TITLE:
Kinetic Study of the Oxidative Degradation of Choibá Oil (Dipteryx oleifera Benth.) with Addition of Rosemary Extract (Rosmarinus officinalis L.)
AUTHORS:
Ana María Piedrahita, Jeanine Peñaloza, Álvaro Cogollo, Benjamín Alberto Rojano
KEYWORDS:
Dipteryx oleifera, Oxidative Stability, Shelf-Life, Rosmarinus officinalis, Lipid Peroxidation, Arrhenius
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.6 No.5,
April
2,
2015
ABSTRACT: Choibá (Dipteryx oleifera Benth.) is a promising
source of edible oil with high nutritional quality and a significant content of
oleic acid (52% - 54%). To promote Choibá as source of edible oil is necessary
to ensure its stability along the time of production, distribution and storage.
Loss of nutritional and organoleptic quality in lipids is mainly due to lipid
peroxidation reactions. The aim of this research was to evaluate the oxidative
stability of Choibá oil at 100°C ± 1°C with aeration (1150 mL air/min)
supplemented with rosemary extract (Rosmarinus
officinalis L.), at 1000 mg/L (RE1000) and 1500 mg/L (RE1500), and with BHT
(200 mg/L) and from this results to evaluate the degradation kinetics and
shelf-life of Choibá oil at 35°C, 45°C and 55°C without addition of antioxidants
(Control) and with addition of best concentration of rosemary extract obtained
from previous study. Progress in oil oxidation was measured through the extent
of oxidation products: peroxide value (PV) and thiobarbituric acid reactive
substances (TBARS). Results revealed that the addition of rosemary extract at
1500 mg/L significantly reduced de formation of hydroperoxides (PV), more than
BHT. Through correlations between concentrations of antioxidant (including
control without antioxidant) with peroxide values, the kinetics of degradation
and shelf-life of Choibá oil with predictive models are evaluated in real time
and accelerated (35°C, 45°C and 55°C) using the Arrhenius equation. In
addition, the oxidation reactions of this oil follow a first order kinetic
model for PV and zero order kinetic model for TBARS. The rate of formation of
PV was dependent on the storage temperature, according to the Arrhenius
equation with the activation energy of 4611.5071 J/mol for Control and
7409.5771 J/mol for RE1500 treatment. The result of TBARS didn’t adjust to
Arrhenius model, thus measurement of malondialdehyde (MDA) wasn’t a useful
parameter for shelf-life determination of Choibá oil.