Studying the metabolic patterns underlying the key quality traits during the growth and development of melon is very important for the quality improvement and breeding of melon fruit. In this study, we employed transcriptomics and metabolomics to analyze the primary metabolic changes occurring in melon ('Xizhoumi 25') across five growth and development stages. We identified a total of 666 metabolites and their co-expressed genes, which were categorized into five different metabolic and gene modules. Through the analysis of these modules, the main metabolic pathways during the growth and development of melon were demonstrated from a global perspective. We also discussed the contribution of sucrose accumulation, the TCA cycle, and amino acid metabolism to the quality and flavor of melon. Enzymes related to amino acid metabolism were proposed, including Amine oxidase (AOC), aldehyde dehydrogenase (ALDH), tryptophan synthase (TRPB), etc. These results and data can provide new insights for further study on the metabolic regulation of melon quality and improve fruit quality.

Studying the metabolic patterns underlying the key quality traits during the growth and development of melon is very important for the quality improvement and breeding of melon fruit. In this study, we employed transcriptomics and metabolomics to analyze the primary metabolic changes occurring in melon ('Xizhoumi 25') across five growth and development stages. We identified a total of 666 metabolites and their co-expressed genes, which were categorized into five different metabolic and gene modules. Through the analysis of these modules, the main metabolic pathways during the growth and development of melon were demonstrated from a global perspective. We also discussed the contribution of sucrose accumulation, the TCA cycle, and amino acid metabolism to the quality and flavor of melon. Enzymes related to amino acid metabolism were proposed, including Amine oxidase (AOC), aldehyde dehydrogenase (ALDH), tryptophan synthase (TRPB), etc. These results and data can provide new insights for further study on the metabolic regulation of melon quality and improve fruit quality.

Carboxypeptidase A(CPA) has a great potential application in the food and pharmaceutical industry due to its capability to hydrolyze ochratoxin A(OTA) and remove the bitterness of peptide. However, CPA is a mesophilic enzyme that cannot adequately exert its catalytic activity at elevated temperatures, which seriously restricts its industrial application. In this study, the rational design of disulfide bonds was introduced to improve the thermostability of CPA. The highly flexible regions of CPA were predicted through the HotSpot Wizard program and molecular dynamics (MD) simulations. Then, DbD and MODIP online servers were conducted to predict potential residue pairs for introducing disulfide bonds in CPA. After the conservativeness analysis of the PSSM matrix and the structural analysis of the MD simulation, two mutants with potentially enhanced thermostability were screened. Results showed that these mutants D93C/F96C and K153C/S251C compared to the wild-type(WT) exhibited increase by 10 and 10 °C in Topt, 3.4 and 2.7 min in t1/2 at 65 °C, in addition to rise of 8.5 and 11.4 °C in T5015, respectively. Furthermore, the molecular mechanism responsible for thermostability was investigated from the perspective of advanced structure and molecular interactions. The enhanced thermostability of both mutants was not only associated with the more stable secondary structure and the introduction of disulfide bonds but also related to the changes in hydrogen bonds and the redistribution of surface charges in mutant regions. This study showed for the first time that the rational design of disulfide bonds is an effective strategy to enhance the thermostability of CPA, providing in this way a broader industrial application.

Carboxypeptidase A(CPA) has a great potential application in the food and pharmaceutical industry due to its capability to hydrolyze ochratoxin A(OTA) and remove the bitterness of peptide. However, CPA is a mesophilic enzyme that cannot adequately exert its catalytic activity at elevated temperatures, which seriously restricts its industrial application. In this study, the rational design of disulfide bonds was introduced to improve the thermostability of CPA. The highly flexible regions of CPA were predicted through the HotSpot Wizard program and molecular dynamics (MD) simulations. Then, DbD and MODIP online servers were conducted to predict potential residue pairs for introducing disulfide bonds in CPA. After the conservativeness analysis of the PSSM matrix and the structural analysis of the MD simulation, two mutants with potentially enhanced thermostability were screened. Results showed that these mutants D93C/F96C and K153C/S251C compared to the wild-type(WT) exhibited increase by 10 and 10 °C in Topt, 3.4 and 2.7 min in t1/2 at 65 °C, in addition to rise of 8.5 and 11.4 °C in T5015, respectively. Furthermore, the molecular mechanism responsible for thermostability was investigated from the perspective of advanced structure and molecular interactions. The enhanced thermostability of both mutants was not only associated with the more stable secondary structure and the introduction of disulfide bonds but also related to the changes in hydrogen bonds and the redistribution of surface charges in mutant regions. This study showed for the first time that the rational design of disulfide bonds is an effective strategy to enhance the thermostability of CPA, providing in this way a broader industrial application.

Soy milk, rich in vitamin D and calcium, is a common alternative to dairy milk. However, its distinct 'beany off-flavor' has limited its acceptance, particularly in Western countries. A new technique employing preformed 'empty' V-type starch has been introduced to scavenge this off-flavor, aiming to promote soy milk consumption. The purpose of this study was to identify predictors of consumers' purchase intention of 'empty' V-type starch deodorized soy milk, particularly among college students. In this cross-sectional study, 105 college students were surveyed by a validated survey instrument that measures their perceptions of sensory quality, healthiness, price, environmental friendliness, food safety, and purchase intention of a novel product – 'empty' V-type starch deodorized soy milk. Additionally, demographic data were gathered to understand any correlations between these factors and the students' willingness-to-purchase of the deodorized soy milk. From the results, more than 80% of the participants expressed a positive attitude toward the 'empty' V-type starch-deodorized soy milk. The two dominant drivers behind their purchasing decision were Sensory Quality and Environmental Concern. Accordingly, it is crucial to highlight the improved sensory profile and the environmental friendliness of this soy milk product in order to achieve marketing success.

Soy milk, rich in vitamin D and calcium, is a common alternative to dairy milk. However, its distinct 'beany off-flavor' has limited its acceptance, particularly in Western countries. A new technique employing preformed 'empty' V-type starch has been introduced to scavenge this off-flavor, aiming to promote soy milk consumption. The purpose of this study was to identify predictors of consumers' purchase intention of 'empty' V-type starch deodorized soy milk, particularly among college students. In this cross-sectional study, 105 college students were surveyed by a validated survey instrument that measures their perceptions of sensory quality, healthiness, price, environmental friendliness, food safety, and purchase intention of a novel product – 'empty' V-type starch deodorized soy milk. Additionally, demographic data were gathered to understand any correlations between these factors and the students' willingness-to-purchase of the deodorized soy milk. From the results, more than 80% of the participants expressed a positive attitude toward the 'empty' V-type starch-deodorized soy milk. The two dominant drivers behind their purchasing decision were Sensory Quality and Environmental Concern. Accordingly, it is crucial to highlight the improved sensory profile and the environmental friendliness of this soy milk product in order to achieve marketing success.

Lily bulbs are valued for their health benefits, and drying is a common method for their preservation. This study employed untargeted metabolomics using UHPLC-QTOF-MS to analyze the phytochemical profiles of lily bulbs dried by hot air (HD), microwave (MD), and vacuum freeze (FD) methods. In terms of appearance, FD samples exhibited minimal browning and wrinkling, while HD bulbs showed the most severe changes. Nineteen potential markers were identified, with HD samples showing higher levels of bitter amino acids, peptides, and N-fructosyl phenylalanine. The markers of FD samples were glutamine, coumarin, and p-coumaric acid. Notably, eleutheroside E was detected in lily bulbs for the first time and confirmed as an MD marker, with levels 1.51-fold and 6.19-fold higher than in FD and HD samples, respectively. MD method shows promise for enriching bioactive compounds in dried lily bulbs.

Lily bulbs are valued for their health benefits, and drying is a common method for their preservation. This study employed untargeted metabolomics using UHPLC-QTOF-MS to analyze the phytochemical profiles of lily bulbs dried by hot air (HD), microwave (MD), and vacuum freeze (FD) methods. In terms of appearance, FD samples exhibited minimal browning and wrinkling, while HD bulbs showed the most severe changes. Nineteen potential markers were identified, with HD samples showing higher levels of bitter amino acids, peptides, and N-fructosyl phenylalanine. The markers of FD samples were glutamine, coumarin, and p-coumaric acid. Notably, eleutheroside E was detected in lily bulbs for the first time and confirmed as an MD marker, with levels 1.51-fold and 6.19-fold higher than in FD and HD samples, respectively. MD method shows promise for enriching bioactive compounds in dried lily bulbs.

Given the side effects associated with synthetic antihypertensive drugs, there is a growing need among researchers to investigate angiotensin-converting enzyme (ACE) inhibitory peptides derived from food protein as safer therapeutic alternatives. This study used seabuckthorn (Hippophae rhamnoides L.) seed meal as the raw material, and the protein was extracted by alkaline extraction and acid precipitation. After enzymatic digestion, peptides with molecular weight less than 3 kDa were selected for study. The screened peptide had an IC50 value of 4.358 mg/mL on ACE with a non-competitive inhibition mechanism and good inhibition stability. By employing infrared (IR) analysis, exclusively β-fold and β-helix structures were identified in the hydrolysate, while no other structural motifs were detected. X-ray diffraction revealed that it had an irregular amorphous structure. The peptide contains 17 amino acids that are both highly acidic and hydrophobic, with glutamic acid ranking first in terms of the number of individual amino acids. Compared with the database (NCBI, Uniport), ten peptides with ACE inhibitory activity were detected, and molecular docking showed the mechanism of each peptide inhibiting ACE, FRVAWTEKNDGQRAPLANN, LIISVAYARVAKKLWLCNMIGDVT-TEQY, VIRSRASDGCLEVKEFEDIPP, AGGGG-GGGGGGSRRL, LQPREGPAGGTT-ALREELSLGPEAALDTPPAGP, DDEARINQLFL, FAVSTLTSYDWSDRDDATQGR-KL, RQLSLEGSGLGVEDLKDN, GGGGGGGGGGGGGGGIGGGGGGGGGGGAR, and KEALGEGCFGNRIDRIGD. According to the results, AGGGGGG-GGGGSRRL is more stable in binding to ACE and may have better inhibitory activity. It has been shown that seabuckthorn protein can be an alternative source of ACE inhibitory peptides.

Given the side effects associated with synthetic antihypertensive drugs, there is a growing need among researchers to investigate angiotensin-converting enzyme (ACE) inhibitory peptides derived from food protein as safer therapeutic alternatives. This study used seabuckthorn (Hippophae rhamnoides L.) seed meal as the raw material, and the protein was extracted by alkaline extraction and acid precipitation. After enzymatic digestion, peptides with molecular weight less than 3 kDa were selected for study. The screened peptide had an IC50 value of 4.358 mg/mL on ACE with a non-competitive inhibition mechanism and good inhibition stability. By employing infrared (IR) analysis, exclusively β-fold and β-helix structures were identified in the hydrolysate, while no other structural motifs were detected. X-ray diffraction revealed that it had an irregular amorphous structure. The peptide contains 17 amino acids that are both highly acidic and hydrophobic, with glutamic acid ranking first in terms of the number of individual amino acids. Compared with the database (NCBI, Uniport), ten peptides with ACE inhibitory activity were detected, and molecular docking showed the mechanism of each peptide inhibiting ACE, FRVAWTEKNDGQRAPLANN, LIISVAYARVAKKLWLCNMIGDVT-TEQY, VIRSRASDGCLEVKEFEDIPP, AGGGG-GGGGGGSRRL, LQPREGPAGGTT-ALREELSLGPEAALDTPPAGP, DDEARINQLFL, FAVSTLTSYDWSDRDDATQGR-KL, RQLSLEGSGLGVEDLKDN, GGGGGGGGGGGGGGGIGGGGGGGGGGGAR, and KEALGEGCFGNRIDRIGD. According to the results, AGGGGGG-GGGGSRRL is more stable in binding to ACE and may have better inhibitory activity. It has been shown that seabuckthorn protein can be an alternative source of ACE inhibitory peptides.

Designing a wound dressing that offers excellent antibacterial properties while providing dual pH/glucose responsiveness for diabetic wound healing remains a considerable challenge. Herein, a 3D cross-linked native protein hydrogel was constructed through a Schiff base reaction based on -NH2 in paramyosin (PM) and -CHO in oxidized dextran (ODA) under mild conditions. Within the hydrogel, both amikacin and glucose oxidase were encapsulated during gelation. The resulting hydrogel exhibited favorable rheological properties, featuring self-healing, antibacterial activity, tissue adhesiveness, and excellent biocompatibility. Notably, the hydrogel demonstrated excellent pH/glucose dual-responsive properties. In infected wounds, the Schiff base bonds dissociated due to low pH, while in uninfected wounds with high blood glucose levels, the encapsulated glucose oxidase was functional, which also lowered the local pH level and dissociated the Schiff base bonds. Furthermore, the hydrogel quickly achieved pH/glucose dual responsiveness, leading to increased amikacin release to reduce bacterial invasion, alleviate oxidative stress, promote re-epithelialization and collagen deposition, and eventually accelerate diabetic wound healing. Collectively, the constructed hydrogel offers brand-new viewpoints on glucose-responsive biomaterials for diabetic wound therapy.

Designing a wound dressing that offers excellent antibacterial properties while providing dual pH/glucose responsiveness for diabetic wound healing remains a considerable challenge. Herein, a 3D cross-linked native protein hydrogel was constructed through a Schiff base reaction based on -NH2 in paramyosin (PM) and -CHO in oxidized dextran (ODA) under mild conditions. Within the hydrogel, both amikacin and glucose oxidase were encapsulated during gelation. The resulting hydrogel exhibited favorable rheological properties, featuring self-healing, antibacterial activity, tissue adhesiveness, and excellent biocompatibility. Notably, the hydrogel demonstrated excellent pH/glucose dual-responsive properties. In infected wounds, the Schiff base bonds dissociated due to low pH, while in uninfected wounds with high blood glucose levels, the encapsulated glucose oxidase was functional, which also lowered the local pH level and dissociated the Schiff base bonds. Furthermore, the hydrogel quickly achieved pH/glucose dual responsiveness, leading to increased amikacin release to reduce bacterial invasion, alleviate oxidative stress, promote re-epithelialization and collagen deposition, and eventually accelerate diabetic wound healing. Collectively, the constructed hydrogel offers brand-new viewpoints on glucose-responsive biomaterials for diabetic wound therapy.

In this study, microfluidization was explored to inactivate autolytic spoilage enzymes (polyphenol oxidase, PPO, and peroxidase, POD) that significantly impact the nutritional and sensory qualities of tender coconut water (TCW). TCW was treated at three different pressure levels (70, 140, and 210 MPa) and five different number of passes/cycles (3, 5, 7, 9, and 11). The highest percentage reduction was obtained in the case of PPO (~61% in the 11th pass, at 210 MPa), while for POD, ~45% reduction was achieved in the 9th pass, at 70 MPa. The impact of different treatment conditions on the physicochemical properties of TCW, such as color, turbidity, total soluble solids (TSS), pH, titratable acidity, total phenolic content (TPC), and protein content was assessed. The pH and TSS remained unaffected; whereas, turbidity showed an increase with treatment intensity from 2.59% ± 0.14% (untreated) to 8.62% ± 0.39% (30,000 psi, 11 passes), and the highest color difference was observed for this sample (ΔE = 4.61 ± 0.018). Furthermore, TPC and antioxidant activity showed minimal changes upon treatment. Overall, the findings of this research provide new insights into the application of microfluidization for the processing of thermally sensitive products such as TCW, extending their shelf life without any additives and providing a clean label solution.

In this study, microfluidization was explored to inactivate autolytic spoilage enzymes (polyphenol oxidase, PPO, and peroxidase, POD) that significantly impact the nutritional and sensory qualities of tender coconut water (TCW). TCW was treated at three different pressure levels (70, 140, and 210 MPa) and five different number of passes/cycles (3, 5, 7, 9, and 11). The highest percentage reduction was obtained in the case of PPO (~61% in the 11th pass, at 210 MPa), while for POD, ~45% reduction was achieved in the 9th pass, at 70 MPa. The impact of different treatment conditions on the physicochemical properties of TCW, such as color, turbidity, total soluble solids (TSS), pH, titratable acidity, total phenolic content (TPC), and protein content was assessed. The pH and TSS remained unaffected; whereas, turbidity showed an increase with treatment intensity from 2.59% ± 0.14% (untreated) to 8.62% ± 0.39% (30,000 psi, 11 passes), and the highest color difference was observed for this sample (ΔE = 4.61 ± 0.018). Furthermore, TPC and antioxidant activity showed minimal changes upon treatment. Overall, the findings of this research provide new insights into the application of microfluidization for the processing of thermally sensitive products such as TCW, extending their shelf life without any additives and providing a clean label solution.

Chilling injury (CI) is a highly common physiological disorder in pomegranates during cold storage. Although several approaches have been investigated to mitigate the CI symptoms among some pomegranate cultivars, the fundamental and crucial environmental factor — the precise storage temperature for the 'Mengzi' cultivation remains unknown. This research evaluated the impact of storage temperatures of 0, 1, 2, 3, and 4 °C on the post-harvest quality of pomegranates. Results indicated that pomegranates stored at 2 °C exhibited the slightest color change and browning index. After storage of 130 d, pomegranates stored at 2 °C exhibited the lower CI index (82.79% reduction) and the lowest decay incidence (24.68% reduction) compared to those stored at 0 °C. The respiratory rate of pomegranates (2 °C) was also evidently suppressed (16.60%), along with a reduction in weight loss (3.46%). Furthermore, pomegranates stored at 2 °C exhibited the lowest activities of polyphenol oxidase (PPO) and peroxidase (POD), accompanied by the highest total phenolic content, which contributed to a reduction in malondialdehyde (MDA) accumulation. Relatively higher concentrations of soluble solids and titratable acid, as well as a higher sensory evaluation, were found in pomegranates stored at 2 °C. Consequently, it was inferred that the optimal temperature maintained cell membrane integrity modulated normal respiratory metabolism, and oxidative balance, and therefore alleviated CI and deterioration. This report can provide the guiding significance for the long-term storage of 'Mengzi' pomegranates under the condition of precise temperature control in phase temperature storage.

Chilling injury (CI) is a highly common physiological disorder in pomegranates during cold storage. Although several approaches have been investigated to mitigate the CI symptoms among some pomegranate cultivars, the fundamental and crucial environmental factor — the precise storage temperature for the 'Mengzi' cultivation remains unknown. This research evaluated the impact of storage temperatures of 0, 1, 2, 3, and 4 °C on the post-harvest quality of pomegranates. Results indicated that pomegranates stored at 2 °C exhibited the slightest color change and browning index. After storage of 130 d, pomegranates stored at 2 °C exhibited the lower CI index (82.79% reduction) and the lowest decay incidence (24.68% reduction) compared to those stored at 0 °C. The respiratory rate of pomegranates (2 °C) was also evidently suppressed (16.60%), along with a reduction in weight loss (3.46%). Furthermore, pomegranates stored at 2 °C exhibited the lowest activities of polyphenol oxidase (PPO) and peroxidase (POD), accompanied by the highest total phenolic content, which contributed to a reduction in malondialdehyde (MDA) accumulation. Relatively higher concentrations of soluble solids and titratable acid, as well as a higher sensory evaluation, were found in pomegranates stored at 2 °C. Consequently, it was inferred that the optimal temperature maintained cell membrane integrity modulated normal respiratory metabolism, and oxidative balance, and therefore alleviated CI and deterioration. This report can provide the guiding significance for the long-term storage of 'Mengzi' pomegranates under the condition of precise temperature control in phase temperature storage.

Serum albumin can bind with a diverse range of small molecules. It could therefore serve a protective or carrier function, and effectively address the issue of anthocyanins' susceptibility to decomposition. The anisotropic effect of the magnetic field (MF) can influence their interaction, thereby playing a distinct role in molecular bonding. In this study, bovine serum albumin (BSA) and cyanidin-3-O-glucoside (C3G) were used as raw materials. The mechanism underlying the formation of BSA-C3G complexes induced by static magnetic field (SMF) was investigated through analyses of secondary structure, functional groups, dipole moment, crystal cell dimensions, and microstructural characteristics. BSA and C3G were treated with 50, 100, 150, and 200 mT, respectively. As the magnetic intensity increased, the secondary structure of the complex changed, the α-spiral content, β-corner content, and irregular curl content decreased, while, the β-folding content increased. The average grain size of the BSA-C3G composite was observed to decrease. Furthermore, alterations in the crystal cell dimensions of the BSA-C3G complex were noted, accompanied by a tendency for the microstructure to become more flattened. This study offers valuable insights into the influence of SMF on the assembly behavior and structural characteristics of proteins and anthocyanins.

Serum albumin can bind with a diverse range of small molecules. It could therefore serve a protective or carrier function, and effectively address the issue of anthocyanins' susceptibility to decomposition. The anisotropic effect of the magnetic field (MF) can influence their interaction, thereby playing a distinct role in molecular bonding. In this study, bovine serum albumin (BSA) and cyanidin-3-O-glucoside (C3G) were used as raw materials. The mechanism underlying the formation of BSA-C3G complexes induced by static magnetic field (SMF) was investigated through analyses of secondary structure, functional groups, dipole moment, crystal cell dimensions, and microstructural characteristics. BSA and C3G were treated with 50, 100, 150, and 200 mT, respectively. As the magnetic intensity increased, the secondary structure of the complex changed, the α-spiral content, β-corner content, and irregular curl content decreased, while, the β-folding content increased. The average grain size of the BSA-C3G composite was observed to decrease. Furthermore, alterations in the crystal cell dimensions of the BSA-C3G complex were noted, accompanied by a tendency for the microstructure to become more flattened. This study offers valuable insights into the influence of SMF on the assembly behavior and structural characteristics of proteins and anthocyanins.