Effects of monoacylglycerols on the oxidative stability of olive oil.
BACKGROUND
The study of pro- and anti-oxidant compounds is important for their influence on the shelf-life and nutritional value of food. The aim of this research was to evaluate the activity of monoacylglycerols (MAG), obtained by partial saponification of a purified olive oil, added in increasing amounts to the same oil and submitted to the Rancimat test and oven test at 60 °C. Besides routine analyses, high-performance size exclusion chromatography analysis of polar compounds was performed.


RESULTS
The addition of MAG led in all cases to a significant slowdown of the oxidative processes. These trends were more evident as the oxidation went on. The purified oil added with 30 g kg(-1) of MAG after 9 days of oven test at 60 °C presented a level of oxidative degradation significantly lower than the control after only 4 days.


CONCLUSIONS
The data showed a marked antioxidant effect of MAG in purified olive oil, contrary to what has been observed by other authors, who noticed either a pro-oxidant or a non-antioxidant activity of these compounds in soybean oil. A different behaviour of MAG during oxidation could depend on the different fatty acid composition of the oil matter they are added to.
Gomes
Tommaso
T
Dipartimento di Progettazione e Gestione dei Sistemi Agro-Zootecnici e Forestali progesa, Sezione di Scienze e Tecnologie Alimentari, Università degli Studi, Via Amendola 165/a, I-70126 Bari, Italy. tommaso.gomes@agr.uniba.it
Caponio
Francesco
F
Bruno
Giuseppina
G
Summo
Carmine
C
Paradiso
Vito Michele
VM
D000975:Antioxidants / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004075:Diglycerides / Q000032:analysis / Q000302:isolation & purification; D005227:Fatty Acids / Q000032:analysis; D005519:Food Preservation / Q000379:methods; D006358:Hot Temperature / Q000009:adverse effects; D006868:Hydrolysis; D007700:Kinetics; D008054:Lipid Peroxides / Q000032:analysis; D050178:Monoglycerides / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D000069463:Olive Oil; D010084:Oxidation-Reduction; D010938:Plant Oils / Q000737:chemistry*; D014280:Triglycerides / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification
D000975:Antioxidants; D004075:Diglycerides; D005227:Fatty Acids; D008054:Lipid Peroxides; D050178:Monoglycerides; D000069463:Olive Oil; D010938:Plant Oils; D014280:Triglycerides