How anaerobic treatment is controlling the volatile components and key odorants of purple-colored leaf tea

Special purple-colored leaf tea products rich in γ-aminobutyric acid (GABA) have recently gained popularity. Although anaerobic treatment could effectively increase the GABA content in tea products, it also imparted an unknown unpleasant aroma. This study aimed to elucidate the dynamic effects of anaerobic treatment on volatile components during the purple-colored leaf tea processing and reveal the key aroma-active components. A total of 112 volatile components were identified, and it was found that anaerobic treatment could facilitate the accumulation of 2-heptanol, (E)− 2-hexenal, ethyl salicylate, phenylethyl alcohol, and (E,E)− 2,4-decadienal, but inhibited the formation of (Z)− 3-hexenyl acetate and methyl jasmonate. Moreover, 17 potent odorants including (E)-β-ionone, linalool, hexanal, 2-heptanol, (Z)− 3-nonen-1-ol, and (E,E)− 2,4-decadienal were distinguished as the key odorants of purple-colored leaf tea products rich in GABA based on gas chromatography–olfactometry and odor activity value analysis. These results provide new insights into the effect of anaerobic treatment on tea volatile metabolites.Universidade de Vigo/CISU

Microstructure and Mechanical Properties of Low-Density, B2-Ordered AlNbZrTi_x Multi-Principal Element Alloys

Low-density multi-principal element alloys (MPEAs) combining a high specific strength and considerable ductility have remained a research hotspot, due to their promising prospects for energy-saving industrial applications. Light Ti-containing AlNbZrTix (x = 1−3) MPEAs were designed and prepared by induction melting and annealing. As the Ti content increases, the microstructure of these MPEAs evolves from dual phase (B2-ordered and Zr5Al3-type structure) into a single-phase B2-ordered structure, while the density reduces by ~8.7%, from ~5.85 g·cm−3 (x = 1) to ~5.34 g·cm−3 (x = 3). Unexpectedly, the AlNbZrTix (x = 1, 2, 3) alloys possess high specific yield strengths of ~270 kPa·m3·kg−1, ~221 kPa·m3·kg−1, >208 kPa·m3·kg−1, along with excellent fracture strains of ~17.8%, 21.8%, and >50%, respectively. These combined compressive properties are superior to the reported data of most BCC/B2-dominant MPEAs. The deformation mechanism of the B2-ordered structure is explained as a dislocation-based mechanism, accompanied by antiphase domains. Here, the effect of Ti on the microstructure and compressive properties of AlNbZrTix MPEAs was investigated, providing scientific support for the development of advanced low-density materials

Additional file 5: Figure S3. of Transcriptional responses and flavor volatiles biosynthesis in methyl jasmonate-treated tea leaves

Unigenes upregulated by MeJA treatment in ι-Linolenic acid metabolism. (DOCX 34 kb

Additional file 7: Figure S6. of Transcriptional responses and flavor volatiles biosynthesis in methyl jasmonate-treated tea leaves

Simplified scheme of the interactions among the biosynthetic pathways responsible for volatiles and non-volatiles stress metabolites in plant. (DOCX 262 kb

Additional file 4: Table S2. of Transcriptional responses and flavor volatiles biosynthesis in methyl jasmonate-treated tea leaves

Pathway classification of tea leaves. (DOC 58 kb

Additional file 6: Figure S4. of Transcriptional responses and flavor volatiles biosynthesis in methyl jasmonate-treated tea leaves

Unigenes upregulated by MeJA treatment in Terpenoid backbone biosynthesis metabolism. (DOCX 52 kb