Peeled walnut kernels,rich in lipids,are prone to oxidation,resulting in undesirable odors such as rancidity and pungency due to the formation of aldehydes,ketones,and acids.This study examined kernels oxidized at 60...Peeled walnut kernels,rich in lipids,are prone to oxidation,resulting in undesirable odors such as rancidity and pungency due to the formation of aldehydes,ketones,and acids.This study examined kernels oxidized at 60℃ over varying periods,assessing odor profiles through sensory evaluation and principal component analysis(PCA)using a gas-phase electronic nose.Threshold values for physicochemical indices such as acid value(AV),peroxide value(POV),p-anisidine value(p-AnV),total oxidation value(TOTOX),and malondialdehyde(MDA)content,were determined based on correlation analysis and oxidation kinetic models.Headspace solid phase microextraction-gas chromatography-mass spectrometry(HS-SPME/GC-MS)was utilized to analyze the volatile components of peeled walnut kernels during different oxidation times,and characteristic odor indices were determined by combining relative odor activity value(ROAV)and partial least squares regression(PLSR).The oxidation process was categorized into five stages(0–10,15,20,25,and 30 days),with significant quality deterioration noted at 15 days,marked by a consumer acceptance score below 6 and dominant rancid odors.The determined threshold values were 0.9 mg/g for AV,1.5 mmol/kg for POV,0.9 for p-AnV,6.0 for TOTOX,and 3.5μg/mL for MDA,respectively.Volatile compounds such as(E,E)-2,4-decadienal,hexanal,and(E)-2-octenal were identified as key contributors to the odor profile.Among these,hexanal and(E)-2-octenal demonstrated strong predictive accuracy for POV and p-AnV,with threshold values were 1.8 and 0.9 mg/kg,respectively.This indicates that physicochemical indicators reached the threshold values at the same time as pronounced lipid oxidation and rancidity.展开更多
Walnut kernel has been applied in daily diets for thousands of years with its memory enhancement effect.For further observing the effect of memory enhancement,the walnut kernel was extracted and separated into active ...Walnut kernel has been applied in daily diets for thousands of years with its memory enhancement effect.For further observing the effect of memory enhancement,the walnut kernel was extracted and separated into active parts,with the evaluation in mice.30%ethanol elution from AB-8 macroporous resin showed a decreased escape latency time and increased cumulative time and crossing frequency through the Morris test.It also increased the latency time and decreased jumps in the step-down test.These results indicated the memory enhancement effect of the fraction.After further separation and purification,four compounds were acquired with tryptamine-like structures first found in the walnut kernel,and compounds III and IV were new ones.Compound III showed decreased escape latency time,increased cumulative time,increased crossing frequency through the Morris test,and increased latency time,decreased jumps in the step-down test.Compound III also alleviated acetylcholinesterase activity and promoted acetylcholine transferase activity.In silico docking and molecular dynamic studies displayed the most polar interactions of compound III on 5-hydroxytryptamine receptor 4(5-HTR4)with the most polar interactions and the lowest binding energies,and anti-degeneration effect to monoamine oxidase A(MAO-A)with the high binding energy and sizeable steric hindrance.These results illustrated the memory enhancement of compound III in the walnut kernel,indicating more potential activities of tryptamine-like components and more applications for walnut kernel in clinical use or daily diets.展开更多
Some physical and chemical properties, mineral content and fatty acid compositions of kernel and oils of several walnut types (Büyük Oba, Kaman2, Kaman5) were determined. The oil yields from these kernels ch...Some physical and chemical properties, mineral content and fatty acid compositions of kernel and oils of several walnut types (Büyük Oba, Kaman2, Kaman5) were determined. The oil yields from these kernels changed between 61.4% to 72.8%. The crude fibre contents of ker nels ranged between 3.77% and 3.80%. In add ition, crude protein contents of kernels ranged between 7.05% and 8.10%. While the peroxide values of kernel oils change between 3.18 meq/ Kg and 3.53 meq/Kg, acidity values ranged be tween 0.35% and 0.56%. The main fatty acids of walnut kernel oils were oleic, linoleic, linolenic and palmitic acids. Linoleic acid contents of ker nel oils varied between 49.7% and 55.5%. On the other hand, oleic acid contents ranged between 20.5% and 26.4%. As a result, the present study showed the walnut kernels of the researched species of walnut kernels from Turkey are a potential source of valuable oil which might be used for edible and other industrial applica tions.展开更多
文摘Peeled walnut kernels,rich in lipids,are prone to oxidation,resulting in undesirable odors such as rancidity and pungency due to the formation of aldehydes,ketones,and acids.This study examined kernels oxidized at 60℃ over varying periods,assessing odor profiles through sensory evaluation and principal component analysis(PCA)using a gas-phase electronic nose.Threshold values for physicochemical indices such as acid value(AV),peroxide value(POV),p-anisidine value(p-AnV),total oxidation value(TOTOX),and malondialdehyde(MDA)content,were determined based on correlation analysis and oxidation kinetic models.Headspace solid phase microextraction-gas chromatography-mass spectrometry(HS-SPME/GC-MS)was utilized to analyze the volatile components of peeled walnut kernels during different oxidation times,and characteristic odor indices were determined by combining relative odor activity value(ROAV)and partial least squares regression(PLSR).The oxidation process was categorized into five stages(0–10,15,20,25,and 30 days),with significant quality deterioration noted at 15 days,marked by a consumer acceptance score below 6 and dominant rancid odors.The determined threshold values were 0.9 mg/g for AV,1.5 mmol/kg for POV,0.9 for p-AnV,6.0 for TOTOX,and 3.5μg/mL for MDA,respectively.Volatile compounds such as(E,E)-2,4-decadienal,hexanal,and(E)-2-octenal were identified as key contributors to the odor profile.Among these,hexanal and(E)-2-octenal demonstrated strong predictive accuracy for POV and p-AnV,with threshold values were 1.8 and 0.9 mg/kg,respectively.This indicates that physicochemical indicators reached the threshold values at the same time as pronounced lipid oxidation and rancidity.
基金This work was financially supported by the Fellowship China Postdoctoral Science Foundation(2021TQ0128)the Key Research and Development Program of Yunnan Province(202202AE090007)+1 种基金the Fundamental Research Funds for the Central Universities(JUSRP222001)the Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province,Jiangnan University.
文摘Walnut kernel has been applied in daily diets for thousands of years with its memory enhancement effect.For further observing the effect of memory enhancement,the walnut kernel was extracted and separated into active parts,with the evaluation in mice.30%ethanol elution from AB-8 macroporous resin showed a decreased escape latency time and increased cumulative time and crossing frequency through the Morris test.It also increased the latency time and decreased jumps in the step-down test.These results indicated the memory enhancement effect of the fraction.After further separation and purification,four compounds were acquired with tryptamine-like structures first found in the walnut kernel,and compounds III and IV were new ones.Compound III showed decreased escape latency time,increased cumulative time,increased crossing frequency through the Morris test,and increased latency time,decreased jumps in the step-down test.Compound III also alleviated acetylcholinesterase activity and promoted acetylcholine transferase activity.In silico docking and molecular dynamic studies displayed the most polar interactions of compound III on 5-hydroxytryptamine receptor 4(5-HTR4)with the most polar interactions and the lowest binding energies,and anti-degeneration effect to monoamine oxidase A(MAO-A)with the high binding energy and sizeable steric hindrance.These results illustrated the memory enhancement of compound III in the walnut kernel,indicating more potential activities of tryptamine-like components and more applications for walnut kernel in clinical use or daily diets.
基金This work was supported by Selçuk University Scientific Research Project(S.U.-BAP.Konya-Turkey).
文摘Some physical and chemical properties, mineral content and fatty acid compositions of kernel and oils of several walnut types (Büyük Oba, Kaman2, Kaman5) were determined. The oil yields from these kernels changed between 61.4% to 72.8%. The crude fibre contents of ker nels ranged between 3.77% and 3.80%. In add ition, crude protein contents of kernels ranged between 7.05% and 8.10%. While the peroxide values of kernel oils change between 3.18 meq/ Kg and 3.53 meq/Kg, acidity values ranged be tween 0.35% and 0.56%. The main fatty acids of walnut kernel oils were oleic, linoleic, linolenic and palmitic acids. Linoleic acid contents of ker nel oils varied between 49.7% and 55.5%. On the other hand, oleic acid contents ranged between 20.5% and 26.4%. As a result, the present study showed the walnut kernels of the researched species of walnut kernels from Turkey are a potential source of valuable oil which might be used for edible and other industrial applica tions.
