Antioxidant Properties Of Mailard Reaction Intermediates In Camellia Oleifera Seed

Camema oleifera Abel.is a unique woody oil.Camema oleifera Abel is one of the ancient woody edible vegetable oils in China.The fatty acid composition,physicochemical properties,nutritional value and physiological efficacy of Camellia oleifera seed oil are similar to olive oil.Long-term consumption of Camellia oleifera seed oil has the effects of preventing cardiovascular sclerosis,lowering blood pressure,lowering blood lipid,anti-hepatitis and cancer.With the extensive attention of the government and society and people's recognition of the nutritional and health value of camellia seed oil,its market value is increasing day by day.At present,the planting area of Camellia oleifera in China has reached 65.5 million,and the annual output of camellia seed oil has reached more than 500,000 tons.In this paper,the effects of different heating methods and conditions on reducing sugar content,free amino acid content,water content,pH value,browning degree,antioxidant activity,water color value,browning degree,Maillard reaction products and antioxidant activity of Camellia oleifera seeds in Zhejiang Province were determined.The occurrence regularity and production of Maillard reaction of Camellia oleifera seeds were studied.The antioxidant mechanism of the compounds.The results are as follows:(1)The oxidative stability of Camellia oleifera seed oil pressed by heated Camellia oleifera seeds was improved.With the prolongation of heating time,the oxidation stabilization time increases first and then tends to be stable.The oxidation stabilization time increases most significantly in the early heating period(20 minutes).The oxidation stabilization time at 30?,60?,90,120? and 150? increases by 2.10,4.46,4.93,5.20 and 6.17 times respectively compared with that before heating.The Maillard reaction of Camellia oleifera seeds occurred in different degrees under heating conditions,and the reaction products had antioxidant activity.The content of reducing sugar,free amino acid,pH value and moisture of Camellia oleifera seeds decreased most with the increase of heating time at 120? and 150?.When heated for 60 minutes,Maillard products produced the most and had obvious antioxidant activity.The DPPH free radical scavenging rates of Maillard products from Camellia oleifera seeds were 43.06%and 48.87%respectively.The ABTS free radical scavenging rates of Maillard products from Camellia oleifera seeds were 81.43%and 89.81%,respectively.(2)The antioxidant Maillard products produced in the heated Camellia oleifera seeds mainly include acetone aldehyde,3-deoxy-oxose and glyoxal.The Maillard product in camellia seed oil was determined by high performance liquid chromatography.It was found that no hydroxymethyl furfural was detected in camellia seed oil before and after heating.With the prolongation of heating time,the content of acetone aldehyde increased first and then decreased.The content of acetone aldehyde reached 0.76?g/g at 150 C for 20 minutes,which was 3.35 times higher than that before heating.3-deoxy-oxosulfone and glyoxal were detected in Camellia oleifera seed oil when heated at 150? for 60 minutes,the contents were 1.11?g/g and 7.03?g/g,respectively.Camellia oleifera seed oil produced the most Maillard products and had obvious antioxidant activity when heated at 150°C for 60 minutes.The DPPH radical scavenging rate was 95.27%,and the antioxidant activity coefficient was 64.17%.(3)Maillard reaction occured mainly in camellia seed kernels.The anti-oxidation ability of the products from the Sierra-Laden reaction of Camellia oleifera seeds treated by infrared radiation,microwave radiation and hot air heating is the strongest.The antioxidant Maillard products included acetone aldehyde and 3-deoxy-ostrosaccharide.With the prolongation of heating time,the production of acetonaldehyde and 3-deoxyosaccharide from Maillard products increased gradually.After 120 minutes of reaction at 150 0C,the contents of acetonaldehyde and 3-deoxyosaccharide in the three drying methods were infrared radiation>microwave radiation>hot air,and the contents of glyoxal were 7.0?g/g.The antioxidant activity of the Maillard products from Camellia oleifera seeds and whole seeds showed that the DPPH free radicals scavenged by Camellia oleifera seeds oil and Camellia oleifera seed oil were 82.02%and 79.59%respectively when the reaction time was 120 minutes at 150 C,and the oxidation stabilization time was 11.92 h and 7.51 h,respectively,indicating that the Maillard reaction products in Camellia oleifera seeds oil had antioxidant activity.It was found that with the prolongation of heating time,the production of acetone aldehyde increased gradually,and glyoxal and 3-deoxyosaccharide were only produced at 150?.The content of glyoxal increased slightly with the prolongation of heating time.The content of acetone aldehyde and 3-deoxyosaccharide in camellia seed oil was 7.94?g/g and 29.7?g/g,respectively,after 120 minutes of reaction at 150?.The content of acetone aldehyde and 3-deoxyosaccharide in camellia seed oil was 7?g/g The content of Maillard reaction was 14.15 ?g/g and 51.94 ?g/g,respectively.The latter was 1.78 and 1.94 times higher than the former,indicating that Maillard reaction occurred mainly in Camellia seed.The DPPH scavenging rate and oxidation stability of camellia seed oil with Maillard reaction were compared.It was found that the antioxidant activity of camellia seed kernel was stronger than that of camellia seed oil.Therefore,the antioxidant Maillard products in Camellia oleifera seed oil were acetone aldehyde and 3-deoxy-ostrose.