Characterization of Atypical Off-Flavor Compounds in Natural Cork Stoppers by Multidimensional Gas Chromatographic Techniques

Aims: To provide a better knowledge of cork-wine interaction, focussing on absorption of liquid by the cork stopper and overall migration of non-volatile compounds from the cork-stopper to liquid.Methods and results: Natural cork stoppers and 1+1 technical cork stoppers (agglomerate cork body ended with natural cork washers), with and without surface treatment, were used to close bottles filled with 12 % v/v ethanolic solution and removed after 3, 6, 12 and 24 months of contact. Mean and limit values of absorption and overall migration at each time are used to compare treated and non-treated stoppers. Variation of absorption with contact time was studied by adjusting the ABSORPTION = a · Ãt model (R2: 0.8572 - 0.9756).Conclusion: Most of the overall migration is due to natural components of cork. Contact time and type of cork stopper are the factors responsible for the greatest variability. Surface treatment increases overall migration (2 mg/stopper) and reduces liquid absorption (more than 10 %).Significance and impact of the study: The results show how a correct characterization of stopper and surface treatment is needed to predict the evolution of cork-wine interaction.

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Extraction, isolation and characterization of Bauhinia variegata flower

Journal of Applied Pharmaceutical Sciences and Research ◽

10.31069/japsr.v3i2.2 ◽

2020 ◽

pp. 9-12

Author(s):

Akanksha Gupta ◽

Abhishek K Tripathi ◽

Pushpraj S Gupta

Keyword(s):

Biological Activities ◽

Molecular Formula ◽

Native Plant ◽

Compound A ◽

Active Constituents ◽

Chromatographic Techniques ◽

Isolation And Characterization ◽

Soxhlet Apparatus ◽

Bauhinia Variegata

Background: Bauhinia variegata Linn. is a native plant of Asia and China. B. variegata is found in tropical regions of the world. It belongs to family Leguminosae. It is used for diarrhea, hemorrhoids, constipation, piles, edema, leprosy, wounds, tumors, etc. Objective: The objective of the present study was to perform extraction of B. variegata flower and isolation of active constituents from the extract. Materials and Methods: The ethanolic extraction of B. variegata flower was performed using the Soxhlet apparatus. The isolation of active constituents from the extract was performed using chromatographic techniques. In column chromatographic studies, n-hexane- [dichloromethane (DCM)] (2:8) was used as an eluting system and further purified through thin layer chromatography (TLC). Compound A and B were isolated through chromatographic techniques, then the molecular formula and characterization of these compounds were carried out with mass and infrared (IR) spectral analysis. Results and Discussion: The percentage yield of B. variegata ethanolic extract (BVE) was found to be 20.8% w/w. The different fractions were F1 having 12.5 grams with n-hexane, F2 (17.1 grams) with CH2Cl2, F3 (21.2 grams) with EtOAc, and F4 (13.4 grams) with EtOH. Compound A and B were isolated from the solvent fractions of n-hexane-DCM (2:8) and EtOAc-DCM (1:9), respectively. The compound A was characterized as 3-hydroxy-6-methoxy-2-phenyl-4H-chromen-4-one. The compound B was characterized as 3-hydroxy-6-methyl-2-phenyl-4H-chromen-4-one. Conclusion: Thus, B. variegata flowers possess active components that need to identify their biological activities.

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Screening a Strain of Klebsiella sp. O852 and the Optimization of Fermentation Conditions for Trans-Dihydrocarvone Production

Molecules ◽

10.3390/molecules26092432 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2432

Author(s):

Li Chen ◽

Lu-Lu Zhang ◽

Jing-Nan Ren ◽

Xiao Li ◽

Gang Fan ◽

...

Keyword(s):

Ethanol Concentration ◽

Flavor Compounds ◽

Accession Number ◽

Reaction Parameters ◽

Isolation And Characterization ◽

Biotransformation Process ◽

Pharmaceutical Industries ◽

Final Ethanol Concentration ◽

Optimization Of Fermentation

Flavors and fragrances have high commercial value in the food, cosmetic, chemical and pharmaceutical industries. It is interesting to investigate the isolation and characterization of new microorganisms with the ability to produce flavor compounds. In this study, a new strain of Klebsiella sp. O852 (accession number CCTCC M2020509) was isolated from decayed navel orange (Citrus sinensis (L.) Osbeck), which was proved to be capable of converting limonene to trans-dihydrocarvone. Besides, the optimization of various reaction parameters to enhance the trans-dihydrocarvone production in shake flask was performed for Klebsiella sp. O852. The results showed that the yield of trans-dihydrocarvone reached up to 1 058 mg/L when Klebsiella sp. O852 was incubated using LB-M medium for 4 h at 36 °C and 150 rpm, and the biotransformation process was monitored for 36 h after adding 1680 mg/L limonene/ethanol (final ethanol concentration of 0.8% (v/v)). The content of trans-dihydrocarvone increased 16 times after optimization. This study provided a basis and reference for producing trans-dihydrocarvone by biotransformation.

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