Supercritical CO2 Extraction and Microencapsulation of Lycopene-Enriched Oleoresins from Tomato Peels: Evidence on Antiproliferative and Cytocompatibility Activities.

Liliana Mihalcea,Ana-Maria Prelipcean,Ionica Gheonea (Dima),Vasilica Barbu,Nicoleta Stănciuc,Gabriela Râpeanu,Oana Crăciunescu,Anca Oancea,Elena Enachi,Gabriela Elena Bahrim

doi:10.3390/antiox10020222

Abstract

Tomato peels are used as a valuable material to extract lycopene-rich oleoresins by supercritical CO2 extraction. The extraction involves continuous circling of CO2 to the extractor after removing the solute in the separators, S40 and S45, where the solvent power of the CO2 is reduced by reducing pressure down to 20 MPa in S40 and 5 MPa in S45, respectively, leading to two extracts. Lycopene is found to be the major compound, representing 93% and 76% of the total carotenoids in S40 and S45 extracts, respectively. The two extracts are microencapsulated in whey protein concentrate and acacia gum by complex coacervation and freeze-drying, leading to corresponding P40 and P45 powders, with antioxidant activity of 8.57 ± 0.74 and 9.37 ± 0.48 mMol TEAC/g DW in P40 and P45, respectively. Different structural and morphological patterns are observed, with finer microparticles of 1–2 µm in P45. Both powders show dose and time-dependent antiproliferative activity. The half-maximal inhibitory concentration values are 100 µg/mL for P40 and 750 µg/mL for P45 sample, indicating a higher antiproliferative effect of P40 over P45 in HT-29 cell culture. The powders have an extended range of cytocompatibility, up to 1000 µg/mL, in L929 normal cells, stimulating the cell growth. Lycopene retention is tested, and values of 48% and 29% in P40 and P45 are found after 21 days at 25 °C, with the degradation rate in P45 significantly higher, due to the higher content of the surface lycopene, which favored its degradation.

Highlights

Introduction published maps and institutional affilIt is well known that tomato processing is one of the most developed within the vegetable processing industry at an international level, being responsible for important amounts of waste, causing a major disposal problem, both in terms of costs and impact on the environment [1]
HT-29 human colorectal adenocarcinoma cell line was purchased from American Type Culture Collection (ATCC), and NCTC clone L929 mouse fibroblast cell line came from European Collection of Authenticated Cell Culture (ECACC)
The results showed a dose-deIn vitro cytotoxicity microencapsulated assessed in HT-29 and L929 pendent decrease of HT-29 of cellthe viability for both testedpowders powders was

Summary

Introduction

It is well known that tomato processing is one of the most developed within the vegetable processing industry at an international level, being responsible for important amounts of waste, causing a major disposal problem, both in terms of costs and impact on the environment [1]. Colle et al [2] suggested that millions of tons of tomatoes are processed into products (sauces, juices, soups, and dried tomatoes) or used as ingredients of ready-to-eat meals, resulting in large amounts of by-products, such as peel, pulp, and seeds, representing 10–40% of the total processed tomatoes. A significant part of these by-products is currently being disposed of in the environment or used as animal feed. The main carotenoid in tomatoes is lycopene, representing approximately 80–90% of the total carotenoids. Due to its open-chain structure with 13 double bonds, with 11 of iations

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