Green extraction of bioactive compounds from apple pomace by ultrasound assisted natural deep eutectic solvent extraction: Optimisation, comparison and bioactivity.

Natural deep eutectic solvents (NADES) coupled with ultrasound assisted extraction (UAE) was evaluated as extraction techniques for bioactive compounds from apple pomace. Seven natural deep eutectic solvents (NADES) with different molar ratios were explored as green extraction solvents to evaluate extraction efficiency in terms of total flavonoid content (TFC), total phenolic content (TPC), lipid peroxidation inhibition (LBI) and antioxidant potential. The solvents which performed better than conventional solvent were DES1 (Choline chloride: glycerol (1:2)), DES2 (Choline chloride: lactic acid (1:3)) and DES5 ((Choline chloride: citric acid (1:1)). These solvents were further evaluated for optimisation of processing parameters in UAE-DES. The maximum TPC value was achieved using sonication time 40 min, water 30 %, solid/liquid ratio 1:30, temperature 40 °C, acoustic intensity 83.2 W/cm2 and duty cycle 75 %. HPLC of optimised extract was utilised for quantification of polyphenol compounds showing quercetin as main compound followed by chlorogenic acid, gallic acid, phloretin, phloridizin and rutin.

Green extraction of lutein from marigold flower petals, process optimization and its potential to improve the oxidative stability of sunflower oil.

Marigold flower petals are considered the richest source of lutein which possesses immense applications in the food and health sector. The study was undertaken to improve the stability of sunflower oil by enriching it with lutein extracted from marigold flower petals using safe and green technology. The extraction of lutein was optimized using Box-Behnken design by ultrasound-assisted extraction (UAE) employing sunflower oil as a solvent. The impact of three independent variables i.e., ultrasonic intensity, solid to solvent ratio, and extraction time were evaluated on the amount of lutein extracted and its antioxidant activity. Highest amount of lutein (21.23 mg/g) was extracted by employing ultrasonic intensity of 70 W/m2, extraction time of 12.5 min, and solid to solvent ratio of 15.75%. FT-IR spectra of lutein extracted by ultrasound and conventional extraction show similar peaks depicting that ultrasound does not have any impact on the functionality of lutein. Sunflower oil incorporated with lutein at 1000 PPM and the synthetic antioxidant (TBHQ) showed good oxidative stability than oil with 500 PPM lutein and no lutein during accelerated storage for a month. The oxidative stability was shown by different oil samples in the following order: TBHQ = 1000PPM lutein˃500PPM lutein ˃control oil. It was concluded that the ultrasound technique extracts lutein efficiently from marigold flowers and this lutein was effective in improving the oxidative stability of sunflower oil under accelerated storage conditions.

Ultrasound assisted extraction of bioactive compounds from pomegranate peel, their nanoencapsulation and application for improvement in shelf life extension of edible oils.

In this study pomegranate peel extract was evaluated as source of antioxidant encapsulated by nano-emulsions in soybean oil. Encapsulating agents maltodextrin (MD), whey proteins isolate (WPI) and complex of maltodextrin and whey protein isolate (MD/WPI) (1:1) were used as wall material. Average droplet size of primary W/O and double W/O/W nanoemulsions stabilised by MD, WPI and MD/WPI were 108 nm, 157.82,189.94 nm and 191.12 nm respectively. Lyophilised nanoemulsion powders were added at 100, 200 and 300 ppm concentration to soyabean and mustard oil and observed for change in various oxidative stability indices during storage and were compared to non-encapsulated extract and synthetic antioxidant BHT. From the results, it can be suggested that nanoencapsulated extract at 300 ppm concentration performed better in controlling oxidative changes in both oils than unencapsulated and synthetic one, however, extract encapsulated by MD/WPI exhibited higher antioxidant effects due to controlled release of bioactive compounds.