There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Much work has been carried out in recent years on the beneficial effect of phenolic compounds which act as natural antioxidants and help to neutralize free radicals. We analysed the antioxidant activity of the rutin (quercetin-3-rhamnosyl glucoside) using different assays including: total antioxidant activity and reducing power, hydroxyl radical scavenging assay, superoxide radical scavenging assay, 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay and lipid peroxidation assay which uses egg yolk as the lipid-rich source. Total antioxidant capacity was determined by the assay based on the decrease in absorbance of β-carotene by the sample. Rutin exhibited strong DPPH radical scavenging activity. At the concentration of 0.05 mg/ml, ascorbic acid (Vc), butylated hydroxytoluene (BHT) and rutin showed 92.8%, 58.8%, and 90.4% inhibition, respectively. In addition, rutin had effective inhibition of lipid peroxidation. Those various antioxidant activities were compared to standard antioxidants such as BHT and Vc.

In vitro antioxidant properties of rutin

Background A large amount of food wastes and by-products are produced from farm to plate. They represent valuable sources for the production of high-added value compounds such as pectin. Pectin is the methylated ester of polygalacturonic acid and presents a wide range of applications in pharmaceutical and cosmetic products as well as in food industry such as gelling agent in fruit-based products, stabilizer in fruit and milk beverages and fruit filling for bakery and confectionary products, among others. Therefore, pectin recovery is of great importance. Scope and Approach The commercially available pectin is almost exclusively derived from citrus peels or apple pomace, by-products from fruit juice manufacturing. But, nowadays the number of novel food waste and by-products sources for pectin extraction are increasing. Moreover, the application of innovative approaches is necessary due to the limitation of conventional processes. The present review will focus on the conventional and innovative processing techniques (microwave extraction, enzymatic extraction, ultrasound-assisted extraction) to extract pectin from different wastes and by-products. Key Findings and Conclusions The pectin extraction differs according to the matrix studied as well as temperature, pH, time, solvents, and solid to liquid ratio. The use of innovative extraction processes such as ultrasound, microwave and enzymes can be a useful tool to increase pectin yield and quality, and reducing extraction time, temperature, use of toxic solvents and strong acidic conditions for pectin recovery. Moreover, the combination of solvent modelling and the use of particular extraction processes can enable the selective recovery of pectin.

An overview of the traditional and innovative approaches for pectin extraction from plant food wastes and by-products: Ultrasound-, microwaves-, and enzyme-assisted extraction

Pectin as a rheology modifier: Origin, structure, commercial production and rheology.

Agnieszka Wikiera

Papers

Endo-xylanase and endo-cellulase-assisted extraction of pectin from apple pomace.

Multicatalytic enzyme preparations as effective alternative to acid in pectin extraction

Development of complete hydrolysis of pectins from apple pomace

Application of Celluclast 1.5L in apple pectin extraction

Prolonged tempe-type fermentation in order to improve bioactive potential and nutritional parameters of quinoa seeds