Volatile profile of Greek dried white figs (Ficus carica L.) and investigation of the role of ß-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 ß-damascenone. Owing to its low detection threshold and minute quantity in fig cultivars, the presence of ß-damascenone was furthermore confirmed through GC/MS/MS and GC/TOF-MS. ß-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 ß-damascenone. © 2017 Society of Chemical Industry.

Herbal distillates: A new era of grape marc distillates with enriched antioxidant profile.

Grape marc distillates are traditional alcoholic beverages, produced mostly in the Mediterranean countries. The present study proposes the enrichment of a Greek traditional grape marc distillate (tsikoudia) with selected herbs to enhance its natural antioxidants and functional properties. Total phenolic content, the antiradical and antioxidant activities, as well as the phenolic and sugar profiles using NMR and FT-IR spectroscopy were evaluated. The enrichment of distillates with Syzygium aromaticum L., Jasminum officinale L. and Eucalyptus globulus Labill. exhibited the highest total phenolic content as well as the highest antioxidant and antiradical activities, whereas the lowest values were observed with Hippophae rhamnoides L. and Lycium Barbarum Mill. The implementation of NMR and FT-IR spectroscopies attested to the presence of phenolic compounds and of specific carbohydrates in herbal distillates, postulating their migration from selected herbal species to tsikoudia and probably contributing to their organoleptic characteristics. The target of this approach leads to new added-value distillates with enhanced characteristics.

An evaluation study of different methods for the production of ß-D-glucan from yeast biomass.

ß-Glucan is a proven beneficial and valuable molecule for human and animal health systems. It can be incorporated as an ingredient in various functional foods and beverages. ß-Glucan has been isolated from various biological sources, fungi, mushrooms, algae, plants, and bacteria. The yeast cell wall comprises a suitable target for the extraction and purification of ß-glucan. Although there are various extraction techniques, significant differences are observed as the technique used affects the final yield and purity, molecular weight, biological activity, solubility, quality, and other biological and functional properties of the extracted ß-glucan. The aim of this review is the evaluation of different extraction methods for the production of ß-glucan from yeast biomass. Furthermore, the use of industrial spent yeast waste from breweries and the wine industry for biotechnological ß-glucan production and the concept of green wineries and breweries are discussed.

Authenticity of the traditional cypriot spirit "zivania" on the basis of 1h NMR spectroscopy diagnostic parameters and statistical analysis.

A previous publication (Kokkinofta et al. J. Agric. Food Chem. 2003, 51, 6233-6239) discussed the use of inductively coupled plasma spectroscopy to differentiate between the traditional Cypriot alcoholic beverage zivania and other spirits similar in alcoholic content collected from different countries. In the present paper (1)H NMR spectroscopy is applied to confirm the previous conclusions and to obtain additional physical-chemical characteristics that may be used to differentiate zivania from other similar beverages. NMR spectroscopy gave a satisfactory degree of prediction and classification between zivanias and other distillings. The validity of quantification of the method was tested using comparative GC data. It appears that chemical analysis can be very helpful for identifying the unique geological and climatic conditions existing in the island of Cyprus that lead to an authentic product.

NMR metabolite profiling of Greek grape marc spirits.

This (1)H NMR based study profiles metabolites in Greek grape marc distillates, tsipouro and tsikoudia. Eightysix samples of indigenous and international varieties, stemming from major vine growing regions of Greece were investigated. The monitoring protocol addressed the global metabolic profile of untreated samples and accomplished the unambiguous assignment of 35 metabolites. NMR spectra were acquired by applying the robust, sensitive and rapid WET1D NMR pulse sequence, which succeeded to unveil the presence of minor compounds in a high ethanol matrix. PCA classified the samples according to their provenance, incorporating also information related to the variety, vintage year and production process within each formed regional assembly. Metabolites such as fusel alcohols, polyols, ethyl esters, mono- and di-saccharides were associated with the classification of samples. OPLS-DA ascribed to samples of common regional entity characteristic genotypic metabolites and probed to the potential influence of the vintage effect. Finally, metabolite profiling underlined the influence of the fermentation and distillation procedures.