Medium‐chain alkyl esters of tyrosol and hydroxytyrosol antioxidants by cuphea oil transesterification

Abstract

Effective lipophilic antioxidants were prepared by non-aqueous enzymatic transesterification of plant phenols with cuphea oil. Tyrosol and hydroxytyrosol, abundantly available phenols from olive oil processing byproduct, were found to be predominately acylated with capric acid derived from the triglyceride fraction of the Cuphea germplasm line PSR 23 (Cuphea Viscosissima  C. lanceolata). The reaction was complete within 2 h, with a >97% conversion of either phenol using immobilized Candida antarctica lipase B. The reaction products were good solvents for tyrosol or hydroxytyrosol, suggesting a facile manufacturing route not dependent on use of organic solvents. Phenolic derivatives were assessed for their ability to serve as antioxidants for preventing the oxidation of polyunsaturated fatty acyl groups. The antioxidant capacities of the cuphea-derived fatty acyl derivatives of tyrosol or hydroxytyrosol were the same as their respective derivatives prepared from decanoic acid. These biobased antioxidants may improve the oxidative stability of sensitive fatty acids in food applications.Practical applications: A new biobased antioxidant was created for the food industry. Foods can contain fats and oils that are susceptible to deterioration during storage, which can limit product quality and shelf-life. Synthetic antioxidants can slow the spoilage process, although there are limitations to how much can be added to foods. The food industry is interested in using natural ingredients to solve storage stability problems. We found that the oil from the plant Cuphea, cultivated in the upper Midwest region of the US, is very useful for modifying olive oil waste molecules to create antioxidants for use in foods. The developed process would be suitable for commercial production. This research creates a new commercial use for a specialty oil seed crop, expands the market for cuphea oil, and has developed two novel antioxidants to help the food industry improve food quality.

Chemo‐enzymatic synthesis of sapienic acid esters of functional phenolics and evaluation of their antioxidant and cytotoxicity activities

“…The observed differences in the FRSA could be attributed to such difference in structures of the prepared derivatives. It was stated that the efficacy of the antioxidants is also influenced by the ability of the phenolic lipids in partitioning to specific interfacial regions such as lipid‐water medium, food emulsions or in cellular matrix . The order of FRSA for the prepared compounds in the present study is as follows: 11 > α–Tocopherol ≈ 10 > 9 > BHT > 7 > 8 ≈ 6 .…”

Regioselective synthesis of diacylglycerol rosmarinates and evaluation of their antioxidant activity in fibroblasts

“…Various methods have been described for linking phenolic compounds to glyceridic structures . Although efficient, they often lead to complex mixtures of phenolipids, containing various isomers or compounds corresponding to different degree of phenolic grafting on the glyceridic backbone, which makes subsequent purification difficult.…”

Strategies to Broaden the Applications of Olive Biophenols Oleuropein and Hydroxytyrosol in Food Products

“…Close tendencies on the above-described antioxidant potential of HT esters were reported by other authors using distinct experimental models. Burattini et al [ 99 ] compared the previously selected three different classes of HT esters, namely with short (C2–C4), medium (C10–C12) and long (C16–C18) acyl side chains and showed that short- and medium-length chain HT esters were more effective than HT in protecting human cells (U937 and C212) from oxidative hemolysis, with HT laurate (C12) being the most effective. This derivative also exhibited better antioxidant activity than HT in the same cellular lines [ 99 ].…”

“…Burattini et al [ 99 ] compared the previously selected three different classes of HT esters, namely with short (C2–C4), medium (C10–C12) and long (C16–C18) acyl side chains and showed that short- and medium-length chain HT esters were more effective than HT in protecting human cells (U937 and C212) from oxidative hemolysis, with HT laurate (C12) being the most effective. This derivative also exhibited better antioxidant activity than HT in the same cellular lines [ 99 ]. In addition, Candiracci et al [ 100 ] found that among HT esters with fatty acids from C2 to C18, those with medium-sized acyl chains were the most effective in protecting human erythrocytes of healthy non-smoking volunteers.…”