Tarımsal Gıda Atıklarından Geleneksel ve Yeşil Çözücülerle Antosiyanin Pigment Ekstraksiyonunun İncelenmesi

Abstract

In this thesis study, the extraction of high-value anthocyanin and betalain pigments from industrial food waste, specifically black carrot and red beet pomaces, was investigated using water, citric acid, and ascorbic acid solutions, and various deep eutectic solvents in a batch system.

In the initial part of the study, the effects of temperature, pretreatment (freezing and drying), stirring speed, particle size range, and solid/liquid ratio on the extraction rate and yield of anthocyanin and betalain pigments from dried black carrot pomace (DBCP) and dried red beet pomace (DRBP) using water as a solvent were examined. For anthocyanin extraction from DBCP with water, the optimal conditions were determined to be a temperature of 50°C, a stirring speed of 160 rpm, a particle size range of 0.065mm<dp<0.355 mm, and a solid/liquid ratio of 1/10. Under these conditions, the equilibrium concentration of anthocyanin in the solvent was found to be 4.97 g anthocyanin/L water, with the amount of anthocyanin extracted per unit mass of DBCP being 0.957 g anthocyanin/g DBCP. For betalain extraction from DRBP with water, the optimal conditions were determined to be a temperature of 20°C, a stirring speed of 160 rpm, a particle size range of 0.355 mm<dp<0.850 mm, and a solid/liquid ratio of 1/10. Under these conditions, the equilibrium concentration of betalain in the solvent was found to be 27.5 g betalain/L water, with the amount of betalain extracted per unit mass of DRBP being 5.59 g betalain/g DRBP.

In the next phase of the study, the effects of different solvents on the extraction rate and yield of anthocyanin from DBCP and betalain from DRBP were investigated. In addition to water, solvents including citric acid and ascorbic acid solutions at various concentrations, and deep eutectic solvents (DES) composed of (Choline Chloride+Ascorbic Acid+Water), (Choline Chloride+Citric Acid+Water), and (Betaine+Ascorbic Acid+Water) were used. It was observed that the most rapid and efficient extraction of anthocyanin from DBCP occurred with the DES composed of (Choline Chloride+Citric Acid+Water), with the highest equilibrium concentration of anthocyanin in the solvent being 10.72 g/L DES and the highest amount of anthocyanin extracted per unit mass of DBCP being 2.10 g anthocyanin/g DBCP. The most rapid and efficient extraction of betalain from DRBP occurred with water, with the highest equilibrium concentration of betalain in the solvent being 27.5 g/L water and the highest amount of betalain extracted per unit mass of DRBP being 5.59 g betalain/g DRBP.

In the subsequent phase, pigment extraction from both pomaces was performed using ultrasound-assisted batch systems under the optimal conditions found in the batch stirred systems. It was found that the extraction capacities obtained from the batch stirred and ultrasound-assisted anthocyanin extraction from DBCP were not significantly different. However, the extraction capacity of betalain from DRBP in the batch stirred system was much higher than that in the ultrasound-assisted system. In the final part of the study, the stability of anthocyanin and betalain pigments in the extracts obtained under the optimal conditions using water, acidic solutions, and DES was investigated under different storage conditions; at room temperature (25°C) with daylight exposure, at room temperature (25°C) in darkness, and at 4°C in darkness. It was observed that the degradation of both pigments was highest under daylight exposure at 25°C and lowest in darkness at 4°C. For anthocyanin, the lowest degradation (5.08%) was observed in the DES composed of (Choline Chloride+Citric Acid+Water) after 15 days under all storage conditions. For betalain, the lowest degradation (2.59%) was observed in water after 7 days under all storage conditions.

Additionally, the kinetic behavior of each extraction system studied in this thesis was described using second-order extraction kinetics, and kinetic constants were determined.

This thesis successfully demonstrated the efficient, economical, and environmentally friendly extraction of high-value anthocyanin and betalain pigments from black carrot and red beet pomaces.