Optimization and kinetic study of ultrasound assisted deep eutectic solvent based extraction: A greener route for extraction of curcuminoids from Curcuma longa.

The use of deep eutectic solvents (DESs) as a new extraction medium is a step towards the development of green and sustainable technology. In the present study, nine DESs based on choline chloride acids, alcohols, and sugar were screened to study the extraction of curcuminoids from Curcuma longa L. Choline chloride and lactic acid DES at 1:1 M ratio gave the maximum extent of extraction. Further, DES based extraction was intensified using ultrasound. The impact of various process parameters such as % (v/v) water in DES, % (w/v) solid loading, particle size, ultrasound power intensity, and pulse mode operation of ultrasound was studied. The maximum curcuminoids yield of 77.13 mg/g was achieved using ultrasound assisted DES (UA-DES) based extraction in 20% water content DES at 5% solid loading and 0.355 mm particle size with 70.8 W/cm2 power intensity and 60% (6 sec ON and 4 sec OFF) duty cycle at 30 ± 2 °C in 20 min of irradiation time. Kinetics of UA-DES extraction was explained using Peleg's model and concluded that it is compatible with the experimental data. Additionally, anti-solvent (water) precipitation technique was applied, which resulted in 41.97% recovery of curcuminoids with 82.22% purity from UA-DES extract in 8 h of incubation at 0 °C. The comparison was made between conventional Soxhlet, batch, DES and UA-DES based processes on the basis of yield, time, solvent requirement, temperature, energy consumption, and process cost. The developed UA-DES based extraction can be an efficient, cost effective, and green alternative to conventional solvent extraction for curcuminoids.

Rapid extraction of watermelon seed proteins using microwave and its functional properties.

Solid food industry waste like watermelon seed is an excellent source of value-added components such as proteins, oil, and carbohydrate. In the present study, protein extraction was carried out using microwave energy from defatted watermelon seeds (DWS), containing 50% of proteins. Microwave-assisted extraction (MAE) was optimized with different parameters, namely, solid to solvent ratio (1:10-1:40), pH (7-10), microwave power (30 W, 50 W, 70 W), extraction time (30 s-8 min) and moisture content or pre-leaching effect. Maximum protein recovery was achieved with 50 W microwave power, solid to solvent ration of 1:30, and pH 10 in 2 minutes of microwave irradiation time. MAE gave higher yield in less time compared to conventional extraction. SDS-PAGE confirmed the molecular weight of watermelon seed proteins (WSP) in the range of 25-250 kDa. A comparative study showed 90% protein recovery with MAE in 2 min with 1:30 (w/v) solid to solvent ratio, whereas ultrasound gave 87% in 9 min with 1:50 (w/v) ratio and batch 72% in 25 min with 1:70 (w/v) ratio. Watermelon seed proteins obtained from MAE method possess excellent functional properties with reference to conventional extraction method indicating its application in food products.

Extraction of curcuminoids from Curcuma longa: comparative study between batch extraction and novel three phase partitioning.

Curcuminoids, the active components of dried rhizome of Curcuma longa have been extracted using batch extraction and three-phase partitioning (TPP) process. The effect of different processing parameters, namely different solvents, extraction time, ammonium sulfate concentration, slurry to tert-butanol ratio, and solute to aqueous ratio on extraction efficiency of TPP, was studied to attain maximum extraction yield. The highest yield of 58.38 mg/g was achieved at 40±2 °C in 150 min, with saturated ammonium sulfate 30% (w/v), slurry to tert-butanol ratio 1:1 (v/v), and turmeric powder to water ratio 1:40 (w/v) in TPP. However, batch extraction using ethanol as a solvent yielded 52.77 mg/g in 180 min extraction time at 40±2 °C with 1:40 (w/v) turmeric powder to water ratio and 400 rpm agitation speed. In view of reference method, i.e., Soxhlet extraction (100%), TPP showed 65.63% yield in 150 min and batch exhibited 59.92% in 180 min. The turmeric extracts obtained by different methods exhibited excellent antioxidant and anti-inflammatory activities equivalent to their respective reference standards. Hence, TPP extraction process assures a rapid and improved recovery of curcuminoids with excellent therapeutic properties.