INFLUENCE OF STORAGE TEMPERATURE ON LIPID OXIDATION, STALE FLAVOR FORMATION AND DISCOLORATION IN LOTUS (NELUMBO NUCIFERA) BEE POLLEN

Abstract

ABSTRACT In this study, lipid oxidation, stale flavor formation and discoloration were investigated during the storage of lotus bee pollen at different temperatures. The primary and secondary oxidation products were quantified using ferrous oxidation-xylenol orange method and thiobarbituric acid reactive substance (TBARS) assay, respectively. The oxidative volatiles were analyzed by solid-phase microextraction/gas chromatography-mass spectrometry. The formation of hydroperoxides in bee pollen samples proceeded at a gentle speed during storage at lower temperatures up to 3 months. However, a decline in hydroperoxide content was observed for samples at 40C after it reached maximum values at the first 15 days of storage. The TBARS value increased with storage temperature over the storage time and the data could be described by zero-order kinetics. Hexanal, heptanal, octanal and 2,4-heptadienal were the main oxidation volatiles in degenerative bee pollen. The results also revealed that carotenoid content was a suitable freshness parameter for estimating the condition and duration of storage for bee pollen samples. PRACTICAL APPLICATIONS There is a growing interest in fresh, natural and healthy bee products with a long shelf life. It is necessary to care for each step of the process and the factors that can lead to deterioration in quality as a consequence of lipid oxidation degradations. This study examines the storage temperature effect on lipid oxidation, stale flavor formation and discoloration in lotus bee pollen. A potential freshness parameter was found for bee product industry to estimate the condition and duration of storage for bee pollen samples. The results can help the apiarists and consumers to better make use of bee pollen.