Search

To enhance the product quality, manufacturers of dried fruits are dedicated to developing reliable methods for assessing ripeness. In this study, a densimetric flotation method was employed to categorize mulberries into five distinct ripening stages (D1–D5, 0.905–1.055 g/cm³). The influence of ripening on mulberry water status, distribution, microstructure, drying characteristics, and product quality was examined. Heat pump drying, utilizing a temperature of 60 °C, relative humidity of 15%, and air velocity of 2 m/s, was employed as the drying technique for mulberries. As ripening progressed, the water binding capability initially decreased and then increased. Simultaneously, water distribution and cell microstructure shifted, resulting in an initial reduction followed by an extension in drying time. The drying time initially decreased and then increased with increasing maturity, with D4 fruits displaying the shortest drying time (13.9 h). This was 35.05%, 24.04%, 20.14%, and 6.47% shorter than the drying times observed in stages D1, D2, D3, and D5, respectively. Ripeness significantly affected the volatile composition, color, texture, and sensory attributes of dried fruits. D1 fruits were not suitable for drying due to their intact cellular structure, lengthy drying time, and poor sensory quality of the resulting product. Conversely, D4 and D5 fruits exhibited shorter drying times and their products possessed a robust fruity aroma, improved palatability, and overall acceptance. This rendered them ideal candidates for the drying process. The findings of this research have practical implications for effective identification and drying procedures during mulberry ripening. [ABSTRACT FROM AUTHOR]

The effects of adding cellulose with different particle sizes and proportions on the gel properties of three common surimi products, namely fish balls, fish intestines, and fish cakes, were studied, and the best particle sizes and proportions were selected. This experiment determined the best particle size and proportion by studying the effects of adding different particle sizes and proportions of cellulose on the whiteness, water holding capacity, gel strength, total texture analysis, water distribution, and sensory aspects of fish balls, fish intestines, and fish cakes. The experiment found that the addition of cellulose could effectively improve the whiteness, water retention, gel strength, and texture characteristics of three common surimi products, and reduce the content of free water. The water holding capacity of fish balls, fish intestines, and fish cakes, gel strength, hardness, chewiness, and the proportion of water that was difficult to flow would increase with the increase of cellulose particle size, and first increase and then decrease with the increase of the addition proportion. It was found that the particle size of cellulose was 200 μm. When the addition ratio was 2%, the sensory evaluation would be more popular with consumers. After comprehensive consideration, the particle size of added cellulose was 200 μm. When the addition ratio was 2%, the quality of three common surimi products could be improved to the greatest extent, and the water holding capacity of fish balls, fish intestines and fish cakes can be increased by 14.5%, 22.1%, and 8.9% respectively. Gel strength increased by 121.9%, 108.7%, nd 65.5%. Hardness increased by 97.5%, 107.0%, and 158.8%. The proportion of non-flowing water increased by 0.8%, 1.7%, and 1.7%. [ABSTRACT FROM AUTHOR]

In order to investigate the changes of internal water content and migration of blueberries with storage time under FIRD-HPD drying method, Low Field Nuclear Magnetic Resonance (LNMR) was used. LF-NMR and its Magnetic Resonance Imaging (MRI) technique were used to collect the relaxation characteristics and proton density image information of blueberry during drying at different water transition points, analyze the changes of their regularity, and further study the changes of blueberry quality before and after drying. The results showed that when the water transfer point was 30%, 40% and 50%, the drying time of blueberry was 480 min, 420 min and 360 min, respectively. The T2 inversion spectrum of blueberry has three distinct relaxation peaks: T21 (0.01-10 ms) bound water, T22 (10-100 ms) immobile water, and T23 (100-1 000 ms) free water. Free water (T23) and non-mobile water (T22) migrated to the direction of short relaxation time. In the late drying period, bound water became the main water state in blueberry, and free water disappeared completely. Based on MRI technology, magnetic resonance imaging of different drying methods at each drying stage was obtained, and the proton signal gradually decreased with the drying process. LF-NMR and MRI techniques can be used to monitor dynamic water distribution and migration during drying. In addition, the dry color and nutritional quality of blueberries under 40% moisture transfer point combined with far-infrared heat pump drying were superior to 30% and 50% moisture transfer point combined with far-infrared heat pump drying. Taking into consideration, the combination of infrared dry moisture conversion point set at 40% is the best choice for processing dried blueberries. [ABSTRACT FROM AUTHOR]

The tobacco waste generated from the tobacco agriculture and industry, including the discarded stem and leaf, often needs dehydration pretreatment before thermal conversion utilization. In order to study the water activity and migration of tobacco waste during the pretreatment process, TG-NMR (Thermogravimetric Nuclear Magnetic Resonance) was used to obtain the drying curves and LF-NMR (Low Field Nuclear Magnetic Resonance) T2 inversion spectrum at each stage of tobacco drying. Meanwhile, the variation pattern of pore distribution during the dehydration process of two types of tobacco waste has been obtained. Combined with the pore distribution changes, a possible spatial migration mode of water was proposed. The change of adsorption energy of water during tobacco drying was calculated, and verified the above hypothesis. This study results provide reference for the optimization of dehydration pretreatment process for different tobacco waste in order to reduce energy consumption during recycling of tobacco biomass. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (2097-2806) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Storage & Process is the property of Tianjin Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to comprehensive evaluate the effects of different drying pretreatment on the quality and microstructure of yam slices. Fresh sliced yam was pretreated by three different methods: High voltage electrostatic field, ultra-high pressure and freezing. Low field nuclear magnetic resonance and characteristic drying curve were used to determine yam's water status, distribution and content, and analyze changes in microstructure, color, rehydration and other characteristics. Results showed that the freezing pretreatment had the most severe damage on yam slices and the minimum drying time, reduced moisture ratio to 0.1 in 160 min. The high voltage electrostatic field pretreatment was better than other methods in preserving the microstructure of yam. The content of original pectin and cellulose in yam were significantly (P

In order to explore the effect of pre-drying methods on the quality attributes of instant controlled pressure drop puffing (DIC) dried whole shiitake (Lentinus edodes) crisps and develop ready-to-eat L. edodes snack food, this study investigated the influence of three different pre-drying methods, viz., hot air drying (HAD), heat pump drying (HPD) and vacuum freeze drying (FD) on the quality attributes of L. edodes crisp. The results showed that the total drying time of L. edodes crisps depended on the pre-drying method, following the order of HAD-DICHAD-DIC>FD-DIC. The rehydration ratio of L. edodes crisps followed the order of FD-DIC>HPD-DIC>HAD-DIC. HAD-DIC resulted in the highest hardness and lowest brittleness. FD-DIC resulted in the lower hardness and crispness. HPD-DIC resulted in the highest crispness and optimal hardness. The total sugar content of L. edodes crisps followed the order of FD-DIC>HPD-DIC>HAD-DIC. Low field nuclear magnetic resonance (LF-NMR) revealed that compared with HAD and FD, the proportion of tightly bound water and immobilized water in L. edodes after HPD was higher, and the proportion of tightly bound water was lower, which was conductive to water flash evaporation during DIC processing thus providing sufficient driving force for the puffing of Lentinus edodes. In conclusion, HPD was the best pre-drying method for L. edodes crisps.

The molecular weight is an important indicator for assessing the aging of polymers. However, existing methods for characterizing the molecular weight of polymers involve complex procedures and destructive tests. Therefore, efficient, rapid, and non-destructive testing methods would be a key development in material degradability evaluation. In this paper, we studied the thermo-oxidative aging process of polybutylene adipate terephthalate (PBAT) using a low-field nuclear magnetic resonance (LF-NMR) analysis method. The degradation mechanism of PBAT during thermo-oxidative aging is characterized by its low-field nuclear magnetic resonance decay curve and inversion curve. A two-component LF-NMR fitting analysis reveals that the thermo-oxidative degradation of PBAT conforms to a random fracture mechanism. Furthermore, a correlation between number average molecular weight and LF-NMR relaxation time during thermo-oxidative degradation of PBAT was constructed, with a correlation coefficient R2 greater than 0.97. The error between the correlation equation used in the molecular weight detection of PBAT and the actual test is less than 10%, indicating that it is feasible and reliable to characterize the number average molecular weight of materials by applying the LF-NMR relaxation time.

The low-field nuclear magnetic resonance (NMR) technique has been used to probe the pore size distribution and the fluid composition in geophysical prospecting and related fields. However, the speed and accuracy of the existing numerical inversion methods are still challenging due to the ill-posed nature of the first kind Fredholm integral equation and the contamination of the noises. This paper proposes a novel inversion algorithmto accelerate the convergence and enhance the precision using empirical truncated singular value decompositions (TSVD) and the linearized Bregman iteration. The L1 penalty term is applied to construct the objective function, and then the linearized Bregman iteration is utilized to obtain fast convergence. To reduce the complexity of the computation, empirical TSVD is proposed to compress the kernel matrix and determine the appropriate truncated position. This novel inversion method is validated using numerical simulations. The results indicate that the proposed novel method is significantly efficient and can achieve quick and effective data solutions with low signal-to-noise ratios. [ABSTRACT FROM AUTHOR]

Copyright of Packaging & Food Machinery is the property of Packaging & Food Machinery Magazine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the effects of slow freezing (−20 ℃) and quick freezing (−80 ℃) on the cell wall structure of waxberry fruits were investigated, and the changes of main nutrient quality components during storage were also studied. The moisture content and migration of waxberry fruits during storage were observed by low field NMR. The results showed that the cell wall morphology of quick-frozen waxberry fruits maintained well, and there were obvious gaps in the cross section of the cell wall of slow-frozen waxberry fruits. During the storage period of 25 days, the water content of fruit gradually decreased, but the range of water transfer of quick-frozen waxberry was small, and the total lateral relaxation time was larger than the relaxation time of slow-frozen waxberry, indicating that quick-frozen waxberry could effectively maintain fruit water activity. The free water signal value of quick-frozen waxberry decreased only by 18%, while the free water signal value of slow-frozen waxberry decreased by 47.75%, indicating that quick-frozen waxberry was beneficial to maintaining fruit water content. In addition, fruit nutrients decreased gradually, but the total sugar content, titratable acid content, total phenols and anthocyanins contents were 13.64 mg/g, 13.43 g/L, 15.43 mg/mL and 0.53 μmol/g, respectively, at the end of storage stage of quick-frozen waxberry. The retention rates of main nutritional indexes were higher than those of slow frozen waxberry. Therefore, quick-freezing can effectively delay the loss of nutrients in waxberry fruits.

Scallop adductors were pretreated with different ethanol concentration, viz., 0, 25, 50, 75, and 100% (coded as CK, E-25, E-50, E-75, and E-100, respectively) to enhance drying efficiency and quality of heat pump dried products. The drying time of scallop adductors was significantly (p < 0.05) reduced by 13.3% for E-100 in comparison to CK at the end of drying process. Low field nuclear magnetic resonance revealed that the immobilized water (T22) was the predominant water status in scallop adductors. With drying proceeding, T22 decreased by more than 60% from initial values in all samples and tended to convert to bound water and/or free water. The Weibull model and Dincer model were well fitted to describe the drying behavior of scallop adductors with high R2 and low RMSE values. The effective moisture diffusivity calculated by Fick's diffusion model, Weibull model, and Dincer model ranged 9.345 − 9.948 × 10−11, 2.453–2.670 × 10−9, and 9.68–11.45 × 10−9m2 s−1, respectively. The total color difference, shrinkage rate and hardness of dried samples with suitable ethanol concentration pretreatment were lower, and rehydration ratio was higher than those of CK. Ethanol pretreatment could be a promising method to effectively enhance drying efficiency and improve product quality of scallop adductors. [ABSTRACT FROM AUTHOR]

Gasification fine slag, a carbon-rich solid waste produced during coal gasification, is currently disposed of through conventional landfilling methods. Its high-water content hampers resource utilization by reducing its calorific value. This study employs low field nuclear magnetic resonance (LF-NMR) analysis to investigate the water occurrence states in a filter cake with 70.7% moisture content derived from fine gasification slag of the Ningxia coal water slurry furnace. The analysis reveals that free water constitutes a major proportion (68.28%), while combined and capillary water accounts for 2.62% and 2.33%, respectively. The removal of moisture from the coal gasification fine slag filter cake is significantly affected by the drying temperature. The drying rate initially increases and then decreases with different temperatures. For drying temperatures of 60, 70, 80, 90, and 100°C, the maximum drying rates are achieved at 1.09, 1.23, 2.18, 3.86, and 4.01%/min, respectively, with corresponding durations of 40, 40, 25, 30, and 35 min. The T22 relaxation peak area continually decreases and shifts leftward on the coordinate axis. The behavior of the T23 and T22 peaks follows a similar pattern, indicating that water with higher mobility is easily eliminated during drying, while the T21 peak exhibits a robust signal strength throughout the drying process. At a drying temperature of 100°C, the proportion of free water (A22) decreases from 87.3% to 0, the A23 fluctuates between 0 and 5.3%, and the bound water peak area (A21) increases from 10.4% to 94.7% as drying time prolongs. A relationship model is developed between the moisture content of the coal gasification fine slag filter cake and the total integral area of the LF-NMR test, enabling rapid detection and analysis of the total moisture content and distinct occurrence states in the filter cake. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, a low field nuclear magnetic resonance (LF-NMR) homogeneous sensor was constructed for detection of Escherichia coli (E. coli) based on the copper metabolism of E. coli triggered click reaction. When live E. coli was present, a large amount of Cu2+ ions were transformed into Cu+ via copper metabolism, which then catalyzed a Cu+-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between two materials, azide group modified gadolinium oxide nanorods (Gd 2 O 3 -Az) and PA-GO@Fe 3 O 4 i.e., graphene oxide (GO) loaded with large amounts of alkynyl (PA) groups and Fe 3 O 4 nanoparticles simultaneously. After magnetic separation, unbound Gd 2 O 3 -Az was dissolved by added hydrochloric acid (HCl) to generate homogeneous Gd3+ solution, enabling homogeneous detection of E. coli. Triple signal amplification was achieved through the CuAAC reaction induced by E. coli copper metabolism, functional nanomaterials, and HCl assisted homogeneous detection. Under the optimal experimental conditions, the linear range and limit of detection (LOD) for E. coli were 10–1.0 × 107 CFU/mL and 3.5 CFU/mL, respectively, and the relative standard deviations (RSDs) were all less than 2.8 %. In addition, the sensor has satisfactory selectivity, stability and practical sample application capability, providing a new approach for the LF-NMR detection of food-borne pathogenic bacteria. [Display omitted] • Triple signal amplification of the sensor was realized for detection of E. coli. • E. coli metabolism-mediated click chemistry was introduced to the LF-NMR sensor. • Acidolysis of signal units from nanomaterials to ions for homogeneous detection. • Homogeneous detection mediated by pure chemical systems to ensure precision and accuracy. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heat Pump Drying (HPD) is especially suitable for the drying of aquatic products, owing to the mild conditions and high energy efficiency. However, the low drying temperature can result in a long drying time for the quality degradation in aquatic products processing. This study aims to enhance the drying efficiency of scallop adductors and quality attributes of dried products, particularly for better HPD application. The scallop adductors were firstly pretreated with ultrasonic (US) pulses. Then, three kinds of edible coating were selected, including Sodium Alginate (SA), Low-Methoxy Pectin (LMP), and Gum Ghatti (GG). Subsequently, the HPD was carried out for the samples with different coating pretreatment. The pretreatment without coating (i.e., merely pretreated with US) was set as the control group (CK). Finally, an investigation was made to determine the effects of three kinds of edible coating pretreatment on the drying kinetics and quality attributes of scallop adductors during US-assisted HPD. The low-field nuclear magnetic resonance (LF-NMR) was utilized to monitor the drying process of scallop adductors. The Univariate Linear (UL) and partial least squares regression (PLSR) models were employed to correlate the LF-NMR parameters with the Moisture Content (MC) and water activity (aw). The effective moisture diffusivity (Deff) of scallop adductors increased with the edible coating pretreatment in the range of 1.32%-8.41%, compared with the CK. The SA and GG pretreatment slowed down the migration rate of immobilized water towards bound water. As such, the flow of free water increased during drying, thus enhancing the drying efficiency of scallop adductors. More importantly, the SA and GG pretreatment increased the hardness, elasticity, cohesion, and chewiness of dried scallop adductors, whereas, decreased the rehydration ratio, shrinkage rate, and total color difference of dried products. There was a decrease in the hardness and total color difference of LMP pretreated samples. In summary, the US-SA was the most suitable pretreatment for the US-assisted HPD of scallop adductors. There was a significant (P<0.05) correlation between the LF-NMR transverse relaxation time (T2) and most quality attributes of dried scallop adductors. The end point of drying was determined in the LF-NMR spectra of samples, indicating the main peak of transverse relaxation time T2 <10 ms and only one peak. The UL model showed that the MC and aw were significantly (P<0.05) positively correlated with the peak area of immobilized water and total peak area, but negatively (P<0.05) correlated with the peak area of bound water. The PLSR model revealed that the regression model with four LF-NMR parameters as the variables accurately predicted the MC and aw of scallop adductors during HPD. This finding can provide a novel non-thermal pretreatment for the drying of scallop adductors, particularly with the enhanced drying efficiency and quality attributes of the dried products. Furthermore, the LF-NMR technology can also provide the theoretical basis and practical reference for the rapid and non-destructive monitoring of scallop adductors during US-assisted HPD. [ABSTRACT FROM AUTHOR]

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dendrobium officinale has been one of the most precious medicinal plants in China. The functions of antioxidant, antitumor, and immune can be attributed to the biologically active components in the plant, including polysaccharides, polyphenols, and dendrobine. The quality of Dendrobium officinale is prone to deteriorate during storage, due mainly to the stems rich in the water content. Therefore, the dried Dendrobium officinale stems can often inhibit the reproduction of spoilage microorganisms and chemical degradation. The present study aims to optimize the drying process for the high quality of dried Dendrobium officinale stems. A systematic investigation was also implemented to clarify the effect of directly cutting, blanching, and freeze-thaw cycles on the drying characteristics and quality of dried Dendrobium officinale stems. The water mobility and distribution were characterized using ¹H Low-Field Nuclear Magnetic Resonance (LF-NMR) and Magnetic Resonance Imaging (MRI) techniques. The results indicated that the pretreatments played an important role in the drying process of Dendrobium officinale stems. Compared with the directly shearing, the blanching and freeze-thaw cycle treatments were beneficial to enhance the effective water diffusion coefficient for the less consumption of energy, and thereby speeding up the drying process. Especially, the freeze-thaw cycle treatment was more effective to improve the drying rate, where the drying time and energy consumption were reduced by 44.4% and 42.76% (P<0.05), respectively. The LF-NMR results showed that there were still three states of water in the stems of Dendrobium officinale. Free water accounted for the largest proportion, followed by the non-flowing water, and the bound water was the least. The MRI images indicated that the moisture on the surface of Dendrobium officinale stems was first removed in the drying process, and then the internal moisture migrated to the surface for evaporation. Scanning Electron Microscopy (SEM) images showed that the intercellular space of dehydrated Dendrobium officinale slices increased, and the cell wall was damaged after blanching and freeze-thaw pretreatments, leading to the changes in water fluidity and distribution for the accelerated migration and removal of water during drying. In the drying characteristics, the free water was removed first in the drying process. Both blanching and freeze-thaw cycle pretreatments were used to reduce the removal time of free water. The freeze-thaw cycle pretreatment took the shortest time (120 min) to remove the free water. It showed that the freeze-thaw cycle greatly contributed to weakening the binding of tissue structure to water for the better fluidity of water. The MRI found that the brightness area of Dendrobium officinale slices decreased with the extension of drying time, whereas, the red gradually decreased, indicating the decrease in water during drying. The freeze-thaw cycle pretreatment was led to the higher retention of polysaccharides and polyphenols in Dendrobium officinale stems, which increased by 10.66% and 12.32%, respectively, whereas, the blanching pretreatment was led to the lower retention of polysaccharides and polyphenols in Dendrobium officinale stems, which was reduced by 11.73% and 14.73%, respectively, compared with the directly shearing during drying. The three pretreatments had no significant effect on the content of dendrobine, which were 1.03, 1.01, and 1.02 mg/g, respectively (P>0.05). In a word, the freeze-thaw cycle pretreatment performed better to speed up the drying process for the high quality of dried Dendrobium officinale stems. The finding can provide the experimental reference to optimize the drying process of Dendrobium officinale stems, further reducing the risk of quality deterioration for the standardization of primary processing of Dendrobium officinale. [ABSTRACT FROM AUTHOR]

Avocado oil (AO) has been found to be adulterated by low-price oil in the market, calling for an efficient method to detect the authenticity of AO. In this work, a rapid and nondestructive method was developed to detect adulterated AO based on low-field nuclear magnetic resonance (LF-NMR, 43 MHz) detection and chemometrics analysis. PCA analysis revealed that the relaxation components area (S23) and relative contribution (P22 and P23) were crucial LF-NMR parameters to distinguish AO from AO adulterated by soybean oil (SO), corn oil (CO) or rapeseed oil (RO). A Soft Independent Modelling of Class Analogy (SIMCA) model was established to identify the types of adulterated oils with a high calibration (0.98) and validation accuracy (0.93). Compared with partial least squares regression (PLSR) models, the support vector regression (SVR) model showed better prediction performance to calculate the adulteration levels when AO was adulterated by SO, CO and RO, with high square correlation coefficient of calibration (R2C > 0.98) and low root mean square error of calibration (RMSEC < 0.04) as well as root mean square error of prediction (RMSEP < 0.09) values. Compared with SO- and CO-adulterated AO, RO-adulterated AO was more difficult to detect due to the greatest similarity in fatty acids' composition being between AO and RO, which is characterized by the high level of monounsaturated fatty acids and viscosity. This study could provide an effective method for detecting the authenticity of AO. [ABSTRACT FROM AUTHOR]

Soybean sprout is one type of edible vegetable that is cultivated by sprouting soybeans. Taking Zhonghuang 13 as the research object, a series of treatments were carried out using the 6-BA solution with concentrations of 0, 1, 3, 5, 7, and 9 mg/L under the same environmental conditions. The water distribution in soybean was measured to determine the growth state under the different concentrations of 6-BA during soybean germination. The low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) were selected to clarify the effect of 6-BA on the germination of soybean. Three procedures included the LF-NMR, LF-NMR/MRI imaging, and the acquirement of soybean physical, chemical, and morphological indexes. The proton density (PD) image was extracted from the nuclear magnetic signals collected by the Carr-Purcell-Meiboom-Gill (CPMG) spin echo pulse sequence. The results show that the water evolution was visually determined during soybean germination using the LF-NMR PD images. The soybean germination was divided into the imbibition (0-8 h), protrusion (8-24 h), and germination stage (24-60 h). The germination cycle from the soaking to germination varied with the concentration of 6-BA solution in the treatment groups. The germination time of soybean seeds with the 0, 1, and 3 mg/L of 6-BA solution was shorter than that of the rest, where the best was the 3 mg/L concentration. The water content in various phases of soybean was quantitatively characterized by LF-NMR data. According to the relaxation time, the water content of soybean was divided into three kinds: the bound water T21, semi bound water T22, and free water T23. The sub peak was disappeared gradually on the left side of bound water (0.1 ms

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Internal fungal infection and pest invasion are defects commonly found in dried longan fruits, which cannot be visualized easily without peeling. The present work was aimed to develop a non-destructive method for discriminating defective dried longan fruits via measuring the transverse relaxation times (T2) by Low-Field Nuclear Magnetic Resonance (LF-NMR) that characterized the bound water in the fruits, with 274 in total and defects versus normal at 107:167. A decreasing tendency of transverse relaxation amplitude in defective samples was observed, consistent to the change of proton density distribution by Magnetic Resonance Imaging (MRI) with weakened signal in moldy/wormy flesh shown compared with normal ones. Both Principal Component Analysis (PCA) and Deep Learning Neural Network (DLNN) models were applied to analyze the T2 relaxation time for predicting the defective fruits. The DLNN model yielded a satisfactory performance and achieved accuracy, recall and F-score marks up to 89 %, 82 % and 86 % for 10-fold cross validation, respectively, compared with approximately 80 %, 60 % and 74 % by PCA cluster. This study highlighted a novel non-destructive approach for discriminating defective dried longan fruits of high efficiency featured by high recall, precision and accuracy using DLNN modeling based on LF-NMR. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wood is an increasingly important material in the sustainable transition of societies worldwide. The performance of wood in structures is intimately tied to the presence of moisture in the material, which directly affects important characteristics such as dimensions and mechanical properties, and indirectly its susceptibility to fungal decomposition. By chemical modification, the durability of wood in outdoor environments can be improved by reducing the amount of moisture present. In this study, we refined a well-known chemical modification with acetic anhydride and showed how the spatial distribution of the modification of Norway spruce (Picea abies (L.) Karst.) could be controlled with the aim of altering the wood-water interactions differently in different parts of the wood structure. By controlling the reaction conditions of the acetylation it was possible to acetylate only the cell wall-lumen interface, or uniformly modify the whole cell wall to different degrees. The spatial distribution of the acetylation was visualised by confocal Raman microspectroscopy. The results showed that by this targeted acetylation procedure it was possible to independently alter the wood-water interactions in and outside of cell walls. The cell wall-lumen interface modification altered the interaction between the wood and the water in cell lumina without affecting the interaction with water in cell walls while the uniform modification affected both. This opens up a novel path for studying wood-water interactions in very moist environments and how moisture distribution within the wood affects its susceptibility towards fungal decomposition. [ABSTRACT FROM AUTHOR]

Studying on the pore size distribution of coal is vital for determining reasonable coalbed methane development strategies. The coalbed methane project is in progress in the southern Junggar Basin of northwestern China, where high volatile bituminous coal is reserved. In this study, with the purpose of accurately characterizing the full-scale pore size distribution of the high volatile bituminous coal of the southern Junggar Basin, two grouped coal samples were applied for mercury intrusion porosimetry, low-temperature nitrogen adsorption, low-field nuclear magnetic resonance, rate-controlled mercury penetration, scanning electron microscopy, and nano-CT measurements. A comprehensive pore size distribution was proposed by combining the corrected mercury intrusion porosimetry data and low-temperature nitrogen adsorption data. The relationship between transverse relaxation time (T2, ms) and the pore diameter was determined by comparing the T2 spectrum with the comprehensive pore size distribution. The macro-pore and throat size distributions derived from nano-CT and rate-controlled mercury penetration were distinguishingly analyzed. The results showed that: 1) comprehensive pore size distribution analysis can be regarded as an accurate method to characterize the pore size distribution of high volatile bituminous coal; 2) for the high volatile bituminous coal of the southern Junggar Basin, the meso-pore volume was the greatest, followed by the transition pore volume or macro-pore volume, and the micro-pore volume was the lowest; 3) the relationship between T2 and the pore diameter varied for different samples, even for samples with close maturities; 4) the throat size distribution derived from nano-CT was close to that derived from rate-controlled mercury penetration, while the macro-pore size distributions derived from those two methods were very different. This work can deepen the knowledge of the pore size distribution characterization techniques of coal and provide new insight for accurate pore size distribution characterization of high volatile bituminous coal. [ABSTRACT FROM AUTHOR]

Aquatic products, such as fish, are popular throughout the world due to their satisfying flavor characteristics as well as rich animal nutrition, and they provide high-value food therapy, but they are easily oxidized and spoiled. It is necessary to detect aquatic products through rapid and accurate technology. Low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) have been widely used in the aquatic product industry due to their sensitivity, fast analysis, non-destructive nature and low cost. The applications of LF-NMR in the measurement of aquatic product quality and nutrients (water, fat, and protein) are summarized in this paper. Applications in aquatic products have been shown to depend on deep processing, storage and authentication. This review discusses the application of MRI technology in the quality control of aquatic products. Therefore, this review will guide the application of the aquatic products industry and aims to supply the reader with both the theory of the method and practical applications of the method for use as a rapid and non-destructive technology in scientific research and the industrial industry.

The mechanism for protein stabilization or destabilization has long been an open quest. In the present study, we have studied the interactions between amino acids and guanidinium (Gdm+)/ammonium (NH 4 +) ions by using low field nuclear magnetic resonance (LF-NMR), where Gdm+ and NH 4 + are denaturant and stabilizer for proteins, respectively. It shows that Gdm+ favors to bind to the thiol group or the hydroxyl group on the side chain but weakly interacts with the α-carboxyl group. In contrast, NH 4 + prefers to bind to the α-carboxyl group but slightly interacts with the thiol group or the hydroxyl group on the side chain of amino acids. 1HNMR reveals the hydrogen bonding between NH 4 + and the α-carboxyl group, which is not involved in the interactions between Gdm+ and cysteine. Our study demonstrates that the strong interactions between the denaturant and the sulfur atom or the disulfide bond promote the direct binding of the denaturant toward proteins, leading to the destabilization. [Display omitted] • The hydrogen exchange between Gdm+/NH 4 + and water are used to probe the interactions between cations and amino acids. • Gdm+ binds to the thiol group or the hydroxyl group on the side chain but weakly interacts with the α-carboxyl group. • NH 4 + interacts strongly with the α-carboxyl group but weakly with the thiol group or the hydroxyl group on the side chain. • Based on the hydrogen exchange, the number of bound cations to different amino acids can be obtained. [ABSTRACT FROM AUTHOR]

Garlic (Allium sativum L.) is a biennial plant in the Liliaceae family. It is widely used as a condiment in cooking and daily life in the world, as well as Chinese herbal medicine. The garlic is rich in biologically active components, including allicin, polysaccharides, amino acids, and volatile oils, thereby mainly relieving fatigue and improve human immunity. Since the garlic has high water content in general, the quality is prone to deterioration during storage. Therefore, the dried garlic can inhibit the reproduction of spoilage microorganisms and chemical degradation, and further retain the original flavor of garlic, thereby extending the shelf life. At present, a commonly used technology of hot-air drying is characterized by the simple operation and large loading capacity, but the low drying efficiency and the long drying time has resulted in low quality of products after drying. In this study, a feasible pretreatment combined with the ultrahigh pressure (UHP) and ultrasound (US) was proposed to improve the drying process and quality of dried garlic slices. A low field nuclear magnetic resonance (LF-NMR) was selected to analyze the influence of pretreatments on the internal moisture migration during the drying process of garlic slices. The results found that the US or UHP during the hot air drying was beneficial to enhance the internal mass transfer of garlic slices, and thereby speed up the drying process. The US, UHP, and UHPs-US pretreatments resulted in a reduction in the drying time of garlic slices by 37.50%, 43.75%, and 62.50%, respectively, compared to the control. Six mathematical models were selected to fit the drying process of garlic slices. All three pretreatments reduced the energy consumption of drying, especially in the UHP-US, 32.31% lower than that with the untreated. The LF-NMR results showed that there were still three states of water in the garlic slices after pretreatments. Free water accounted for the largest proportion, followed by the non-flowing water, and the bound water was the least. In the drying characteristics, the free water was removed first in the drying process. All the US, UHP, and UHP-US reduced the removal time of free water. The UHP-US pretreatment took the shortest time (90 min) to remove the free water, indicating that the UHP-US was more conducive to weakening the binding of tissue structure to water for the better fluidity of water. Scanning electron microscopy (SEM) images revealed that the intercellular space of dehydrated garlic slices increased, and the cell wall was severely damaged after the UHP. The porous structure appeared in the dried garlic slices after the US and UHP-US pretreatments, where the cell wall contour became clear. The larger pore size indicated that the UHP-US was more contribute to improving the fluidity of water. The color difference of dried garlic slices was reduced after the three pretreatments, and the rehydration ratio and allicin content were significantly increased (P<0.05). Furthermore, the combined UHP-US pretreatment achieved the best quality of the dried garlic slices, with the color difference value of 16.11, while the allicin content of 2.67 mg/g, and the rehydration ratio of 2.90 g/g. The experimental findings can provide a theoretical reference for the potential technology of garlic drying with high efficiency, energy-saving, and high quality of dried garlic slices. [ABSTRACT FROM AUTHOR]

Avocado oil (AO) has been found to be adulterated by low-price oil in the market, calling for an efficient method to detect the authenticity of AO. In this work, a rapid and nondestructive method was developed to detect adulterated AO based on low-field nuclear magnetic resonance (LF-NMR, 43 MHz) detection and chemometrics analysis. PCA analysis revealed that the relaxation components area (S23) and relative contribution (P22 and P23) were crucial LF-NMR parameters to distinguish AO from AO adulterated by soybean oil (SO), corn oil (CO) or rapeseed oil (RO). A Soft Independent Modelling of Class Analogy (SIMCA) model was established to identify the types of adulterated oils with a high calibration (0.98) and validation accuracy (0.93). Compared with partial least squares regression (PLSR) models, the support vector regression (SVR) model showed better prediction performance to calculate the adulteration levels when AO was adulterated by SO, CO and RO, with high square correlation coefficient of calibration (R2C > 0.98) and low root mean square error of calibration (RMSEC < 0.04) as well as root mean square error of prediction (RMSEP < 0.09) values. Compared with SO- and CO-adulterated AO, RO-adulterated AO was more difficult to detect due to the greatest similarity in fatty acids’ composition being between AO and RO, which is characterized by the high level of monounsaturated fatty acids and viscosity. This study could provide an effective method for detecting the authenticity of AO.

The moisture distribution changes in Chinese yam slices subjected to microwave freeze drying (MFD) were analyzed using low-field nuclear magnetic resonance (LF-NMR). During this process, the mutual transformation of the water binding state and moisture diffusion characteristics of Chinese yam were analyzed together with changes in the effective water diffusion coefficient, water content, drying rate and pore network structure. Notably, moisture migrated from a high to a low degree of freedom during the MFD process. The effective water diffusion coefficient and water migration velocity increased with increasing microwave power density, and the extent of the conversion of unbound to bound water also gradually increased. During the early stage of drying, moisture diffusion was mainly dominated by liquid phase diffusion. At later stages of drying, moisture diffusion shifted gradually from liquid phase diffusion to gas phase diffusion and was eventually dominated by the latter. [ABSTRACT FROM AUTHOR]

The tobacco waste generated from the tobacco agriculture and industry, including the discarded stem and leaf, often needs dehydration pretreatment before thermal conversion utilization. In order to study the water activity and migration of tobacco waste during the pretreatment process, TG-NMR (Thermogravimetric Nuclear Magnetic Resonance) was used to obtain the drying curves and LF-NMR (Low Field Nuclear Magnetic Resonance) T2 inversion spectrum at each stage of tobacco drying. Meanwhile, the variation pattern of pore distribution during the dehydration process of two types of tobacco waste has been obtained. Combined with the pore distribution changes, a possible spatial migration mode of water was proposed. The change of adsorption energy of water during tobacco drying was calculated, and verified the above hypothesis. This study results provide reference for the optimization of dehydration pretreatment process for different tobacco waste in order to reduce energy consumption during recycling of tobacco biomass., Competing Interests: Authors WZ, BZ, DH, BW, and BL were employed by Zhengzhou Tobacco Research Institute of CNTC. Authors KD and LH were employed by China Tobacco Henan Industrial Co., Ltd. Authors RZ and WW were employed by China Tobacco Sichuan Industrial Co., Ltd., (Copyright © 2024 Zhu, Zhou, Duan, Huang, Han, Zhang, Wen, Wang and Li.)

Copyright of Chinese Journal of Bioprocess Engineering is the property of Chinese Journal of Bioprocess Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Based on superparamagnetic nanoparticles, a responsive polyacrylamide hydrogel self-assembled by nucleic acid hairpin hybridization chain reaction was designed, and a universal low field nuclear magnetic resonance sensing platform was successfully constructed. As the target was gradually added, the hydrogel coating on the surface of the magnetic nanoparticle was opened layer by layer through binding with the aptamer, which specifically bonded thereto, causing different degrees of exposure of the magnetic nanoparticle, resulting in changes of low field nuclear magnetic resonance signals. This method was originally applied to the rapid detection of adenosine triphosphate (ATP), and the versatility of the method was verified using polychlorinated biphenyl 77 (PCB77). This method had the advantage of being fast, convenient, and low cost, and it can be easily operated with high repeatability. This universal method can detect a variety of targets by replacing aptamers and may be useful in controlling food quality and for rapidly detecting cancer cells in vitro. Image 1 • Ultra-sensitive aptasensor was constructed based on LF-NMR technology and hydrogel-coated superparamagnetic particles. • Signal amplification was achieved by designed novel self-assembled hydrogel probes and superparamagnetic particles. • The method had the characteristics of fast, sensitive, non-destructive and repeatable. • This aptasensor achieved investigation of ATP levels in water samples with detection limits of 0.1961 mg/ml. • This method can be applied to the detection of multiple targets by designing recognition probes. [ABSTRACT FROM AUTHOR]

Pectin is a commonly used food additive, however, the freeze-drying characteristics of restructured strawberries with pectin addition are currently unclear. This study investigated the effects of 0, 3, 6, and 9 g/kg pectin addition on moisture content, drying date, moisture ratio, water state distribution during the freeze-drying process, as well as water uptake and volatile compounds of freeze-dried restructured strawberry blocks (FRSB). The drying rates at the four levels of pectin addition presented similar early acceleration and later deceleration trends. Moisture content in FRSB was linearly predicted by peak area of low field nuclear magnetic resonance with R2 higher than 0.90 for all the four groups. High pectin addition resulted in higher sulfides response values. Compared with the control group, the water uptake of FRSB samples in 0, 3, 6, and 9 g/kg group decreased by 12, 22, and 31%, respectively, which can be reasoned that pectin addition shielded hydrophilic functional groups from external water molecules. These results provide guidance for improving the drying characteristics, volatile compounds, and water uptake of FRSB by adding pectin. • Higher content of pectin, resulted in higher water content during drying. • Pectin addition increased the volatile compound content of samples. • Pectin addition reduced the hygroscopicity of samples during storage. • Relaxation peak area could linearly predict water content. [ABSTRACT FROM AUTHOR]

• The pore structure characteristics of ECC incorporating RS were investigated. • MIP and NMP were employed to examine the pore structure of the ECC. • The mechanical properties of ECC were elucidated on the basis of micromorphological and pore structure characteristics. The mechanical properties of recycled sand (RS) modified ECC are intimately linked to its pore structure characteristics, but the internal pore size and distribution of RS modified ECC and its impact mechanism on the mechanical properties are still unclear. This study employed mercury intrusion porosimetry (MIP) and low field nuclear magnetic resonance (LF-NMR) techniques to analyze the pore structure of ECC incorporating RS. Furthermore, compression and tension mechanical experiments were conducted to investigate the correlation between the evolution of pore structure and mechanical properties of ECC incorporating RS. The findings demonstrate that the addition of RS increases the porosity of ECC. When replacement ratio of RS is 100 %, the volume fraction of pores decreases within the range of 10 nm to 100 nm , whereas it exhibits an increasing trend within a ranging from 100 nm to 1 μ m. The incorporation of RS results in a decrease of the volume fraction of gel pores and the increase of capillary pores in ECC owing to its high-water absorption and porous, as well as the reduction of calcium-silicate-hydrate (C-S-H) due to the surface attached old mortar. Therefore, addition of RS lead to a reduction in both the compressive strength and tensile strength of ECC. However, as a result of the pore structural flaw inherent in the recycled fine aggregate, the occurrence of multi-crack cracking, induced by interfacial imperfections between the recycled fine aggregate and matrix, contributing to development of cracks in ECC and thus enhancing its tensile strain capacity. [ABSTRACT FROM AUTHOR]

The molecular weight is an important indicator for assessing the aging of polymers. However, existing methods for characterizing the molecular weight of polymers involve complex procedures and destructive tests. Therefore, efficient, rapid, and non-destructive testing methods would be a key development in material degradability evaluation. In this paper, we studied the thermo-oxidative aging process of polybutylene adipate terephthalate (PBAT) using a low-field nuclear magnetic resonance (LF-NMR) analysis method. The degradation mechanism of PBAT during thermo-oxidative aging is characterized by its low-field nuclear magnetic resonance decay curve and inversion curve. A two-component LF-NMR fitting analysis reveals that the thermo-oxidative degradation of PBAT conforms to a random fracture mechanism. Furthermore, a correlation between number average molecular weight and LF-NMR relaxation time during thermo-oxidative degradation of PBAT was constructed, with a correlation coefficient R2 greater than 0.97. The error between the correlation equation used in the molecular weight detection of PBAT and the actual test is less than 10%, indicating that it is feasible and reliable to characterize the number average molecular weight of materials by applying the LF-NMR relaxation time. • A non-destructive method for characterizing the molecular weight. • The thermo-oxidative degradation of PBAT was studied by LF-NMR. • The error between the method used by LF-NMR and the actual test is less than 10%. [ABSTRACT FROM AUTHOR]

Shale reservoirs are rich in micro and nanoscale pores and fractures, resulting in a very complex interaction mechanism between oil and water. In this paper, firstly, the differences in fluid enrichment mechanisms and evolution model characteristics within multi-level pore networks are revealed. Secondly, a linkage mechanism model of "relaxation time - multistage pore structure - fluid evolution" is constructed. Thirdly, the interaction mechanism of the coupling of mineral types, multiphase fluid evolution, and pore-fracture networks is clarified. Results show that: (a) For the 4 shale samples, the distribution of p 1 peak is less than 1 ms, p 2 peak is between 1 ms and 20 ms, and p 3 peak is greater than 20 ms. (b). The distribution of p 1, p 2, and p 3 peaks in the T 2 spectrum of saturated oil from different shale samples is different. (c) For a typical sample, the total porosity of saturated water in the felsic shale in Research Area 1 is 6.73%; the total porosity of saturated oil is 4.15%. • The differences in fluid enrichment mechanisms and evolution model characteristics are revealed; • A coupled model of "relaxation time - multistage pore structure - fluid evolution" is constructed; • The mechanism of coupling of mineral types, fluid evolution, and pore-fracture networks is clarified. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The change of the evaporable water content in the early hydration process of cement paste with different water-to-cement ratios was monitored by low field nuclear magnetic resonance (LF-NMR) relaxometry. The hydration degree and gel/space ratio were accordingly calculated and analyzed. The test results show that the first derivative curves of the transverse magnetization are in good agreement with the known five stages of cement hydration process at an early age. The initial and final setting times of the cement paste are closely related to the times the gel/space ratio reaches a fixed value. The early compressive strength of the hardened cement paste exhibits a power function relationship with the gel/space ratio. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)