-treatments of figs decrease significantly the drying time. The best thin-layer drying model in terms of fitting performance was Wang and Singh model. The major volatile compound in dried figs was benzaldehyde. After benzaldehyde, the most abundant aldehyde in dried figs was hexanal. The comparison among dried figs showed the highest abundance of aldehydes, in general, in non-treated (control) dried figs compared to pre-treated samples. Furthermore, ascorbic acid was the most efficient in preserving esters and alcohols in case of Bružetka Bijela, whereas in case of Zimnica, sulphur dioxide was in advance compared to ascorbic acid. Ethyl acetate was the most abundant ester found in dried figs. Among other compounds, 2-butanone,3-hydroxy was the most abundant identified volatiles. Linalool, as the only identified terpen, was in case of both dried fig varieties, preserved by immersion into ascorbic acid. The immersion into citric acid has not been so successful in volatiles conservation.

Chemical composition and bioactivity of dried fruits and honey of Ficus carica cultivars Dottato, San Francesco and Citrullara

BACKGROUND

The aim of this study is to evaluate, for the first time, the chemical profile, antioxidant properties and cholinesterase inhibitory activity of dried fruits and honey of Ficus carica (fig) cultivars Dottato, Citrullara, and San Francesco.

RESULTS

Gas chromatography-mass spectrometry (GC-MS) analysis of fig extracts identified terpenes, sterols and fatty acids as major constituents. The aroma profile of honey obtained from a mixture of the three cultivars was investigated by solid-phase micro-extraction/GC-MS. 5-(Hydroxymethyl)-2-furancarboxaldehyde, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one and 1,3-dihydroxy-2-propanone were the main compounds. Total phenol, flavonoid and anthocyanin content are also reported. The San Francesco cultivar is characterised by the highest phenol and flavonoid content, while Dottato showed the major anthocyanin content. The Dottato cultivar exhibited the best radical scavenging activity against both 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl radicals (IC50 values of 5.4 and 22.6 µg mL(-1) , respectively). This cultivar also showed the highest inhibitory activity against both acetylcholinesterase and butyrylcholinesterase, with IC50 values of 26.9 and 31.8 µg mL(-1) , respectively.

CONCLUSION

Dried figs are a convenient source of bioactive compounds that demonstrated potential neuroprotection and antioxidant effects. Therefore, the addition of figs to the human diet should be recommended by dieticians and nutritionists.

Medicinal plants used for dermatological affections in Navarra and their pharmacological validation

AIM OF THE STUDY

This paper provides significant ethnopharmacological information on plant used in dermatological affections in Navarra.

MATERIAL AND METHODS

Information was collected using semi-structured ethnobotanical interviews with 667 informants (mean age 72; 55.47% women, 44.53% men) in 265 locations. In order to confirm the pharmacological validation of the uses reports, the European Scientific Cooperative on Phytotherapy (ESCOP), German Commission E, World Health Organization (WHO), European Medicines Agency (EMA), European Pharmacopoeia (Ph. Eur.) and Real Farmacopea Española (RFE) monographs have been revised. A literature review has been carried out with the plants without monograph and high frequency citations, using a new tool of the University of Navarra, UNIKA.

RESULTS

A total of 982 pharmaceutical uses are reported from the informants, belonging to 91 plants and 42 families, mainly represented by Asteraceae, Lamiaceae, Euphorbiaceae and Crassulaceae. The most frequently used parts of the plants are aerial parts followed by leaves and inflorescences. Seventeen out of 91 plants (19%) and 148 of 982 popular uses (15%), have already been pharmacologically validated.

CONCLUSIONS

The authors propose seven species for their validation (Allium cepa, Sambucus nigra, Hylotelephium maximum, Chelidonium majus, Ficus carica, Allium sativum and Anagallis arvensis).

Color and antioxidant characteristics of some fresh fig (Ficus carica L.) genotypes from northeastern Turkey

Fruit skin color, total phenolics, total anthocyanins, soluble solids content, titratable acidity and total antioxidant capacity in fresh fruits of a number of local and well-known fig (Ficus carica L.) genotypes and cultivars grown in northeastern Turkey were determined. TEAC (Trolox equivalent antioxidant capacity) and FRAP (ferric reducing antioxidant power) assays were used to determine total antioxidant capacity. Fruit skin color of genotypes were found to be very diverse, i.e., light green, light purple, purple, dark purple and black. The content of total phenolics, soluble solids content (SSC) and titratable acidity greatly varied in the range from 24 to 237 mg of gallic acid equivalent per 100 g fresh weight, 18.60 to 26.30 % and 0.16 to 0.47 % in local genotypes and studied cultivars. In general, total antioxidant capacities determined by two methods expressed higher values in the local fig genotypes compared with the cultivars. The results suggested that genotype is the main factor that determines difference in the composition of bioactive compounds in figs and provide information on putative health benefits locally grown genotypes.

Effect of drying of figs (Ficus carica L.) on the contents of sugars, organic acids, and phenolic compounds

Fresh figs were subjected to two different drying processes: sun-drying and oven-drying. To assess their effect on the nutritional and health-related properties of figs, sugars, organic acids, single phenolics, total phenolics, and antioxidant activity were determined before and after processing. Samples were analyzed three times in a year, and phenolic compounds were determined using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). In figs, monomer sugars predominate, which is important nutritional information, and the content of sugars as well as organic acids in fresh figs was lower than in dried fruits. However, the best sugar/organic acid ratio was measured after the sun-drying process. Analysis of individual phenolic compounds revealed a higher content of all phenolic groups determined after the oven-drying process, with the exception of cyanidin-3-O-rutinoside. Similarly, higher total phenolic content and antioxidant activity were detected after the drying process. With these results it can be concluded that the differences in analyzed compounds in fresh and dried figs are significant. The differences between the sun-dried and oven-dried fruits were determined in organic acids, sugars, chlorogenic acid, catechin, epicatechin, kaempferol-3-O-glucoside, luteolin-8-C-glucoside, and total phenolic contents. The results indicate that properly dried figs can be used as a good source of phenolic compounds.

Metabolite profiling on apple volatile content based on solid phase microextraction and gas-chromatography time of flight mass spectrometry

A headspace SPME GC-TOF-MS method was developed for the acquisition of metabolite profiles of apple volatiles. As a first step, an experimental design was applied to find out the most appropriate conditions for the extraction of apple volatile compounds by SPME. The selected SPME method was applied in profiling of four different apple varieties by GC-EI-TOF-MS. Full scan GC-MS data were processed by MarkerLynx software for peak picking, normalisation, alignment and feature extraction. Advanced chemometric/statistical techniques (PCA and PLS-DA) were used to explore data and extract useful information. Characteristic markers of each variety were successively identified using the NIST library thus providing useful information for variety classification. The developed HS-SPME sampling method is fully automated and proved useful in obtaining the fingerprint of the volatile content of the fruit. The described analytical protocol can aid in further studies of the apple metabolome.

Ultrasensitive electrochemical immunoassay of staphylococcal enterotoxin B in food using enzyme-nanosilica-doped carbon nanotubes for signal amplification

A new sandwich-type electrochemical immunoassay for ultrasensitive detection of staphylococcal enterotoxin B (SEB) in food was developed using horseradish peroxidase-nanosilica-doped multiwalled carbon nanotubes (HRPSiCNTs) for signal amplification. Rabbit polyclonal anti-SEB antibodies immobilized on the screen-printed carbon electrode (SPCE) and covalently bound to the HRPSiCNTs were used as capture antibodies and detection antibodies, respectively. In the presence of SEB analyte, the sandwich-type immunocomplex could be formed between the immobilized anti-SEB on the SPCE and anti-SEB-labeled HRPSiCNTs, and the carried HRP could catalyze the electrochemical reduction of H2O2 with the help of thionine. The high content of HRP in the HRPSiCNTs could greatly amplify the electrochemical signal. Under optimal conditions, the reduction current increased with the increase of SEB in the sample, and exhibited a dynamic range of 0.05-15 ng/mL with a low detection limit (LOD) of 10 pg/mL SEB (at 3σ). Intra- and interassay coefficients of variation were below 10%. In addition, the assay was evaluated with SEB spiked samples including watermelon juice, soymilk, apple juice, and pork food, receiving excellent correlation with results from commercially available enzyme-linked immunosorbent assay (ELISA).