112: Entrapment of Anthocyanin From Black Carrot (Daucus Carota, Atrorubens) in Proteins From Plant, Insect, and Animal Origins: A Comparison

Introduction

Anthocyanins are chemical compounds known for providing fruits and vegetables with their pigmentation. Interest in them increased due to their health benefits based on their antioxidant activity and being linked to the prevention of cardiovascular diseases, inflammation, diabetes, and cancer. Black carrots (BC) have a high ANC content reported to be around 1750 mg/kg.; however, their low stability to light, pH and temperature changes limit their application in food products. Previous encapsulation studies have demonstrated that it is possible to protect anthocyanins by coating them with different agents to enhance their stability during storage and processing, where different encapsulating materials presented different interactions with ACN and therefore different levels of protection and stability.

Methods

BC extract was used to isolate the ACN which was standardized to a stock concentration in terms of mg of Cyanidin-3-Glucoside (C3G) equivalents/L. Three concentrations of BC-ACN stock solution (5, 15, and 25 mg) were mixed with 20 μM of protein from CF, SPI, WPI, and α-L. Stability of ACN-protein complexes was characterized using dynamic oscillatory testing to assess the viscoelasticity and relaxation time of the structures. Entrapment efficiency (EE%) and loading capacity (LC) were characterized by spectroscopy analysis. Particle size and morphology were tested using Transmission Electron Microscopy. Thermal Analysis was conducted by Differential Scanning Calorimetry.

Results

α-L samples yielded higher %EE (91%), LC (4mg/g), and ACN-protein ratios overall, while the SPI and CF complexes yielded the lowest ratios and the lowest EE ranging between 54-83%. Most of the BC-ACN complexes were round shaped while only CF systems presented irregularities, and α-L samples showed the largest diameters (~120nm). DSC results showed α-L complexes to be the most resistant to temperature fluctuations with a melting point of 78°C. Rheological results showed higher stability to shearing (higher storage moduli and relaxation time) for the dairy-based proteins, correlating well with EE and LC results.

Significance

Encapsulation of ACN particles in proteins from animal origin (WPI and α-L) is a more viable option to protect the entrapped antioxidant efficiently in comparison to SPI and CF. This study demonstrated the capability of α-L complexes as excellent protectors/carriers of BC-ACN molecules.

Authors: Mauricio Martinon, M.E. Castell-Perez, Rosana G. Moreira