Phenolic profile of sugarcane juice: Effects of harvest season and processing by ohmic heating and ultrasound.

In the present work, a comprehensive phenolic analysis of fresh sugarcane juice from three different harvest seasons was performed and the effect of ohmic heating and ultrasound treatments on the phenolic content and color of the juice was evaluated. Among the 32 phenolic compounds identified, a total of 17 were quantified, comprising, in decreasing order of abundance, flavones (38-49 mg/L), dilignols (22-29 mg/L), and phenolic acid derivatives (17-30 mg/L). The main phenolic groups affected by the crop season (year and season) were flavones and phenolic acid derivatives. Juice treated by ohmic heating and ultrasound showed a total phenolic content similar to fresh juice, indicating the absence of additional non-thermal effects. Regarding color, both treatments promoted only a slight difference by visual perception. Considering these two quality parameters, ultrasound and ohmic heating seem to be a good alternative for sugarcane juice pasteurization.

Extraction and identification by mass spectrometry of phenolic compounds from canola seed cake.

BACKGROUND: Canola oil processing generates as by-products cakes rich in proteins, which have high nutritional value. These cakes contain an expressive amount of phenolic compounds which are important as antioxidants, but can interfere in proteins nutritional value. The aim of this work was to identify the phenolic compounds present in canola seed cake and to maximize their extraction by investigating the factors: temperature (20-70 °C), ethanol concentration in water (0-85%) and sample/solvent ratio (1:5-1:20). RESULTS: The maximum phenolic compounds amount was obtained at 65 °C, ethanol concentration of 35% and sample/solvent ratio of 1:20. At this condition, more than 95% of these compounds were extracted from the canola seed cake. It was observed that the solvent could be re-used for additional extractions, reducing the solvent consumption. A large number of phenolic compounds were identified (24 compounds) and quantified, including sinapic acid derivatives, flavonoid glycosides derivatives and major and minor sinapoyl choline derivatives. CONCLUSION: The phenolic compounds can be easily extracted from the canola seed cake, resulting in a cake with low antinutrients content and, in contrast, an extract rich in antioxidant compounds with possible use as a natural source of antioxidants. © 2019 Society of Chemical Industry.

Sequential extraction of phenolics and pectin from mango peel assisted by ultrasound.

The present work evaluated the use of ultrasound to extract sequentially phenolics and pectin from mango peel. Initially, the influence of ethanol and ultrasound on the phenolics extraction was investigated. The results showed that the ultrasound did not affect the extraction yield of these compounds. The best total phenolics yield (67%) was obtained with an extraction solution consisting of 50% of ethanol in water (v/v) and without ultrasound application, according to the experimental design. As an innovative extraction methodology, the residue of this extraction was then used to extract pectin assisted by ultrasound. The use of ultrasound increased over than 50% of the pectin extraction yield and did not affect its quality, measured by the galacturonic acid content and the degree of esterification. The sequential extraction of phenolics and pectin shows to be an alternative to use the whole residue from mango peel.

Influence of coffee genotype on bioactive compounds and the in vitro capacity to scavenge reactive oxygen and nitrogen species.

The influence of green coffee genotype on the bioactive compounds and the in vitro antioxidant capacity against the principal reactive oxygen (ROO(•), H2O2, HO(•), and HOCl) and nitrogen (NO(•) and ONOO(-)) species of biological relevance was investigated. This is the first report on the capacity of green coffee to scavenge H2O2, HOCl, and NO(•). Variations in the contents of total chlorogenic acids (22.9-37.9 g/100 g), cinnamoyl-amino acid conjugates (0.03-1.12 g/100 g), trigonelline (3.1-6.7 g/100 g), and caffeine (3.9-11.8 g/100 g) were found. Hydrophilic extracts of Coffea canephora and Coffea kapakata were the most potent scavengers of ROO(•), H2O2, HO(•), NO(•), and ONOO(-) due to their chlorogenic acid contents, which were, on average, 30% higher than those found in Coffea arabica and Coffea racemosa. The results showed that genotype is a determinant characteristic in the bioactive compound contents and consequently in the antioxidant capacity of green coffee.