The results demonstrated that HS-SPME and HS-SDME can be applied successfully for the extraction and separation of volatiles in aromatic plants, and these techniques are easier to perform, and more effective than HD for collection of more volatile compounds.
In this study, the effect of postharvest coating of chitosan (CH) 1.0%, gum ghatti (GG) 1.0% and combine of each other, on nutritional properties, phenolic compounds and antioxidant capacity of ‘Rishbaba’ grape (
Vitis vinifera
L.) was evaluated during 60 days of cold storage. Coating with 1.0% CH solely or in combined with 1.0% GG caused a considerable retain in grape berries phenolic acids compared to uncounted samples after the 60th day. Moreover, flavanols and flavan-3-ols content were found to be highest in fruits treated with CH and GG complex. At the end of storage, the highest concentrations of delphinidin, cyanidin, pelargonidin and malvidin were found in grapes coated with CH in combined with GG. The highest antioxidant capacity and the lowest polyphenol oxidase activity were related to samples treated with CH and GG complex. Also, the combination effects of CH and GG at 1.0% were the most efficient for soluble sugars and polyamines accumulation. The CH + GG complex had the best result on prohibiting grape fungal decay. The results showed a research increase of this complex that these are a strong potential strategy to produce coatings for improving the postharvest quality of fruits and could be considered as a good solution to preserve many components of them.
Electrochemical oxidation of rosmarinic acid (RA) in aqueous solutions has been studied using cyclic voltammetry, linear sweep voltammetry and differential pulse voltammetry. RA (1) has two catechol rings, and the electrochemical study of it shows two oxidation-reduction peaks (E r E r mechanism). In the first step oxidation RA (1) converted to OX 1-1 , and in the second step of oxidation the produced OX 1-1 oxidized to OX 2 . Two possible structures were designed for the first step of oxidation and optimized at the B3LYP/6-311 G (d, p) level of theory. To confirm the results, the oxidation potential of RA (1) was compared with some catechol species at pH = 0.0. Plotted diagram of the oxidation potential versus G tot showed a good correlation between the electrochemical oxidation potential (E pA0 ) and calculated G tot of electrochemical oxidation of studied species. The voltammetric study in the basic solutions shows a dimerization reaction after electron transfer process. Analysis of the voltammograms shows a partially adsorption behavior in the electrochemical oxidation of RA (1). Also, pKa of RA (1) was determined by the use of acid-base titration and effect of deprotonation of RA (1) on voltammograms was studied.
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.