Response surface methodology was used to optimize the extraction conditions of oil from watermelon seeds. Based on single factor experiments, the material to liquid ratio, extraction time and extraction solvent exhibi...Response surface methodology was used to optimize the extraction conditions of oil from watermelon seeds. Based on single factor experiments, the material to liquid ratio, extraction time and extraction solvent exhibited the highest effects on oil extraction. The mathematical model was established according to the Box-Behnken central composite design. The optimal extraction conditions consisted of a material to liquid ratio of 1：16.3 （g/ml）, an extraction time of 45.4 min, and petroleum ether as the organic solvent. The predicted and actual yields of watermelon seed oil were 27.92% and 28.04%, respectively. The extracted oil was analyzed by GC-MS. The results revealed that watermelon seed oil contained several types of acids and esters ; the relative percentages of the components were determined by a normalization method. The main fatty acids included linoleic acid, palmitic acid, oleic acid, and stearic acid, which accounted for 91.24% of the total components.展开更多
Seed watermelon kernel is a typical complex food with high fat and protein contents.During storage and processing,it is often affected by various factors to undergo interactions between components,which lead to its qu...Seed watermelon kernel is a typical complex food with high fat and protein contents.During storage and processing,it is often affected by various factors to undergo interactions between components,which lead to its quality change.In this experiment,seed watermelon kernels were used as research objects,and the effects of 2-Azobis(2-amidinopropane)dihydrochloride(AAPH)on seed watermelon kernel protein isolates(WMP)were investigated.The structure and digestion characteristics of WMP after oxidation were studied.The results showed that with the increase of AAPH concentration(0.05−5 mol/L),WMP showed obvious aggregation,and its solubility decreased from 6.76 mg/mL to 9.59 mg/mL.The free sulfhydryl content of WMP was 18.24 mmol/g decreased to 11.25 mmol/g,α-helix decreased andβ-sheet decreased in secondary structure,and its disulfide bond increased by 43.06 mmol/g from 39.57 mmol/g,enthalpy(H)and denaturation temperature increased(Td)(P<0.05).By mass spectrometry results of simulated gastric digestion products,it was found that oxidation adversely affected the digestion characteristics of WMP.It can be seen that the lipid oxidation product APPH of seed watermelon kernel can significantly affect the structure and function of the protein extracted from the seed kernel.展开更多
基金Supported by Fund for Independent Innovation of Agricultural Science in Jiangsu Province(CX-125067)
文摘Response surface methodology was used to optimize the extraction conditions of oil from watermelon seeds. Based on single factor experiments, the material to liquid ratio, extraction time and extraction solvent exhibited the highest effects on oil extraction. The mathematical model was established according to the Box-Behnken central composite design. The optimal extraction conditions consisted of a material to liquid ratio of 1：16.3 （g/ml）, an extraction time of 45.4 min, and petroleum ether as the organic solvent. The predicted and actual yields of watermelon seed oil were 27.92% and 28.04%, respectively. The extracted oil was analyzed by GC-MS. The results revealed that watermelon seed oil contained several types of acids and esters ; the relative percentages of the components were determined by a normalization method. The main fatty acids included linoleic acid, palmitic acid, oleic acid, and stearic acid, which accounted for 91.24% of the total components.
基金This study was supported by National Natural Science Foundation of China(No:31760477)Beijing Advanced Innovation Center for Food Nutrition and Human Health(No:20181007)Youth Science and Technology Innovation,Leader in Corps(No:2016BC001).
文摘Seed watermelon kernel is a typical complex food with high fat and protein contents.During storage and processing,it is often affected by various factors to undergo interactions between components,which lead to its quality change.In this experiment,seed watermelon kernels were used as research objects,and the effects of 2-Azobis(2-amidinopropane)dihydrochloride(AAPH)on seed watermelon kernel protein isolates(WMP)were investigated.The structure and digestion characteristics of WMP after oxidation were studied.The results showed that with the increase of AAPH concentration(0.05−5 mol/L),WMP showed obvious aggregation,and its solubility decreased from 6.76 mg/mL to 9.59 mg/mL.The free sulfhydryl content of WMP was 18.24 mmol/g decreased to 11.25 mmol/g,α-helix decreased andβ-sheet decreased in secondary structure,and its disulfide bond increased by 43.06 mmol/g from 39.57 mmol/g,enthalpy(H)and denaturation temperature increased(Td)(P<0.05).By mass spectrometry results of simulated gastric digestion products,it was found that oxidation adversely affected the digestion characteristics of WMP.It can be seen that the lipid oxidation product APPH of seed watermelon kernel can significantly affect the structure and function of the protein extracted from the seed kernel.
