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ObjectiveThe hygroscopic properties of Mume Flos decoction pieces were studied from the perspectives of macroscopic［water activity（Aw）］ and microscopic（water molecular mobility）， which provided a theoretical basis for the determination of the safe storage moisture content. MethodAdsorption isotherm of Mume Flos decoction pieces was obtained by static weighing method， and seven common hygroscopic models were fitted and estimated. The best model was selected according to the principle that determination coefficient（R2） was closer to 1， residual sum of squares（RSS） was closer to 0 and Akaike information criterion（AIC） was smaller. According to the optimal model， the absolute and relative safe moisture contents of Mume Flos decoction pieces at 25， 35， 45 ℃ was calculated. Low-field nuclear magnetic resonance（LF-NMR） was used to measure the water molecular mobility in the hygroscopic process of Mume Flos decoction pieces. ResultThe best model to describe the adsorption isotherm of Mume Flos decoction pieces was the Peleg model. According to the model expression， the absolute safe moisture contents of Mume Flos decoction pieces at 25， 35， 45 ℃ were 9.59%， 7.96% and 7.68%， and the relative safe moisture contents were 13.05%， 11.99%， 11.77%， respectively. Mume Flos decoction pieces all contained two water states during the process of hygroscopic absorption at different temperatures， namely bound water T21 and free water T22. During the process of hygroscopic absorption， bound water had the largest increase in peak area. The sum of peak areas of the bound water and free water had a good linear relationship with the moisture contents， and the R2 were 0.959 9， 0.911 8 and 0.974 7 at 25， 35， 45 ℃， respectively. When Aw<0.57， T21 did not change， and the water molecular mobility remained unchanged. When Aw>0.57， T21 showed an increasing trend， and the water molecular mobility increased. The moisture contents of Mume Flos decoction pieces were 8.44%， 6.81% and 6.25% when the water molecular mobility increased at 25， 35， 45 ℃， respectively. ConclusionCombined with the theory of water activity and water molecular mobility， 6.25% is recommended as the safe storage moisture content of Mume Flos decoction pieces， this study can provide reference for determining the safe storage moisture content of other decoction pieces.
RESUMO
ObjectiveModern scientific methods and techniques were used to scientifically characterize the traditional softening process of Corydalis Rhizoma， so as to clarify the scientificity and rationality of the traditional process， and provide reference for inheriting the processing methods and experience of traditional Chinese medicine. MethodLow-field nuclear magnetic resonance imaging （LF-NMR/MRI） was used to characterize the water types and distribution in the softening process of Corydalis Rhizoma. Samples during the softening process was cut into thick slices and its section was observed by stereoscopic microscope. High performance liquid chromatography （HPLC） was employed to determine the content change of tetrahydropalmatine during the softening process with the mobile phase of methanol-0.1% phosphoric acid solution （60∶40， triethylamine regulated to pH 6.5） and detection wavelength at 280 nm. The determination method of softening endpoint of Corydalis Rhizoma was simulated by texture analyzer （hand pinch method）， and the softening degree of the finished products was determined after optimizing the relevant parameters. ResultLF-NMR/MRI showed that the water could penetrate through the core and distribute evenly in Corydalis Rhizoma softened by Zhangbang method. The water first entered into the medicinal material from the epidermis and stem marks in the soaking stage as the form of free water， and then penetrated into the inner core to achieve redistribution in the moistening stage. Under stereoscopic microscope， it was observed that Corydalis Rhizoma softened by the Zhangbang method could be sliced well， but the core bursting slices were easy to appear if the softening time was not enough， and the softening of samples was caused by the keratine-like powder after absorbing water. HPLC measurement showed that the loss of tetrahydropalmatine in the softening method was small， its content decreased about 5% in the soaking process， and its content was almost unchanged during the moistening process. The softening degree of Corydalis Rhizoma could be quantified by the texture analyzer， and the optimum parameters were 2 mm·s-1 of speed before test， test speed and speed after test， 20 g of the trigger force， 20% of compression degree. The compressive force of the qualified softened Corydalis Rhizoma was 12.75-15.69 N with the relative standard deviation （RSD） of 6.8%. ConclusionModern scientific methods and techniques can characterize the scientificity and rationality of the traditional processing methods， and confirm that the Zhangbang softening method has the advantages of high efficiency， convenience and small loss of index components. The texture analyzer can simulate the softening endpoint judgment method （hand pinch method）， and realize the goal from subjective experience judgment to objective technology quantification， which has a good demonstration role for the modern inheritance of traditional processing technology.
RESUMO
ObjectiveModern scientific methods and techniques were used to scientifically characterize the traditional softening process of Corydalis Rhizoma， so as to clarify the scientificity and rationality of the traditional process， and provide reference for inheriting the processing methods and experience of traditional Chinese medicine. MethodLow-field nuclear magnetic resonance imaging （LF-NMR/MRI） was used to characterize the water types and distribution in the softening process of Corydalis Rhizoma. Samples during the softening process was cut into thick slices and its section was observed by stereoscopic microscope. High performance liquid chromatography （HPLC） was employed to determine the content change of tetrahydropalmatine during the softening process with the mobile phase of methanol-0.1% phosphoric acid solution （60∶40， triethylamine regulated to pH 6.5） and detection wavelength at 280 nm. The determination method of softening endpoint of Corydalis Rhizoma was simulated by texture analyzer （hand pinch method）， and the softening degree of the finished products was determined after optimizing the relevant parameters. ResultLF-NMR/MRI showed that the water could penetrate through the core and distribute evenly in Corydalis Rhizoma softened by Zhangbang method. The water first entered into the medicinal material from the epidermis and stem marks in the soaking stage as the form of free water， and then penetrated into the inner core to achieve redistribution in the moistening stage. Under stereoscopic microscope， it was observed that Corydalis Rhizoma softened by the Zhangbang method could be sliced well， but the core bursting slices were easy to appear if the softening time was not enough， and the softening of samples was caused by the keratine-like powder after absorbing water. HPLC measurement showed that the loss of tetrahydropalmatine in the softening method was small， its content decreased about 5% in the soaking process， and its content was almost unchanged during the moistening process. The softening degree of Corydalis Rhizoma could be quantified by the texture analyzer， and the optimum parameters were 2 mm·s-1 of speed before test， test speed and speed after test， 20 g of the trigger force， 20% of compression degree. The compressive force of the qualified softened Corydalis Rhizoma was 12.75-15.69 N with the relative standard deviation （RSD） of 6.8%. ConclusionModern scientific methods and techniques can characterize the scientificity and rationality of the traditional processing methods， and confirm that the Zhangbang softening method has the advantages of high efficiency， convenience and small loss of index components. The texture analyzer can simulate the softening endpoint judgment method （hand pinch method）， and realize the goal from subjective experience judgment to objective technology quantification， which has a good demonstration role for the modern inheritance of traditional processing technology.
RESUMO
Objective To study the moisture transfer laws of Chaenomeles sinensis in different drying processes. Methods Using the non-destructive and non-invasive technique of low field-nuclear magnetic resonance (LF-NMR), the transverse relaxation time (T2) inversion spectrum of C. sinensis slice was monitored under different drying methods (hot air drying, drying after evaporation, segmental drying and drying in the shade) to analyze the changes of moisture migration. Results There were three different types water that were detected in C. sinensis (free water > bound water > immobilized water). The internal water distribution and water content changed during drying process. The moisture changes were similar in hot air drying, drying after steaming, and drying in shade, the total water gradually decreased, and the combining degree between moisture and non-water components enhanced. Steaming promoted the water loss rate of C. sinensis slice, the water loss rate was higher in drying after steaming than in hot air drying, and the difference was significant (P < 0.05). During the intermittent drying, the conversion of different states of water would occur in order to return to a relatively stable equilibrium. During the low temperature drying process, immobilized water content decreased and free water content increased. The low-temperature drying has less damage to the tissue, which is more conducive to the conversion of immobilized water into free water, and thus the water dissipated faster. During the early of drying, high temperature caused tissue structure damage, the bonding force between water and non-aqueous tissue would be strengthened because of the tissue shrinkage. Conclusion The three different types water content and peak area in T2 was positively correlated. The LF-NMR technique would provide useful guides for the investigation of water distribution and variation of C. sinensis, which will provide a theoretical basis for C. sinensis processing.
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Abstract Physical-chemical and rheological properties of pork batters as affected by replacing pork back-fat with pre-emulsified sesame oil were investigated. Replacement of pork back-fat with pre-emulsified sesame oil, improved L* value, moisture and protein content, hardness, cohesiveness, and chewiness, declined a* value, fat content and energy, but not affect cooking yield. When used pre-emulsified sesame oil to replace pork back-fat 50%, the sample had the highest L* value and texture. According to the results of dynamic rheological, replaced pork back-fat by pre-emulsified sesame oil increased the storage modulus (G') values at 80 °C, and formed firm gel. The result of Low-field nuclear magnetic resonance (LF-NMR) shown that the batters with pre-emulsified sesame oil had higher water holding capacity than the control. Overall, the batters with pre-emulsified sesame oil enabled lowering of fat and energy contents, making the pork batter had better texture.