Chemical Variation and Pharmacological Properties of Dyssodia decipiens Essential Oil.

Dyssodia decipiens is one of the seven recognized species within the Dyssodia genus, which has economic and social relevance in Mexico. Herein, we report on the volatile characterization and pharmacological activity of D. decipiens. The essential oils (2017-2019) contained verbenone (30.8-60.9 %), limonene (5.6-35.5 %), ß-caryophyllene (7.8-19.8 %) and linalool (4.5-12.4 %) as major constituents along the studied years. Antifungal properties were probed on Candida albicans ATCC 90028, ATCC 10231 (fluconazole resistant) and five clinical isolates (IS1-IS5). Flower essential oils had the best anti-C. albicans activity (MIC 59.2-93.5 µg mL-1 ), and limonene (MIC 125.5-188.4 µg mL-1 ) and ß-caryophyllene (MIC 104.3-184.2 µg mL-1 ) were involved in this effect. SEM examination revealed that D. decipiens essential oils produced an evident lysis on the fungus. Mosquito repellent activity was demonstrated on Aedes aegypti, a vector of dengue, chikungunya and zika viruses. The repellent activity of leaf essential oils (20 %) was effective within 1-5 h post-treatment (>90 %) and it was stronger (p<0.01) than that of commercial DEET. The evaluation of the four major volatiles (10 % each) produced similar results to those of essential oils. Finally, leaf essential oils showed a moderate antiproliferative activity on the lines OVCAR-3 (LD50 56.5-85.7 µg mL-1 ), and verbenone (LD50 65.3 µg mL-1 ) and ß-caryophyllene (LD50 43.6 µg mL-1 ) were linked to this effect.

Whey acerola-flavoured drink submitted Ohmic Heating: Bioactive compounds, antioxidant capacity, thermal behavior, water mobility, fatty acid profile and volatile compounds.

Whey acerola-flavoured drink was subjected to Ohmic Heating (OH) under different operational conditions (45, 60, 80 V at 60 Hz and 10, 100, 1000 Hz with 25 V, 65 °C/30 min) and conventional pasteurization (65 °C/30 min). Bioactive compounds (total phenolics, DPPH, FRAP, ACE levels), fatty acid profile, volatile compounds (CG-MS), thermal behaviors (DSC) and water mobility (TD-NMR) were performed. Reduction of frequency (1000-10 Hz) resulted in a lower bioactive compounds and antioxidant capacity of the samples, except for the DPPH values. Concerning the thermal behaviors, fatty acids profile and volatile compounds, different findings were observed as a function of the parameters used (voltage and frequency). In respect of TD-NMR parameters, OH led to a slightly reduction of the relaxation time when compared to the conventional treatment, suggesting more viscous beverages. Overall, OH may be interesting option to whey acerola-flavoured drink processing.

Ohmic Heating: A potential technology for sweet whey processing.

The use of Ohmic Heating (OH) for sweet whey processing was investigated in this study. Whey samples were subjected to both different OH parameters (2, 4, 5, 7 and 9 V·cm-1 at 60 Hz, up to 72-75 °C/15 s) and conventional processing (72-75 °C/15 s). Physicochemical analyses (pH), color measurements (L*, a*, b*), rheological properties (flow curves and particle size distribution), microstructure (optical microscopy), bioactive compounds (ACE and antioxidant capacity), microbiological characterization (mesophilic bacteria, total coliforms, and thermotolerant coliforms), water mobility (TD-magnetic resonance domain), and sensory evaluation (descriptive analysis) were carried out. The OH effects on sweet whey characteristics depended on the applied electric field intensity. Higher saturation, higher color variation (ΔE*), and higher luminosity (L*) were observed in low electric fields. For bioactive compounds, the increase of the electric field negatively affected the preservation of the antioxidant capacity and the ACE Inhibitory Activity of bioactive peptides. OH and conventional samples exhibited a pseudo-plastic behavior (n < 1). OH performed at 4 and 5 V·cm-1 was able to provide similar levels of sensory profile and higher volatile compounds levels. The results suggested the OH technology as an interesting alternative to whey processing.

Identification of volatile compounds associated with the aroma of white strawberries (Fragaria chiloensis).

BACKGROUND: Fragaria chiloensis (L.) Mill spp. chiloensis form chiloensis, is a strawberry that produces white fruits with unique aromas. This species, endemic to Chile, is one of the progenitors of Fragaria x ananassa Duch. In order to identify the volatile compounds that might be responsible for aroma, these were extracted, and analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O) and compared with sensory analyses. RESULTS: Three methods of extraction were used: solvent-assisted evaporation (SAFE), headspace solid phase micro-extraction (HS-SPME) and liquid-liquid extraction (LLE). Ninety-nine volatile compounds were identified by GC-MS, of which 75 showed odor activity using GC-O. Based on the highest dilution factor (FD = 1000) and GC-O intensity ≥2, we determined 20 major compounds in white strawberry fruit that contribute to its aroma. We chose 51 compounds to be tested against their commercial standards. The identities were confirmed by comparison of their linear retention indices against the commercial standards. The aroma of white strawberry fruits was reconstituted with a synthetic mixture of most of these compounds. CONCLUSION: The volatile profile of white strawberry fruit described as fruity, green-fresh, floral, caramel, sweet, nutty and woody will be a useful reference for future strawberry breeding programs.