Starch retrogradation is a primary contributor to the staling of bread.The impact of the surfactant glyceryl monostearate(GMS)on the structure and retrogradation characteristics of wheat starch gels was explored durin...Starch retrogradation is a primary contributor to the staling of bread.The impact of the surfactant glyceryl monostearate(GMS)on the structure and retrogradation characteristics of wheat starch gels was explored during storage at 4℃ for 2 h and 5 d.In this research,the incorporation of GMS(0.14%,W/W,based on flour weight)significantly reduced the crumb firmness(P<0.05).Molecular dynamics simulation vividly demonstrated the formation process of the single-helical amylose-GMS complex within 150 ns during the short-term retrogradation process of cooling the gelatinized starch for 2 h.X-ray diffraction analysis revealed that GMS slightly decreased the relative crystallinity of starch from 8.9%to 7.8%during long-term retrogradation.The reduction in R1047/1022 detected by Fourier-transform infrared spectroscopy indicated that GMS could reduce the degree of retrogradation.Solid-state ^(13)C NMR analysis showed a characteristic resonance peak at 31.7 ppm for the GMSstarch complex.This study indicates that GMS holds great application potential in retarding starch retrogradation.展开更多
Retrogradation of semi-dry rice noodles severely reduced their eating quality during storage.Three commonly used modified starches(oxidized starch,acetylated starch,and hydroxypropyl starch)were applied to investigate...Retrogradation of semi-dry rice noodles severely reduced their eating quality during storage.Three commonly used modified starches(oxidized starch,acetylated starch,and hydroxypropyl starch)were applied to investigate the anti-retrogradation effects of semi-dry rice noodles during cold storage.Loss of water content,migration of water,and increase in relative crystallinity,retrogradation enthalpy,and hardness could be retarded by adding chemically modified starches,especially hydroxypropyl starches.The effect of hydroxypropyl starch addition levels(2%,4%,6%,8%,and 10%)on the properties of rice flour and the edible quality of semi-dry rice noodles was further evaluated.The water solubility index of rice flour decreased with the addition of hydroxypropyl starch,while the swelling power showed the opposite trend.The quality of semi-dry rice noodles were improved with the addition of hydroxypropyl starch.Compared to the control,semi-dried rice noodles with 8%hydroxypropyl starch possessed superior properties,i.e.lower cooking loss(decreasing from 12.89%to 6.62%),lower adhesiveness(decreasing from 5.40 to 4.31 g·s),and higher hardness(rising from 10.89 to 13.81 N).These findings demonstrated that the incorporation of hydroxypropyl starch is a promising strategy for the preparation of semi-dry rice noodles with satisfactory cooking and edible qualities as well as a long shelf life.展开更多
The polysaccharides, such as κ-carrageenan, ι-carrageenan, agarose (agar), gellan gum, amylose, curdlan, alginate, and deacetylated rhamsan gum, in water changed into an ice-like structure with hydrogen bonding betw...The polysaccharides, such as κ-carrageenan, ι-carrageenan, agarose (agar), gellan gum, amylose, curdlan, alginate, and deacetylated rhamsan gum, in water changed into an ice-like structure with hydrogen bonding between polymer and water molecules, and between water-water molecules even at a concentration range of 0.1% - 1.0% (W/V) at room temperature, resulting in gelation. Such dramatic changes from liquid into gels have been understood at the molecular level in principles. In this review, we describe the structure-function relationship of starch on the view point of rheological aspects and discuss gelatinization and retrogradation mechanism including water molecules at molecular level. The starch molecules (amylose and amylopectin) play a dominant role in the center of the tetrahedral cavities occupied by water molecules, and the arrangement is partially similar to a tetrahedral structure in a gelatinization process. The arrangement should lead to a cooperative effect stabilizing extended regions of ice-like water with hydrogen bonding on the surface of the polymer molecules, where hemiacetal oxygen and hydroxyl groups might participate in hydrogen bonding with water molecules. Thus, a more extended ice-like hydrogen bonding within water molecules might be achieved in a retrogradation process. Though many investigations not only include starch gelatinization and retrogradaion, but also the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, no other researchers have established mechanism at the molecular level. There is reasonable consistency in our investigations.展开更多
Tea Polysaccharides(TPS) has been acknowledged of one of the most important components with various bioactivities in tea.The extraction of TPS from wide tea sources was the previous and determinant work before further...Tea Polysaccharides(TPS) has been acknowledged of one of the most important components with various bioactivities in tea.The extraction of TPS from wide tea sources was the previous and determinant work before further studies done.While the extraction procedures of TPS would be different due to the later utilization.In this work,the extraction conditions of TPS were previously optimized by respond surface methodology.A quadric model was obtained as Y = 3.16 + 0.31X1- 0.55X2- 0.47X3- 0.034X1X2+ 0.022X1X3- 0.041X2X3- 0.90X12-0.40X22- 0.73X32.The model was tested and proved through the ANOVA with F-value and p-value.Furthermore,the optimal condition was achieved as extraction temperature of 82℃,extraction time of 106 min and ratio of water to material of 33∶ 1(mL/g),meanwhile the highest yield of TPS showed 3.39% ± 0.08%.The crude TPS was later refined to be of purity of 81.3%.The refined TPS was incorporated with starch as to state the role of TPS in the starch retrogradation of starch-based food.The results showed that TPS-wheat starch mixture has a relatively low degree of retrogradation,which indicated that TPS has a delayed or resistant effect on wheat starch retrogradation.This work may provide a practical evidence for the promising starch-based food incorporated tea.展开更多
背景与目的:临床中复杂的结石性胆管炎常合并Vater壶腹部狭窄,从而增加治疗的难度和复杂性。若只取除胆管内结石而不处理壶腹部狭窄问题,后期疾病容易反复发作。既往大多采取的方法主要是经内镜逆行胆胰管造影(ERCP)入路导丝顺向引导十...背景与目的:临床中复杂的结石性胆管炎常合并Vater壶腹部狭窄,从而增加治疗的难度和复杂性。若只取除胆管内结石而不处理壶腹部狭窄问题,后期疾病容易反复发作。既往大多采取的方法主要是经内镜逆行胆胰管造影(ERCP)入路导丝顺向引导十二指肠乳头括约肌切开、取石术联合后期腹腔镜胆囊切除的方式处理。然而,ERCP在处理复杂情况时仍有一定局限性。为此,笔者团队首创了一种新型经腹腔入路治疗结石性胆管炎合并Vater壶腹部狭窄的方法。本研究探讨该方法的可行性与疗效,以期为临床提供新的治疗选择。方法:采用随机对照研究的方法,将2021—2023年因胆囊结石、胆管结石伴Vater壶腹部狭窄于成都市第二人民医院治疗的120例患者分为观察组和对照组,每组各60例,观察组行腹腔镜胆囊切除+胆管切开取石,并顺势从切开的胆管中插入导管逆向引导十二指肠乳头切开,同时处理胆囊、胆管结石及Vater壶腹部狭窄;对照组行传统ERCP入路乳头切开、胆管取石+腹腔镜胆囊切除术。收集两组患者围手术期相关指标,比较两组手术效果。结果:120例患者中,男性54例,女性66例。两组在胆道取石成功率、术中出血量、术后24 h总胆红素、直接胆红素、转氨酶、白细胞计数、黄疸缓解时间及胆汁漏、腹膜后出血/感染、重症胰腺炎发生率等方面,差异无统计学意义(均P>0.05)。观察组平均手术时间、术后住院时间均明显短于对照组(98.67 min vs. 110.8 min,P<0.05;3.81 d vs. 5.61 d,P<0.05),并且观察组术后高淀粉酶血症和(或)高脂肪酶血症、轻型胰腺炎发生率均明显更低(1.67%vs. 25.00%,P<0.001;0 vs. 10%,P=0.027)。结论:新型经腹腔入路在缩短手术时间、住院时间方面明显优于ERCP入路,术后发生轻症胰腺炎及高淀粉酶血症和(或)高脂肪酶血症的风险更低,并且胆管取石成功率不劣于ERCP入路,是一种可选择的治疗方式。展开更多
基金supported by the Zhejiang Provincial Natural Science Foundation of China(LQ23C200003)National Natural Science Foundation of China(32202076)Natural Science Foundation of Shandong Province(Project No.ZR2023QC083).
文摘Starch retrogradation is a primary contributor to the staling of bread.The impact of the surfactant glyceryl monostearate(GMS)on the structure and retrogradation characteristics of wheat starch gels was explored during storage at 4℃ for 2 h and 5 d.In this research,the incorporation of GMS(0.14%,W/W,based on flour weight)significantly reduced the crumb firmness(P<0.05).Molecular dynamics simulation vividly demonstrated the formation process of the single-helical amylose-GMS complex within 150 ns during the short-term retrogradation process of cooling the gelatinized starch for 2 h.X-ray diffraction analysis revealed that GMS slightly decreased the relative crystallinity of starch from 8.9%to 7.8%during long-term retrogradation.The reduction in R1047/1022 detected by Fourier-transform infrared spectroscopy indicated that GMS could reduce the degree of retrogradation.Solid-state ^(13)C NMR analysis showed a characteristic resonance peak at 31.7 ppm for the GMSstarch complex.This study indicates that GMS holds great application potential in retarding starch retrogradation.
基金funded by the fund of national natural science foundation of China(32101996,32160530)the training plan for academic and technical leaders of major disciplines in Jiangxi province(20232BCJ23024)+1 种基金the key research and development program of Jiangxi province(20232BBF60023)“Shuangqian Project”of Jiangxi Province(jxsq2023201042)。
文摘Retrogradation of semi-dry rice noodles severely reduced their eating quality during storage.Three commonly used modified starches(oxidized starch,acetylated starch,and hydroxypropyl starch)were applied to investigate the anti-retrogradation effects of semi-dry rice noodles during cold storage.Loss of water content,migration of water,and increase in relative crystallinity,retrogradation enthalpy,and hardness could be retarded by adding chemically modified starches,especially hydroxypropyl starches.The effect of hydroxypropyl starch addition levels(2%,4%,6%,8%,and 10%)on the properties of rice flour and the edible quality of semi-dry rice noodles was further evaluated.The water solubility index of rice flour decreased with the addition of hydroxypropyl starch,while the swelling power showed the opposite trend.The quality of semi-dry rice noodles were improved with the addition of hydroxypropyl starch.Compared to the control,semi-dried rice noodles with 8%hydroxypropyl starch possessed superior properties,i.e.lower cooking loss(decreasing from 12.89%to 6.62%),lower adhesiveness(decreasing from 5.40 to 4.31 g·s),and higher hardness(rising from 10.89 to 13.81 N).These findings demonstrated that the incorporation of hydroxypropyl starch is a promising strategy for the preparation of semi-dry rice noodles with satisfactory cooking and edible qualities as well as a long shelf life.
文摘The polysaccharides, such as κ-carrageenan, ι-carrageenan, agarose (agar), gellan gum, amylose, curdlan, alginate, and deacetylated rhamsan gum, in water changed into an ice-like structure with hydrogen bonding between polymer and water molecules, and between water-water molecules even at a concentration range of 0.1% - 1.0% (W/V) at room temperature, resulting in gelation. Such dramatic changes from liquid into gels have been understood at the molecular level in principles. In this review, we describe the structure-function relationship of starch on the view point of rheological aspects and discuss gelatinization and retrogradation mechanism including water molecules at molecular level. The starch molecules (amylose and amylopectin) play a dominant role in the center of the tetrahedral cavities occupied by water molecules, and the arrangement is partially similar to a tetrahedral structure in a gelatinization process. The arrangement should lead to a cooperative effect stabilizing extended regions of ice-like water with hydrogen bonding on the surface of the polymer molecules, where hemiacetal oxygen and hydroxyl groups might participate in hydrogen bonding with water molecules. Thus, a more extended ice-like hydrogen bonding within water molecules might be achieved in a retrogradation process. Though many investigations not only include starch gelatinization and retrogradaion, but also the gelling properties of the polysaccharides have been undertaken to elucidate the structure-function relationship, no other researchers have established mechanism at the molecular level. There is reasonable consistency in our investigations.
基金supported by the National Key Technology R&D Program (2012BAD36B06)
文摘Tea Polysaccharides(TPS) has been acknowledged of one of the most important components with various bioactivities in tea.The extraction of TPS from wide tea sources was the previous and determinant work before further studies done.While the extraction procedures of TPS would be different due to the later utilization.In this work,the extraction conditions of TPS were previously optimized by respond surface methodology.A quadric model was obtained as Y = 3.16 + 0.31X1- 0.55X2- 0.47X3- 0.034X1X2+ 0.022X1X3- 0.041X2X3- 0.90X12-0.40X22- 0.73X32.The model was tested and proved through the ANOVA with F-value and p-value.Furthermore,the optimal condition was achieved as extraction temperature of 82℃,extraction time of 106 min and ratio of water to material of 33∶ 1(mL/g),meanwhile the highest yield of TPS showed 3.39% ± 0.08%.The crude TPS was later refined to be of purity of 81.3%.The refined TPS was incorporated with starch as to state the role of TPS in the starch retrogradation of starch-based food.The results showed that TPS-wheat starch mixture has a relatively low degree of retrogradation,which indicated that TPS has a delayed or resistant effect on wheat starch retrogradation.This work may provide a practical evidence for the promising starch-based food incorporated tea.
文摘背景与目的:临床中复杂的结石性胆管炎常合并Vater壶腹部狭窄,从而增加治疗的难度和复杂性。若只取除胆管内结石而不处理壶腹部狭窄问题,后期疾病容易反复发作。既往大多采取的方法主要是经内镜逆行胆胰管造影(ERCP)入路导丝顺向引导十二指肠乳头括约肌切开、取石术联合后期腹腔镜胆囊切除的方式处理。然而,ERCP在处理复杂情况时仍有一定局限性。为此,笔者团队首创了一种新型经腹腔入路治疗结石性胆管炎合并Vater壶腹部狭窄的方法。本研究探讨该方法的可行性与疗效,以期为临床提供新的治疗选择。方法:采用随机对照研究的方法,将2021—2023年因胆囊结石、胆管结石伴Vater壶腹部狭窄于成都市第二人民医院治疗的120例患者分为观察组和对照组,每组各60例,观察组行腹腔镜胆囊切除+胆管切开取石,并顺势从切开的胆管中插入导管逆向引导十二指肠乳头切开,同时处理胆囊、胆管结石及Vater壶腹部狭窄;对照组行传统ERCP入路乳头切开、胆管取石+腹腔镜胆囊切除术。收集两组患者围手术期相关指标,比较两组手术效果。结果:120例患者中,男性54例,女性66例。两组在胆道取石成功率、术中出血量、术后24 h总胆红素、直接胆红素、转氨酶、白细胞计数、黄疸缓解时间及胆汁漏、腹膜后出血/感染、重症胰腺炎发生率等方面,差异无统计学意义(均P>0.05)。观察组平均手术时间、术后住院时间均明显短于对照组(98.67 min vs. 110.8 min,P<0.05;3.81 d vs. 5.61 d,P<0.05),并且观察组术后高淀粉酶血症和(或)高脂肪酶血症、轻型胰腺炎发生率均明显更低(1.67%vs. 25.00%,P<0.001;0 vs. 10%,P=0.027)。结论:新型经腹腔入路在缩短手术时间、住院时间方面明显优于ERCP入路,术后发生轻症胰腺炎及高淀粉酶血症和(或)高脂肪酶血症的风险更低,并且胆管取石成功率不劣于ERCP入路,是一种可选择的治疗方式。
