Phytosterol esters can effectively decrease serum cholesterol concentration in the human body and prevent cardio-cerebrovascular diseases.It was found that phytosterol esters exhibited better solubility and bioavailab...Phytosterol esters can effectively decrease serum cholesterol concentration in the human body and prevent cardio-cerebrovascular diseases.It was found that phytosterol esters exhibited better solubility and bioavailability than free phytosterols.In recent years,phytosterol esters have attracted increasing attention.However,during food processing,phytosterol esters are susceptible to degradation at high temperatures,resulting in certain losses and formation of potentially harmful substances for humans.This paper reviews the relevant literatures and updates on the thermal oxidation stability of phytosterol esters in recent years from the following aspects:(i)Sources,physiological activities,and applications of phytosterol esters;(ii)Oxidation mechanism of phytosterol esters;(iii)Effects of phytosterols species,the volume of addition,food matrix,heating temperature and time,and antioxidants on the thermal loss and oxidation stability of phytosterol esters.The research progress on the safety of phytosterol esters is also discussed in detail.Additionally,the prospects for future research are highlighted.展开更多
Phytosterols,which are naturally occurring in plants,have excellent nutritional and health values on lowering both the blood cholesterol level and the risk of cardiovascular diseases.Edible oils are the main source of...Phytosterols,which are naturally occurring in plants,have excellent nutritional and health values on lowering both the blood cholesterol level and the risk of cardiovascular diseases.Edible oils are the main source of daily intake of phytosterols,whereas the properties of phytosterols may vary a lot depending on their sources.During the processing of edible oil including refining and frying,phytosterol's content fluctuates,which influences the properties of the final product.Phytosterols and their derivatives undergo physical migration between different phases and chemical conversion during the processing,which reduces the quality and the commercial value of edible oils.Therein,the loss of phytosterols is the major concern in the process of neutralization and deodorization.In addition,oxidation and thermal degradation of phytosterols occur simultaneously during frying,which also reduces the content of phytosterols.Nevertheless,the oil matrix has a promoting or an inhibitory effect on the thermal oxidation of phytosterols.Therefore,various efforts have been devoted to analyzing and improving the remaining contents of phytosterols in edible oil.Regardless of the processing method,temperature plays an important role in the loss of phytosterols.At present,themain analysismethods of phytosterols include gas chromatography and liquid chromatography,inwhich the pretreatment of different types of phytosterols is also a crucial step.This review focused on the following topics comprehensively:(i)the distribution of phytosterols in the oil-containing plants and edible oils during the refining processing;(ii)the pretreatment and analysis methods of various phytosterols(free phytosterols,phytosteryl fatty acid esters,phytosteryl glycosides and acylated phytosteryl glycosides);(iii)the variation of phytosterols in process of esterification and oxidation,storage and so on.The study also proposed that the investigation in the loss and safety of phytosterols during processing of the vegetable oils should be proceeded further in combination with efficient and accurate chromatography methods.展开更多
Phytosterols have received extensive attention owing to their excellent cholesterol-lowering activity and the role in cardiovascular diseases prevention. However, poor solubility in both oil and water limited the appl...Phytosterols have received extensive attention owing to their excellent cholesterol-lowering activity and the role in cardiovascular diseases prevention. However, poor solubility in both oil and water limited the application of free phytosterols in the food industry. Chemical or enzymatic modifications were effective to improve the physicochemical properties as well as the bioavailability and cholesterollowering activity of phytosterols. Higher oil solubility and lower melting point of phytosterols have been achieved by esterification and transesterification with fatty acids and triacylglycerols so as to enhance the bioavailability, reduce formation of precipitates, and improve the sensory quality of products.While the researches on the improvement on its water solubility is a hot topic. Hydrophilic phytosterol derivatives have promising applications in the food industry because most of foods belong to aqueous matrix. Hydrophilic modification is useful and meaningful for phytosterols in both industrial and commercial applications. This review mainly highlights the hydrophilic phytosterol derivatives in the following aspects:(i) hydrophilic modifications of phytosterols by coupling with various polar components;(ii) cholesterol-lowering activity and possible molecular mechanisms of hydrophilic phytosterol derivatives on reducing serum cholesterol level;and(iii) safety evaluation of hydrophilic phytosterol derivatives in cell-culture studies, animal models and clinical trials.展开更多
The sulfatc soap is refined through extracting unsaponifiable neutral substance using ethyl acetate and hcxane-acetone. The content of neutral substance in tall oil decreases from 32.8% to 17.4% and 18%. The acid numb...The sulfatc soap is refined through extracting unsaponifiable neutral substance using ethyl acetate and hcxane-acetone. The content of neutral substance in tall oil decreases from 32.8% to 17.4% and 18%. The acid number of tall oil increases from 119 to 169 and 153. The quality of tall oil is greatly improved. This provides a favorable condition for distillation of tall oil. The unsaponifiable neutral substance from crude sulfate soap mainly consists of tcrpene aldehydes, tcrpcnc alcohols, fatty alcohols and stcrols in which larixol is 26.3% and 18. 5%, stcrols arc 17% and 27.1% separately. The white crystals containing stcrols of 96.9% are obtained by crystallization and rccrystallization. The stcrols arc mainly β-sitostcrol and campcsterol.展开更多
基金The authors sincerely acknowledge the financial support from the basic research project of the key scientific research projects of colleges and universities in Henan Province(21zx010).
文摘Phytosterol esters can effectively decrease serum cholesterol concentration in the human body and prevent cardio-cerebrovascular diseases.It was found that phytosterol esters exhibited better solubility and bioavailability than free phytosterols.In recent years,phytosterol esters have attracted increasing attention.However,during food processing,phytosterol esters are susceptible to degradation at high temperatures,resulting in certain losses and formation of potentially harmful substances for humans.This paper reviews the relevant literatures and updates on the thermal oxidation stability of phytosterol esters in recent years from the following aspects:(i)Sources,physiological activities,and applications of phytosterol esters;(ii)Oxidation mechanism of phytosterol esters;(iii)Effects of phytosterols species,the volume of addition,food matrix,heating temperature and time,and antioxidants on the thermal loss and oxidation stability of phytosterol esters.The research progress on the safety of phytosterol esters is also discussed in detail.Additionally,the prospects for future research are highlighted.
基金supported by the NationalNatural Science Foundation of China(No.31972110)the National Key R&D Program of China(No.2018YFD0401102).
文摘Phytosterols,which are naturally occurring in plants,have excellent nutritional and health values on lowering both the blood cholesterol level and the risk of cardiovascular diseases.Edible oils are the main source of daily intake of phytosterols,whereas the properties of phytosterols may vary a lot depending on their sources.During the processing of edible oil including refining and frying,phytosterol's content fluctuates,which influences the properties of the final product.Phytosterols and their derivatives undergo physical migration between different phases and chemical conversion during the processing,which reduces the quality and the commercial value of edible oils.Therein,the loss of phytosterols is the major concern in the process of neutralization and deodorization.In addition,oxidation and thermal degradation of phytosterols occur simultaneously during frying,which also reduces the content of phytosterols.Nevertheless,the oil matrix has a promoting or an inhibitory effect on the thermal oxidation of phytosterols.Therefore,various efforts have been devoted to analyzing and improving the remaining contents of phytosterols in edible oil.Regardless of the processing method,temperature plays an important role in the loss of phytosterols.At present,themain analysismethods of phytosterols include gas chromatography and liquid chromatography,inwhich the pretreatment of different types of phytosterols is also a crucial step.This review focused on the following topics comprehensively:(i)the distribution of phytosterols in the oil-containing plants and edible oils during the refining processing;(ii)the pretreatment and analysis methods of various phytosterols(free phytosterols,phytosteryl fatty acid esters,phytosteryl glycosides and acylated phytosteryl glycosides);(iii)the variation of phytosterols in process of esterification and oxidation,storage and so on.The study also proposed that the investigation in the loss and safety of phytosterols during processing of the vegetable oils should be proceeded further in combination with efficient and accurate chromatography methods.
基金supported by the National Natural Science Foundation of China(No.31972110)。
文摘Phytosterols have received extensive attention owing to their excellent cholesterol-lowering activity and the role in cardiovascular diseases prevention. However, poor solubility in both oil and water limited the application of free phytosterols in the food industry. Chemical or enzymatic modifications were effective to improve the physicochemical properties as well as the bioavailability and cholesterollowering activity of phytosterols. Higher oil solubility and lower melting point of phytosterols have been achieved by esterification and transesterification with fatty acids and triacylglycerols so as to enhance the bioavailability, reduce formation of precipitates, and improve the sensory quality of products.While the researches on the improvement on its water solubility is a hot topic. Hydrophilic phytosterol derivatives have promising applications in the food industry because most of foods belong to aqueous matrix. Hydrophilic modification is useful and meaningful for phytosterols in both industrial and commercial applications. This review mainly highlights the hydrophilic phytosterol derivatives in the following aspects:(i) hydrophilic modifications of phytosterols by coupling with various polar components;(ii) cholesterol-lowering activity and possible molecular mechanisms of hydrophilic phytosterol derivatives on reducing serum cholesterol level;and(iii) safety evaluation of hydrophilic phytosterol derivatives in cell-culture studies, animal models and clinical trials.
文摘The sulfatc soap is refined through extracting unsaponifiable neutral substance using ethyl acetate and hcxane-acetone. The content of neutral substance in tall oil decreases from 32.8% to 17.4% and 18%. The acid number of tall oil increases from 119 to 169 and 153. The quality of tall oil is greatly improved. This provides a favorable condition for distillation of tall oil. The unsaponifiable neutral substance from crude sulfate soap mainly consists of tcrpene aldehydes, tcrpcnc alcohols, fatty alcohols and stcrols in which larixol is 26.3% and 18. 5%, stcrols arc 17% and 27.1% separately. The white crystals containing stcrols of 96.9% are obtained by crystallization and rccrystallization. The stcrols arc mainly β-sitostcrol and campcsterol.
