Extraction of Carotenoids from Tomato Pomace via Water-Induced Hydrocolloidal Complexation.

Agro-industrial waste is a largely untapped natural resource of bioactive compounds including carotenoids and pectin. However, conventional solvent extraction involves the excessive use of organic solvents, costly equipment, and tedious operation. These limitations of conventional extraction methods could be prospectively overcome by the carotenoid-pectin hydrocolloidal complexation. The complexation of lycopene and pectin was efficiently promoted in an aqueous environment, resulting in the colloidal complexes that can be subsequently recovered by sedimentation or centrifugation. In this study, the potential of carotenoid-pectin complexation on tomato pomace containing carotenoids and pectin was evaluated. Tomato pomace is a rich source of lycopene, ß-carotene as well as pectin, making it suitable as the raw material for the carotenoid extraction. The extraction of carotenoid and pectin from tomato pomace was optimized using response surface methodology. The maximum recovery was 9.43 mg carotenoid fractions/100 g tomato pomace, while the purity of carotenoid-rich fractions was 92%. The antioxidant capacity of carotenoids extracted from the complexation method was found to be higher than that from the solvent extraction method. Moreover, extraction yield and antioxidant capacity of carotenoid obtained from the carotenoid-pectin complexation were comparable to that from solvent extraction. The carotenoid-pectin complexation is a promising green approach to valorize agro by-products for the extraction of valuable carotenoids.

A facile water-induced complexation of lycopene and pectin from pink guava byproduct: Extraction, characterization and kinetic studies.

The redfleshed pulp discarded from pink guava puree industry is a rich source of lycopene and pectin. In this study, we developed a facile extraction process employing water as the primary extraction medium to isolate the lycopene and pectin from pink guava decanter. When the decanter was suspended in water, the complexation of lycopene and pectin formed the cloudy solution, where the colloidal complexes were recovered through centrifugation. The presence of lycopene and pectin in the complex was confirmed by the spectroscopic, microscopic and chromatographic analyses. The lycopene fractionated from the complexes had a purity level of 99% and was in all-trans configuration. The colloidal complexes yielding the highest concentration of lycopene was obtained at pH 7, 1% (w/v) solid loading and 25 °C. The experimental data of time-course extraction of lycopene-pectin complex were best fitted with two-site kinetic model, hinting the fast- and slow-release phases in the extraction process.