How to measure carotenoid in plant?5 answersCarotenoids in plants can be measured using reverse-phase high-performance liquid chromatography (HPLC) methods. These methods involve extracting, purifying, and quantifying carotenoids using HPLC systems equipped with Diode Array Detectors (DAD) and specific columns like C18 or C30. By separating carotenoids based on their UV-Vis absorption spectra and retention times, individual carotenoids can be identified and quantified accurately. Standard calibration curves using known quantities of purified or commercially available carotenoids enable absolute quantification of various carotenoid species. Additionally, the use of a fast and sensitive HPLC method with a C30 column allows for the resolution of major carotenoids, including isomers, within a short runtime of 20 minutes, showcasing versatility and robustness in analyzing different plant tissues.
How to measure colour in plant leaves?4 answersColor measurement in plant leaves can be done using colorimetric methods. One common method involves measuring the absorbance values at specific wavelengths using an ultraviolet spectrophotometer. The absorbance values at 663nm, 646nm, and 470nm are measured, and the contents of chlorophyll a, chlorophyll b, and carotenoid are calculated using the Wellburn formula (1984). Another method is spectrometric color measurement, where the reflection spectrum of visible light is measured at 5-nm intervals on the surface of leaves or petals. The spectral data is then integrated to obtain RGB or XYZ intensities, which can be further calculated to obtain hue, saturation, and lightness. Additionally, portable spectrophotometers can be used with cardboard adaptors to measure color in small samples, such as small leaves. Adaptors in black and white can be used to reduce the measuring area, and statistical analysis suggests the use of a 50%-reducing adaptor on a 3-mm aperture.
How to measure Total soluble solid of tomato?4 answersTotal soluble solids (TSS) of tomatoes can be measured using nondestructive near-infrared (NIR) spectroscopy techniques. Several studies have explored the use of NIR spectroscopy to evaluate the TSS of tomatoes. Dongyan Zhang et al. developed prediction models using Vis/NIR spectroscopy in the wavelength range of 900-1400 nm, achieving desirable results with Rp and RMSEP of 0.830 and 0.316 °Brix, respectively. M. Égei et al. also used Vis-NIR spectroscopy, comparing different preprocessing methods and multivariate data analysis techniques. They found that the best predictive ability for SSC was obtained using raw absorbance data and multiplicative scatter correction (MSC) in the Vis-NIR range. Additionally, Nafis Khuriyati et al. developed a nondestructive NIR instrument that successfully determined the SSC of tomato fruits with a correlation coefficient (r) of 0.91 and a standard error of performance (SEP) of 0.73%. These studies demonstrate the effectiveness of NIR spectroscopy for measuring the TSS of tomatoes.
What is the protein content of tomato paste?2 answersThe protein content of tomato paste varies depending on the specific product. One study found that a tomato chili sauce contained 1.2-2.1 g of protein per 100 g of product. Another study focused on an intermediary food product made from tomato paste and found that it added nutritive value through increased fiber, lycopene, and polyunsaturated fats, but did not specify the exact protein content. A meaty tomato chili sauce was found to contain abundant proteins, but the exact amount was not specified. A spicy tomato paste was described as rich in nutrition, but again, the specific protein content was not mentioned. Overall, the protein content of tomato paste can vary depending on the specific recipe and processing methods used.
How long and which temperature heat stress application method in tomato experiment?5 answersHeat stress application methods and durations varied across the tomato experiments. In one study, tomato plants were subjected to heat stress at 40 °C for 20 hours in darkness. Another experiment applied heat stress at temperatures ranging from 35 to 60 °C with gradual increments every 30 minutes. Additionally, two growth chambers were used in different experiments, with temperatures set at 25 and 45 °C. The duration of heat stress and specific temperature ranges were not mentioned in the abstracts.
How to monitor the skin of a tomato?5 answersThe skin of a tomato can be monitored using various techniques. One method is to evaluate the external and internal quality of the tomato fruit at different stages of maturity. This can be done by assessing parameters such as fruit skin color, soluble solids content, total titratable acids, ascorbic acid content, and total antioxidant potential. Another approach is to separate and determine the composition of phenolic compounds in the tomato skin extract using capillary electrophoresis and high-performance liquid chromatography. The antioxidative capability of the extract can also be measured using a stable free radical assay. Additionally, a tomato screening device can be used to avoid breaking the skin of tomatoes during the screening process and to screen out fine gravel attached to the surfaces of the tomatoes, thereby improving the product quality. Finally, the skin strength of tomato fruit can be measured under tension using techniques such as the loop technique, which allows for the evaluation of the effect of fertilization on skin strength.