Hemp (Cannabis sativa L.) has become widely used in several sectors due to the presence of various bioactive compounds such as terpenes and cannabidiol. In general, terpenes and cannabidiol content is determined separately, which is time consuming. Thus, a fast gas chromatography with flame ionization detection method was validated for simultaneous determination of both terpenes and cannabidiol in hemp. The method enabled a rapid detection of 29 different terpenes and cannabidiol within a total analysis time of 16 min, with satisfactory sensitivity (limit of detection = 0.03–0.27 µg/mL, limit of quantitation = 0.10–0.89 µg/mL). The inter‐ and intraday precision (RSD) was <7.82 and <3.59%, respectively. Recoveries at two spiked concentration levels (low, 3.15 µg/mL; high, 20.0 µg/mL) were determined on both apical leaves (78.55–101.52%) and inflorescences (77.52–107.10%). The reproducibility (RSD) was <5.94 and <5.51% in apical leaves and inflorescences, respectively. The proposed and validated method is highly sensitive, robust, fast, and accurate for determination of the main terpenes and cannabidiol in hemp and could be routinely used for quality control.
Lipids and lipid-containing foods are particularly sensitive to microwave heating as the specific heat of lipids is low and thus they are quickly warmed up. Microwave heating mainly promotes lipid oxidation, but it can also cause lipolysis and polymerization. This cooking method can differently impact lipid oxidation depending on the treatment conditions used (power, temperature and time), as well as on food composition. This review provides a picture of the main degradation effects of microwave heating on vegetable oils and lipid-containing foods with emphasis on both fatty acids and cholesterol oxidation.
The oxidative stability of phytosterols during microwave heating was evaluated. Two different model systems (a solid film made with a phytosterol mixture (PSF) and a liquid mixture of phytosterols and triolein (1:100, PS + TAG (triacylglycerol))) were heated for 1.5, 3, 6, 12, 20, and 30 min at 1000 W. PS degraded faster when they were microwaved alone than in the presence of TAG, following a first-order kinetic model. Up to 6 min, no phytosterol oxidation products (POPs) were generated in both systems. At 12 min of heating, the POP content reached a higher level in PSF (90.96 μg/mg of phytosterols) than in PS + TAG (22.66 μg/mg of phytosterols), but after 30 min of treatment, the opposite trend was observed. 7-Keto derivates were the most abundant POPs in both systems. The extent of phytosterol degradation depends on both the heating time and the surrounding medium, which can impact the quality and safety of the food product destined to microwave heating/cooking.
A Fast gas chromatography and mass spectrometry method for plant sterols/stanols analysis was developed, using a short capillary gas chromatography column (10 m × 0.1 mm internal diameter × 0.1 μm film thickness) coated with 5% diphenyl-polysiloxane. A silylated mixture of the main plant sterols/stanols standards (β-sitosterol, campesterol, stigmasterol, campestanol, sitostanol) was well separated in 1.5 min, with a good peak resolution (>1.4, determined on a critical chromatographic peak pair (β-sitosterol and sitostanol)), repeatability (<13%), and sensitivity (<0.017 ng/mL). The suitability of this Fast chromatography method was tested on plant sterols/stanols-enriched dairy products (yogurt and milk), which were subjected to lipid extraction, cold saponification, and silylation prior to injection. The analytical performance (sensitivity < 0.256 ng/mL and repeatability < 10.36%) and significant reduction of the analysis time and consumables demonstrate that Fast gas chromatography-mass spectrometry method could be also employed for the plant sterols/stanols analysis in functional dairy products.
As emulsifiers become saturated on
the surface of an emulsion droplet, any additional emulsifier migrates to the
aqueous phase. Continuous phase surfactants have been shown to increase
α-tocopherol efficacy, but it is unclear if this is the result
of chemical or physical effects. The addition of α-tocopherol
to an oil-in-water emulsion after homogenization resulted in a 70%
increase of α-tocopherol in the continuous phase when sodium
dodecyl sulfate (SDS) was at levels that were greater than the SDS
critical micelle concentration. Conversely, when α-tocopherol
was dissolved in the lipid before emulsification, continuous phase
SDS concentrations did not increase. When SDS concentration led to
an increase in the aqueous phase α-tocopherol, the oxidative
stability of oil-in-water emulsions increased. Data indicated that
the increased antioxidant activity was the result of surfactant micelles
being able to decrease the prooxidant activity of α-tocopherol.
Considering these results, surfactant micelles could be an important
tool to increase the effectiveness of α-tocopherol.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.