Publications by authors named "Shenghua Ding"

22 Publications

  • Page 1 of 1

Screening and heterologous expression of flavone synthase and flavonol synthase to catalyze hesperetin to diosmetin.

Biotechnol Lett 2021 Sep 12. Epub 2021 Sep 12.

Longping Branch Graduate School of Hunan University, Changsha, 410125, People's Republic of China.

Objectives: In this study, 44 flavone synthases (FNS) and flavonol synthases (FLS) from different origins were collected. The instability index and conserved domain of the enzymes were analyzed through bioinformatics analysis, the results of which allowed us to screen suitable enzymes for constructing recombinant Escherichia coli. Defective enzymes were selected as controls.

Results: Native- and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were conducted to isolate the heterologously expressed proteins. Liquid chromatography-mass spectrometry, H nuclear magnetic resonance, and ultra-performance liquid chromatography were performed to qualitatively and quantitatively analyze the products. The cellular transformation results showed that recombinant E. coli catalyzed the synthesis of diosmetin from hesperetin, and in vitro catalysis showed that heterologously expressed FNS/FLS played a catalytic role in this reaction. AnFNS (from Angelica archangelica) showed the highest substrate conversion (38.80% for cellular transformation, 12.93% for in vitro catalysis).

Conclusions: The catalytic capacity of FNS/FLS from different origins exhibited the expected results, indicating that bioinformatics analysis is useful for screening enzymes. In addition, the catalytic properties of AnFNS and CaFLS (from Camellia sinensis) differed significantly, although these enzymes are structurally similar. Based on this difference, C-2 was predicted as the key site for FNS/FLS catalytic synthesis of diosmetin rather than C-3.
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http://dx.doi.org/10.1007/s10529-021-03184-0DOI Listing
September 2021

Effect of hydrothermal-calcium chloride treatment on pectin characteristics and related quality in green peppers during storage.

J Food Sci Technol 2021 Oct 29;58(10):3712-3724. Epub 2020 Sep 29.

College of Food Science and Technology, Hunan Agricultural University, Changsha, 410128 China.

Effects of hydrothermal (HT)-calcium chloride (CaCl) treatment on pectin characteristics and related quality in green peppers during storage were assessed. The results showed that the changes of physicochemical quality in all green peppers were similar during storage. Weight loss percentage increased, firmness, the content of free water and bound water decreased during storage. Water-soluble pectin (WSP) notably increased, but sodium carbonate-soluble pectin (SSP) and chelate-soluble pectin (CSP) decreased. Galacturonic acid (GalUA), rhamnose (Rha), galactose (Gal), and arabinose (Ara) were the crucial compositions in the backbone and branched chains of pectin in green peppers. Rha and Gal increased, but Ara decreased in pectin after storage. The changes in the ratio of Rha/GalUA, Ara/Gal, and (Gal + Ara)/Rha represented that the backbone and branched chains of pectin in green peppers depolymerized to some extent after storage. Comparing with other green peppers, HT-CaCl treated green peppers posed lower weight loss percentage and WSP content, higher firmness, the content of free water, bound water, SSP, and CSP during storage. Otherwise, most pectin compositions in HT-CaCl treated green peppers showed high molar ratio after storage. Hence, HT-CaCl treatment was an effective way to retain pectin characteristics and related quality of green peppers, and further inhibited the softening of green peppers during storage.
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http://dx.doi.org/10.1007/s13197-020-04829-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8357889PMC
October 2021

Changes in pectin characteristics of jujube fruits cv "Dongzao" and "Jinsixiaozao" during cold storage.

J Food Sci 2021 Jul 19;86(7):3001-3013. Epub 2021 Jun 19.

College of Food Science and Technology, Hunan Agricultural University, Changsha, China.

Softening is one of the main factors affecting market value and consumer preferences for jujubes, and it was closely related to the modification and depolymerization of pectin. Changes in characteristics of three pectins (water-soluble pectin (WSP), sodium carbonate-soluble pectin (SSP) and chelate-soluble pectin (CSP)), including their contents, degree of methylesterification (DM), neutral sugar compositions, the molecular weight (M ) distributions and nanostructures, from two jujube fruits cv Dongzao (DZ) and Jinsixiaozao (JS) during cold storage were assessed. The results showed that variation in pectin characteristics during cold storage was similar between DZ and JS. The reduction of firmness corresponded to a conversion of water-insoluble pectin to WSP during cold storage. DM of WSP presented an increase trend in the late storage. Rhamnose (Rha), arabinose (Ara) and glucose (Glc) were the crucial compositions in three pectins, and most neutral sugar compositions in three pectins first increased and then decreased during cold storage. Changes in the ratio of (galactose (Gal)+Ara)/Rha and Ara/Gal represented that the branch chains of rhamnogalacturonan-I in three pectins depolymerized after storage. The high M in WSP and SSP of jujubes were solubilized and extensively depolymerized into pectin with lower M after storage. AFM images showed an increase in short chains and branch structures of three pectins after storage. Overall, three pectins in DZ and JS depolymerized and solubilized during cold storage. WSP and SSP were more contributed to the softening of jujubes compared to CSP, and they played the critical role for regulating the softening of jujube fruits during cold storage. PRACTICAL APPLICATION: Softening is one of the main factors affecting market value and consumer preferences for jujubes, and it was closely related to the modification and depolymerization of pectin. Changes in characteristics of three pectins (WSP, SSP, CSP), including their contents, degree of methylesterification, neutral sugar compositions, the molecular weight distributions and nanostructures, from two jujube fruits cv Dongzao (DZ) and Jinsixiaozao (JS) during cold storage were assessed. Three pectins in DZ and JS depolymerized and solubilized during cold storage. WSP and SSP were more contributed to the softening of jujubes compared to CSP, and they played the critical role for regulating the softening of jujube fruits during cold storage. This study would elucidate the mechanism of jujube softening and help to regulate the postharvest quality during cold storage.
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http://dx.doi.org/10.1111/1750-3841.15800DOI Listing
July 2021

Effects of ultra-high pressure on the morphological and physicochemical properties of lily starch.

Food Sci Nutr 2021 Feb 24;9(2):952-962. Epub 2020 Dec 24.

Longping Branch Graduate School Hunan University Changsha China.

In this study, starch extracted from lily bulbs were modified using an ultra-high pressure (UHP) treatment at six different pressure levels (100, 200, 300, 400, 500, and 600 MPa). The effects of UHP treatment on the physicochemical and morphological properties of lily starch were investigated. The morphological observation revealed that UHP treatment led to particle expansion and aggregation. Compared with the native and lily starch treated at 100-500 MPa, the lily starch treated at 600 MPa exhibited almost completely disrupted morphology and a larger particle size, indicating nearly complete gelatinization of the starch. The relative crystallinity of the UHP-treated starch remarkably reduced. Gelatinization temperatures via differential scanning calorimetry decreased with increasing pressure. The rapid viscoanalyzer results revealed that the lily starch treated with UHP at 600 MPa showed low values of peak viscosity, trough viscosity, breakdown, final viscosity, and setback. These results indicated that UHP was an effective physical modification method for lily starch, UHP treatment (600 MPa, 30 min) caused nearly complete gelatinization of lily starch, and lily starch modified using UHP might expand the application of lily in the food field.
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http://dx.doi.org/10.1002/fsn3.2060DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7866584PMC
February 2021

A novel method for the nondestructive classification of different-age Citri Reticulatae Pericarpium based on data combination technique.

Food Sci Nutr 2021 Feb 8;9(2):943-951. Epub 2020 Dec 8.

Hunan Agricultural Product Processing Institute Hunan Academy of Agricultural Sciences Changsha China.

The quality of Citri Reticulatae Pericarpium (CRP) is closely correlated with the aging time. However, CRPs in different storage ages are similar in appearance, and the young CRP may be labeled as the aged one to obtain the excess profit by some unscrupulous traders. Most traditional analysis methods are laborious and time-consuming, and they can hardly realize the nondestructive classification. In this paper, a novel method based on near-infrared diffuse reflectance spectroscopy (NIRDRS) and data combination technique for the nondestructive classification of different-age CRPs was proposed. The CRPs in different storage ages (5, 10, 15, 20, and 25 years) were measured. The near-infrared spectra of outer skin and inner capsule were obtained. Principal component analysis (PCA), soft independent modeling of class analogy (SIMCA), and Fisher's linear discriminant analysis (FLD), with different data pretreatment methods, were used for the classification analysis. Data combination of the outer skin and inner capsule spectra was discussed for further improving the classification results. The results show that multiple sensors provide more useful and complementary information than a single sensor does for improving the prediction accuracy. With the help of data combination strategy, 100% prediction accuracy can be obtained with both second-order derivative-FLD and continuous wavelet transform-multiplicative scatter correction-FLD methods.
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http://dx.doi.org/10.1002/fsn3.2059DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7866605PMC
February 2021

Characteristic Volatile Fingerprints and Odor Activity Values in Different Citrus-Tea by HS-GC-IMS and HS-SPME-GC-MS.

Molecules 2020 Dec 19;25(24). Epub 2020 Dec 19.

Longping Branch Graduate School, Hunan University, Changsha 410125, China.

Citrus tea is an emerging tea drink produced from tea and the pericarp of citrus, which consumers have increasingly favored due to its potential health effects and unique flavor. This study aimed to simultaneously combine the characteristic volatile fingerprints with the odor activity values (OAVs) of different citrus teas for the first time by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Results showed that the establishment of a citrus tea flavor fingerprint based on HS-GC-IMS data can provide an effective means for the rapid identification and traceability of different citrus varieties. Moreover, 68 volatile compounds (OAV > 1) were identified by HS-SPME-GC-MS, which reflected the contribution of aroma compounds to the characteristic flavor of samples. Amongst them, the contribution of linalool with sweet flower fragrance was the highest. Odorants such as decanal, -lonone, -ionone, -myrcene and -limonene also contributed significantly to all samples. According to principal component analysis, the samples from different citrus teas were significantly separated. Visualization analysis based on Pearson correlation coefficients suggested that the correlation between key compounds was clarified. A comprehensive evaluation of the aroma of citrus tea will guide citrus tea flavor quality control and mass production.
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http://dx.doi.org/10.3390/molecules25246027DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7766395PMC
December 2020

Fabrication and characterization of Pickering emulsion gels stabilized by zein/pullulan complex colloidal particles.

J Sci Food Agric 2021 Jul 22;101(9):3630-3643. Epub 2020 Dec 22.

Longping Branch Graduate School, Hunan University, Changsha, China.

Background: Zein particles are unsuitable as stabilizers of Pickering emulsions because of their high hydrophobicity. However, few studies have reported on the use of a strong hydrophilic neutral polysaccharide to regulate its wettability. In this work, zein/pullulan complex particles (ZPPs) were formulated by an anti-solvent method to fabricate Pickering emulsions.

Results: The presence of pullulan increased the size, decreased the zeta, and provided excellent resistance to the gravitational separation of zein. Scanning electron microscopy (SEM) revealed that the shape of zein particles changed from spherical as they became aggregated ZPP nanoparticles. Fourier transform infrared (FTIR) spectroscopy indicated that the flocculation phenomenon of ZPPs was related to the hydrogen bond between zein and pullulan. Moreover, the hydrophobicity of zein was modified by hydrophilic pullulan to endow the ZPPs with nearly neutral wettability when the mass ratio was 15:1, allowing for the preparation of stable Pickering emulsions. In contrast to zein, the ZPPs contributed to building a compact interface layer around the droplets and smaller emulsion droplets. Under a certain ZPP concentration, the size and viscosity of emulsion increased with an increase in the oil volume fraction, indicating that the Pickering emulsions stabilized by ZPPs showed better stability against coalescence. Confocal laser scanning microscopy (CLSM) revealed that the ZPPs constructed a dense filling layer on the surface of oil droplets, thus further emphasizing that ZPPs can potentially be used in fabricating Pickering emulsion gels.

Conclusion: Zein/pullulan complex particles are an excellent Pickering emulsion gel stabilizer that can be used in the delivery system of bioactive substances in food formulations. © 2020 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.10992DOI Listing
July 2021

Comparison of the biochemical properties and thermal inactivation of polyphenol oxidase from three lily bulb cultivars.

J Food Biochem 2020 10 17;44(10):e13431. Epub 2020 Aug 17.

Longping Branch Graduate School, Hunan University, Changsha, China.

The biochemical properties and thermal inactivation of polyphenol oxidase (PPO) from three main planted lily cultivars in China, namely, Lilium lancifolium Thunb, Lilium brownie var. viridulum, and Lilium davidii var. unicolor cotton were evaluated. Data indicate that the PPO from three cultivars showed two optimum pH levels of 4.0 and 6.5-7.0 and temperature of 15°C and exhibited the highest affinity toward 4-methylcatechol. However, this enzyme did not exhibit monophenolase activity. Thiourea and L-cysteine were more effective than other inhibitors. The enzymatic activity of L. lancifolium Thunb PPO crude extract was higher than that of L. brownie var. viridulum and L. davidii var. unicolor cotton. For thermal inactivation, L. davidii var. unicolor cotton PPO showed the best thermal resistance at 65-75°C, and L. lancifolium Thunb showed stability at 45°C. The deactivation of the three types of PPO followed the first-order reaction kinetics, and the activation energy (E) was 144.28, 138.00, and 107.12 kJ/mol for L. lancifolium Thunb PPO, L. brownie var. viridulum PPO, and L. davidii var. unicolor cotton PPO, respectively. PRACTICAL APPLICATIONS: Lilium is an ornamental and edible plant typically used for food and traditional Chinese medicine. Its flowers are used for decoration, and its underground bulbs are rich in various bioactive substances. Fresh lily bulbs easily turn brown and lose economic value during storage and processing. Polyphenol oxidase (PPO) is a crucial molecule involved in the enzymatic browning of fruit and vegetables. In this study, PPO was extracted from three main planted lily cultivars in China. Namely, Lilium lancifolium Thunb, Lilium brownie var. viridulum, Lilium davidii var. unicolor cotton and was partially characterized. The results are of considerable importance to further understand the PPO of lily bulbs and provide guidance for the inactivation of enzymes and the processing of lily bulb juice.
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http://dx.doi.org/10.1111/jfbc.13431DOI Listing
October 2020

Changes in free amino acids of fermented minced peppers during natural and inoculated fermentation process based on HPLC-MS/MS.

J Food Sci 2020 Sep 13;85(9):2803-2811. Epub 2020 Aug 13.

College of Food Science and Technology, Hunan Agricultural University, Changsha, 410128, China.

Free amino acids (FAAs) participate in the synthesis of quality characteristic ingredients and taste substances in fermented minced peppers (FMPs), and they can be affected by fermentation method and time. In this study, changes in FAAs of FMP during natural fermentation (NF) and inoculated fermentation (IF) process were characterized by HPLC-MS/MS. The results showed that a total of 20 FAAs were identified, including 8 essential amino acids (AAs), 2 semiessential AAs, and 10 nonessential AAs. Comparing with other FAAs, Gln, Arg, and Asn presented higher content in the whole NF or IF periods. The FAAs content of NF and IF samples showed similar tendency during fermentation process, which first increased and then decreased. The highest content of most FAAs in IF and NF samples was obtained on the 18- and 12-day, respectively. Moreover, the FAA content in IF samples was higher than that in NF ones at the same fermentation time. The taste AAs content accounted for 23.3% to 50.0% in total FAAs, and taste activity value of bitter and umami was higher than sweet and aromatic ones. Based on principal component analysis, comprehensive analysis ranking, and heat map clustering analysis, FMP obtained by IF posed better FAAs quality than NF samples during fermentation process. PRACTICAL APPLICATION: Free amino acids (FAAs) participate in the synthesis of quality characteristic ingredients and taste substances in fermented minced peppers (FMPs), and they can be affected by fermentation method and time. Changes in FAA varieties and level in FMP during natural fermentation (NF) and inoculated fermentation (IF) process were analyzed using HPLC-MS/MS. Then, they were performed by principal component analysis (PCA), and clustered with the heat map. The results showed that FMP obtained by IF posed better FAAs quality than NF samples in the whole fermentation. HPLC-MS/MS was a reliable and effective mean for determining the FAAs and could provide regulation guidelines for improving the quality of FMP during fermentation process.
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http://dx.doi.org/10.1111/1750-3841.15363DOI Listing
September 2020

Changes in volatile compounds of fermented minced pepper during natural and inoculated fermentation process based on headspace-gas chromatography-ion mobility spectrometry.

Food Sci Nutr 2020 Jul 12;8(7):3362-3379. Epub 2020 May 12.

College of Food Science and Technology Hunan Agricultural University Changsha China.

Changes in volatile compounds of fermented minced pepper (FMP) during natural fermentation (NF) and inoculated fermentation (IF) process were analyzed by the headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). A total of 53 volatile compounds were identified, including 12 esters, 17 aldehydes, 13 alcohols, four ketones, three furans, two acids, one pyrazine, and one ether. Generally, fermentation time played an important role in volatile compounds of FMP. It was found that most esters, aldehydes, and alcohols obviously decreased with the increase in fermentation time, including isoamyl hexanoate, methyl octanoate, gamma-butyrolactone, phenylacetaldehyde, methional, and E-2-hexenol. Only a few volatile compounds increased, especially for 2-methylbutanoic acid, 2-methylpropionic acid, linalool, ethanol, and ethyl acetate. However, no significant difference in volatile compounds was found between NF and IF samples at the same fermentation time. In addition, the fermentation process in all samples was well discriminated as three stages (0 days; 6 day; and 12, 18, and 24 days), and all volatile compounds were divided into two categories (increase and decrease) based on principal component analysis and heat map.
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http://dx.doi.org/10.1002/fsn3.1616DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7382115PMC
July 2020

Effects of atorvastatin combined with bivalirudin on coagulation function, cardiac function, and inflammatory factors of percutaneous coronary intervention in elderly patients with acute myocardial infarction.

Ann Palliat Med 2020 Jul 22;9(4):1905-1911. Epub 2020 Jun 22.

Department of Cardiology, Joint Logistic Support Force of Chinese People's Liberation Army Tianjin Rehabilitation and Recuperation Center, Tianjin 300381, China.

Background: Acute myocardial infarction (AMI) occurs when atherosclerotic lesions which present in the coronary arteries cause the intravascular plate to rupture and with the result of myocardial ischemia, hypoxia, and infarct. The preferred treatment for AMI is currently percutaneous coronary intervention (PCI), for which the key to the success is the choice of anticoagulant and thrombolytic drugs during surgery. Here, we aim to explore the effects of atorvastatin combined with bivalirudin on coagulation function, cardiac function, and inflammatory factors in elderly patients with AMI who underwent PCI.

Methods: The clinical data of 86 AMI patients who were admitted to our hospital between February 2016 and May 2018 were retrospectively analyzed. Based on different treatments, the patients were divided into the control group and the observation group, with 43 patients in each group. The control group patients were treated with bivalirudin, and the observation group was treated with bivalirudin plus atorvastatin. Both groups of patients underwent PCI and the clinical efficacy, coagulation function, cardiac function, inflammatory factor levels and cardiovascular events (MACE), and other clinical data were compared between the groups.

Results: The total clinical effective rate in the observation group was significantly higher than that in the control group (90.90% vs. 72.09%) (P<0.05). Fibrinogen (Fg) and D-dimer (D-D) levels were significantly decreased after treatment in both groups but were significantly lower in the observation group than in the control group. The prothrombin time (PT) was significantly prolonged after treatment in both groups but was significantly longer in the observation group than in the control group after treatment (P<0.05). Meanwhile, the left ventricular end-diastolic diameter (LVEDD) and left ventricular end-systolic diameter (LVESD) were significantly reduced after treatment in both groups but were significantly lower in the observation group than in the control group, whereas the left ventricular ejection fraction (LVEF) was significantly higher in the observation group compared with the control group after treatment (P<0.05). After treatment, serum levels of transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), and IL-6 were significantly reduced in both groups but the levels were significantly lower in the observation group than in the control group (P<0.05). The overall incidence of MACE in the observation group was significantly lower than that in the control group (9.30% vs. 30.23%) (P<0.05).

Conclusions: Atorvastatin combined with bivalirudin can improve the efficiency of clinical treatment in elderly AMI patients who undergo PCI, while simultaneously improving blood coagulation function and reducing the occurrence of bleeding, compared with bivalrudin alone. It can also decrease the level of inflammatory factors, promote vascular recanalization, and improve myocardial ischemia, thereby reducing the incidence of MACE and improving patient prognosis.
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http://dx.doi.org/10.21037/apm-20-925DOI Listing
July 2020

A simple and nondestructive approach for the analysis of soluble solid content in citrus by using portable visible to near-infrared spectroscopy.

Food Sci Nutr 2020 May 14;8(5):2543-2552. Epub 2020 Apr 14.

Hunan Agricultural Product Processing Institute Hunan Academy of Agricultural Sciences Changsha China.

A simple and nondestructive method for the analysis of soluble solid content in citrus was established using portable visible to near-infrared spectroscopy (Vis/NIRS) in reflectance mode in combination with appropriate chemometric methods. The spectra were obtained directly by the portable Vis/NIRS without destroying samples. Outlier detection was performed by using leave-one-out cross-validation (LOOCV) with the 3σ criterion, and the calibration models were established by partial least squares (PLS) algorithm. Besides, different data pretreatment methods were used to eliminate noise and background interference before calibration, to determine the one that will lead to better model accuracy. However, the correlation coefficients are all <0.62 and the results of all pretreatments are still unsatisfactory. Variable selection methods were discussed for improving the accuracy, and variable adaptive boosting partial least squares (VABPLS) method was used to get higher robustness models. The results show that standard normal variate (SNV) transformation is the best pretreatment method, while VABPLS can significantly simplify the calculation and improve the result even without pretreatment. The correlation coefficient of the best prediction models is 0.82, while the value is 0.48 for the raw data. The high performance shows the feasibility of portable Vis/NIRS technology combination with appropriate chemometric methods for the determination of citrus soluble solid content.
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http://dx.doi.org/10.1002/fsn3.1550DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7215219PMC
May 2020

A Rapid and Nondestructive Approach for the Classification of Different-Age Citri Reticulatae Pericarpium Using Portable Near Infrared Spectroscopy.

Sensors (Basel) 2020 Mar 12;20(6). Epub 2020 Mar 12.

Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410128, China.

Citri Reticulatae Pericarpium (CRP), has been used in China for hundreds of years as a functional food and medicine. However, some short-age CRPs are disguised as long-age CRPs by unscrupulous businessmen in order to obtain higher profits. In this paper, a rapid and nondestructive method for the classification of different-age CRPs was established using portable near infrared spectroscopy (NIRS) in diffuse reflectance mode combination with appropriate chemometric methods. The spectra of outer skin and inner capsule of CRPs at different storage ages were obtained directly without destroying the samples. Principal component analysis (PCA) with single and combined spectral pretreatment methods was used for the classification of different-age CRPs. Furthermore, the data were pretreated with the PCA method, and Fisher linear discriminant analysis (FLD) with optimized pretreatment methods was discussed for improving the accuracy of classification. Data pretreatment methods can be used to eliminate the noise and background interference. The classification accuracy of inner capsule is better than that of outer skin data. Furthermore, the best results with 100% prediction accuracy can be obtained with FLD method, even without pretreatment.
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http://dx.doi.org/10.3390/s20061586DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7146621PMC
March 2020

Changes in volatile flavor compounds of peppers during hot air drying process based on headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS).

J Sci Food Agric 2020 May 15;100(7):3087-3098. Epub 2020 Mar 15.

College of Food Science and Technology, Hunan Agricultural University, Changsha, China.

Background: Flavor plays a critical role in defining sensory and consumer acceptance of dried pepper, and it can be affected by temperature and moisture content during hot air drying (HAD). Thus, headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) was used to analyze changes in volatile compounds of pepper during the HAD process with different drying temperatures.

Results: A total of 45 volatile flavor compounds were identified, including 11 esters, 11 aldehydes, nine alcohols, five ketones, three furans, three acids, two pyrazines, and one ether. The results showed that with the loss of moisture during drying, aldehydes and alcohols decreased, esters initially increased and then decreased. However, propyl acetate, 2,3-butanediol, 2-acetylfuran, and 2-methylpyrazine increased. Moreover, drying temperature was closely related to the change of volatile flavor compounds. Aldehydes, alcohols, and some other volatile flavor compounds (methyl salicylate, ethyl acetate, 2-methylpyrazine, dipropyl disulfide) decreased with an increase of temperature (60-80 °C) at the same moisture content, while high temperature could promote the formation of ethyl octanoate, methyl octanoate, benzaldehyde, furfurol, acetal, 5-methylfurfural, and 2-acetylfuran. Based on principal components analysis and heat map clustering analysis, peppers dried at 70 or 80 °C presented similar composition, and the loss of volatile flavor compounds was more than samples died at 60 °C during the HAD process.

Conclusion: Overall, the flavor quality of peppers dried at 60 °C was better than that of other treatments during the HAD process. HS-GC-IMS was a reliable and effective means of analyzing volatile flavor compounds in peppers during the drying process. © 2020 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.10341DOI Listing
May 2020

Effects of heat-moisture and acid treatments on the structural, physicochemical, and in vitro digestibility properties of lily starch.

Int J Biol Macromol 2020 Apr 20;148:956-968. Epub 2020 Jan 20.

Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Hunan Provincial Key Laboratory for Fruits and Vegetables Storage Processing and Quality Safety, Changsha 410125, China; Longping Branch Graduate School, Hunan University, Changsha 410081, China. Electronic address:

Starch extracted from lily bulb (Lilium brownii var. Viridulum Baker) was modified via heat-moisture treatment (HMT) at different moisture levels (15-35%) and acid treatment (AT) with hydrochloric acid at five different concentrations (0.25-2.0 M). The effects of HMT and AT on the physicochemical properties and in vitro digestibility of lily starch were investigated. HMT and AT led to the clustering of the starch granules, whose surface became rougher, thereby increasing the particle size. X-ray diffraction results showed that HMT increased the relative crystallinity and transformed the crystalline structure from B- to A-type. The relative crystallinity and X-ray patterns of the AT starch significantly increased. The swelling power of HMT and AT starch was significantly reduced, whereas the solubility of HMT starch decreased. The solubility of AT starch was significantly higher than that of native starch (NS) (p < 0.05). Differential scanning calorimetry revealed that the gelatinization temperature of lily starch was higher than that of NS after two modifications, whereas the gelatinization enthalpy of the NS was lower than that of the modified samples. The starch with HMT at 25% showed the highest resistant starch content of 44.15% in cooked samples.
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http://dx.doi.org/10.1016/j.ijbiomac.2020.01.181DOI Listing
April 2020

Changes in Cuticle Components and Morphology of 'Satsuma' Mandarin () during Ambient Storage and Their Potential Role on Infection.

Molecules 2020 Jan 19;25(2). Epub 2020 Jan 19.

Provincial Key Laboratory for Fruits and Vegetables Storage Processing and Quality Safety, Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China.

To elucidate the role of fruit cuticle in fungal infection, changes in cuticle composition and morphology of 'Satsuma' mandarin during ambient (at 25 °C) storage and their role in infection were investigated. Results showed that the epicuticular wax yield increased from 1.11 μg cm to 4.21 μg cm during storage for 20 days and then decreased to 1.35 μg cm as storage time prolonged to 40 days. Intracuticular wax content of fruits stored for 20 days showed a peak value that was 1.7-fold higher than that of fruits stored for 40 days. The contents of cutin monomers of fruits showed a decreased trend during storage, while their proportions in the cutin stayed stable. Acids were identified as the most abundant components in epicuticular wax independently of the storage time, followed by alkanes and terpenoids. Terpenoids were found as the predominant components in intracuticular wax during the whole storage, followed by alkanes and acids. The flattened platelets crystals of fruits at harvest changed into small granule-like wax ones after 10 days of storage then gradually distributed across the surface of the fruits as stored for 40 days. Results of in vitro tests showed that mycelial growth of could be promoted by epicuticular wax and conidial germination could be inhibited by cutin at different storage stages. These results shed new light on the chemical basis for cuticle involvement in fungal infection.
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http://dx.doi.org/10.3390/molecules25020412DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7024380PMC
January 2020

Characterization of Volatile Component Changes in Jujube Fruits during Cold Storage by Using Headspace-Gas Chromatography-Ion Mobility Spectrometry.

Molecules 2019 Oct 30;24(21). Epub 2019 Oct 30.

Longping Branch Graduate School, Hunan University, Changsha 410125, China.

Volatile components in jujube fruits from Mill. . Dongzao (DZ) and Mill. . Jinsixiaozao (JS) were analyzed under different cold storage periods via headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). Results identified 53 peaks that corresponded to 47 compounds and were mostly alcohols, aldehydes, esters, and ketones. Differences in the volatile components of jujube fruits were revealed in topographic plots and fingerprints. For DZ, 3-pentanone was the characteristic component of fresh fruits. After storage for 15 days, dipropyl disulfide became the most special substance. Moreover, when stored for 30 and 45 days, the fruits had some same volatile components, like 2-pentyl furan and diallyl sulfide. However, for DZ stored for 60 days, esters were the prominent constituent of the volatile components, simultaneously, some new alcohols appeared. For JS, 2-ethyl furan was the representative of fresh fruits, and 2-butoxyethanol content was the most abundant after 15 and 30 days of storage. Different from that in DZ, the content of ester in JS increased after storage for 45 days. Substances such as amyl acetate dimer, methyl salicylate, and linalool greatly contributed to the jujube flavor during the late storage period. Principal component analysis (PCA) showed that fresh samples and refrigerated fruits were effectively distinguished. Heat map clustering analysis displayed the similarity of volatile components in different samples and was in accordance with PCA results. Hence, the volatile components of jujube fruits can be readily identified via HS-GC-IMS, and jujube fruits can be classified at different periods based on the difference of volatile components.
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http://dx.doi.org/10.3390/molecules24213904DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6864690PMC
October 2019

Effects of High-Pressure Homogenization on the Structural, Physical, and Rheological Properties of Lily Pulp.

Foods 2019 Oct 10;8(10). Epub 2019 Oct 10.

Longping Branch Graduate School, Hunan University, Changsha 410125, China.

The effects of high-pressure homogenization (HPH) on the structural, physical, and rheological properties of lily pulp (15%, /) were investigated. Different pressures ranging from 0 MPa to 100 MPa were used. The focus was on evaluating the changes in the particle size distribution (PSD), structure, pulp sedimentation behavior, serum cloudiness (SC), total soluble solids (TSS), color, and rheological behavior of the pulps. PSD analysis showed that the diameter of suspended lily particles significantly decreased with an increasing homogenization pressure. The suspended particles observed through optical microscopy became small after homogenization, highlighting the effect of HPH on disrupting the suspended particles. Compared with the untreated pulp, the SC and sedimentation velocity of the homogenized pulps decreased due to the disruption of the suspended particles. The effects of HPH on the sedimentation index and SC exhibited an asymptotic behavior similar to that of the changes in the particle size of lily pulp. Moreover, HPH processing reduced the viscosity of lily pulp and increased the TSS and lightness of the homogenized pulps. HPH significantly modified the structural, physical, and rheological properties of lily pulp. The pulp homogenized above 60 MPa had good suspension stability. This finding indicates that HPH technology can be used to improve the stability of lily pulp.
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http://dx.doi.org/10.3390/foods8100472DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6835810PMC
October 2019

Changes in the Volatile Components of Candied Kumquats in Different Processing Methodologies with Headspace-Gas Chromatography-Ion Mobility Spectrometry.

Molecules 2019 Aug 22;24(17). Epub 2019 Aug 22.

Longping Branch Graduate School, Hunan University, Changsha 410125, China.

The effects of two different processing methods on the volatile components of candied kumquats were investigated via headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). The characteristic volatile fingerprints of fresh kumquats (FKs), vacuum sugaring osmosis combined with hot-air drying kumquats (VS-ADKs), and atmospheric pressure sugaring osmosis combined with hot-air drying kumquats (AS-ADKs) were established using 3D topographic plots. From the fingerprints, 40 signal peaks for 22 compounds were confirmed and quantified in all types of kumquats, namely, two terpenes, four esters, seven aldehydes, three ketones, and six alcohols. 3-Pentanone was identified as the major component of FKs; followed by 1-hexanol and the -3-hexen-1-ol dimer. The hexanal dimer, 2-hexen-1-ol, and the ethyl acetate dimer were the major markers of VS-ADKs. Benzaldehyde and furfurol were the prominent constituent parts of AS-ADKs. Compared with that in FKs, the pentanal and dimethyl ketone contents of VS-ADKs and AS-ADKs exhibited a dramatic increase ( < 0.05). By contrast, the change in ethanol dimer tended to decrease ( < 0.05). Principal component analysis (PCA) clearly showed that the samples, which were distributed in a separate space could be well-distinguished. Furthermore, the similarity of different processed kumquats and their corresponding volatile components was demonstrated via heat map clustering analysis. The results confirmed the potential of HS-GC-IMS-based approaches to evaluate processed kumquats with various volatile profiles.
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http://dx.doi.org/10.3390/molecules24173053DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6749507PMC
August 2019

Effect of drying temperature on the sugars, organic acids, limonoids, phenolics, and antioxidant capacities of lemon slices.

Food Sci Biotechnol 2017 13;26(6):1523-1533. Epub 2017 Dec 13.

1Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha, 410125 China.

Changes in contents of sugars, organic acids, limonoids, phenolics contents, and antioxidant capacities of lemon slices dried at different temperatures were evaluated. Air drying (AD) promoted losses of sugars, citric acid, ascorbic acid, extractable phenolics (EPs), and non-extractable phenolics (NEPs), while it introduced an increase in limonoids. Phenolics of lemon were mainly presented in their extractable form. Hesperidin and eriocitrin were the main EPs; protocatechuic acid and poncirin were the predominant NEPs. The decrease in extractable phenolic acid, EP, and NEP content in lemon is lower at low drying temperatures, while the increase in non-extractable phenolic acid content is higher at high drying temperatures. The antioxidant capacity of EP was higher than that of NEP. Phenolics contributed to antioxidant capacities of lemon slices, and flavonoids were the main contributors among phenolics. Considering limonoids contents and the high levels of EP, NEP, and antioxidant capacities, AD at 60 °C could be an appreciate treatment for dehydrating lemon slices.
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http://dx.doi.org/10.1007/s10068-017-0221-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049725PMC
December 2017

Changes in pectin characteristics during the ripening of jujube fruit.

J Sci Food Agric 2017 Sep 10;97(12):4151-4159. Epub 2017 Apr 10.

Department of Food Science and Technology, Jinan University, Guangzhou, China.

Background: Pectin is related to fruit maturation and loss of flesh firmness. In this research, changes in pectin characteristics, including pectin content, neutral sugar composition, molecular weight (M ) distribution and degree of methylesterification (DM), in six different growth stages (S1 to S6) of jujube fruit were assessed.

Results: The growth of jujube fruit corresponded to an increase in water-soluble pectin (WSP) and a decrease in sodium carbonate-soluble pectin (SSP). The chelate-soluble pectin (CSP) content reached a maximum level at S3 but decreased significantly from S3 to S4. Arabinose proved to be the principal branched neutral monosaccharide in pectin during growth and was lost from WSP, CSP and SSP in S4 to S6. The ratios of (arabinose + galactose)/rhamnose indicated that the branched chains of WSP, CSP and SSP degraded in S2, S3 and S4 respectively. SSP depolymerized from S2 and increased as jujube fruit ripened. By contrast, WSP depolymerized throughout ripening. The DM of pectins ranged from 45.38 to 92.21%. Among the obtained DMs, the lowest was observed in WSP from ripened jujube fruit (S6).

Conclusion: The content, neutral sugar composition, DM and M distribution of pectins changed markedly as jujube fruit ripened. Jujube fruit could be a promising alternative source of pectins in terms of maturation degree. WSP from S6 and CSP from S1 or S2 could be used as gelling agents in low-sugar-containing products because of their low methoxyl pectin contents. WSP from S1 could also be applied as a thickener or emulsifier owing to its high M distribution. © 2017 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.8285DOI Listing
September 2017

Effect of dehydration methods on antioxidant activities, phenolic contents, cyclic nucleotides, and volatiles of jujube fruits.

Food Sci Biotechnol 2016 29;25(1):137-143. Epub 2016 Feb 29.

1College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083 China.

Changes in antioxidant activities, phenolic contents, cyclic nucleotides, and volatiles of jujube after dehydration using freeze-drying (FD), air drying (AD), sun drying (SD), and microwave drying (MD) were investigated. All dehydration methods caused a decrease in antioxidant activities, aldehyde, acid, and alkane contents. Esters were increased by the dehydration. FD was superior to other dehydration methods for retention of total phenolics, total flavonoids, and antioxidant activities. MD caused an increase of catechin and epichtechin levels. Although AD, MD, and SD caused declines in cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) contents, AD at 50oC was a good choice to obtain jujubes with high levels of cAMP and cGMP. Theoretical fundamentals for selection of suitable drying techniques to minimize the negative effects caused by dehydration and for meeting production requirements are provided.
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http://dx.doi.org/10.1007/s10068-016-0021-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049381PMC
February 2016
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