Sensory-directed flavor analysis of key odorants compounds development of French fries and oils in the break-in,optimum and degrading frying stage

The flavor is a decisive sensory characteristic that determines the popularity of French fries(FFs).During high-oleic rapeseed oil(RO)frying,the flavor development of FFs showed three noticeable stages including break-in(3.5%-7.5%of total polar compounds(TPC)),optimum(7.5%-22.18%of TPC),and degrading stages(above 22.18%of TPC).Further,in order to distinguish the key aroma compounds in each stage,the FFs prepared in RO at TPC of 3.5%(FF4),14.5%(FF15),and 26.96%(FF27)and their relevant oils(RO4,RO15,RO27)were selected for sensory-directed analysis.The results revealed that the FF4 had low contents of(E,E)-2,4-decadienal(deep-fried odor)which also caused lower sensory score in FF4 sample.The higher contents of(E,E)-2,4-decadienal in FF15 induced its higher deep-fried odor.The FF27 had higher hexanoic acid(sweaty odor),heptanoic acid,nonanoic acid,benzene acetaldehyde(stale odor),and trans-4,5-epoxy-(E)-2-decenal(metallic odor)compared with FF4 and FF15,thus leading to the undesirable flavor of FF27.Moreover,the decrease of 2,5-dimethylpyrazine and 2-ethyl-6-methyl-pyrazine in FF27 induced the lower roasty flavor,which may also lead to the decline of the sensory score.Similarly,the higher contents of(E)-2-undecenal,hexanoic acid,heptanoic acid,and nonanoic acid in RO27 lead to increase its rancid score and thus lower the sensory score.

Study on the interaction mechanism of virgin olive oil polyphenols with mucin and α-amylase

The interaction mechanism of mucin and α-amylase with virgin olive oil (VOO) polyphenols (oleuropein (OL),tyrosol (TY),hydroxytyrosol (HT)) was analyzed by fluorescence,ultraviolet (UV) absorption,attenuated total reflection Fourier transform infrared (ATR-FTIR),circular dichroic (CD) spectroscopy and molecular docking.A total of 17 polyphenols have been identified in the selected VOO,and the TY,HT and OL were the main compounds.The quenching mechanism between mucin/α-amylase and three VOO polyphenols was static,mainly through van der Waals forces and hydrogen bonds.The results of UV absorption,ATR-FTIR,and CD spectroscopy revealed that the conformation of mucin changed after combining with the three polyphenols,while that of the α-amylase changed little.Molecular docking predicted the interaction sites of the three polyphenols with human salivary mucin and α-amylase.The present study could provide the theoretical foundation for further research on the interaction between human salivary protein and phenolic compounds in VOO.