Effects of biochar treatments on the elemental composition of tobacco (Nicotiana tabacum L.) leaves based on the priming period

This study determined the effects of different doses of biochars (B) on Virginia tobacco (Nicotiana tabacum L.) cultivar, on first and second harvest dependent change in plant nutrients (N, P, K, Ca, Mg, Cl, Zn, Fe, Mn, Cu, and B), leaf color parameters (L*, a*, and b*), chlorophyll value (SPAD), electrolyte leakage (EL), crude ash, number of leaves, and plant height. Pot experiments were conducted with biochar treatments of 10 tons ha-1 (B1), 20 tons ha-1 (B2), 40 tons ha-1 (B3), and 80 tons ha-1 (B4). Tobacco leaf macroelement (N, P, K, Ca, and Mg) levels increased with increasing biochar doses. The highest values were obtained for B4 treatments (80 tons ha-1) and the lowest for control (B0) treatments. Microelements (Fe, Zn, Mn, and B) exhibited a non linear change, while Cl and Cu exhibited a linear change. Color parameters (L*, a*, and b*) for the first and second priming showed the highest L* and b* values for B2 and B3 treatments, respectively, and the highest a* values for the B2 treatment. Leaf SPAD values increased with increasing biochar doses; further, the obtained SPAD values were ordered as B4 > B3 > B2 > B1 > B0. Leaf electrolyte leakage values were 25.90 %-37.25 % in the first priming and 26.90 %-40.59 % in the second priming. For both the primings, the highest crude ash values (21.94 % and 19.05 %) were observed for the B4 treatments, whereas the lowest values (17.89 % and 17.01 %) were observed for the B0 treatments. the tallest plant height (121.9 cm) and the highest number of leaves (45.3) were determined in B4 applications. Overall, considering the nutrition and quality of tobacco, B2 application is recommended.

Quality evaluation of raw and processed Corni Fructus by UHPLC-QTOF-MS and HPLC coupled with color determination

Corni Fructus (CF), used for thousands of years in Asia as food and medicine, has different therapeutic effects before and after processing. In the past work, the quality assessment of Corni Fructus focused on the limited chemical compounds and rarely correlated external properties, such as color. The traditional sensory assessment relies partly on human eyes, which is quick but lacks objectivity. On a Shimadzu LC-20AD liquid chromatograph system equipped with a diode-array detector (DAD), we determined six major compounds (gallic acid, 5-hydroxymethyl-2-furaldehyde, morroniside, loganin, sweroside, and cornuside I). The extract was analyzed using ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS) after the solid-phase extraction (SPE) step. Totally 58 compounds in raw and processed Corni Fructus were identified in negative and positive ion modes according to tandem mass spectrometry (MS/MS) fragments. Iridoids, carboxylic acids, tannins, flavonoids, triterpenes, fatty acids, saccharides, phospholipids, polysaccharide, amino acid, amide, furan, catechol, aldehyde, fatty alcohol and vitamin were included. A multivariate statistical analysis based on UHPLC-QTOF-MS filtered 17 differential compounds between raw and processed products. The CM-5 colorimeter was applied for digitizing surface and powder color. The contents of gallic acid, morroniside, loganin, cornuside I, and sweroside significantly correlated with color parameters in raw Corni Fructus, particularly adp* and bdp* , but not in processed products, according to Spearman correlation analysis. MS peak area of four compounds in raw products correlated significantly with color parameters Ldp* , adp* , bdp* , Lpd* , apd* , bpd* , respectively, while three compounds in processed products with Lpd* , apd* , bpd* . It revealed the relationship between compounds and color of Corni Fructus and the crucial compounds to color. In this study, we successfully developed a method for comprehensive quality evaluation of Corni Fructus that combines HPLC, UHPLC-QTOF-MS, and color determination.

Color comparison between non-vital and vital teeth

PURPOSE

The aim of this study was to define a color space of non-vital teeth and to compare it with the color space of matched vital teeth, recorded in the same patients.

MATERIALS AND METHODS

In a group of 218 patients, with the age range from 17 to 70, the middle third of the buccal surface of 359 devitalized teeth was measured using a clinical spectrophotometer (Vita Easyshade Advance). Lightness (L^*), chromatic parameters (a^*, b^*), chroma (C^*), hue angle (h) and the closest Vita shade in Classical and 3D Master codifications were recorded. For each patient, the same data were recorded in a vital reference tooth. The measurements were performed by the same operator with the same spectrophotometer, using a standardized protocol for color evaluation.

RESULTS

The color coordinates of non-vital teeth varied as follows: lightness L^*: 52.83–92.93, C^*: 8.23–58.90, h: 51.20–101.53, a^*: −2.53–24.80, b^*: 8.10–53.43. For the reference vital teeth, the ranges of color parameters were: L^*: 60.90–97.16, C^*: 8.43–39.23, h: 75.30–101.13, a^*: −2.36–9.60, b^*: 8.36–39.23. The color differences between vital and non-vital teeth depended on tooth group, but not on patient age.

CONCLUSION

Non-vital teeth had a wider color space than vital ones. Non-vital teeth were darker (decreased lightness), more saturated (increased chroma), and with an increased range of the hue interval. An increased tendency towards positive values on the a^* and b^* axes suggested redder and yellower non-vital teeth compared to vital ones.