The effect of traditional stir-frying process on hydrophilic and lipophilic antioxidant capacities of pine nut kernels.
The effect of traditional stir-frying process at different heating temperatures (50-150 °C) and time periods (5-20 min) on hydrophilic part (total and individual phenolics), lipophilic part (tocopherol and phytosterol compounds) and their corresponding antioxidant capacities in pine nut kernels were investigated. The concentrations of total phenolics, phenolic acids, tocopherols and phytosterols in raw pine nut kernels were 15.76 mg gallic acid equivalents/100 g dry weight (mg GAE/100 g DW), 12.15 mg/100 g DW, 28.67 mg/100 g DW and 198.81 mg/100 g DW, respectively. Stir-frying at low temperatures over short time periods led to an increase of phenolics, phytosterols and hydrophiliic antioxidant capacities. However, these values decreased under the longer heating time and the higher temperature. Tocopherols and lipophilic antioxidant capacities did not show clear changes at lower heating temperatures or shorter heating times, while they had an apparent decreasing trend at higher heating temperatures or longer heating times. Gallic acid might be the main component, which is responsible for the hydrophilic antioxidant capacity (R(2 )= 0.84, 0.81 and 0.81 using DPPH, FRAP and H-ORAC assays), and tocopherols might be the main antioxidant components in the lipophilic part (R(2 )= 0.87 and 0.89 using DPPH and L-ORAC assays).
a Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Key Laboratory for Agro-Food Risk Assessment of Ministry of Agriculture, College of Biosystems Engineering and Food Science, Fuli Institute of Food Science, Zhejiang University , Hangzhou , China and.
Shuqin
S
Mao
a Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Key Laboratory for Agro-Food Risk Assessment of Ministry of Agriculture, College of Biosystems Engineering and Food Science, Fuli Institute of Food Science, Zhejiang University , Hangzhou , China and.
Fei
F
Zhou
b Department of Applied Technology , Zhejiang Economic & Trade Polytechnic , Hangzhou , China.
Weisu
W
Huang
a Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Key Laboratory for Agro-Food Risk Assessment of Ministry of Agriculture, College of Biosystems Engineering and Food Science, Fuli Institute of Food Science, Zhejiang University , Hangzhou , China and.
Baiyi
B
Lu
a Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Key Laboratory for Agro-Food Risk Assessment of Ministry of Agriculture, College of Biosystems Engineering and Food Science, Fuli Institute of Food Science, Zhejiang University , Hangzhou , China and.
Jiajia
J
Yang
a Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Key Laboratory for Agro-Food Risk Assessment of Ministry of Agriculture, College of Biosystems Engineering and Food Science, Fuli Institute of Food Science, Zhejiang University , Hangzhou , China and.
Lilin
L
He
a Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Key Laboratory for Agro-Food Risk Assessment of Ministry of Agriculture, College of Biosystems Engineering and Food Science, Fuli Institute of Food Science, Zhejiang University , Hangzhou , China and.
Yiying
Y
Zhao
D000872:Anthocyanins / Q000032:analysis; D000975:Antioxidants / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis; D005511:Food Handling; D005707:Gallic Acid / Q000032:analysis; D057927:Hydrophobic and Hydrophilic Interactions; D009754:Nuts / Q000737:chemistry*; D010840:Phytosterols / Q000032:analysis; D028223:Pinus; D059808:Polyphenols / Q000032:analysis; D024505:Tocopherols / Q000032:analysis; D014810:Vitamin E / Q000032:analysis
D000872:Anthocyanins; D000975:Antioxidants; D005419:Flavonoids; D010840:Phytosterols; D059808:Polyphenols; D014810:Vitamin E; D005707:Gallic Acid; D024505:Tocopherols
Hydrophilic antioxidant; phenolic compounds; phytosterolslipophilic antioxidant; pine nut; tocopherols