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Chen J.,China Agricultural University | Chen J.,National Engineering Research Center for Fruits and Vegetables Processing | Ren X.,China Agricultural University | Ren X.,National Engineering Research Center for Fruits and Vegetables Processing | And 2 more authors.
Quality Assurance and Safety of Crops and Foods | Year: 2017

The near infrared (NIR) spectroscopy models developed for rapid and accurate determination of nine essential amino acids and protein in foxtail millet were investigated. The effects of the status of the samples (intact or ground), amino acid/protein correlation and variable selection methods on the predictive ability of the models were analysed. According to results, although the average spectral patterns of the intact and ground samples were similar, the absolute values of peaks and valleys for the intact samples were slightly higher. The modelling results of intact samples were similar to those obtained with ground samples. In the results of the partial least squares models with full spectra, 81-94% of the amino acid variance could be explained, except for lysine, tryptophan and methionine with the coefficients of determination of cross-validation less than 0.70. The correlation between various amino acids and protein might affect the predictive ability of NIR spectroscopy for essential amino acids. After variable selection, the models for isoleucine, leucine, phenylalanine, threonine, tryptophan and valine were remarkably improved by the successive projections algorithm method. The results indicated that short-wave NIR spectroscopy coupled with variable selection is a promising approach for determination of essential amino acids in foxtail millet. © 2016 Wageningen Academic Publishers.


Guo X.,China Agricultural University | Guo X.,Key Laboratory of Fruits and Vegetables Processing | Guo X.,National Engineering Research Center for Fruits and Vegetables Processing | Han D.,China Agricultural University | And 17 more authors.
Carbohydrate Polymers | Year: 2012

Ultra-high pressure (UHP) was applied for pectin extraction from navel orange peel. The effects of pressure, temperature and pressure-holding time on the extraction yield and viscosity of pectin were investigated. A 2-factor 3-level design, following a single-factor experiment, was carried out to optimize the extraction parameters and the optimal conditions of UHP extraction were determined as pressure 500 MPa, temperature 55°C, pressure-holding time 10 min. Under the optimal conditions, the yield of pectin (20.44% ± 0.64) was significantly higher than those extracted by traditional heating (15.47% ± 0.26) and microwave (18.13% ± 0.23). The physicochemical properties and rheological characteristics of pectin extracted by ultra-high pressure, traditional heating and microwave as well as commercial pectin were also compared. The results showed that the intrinsic viscosity and viscosity-average molecular weight of pectin extracted by UHP (0.7604 L/g and 3.063 × 10 5 Da) were much higher than those extracted by traditional heating (0.4276 L/g and 1.521 × 10 5 Da), microwave (0.3591 L/g and 1.230 × 10 5 Da), and the commercial pectin (0.2160 L/g and 0.663 × 10 5 Da). The same results were also obtained in the rheological characteristics, activation energy and gelling properties determination. These results clearly demonstrated that UHP is a more efficient, time saving, and eco-friendly alternative for pectin extraction from navel orange peel, especially for pectin with higher viscosity and stability. © 2011 Elsevier Ltd. All rights reserved.


Song Y.,National Engineering Research Center for Fruits and Vegetables Processing | Song Y.,China Agricultural University | Yang Y.,National Engineering Research Center for Fruits and Vegetables Processing | Yang Y.,China Agricultural University | And 13 more authors.
Carbohydrate Polymers | Year: 2013

Acetylation of pumpkin (Cucurbita pepo, lady godiva variety) polysaccharide using acetic anhydride with pyridines as catalyst under different conditions was conducted to obtain different degrees of acetylation on a laboratory scale. Furthermore, antioxidant activities and cytoprotective effects of pumpkin polysaccharide and its acetylated derivatives were investigated employing various established in vitro systems. Results showed that addition of pyridine as catalyst could increase the degree of substitution, whereas volume of acetic anhydride had little effect. The acetylated polysaccharides in DPPH scavenging radical activity assay, superoxide anion radical activity assay and reducing power assay exhibited higher antioxidant activity than that of unmodified polysaccharide. H2O2-induced oxidative damages on rat thymic lymphocyte were also prevented by pumpkin polysaccharide and its acetylated derivatives and the derivatives presented higher protective effects. On the whole, acetylated polysaccharide showed relevant antioxidant activity both in vitro and in a cell system. © 2013 Elsevier Ltd. All rights reserved.


Zhang Y.,China Agricultural University | Zhang Y.,National Engineering Research Center for Fruits and Vegetables Processing | Zhang Y.,Key Laboratory of Fruits and Vegetables Processing
Innovative Food Science and Emerging Technologies | Year: 2013

This study was carried out to evaluate the effect of high hydrostatic pressure on microbiological and physical qualities changes of bay scallop (Argopecten irradians) during storage time at - 18 C. High hydrostatic pressure (HHP), at pressure levels from 150 to 400 MPa was used for shucking bay scallop. 100% detachment of adductor muscle was observed when scallops were treated at 200 MPa/3 min and 350 MPa/0 min. HHP-shucked scallops obtained higher yield (17.26% higher for tissue and 3.48% higher for adductor muscle) than manual shucking samples (P < 0.05). HHP shucking produced reductions in the aerobic plate count and coliform. Moreover, HHP-shucked adductor muscles showed significantly higher pH (6.14 to 6.40), moisture (78.95% to 80.47%) and thawing drip loss (4.41% to 9.67%) than control (P < 0.05). The hardness of HHP-shucked adductor muscles increased, while the springiness showed no difference changes. Furthermore, the HHP shucking significantly increased L* value (52.40 to 53.96) of adductor muscles, while a* (- 2.05 to - 4.15) and b* values (0.18 to - 4.68) decreased (P < 0.05). At the end of frozen storage (150 days), most of quality parameters showed no significant changes. In addition, the HHP-shucked adductor muscles presented better sensory attributes. In short, HHP as an effective shucking method showed a broad prospect for application in scallop processing industry. Industrial relevance This research paper which presented a fair comparison of high pressure shucking and hand shucking on bay scallops, could provide information about shucking attributes and biochemical stability of adductor muscles under frozen storage time which are quite scarce. The available data are provided for the evaluation and application of HHP in the bivalve processing industry, and criteria for commercial production of high quality scallop adductor muscle with safety requirements could be established. Crown Copyright © 2013 Published by Elsevier Ltd. All rights reserved.


Chen J.,China Agricultural University | Chen J.,National Engineering Research Center for Fruits and Vegetables Processing | Ren X.,China Agricultural University | Ren X.,National Engineering Research Center for Fruits and Vegetables Processing | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

Compound fermented wheat flour paste is favored by Chinese consumers as a traditional condiment, which is made of fermented wheat flour by Aspergillus oryzae. During the fermentation process, sterilization plays a key role, because the compound fermented wheat flour paste is prone to getting polluted. Heat sterilization is a conventional and simple method to kill the microorganisms in the products. However, the method has undesirable influences on the qualities of the product such as texture and flavor due to uneven heating. Besides, the microorganisms cannot be killed thoroughly. The high-pressure thermal sterilization (HPTS) is a new type of sterilization technology which combines the methods of pressure and temperature. And this approach can extend the shelf life and maintain the safety of the products. The properties such as rheological characteristics, color, specific aroma compositions and fatty acid compositions in the compound fermented wheat flour paste before and after processed by the HPTS were analyzed, in order to study on the quality of the compound fermented wheat flour paste. Samples were subjected to different pressure treatments (300, 400 and 500 MPa) for 10 min at 45℃, and then the properties of rheological characteristics, color, specific aroma compositions of all the samples were analyzed by rheometer, automatic chromatic meter, and GC-MS, respectively. The results showed that under HPTS treatment the viscosity of the compound fermented wheat flour paste reduced, and with the increasing of the pressure, the viscosity decreased. However, the compound fermented wheat flour paste was still pseudoplastic fluid, and the type of the fluid was not changed after the processing. Besides, after dealed with the HPTS processing, the chromatic aberration of these samples reduced significantly, and the brown index (BI) declined. But there was no significant change in the level of the parameter of the properties of color (L* and a*), which present the brightness and the degree of the red and green, respectively. In addition, the volatile flavor substances in the compound fermented wheat flour paste mainly contained aldehydes and esters. 5-Methyl-2-phenyl-2-hexenal, Furfural and ethyl oleate were the main aroma components. After treated, various aldehydes content decreased significantly. In particular ethyl oleate cannot be detected in the processed samples. However, the contents of phenylacetaldehyde and limonene increased. Moreover, there were new compositions such as benzaldehyde and phenethyl alcohol found in the processed samples. Finally, the fatty acids contents of the samples were analyzed and the fatty acids composition didn't change significantly after the HPTS treatment at 400 MPa, 45℃, 10min, except the content of the oleic acid. To sum up, there was no significant change in the properties of color (L* and a*), specific aroma compositions and fatty acids compositions of the compound fermented wheat flour paste; the viscosity of the samples treated at 400 MPa was similar with the unprocessed samples than the samples treated at 500 MPa HPTS. Therefore, the treatment of HPTS at 400 MPa, 45℃, 10min could maintain the quality of the compound fermented wheat flour paste such as texture, color, specific aroma compositions and fatty acids compositions. ©, 2015, Chinese Society of Agricultural Engineering. All right reserved.


Dong P.,China Agricultural University | Dong P.,National Engineering Research Center for Fruits and Vegetables Processing | Dong P.,Key Laboratory of Fruits and Vegetables Processing | Dong P.,German Institute of Food Technologies DIL | And 5 more authors.
Frontiers in Microbiology | Year: 2015

Ultra high pressure homogenization (UHPH) opens up new areas for dynamic high pressure assisted thermal sterilization of liquids. Bacillus amyloliquefaciens spores are resistant to high isostatic pressure and temperature and were suggested as potential surrogate for high pressure thermal sterilization validation. B. amyloliquefaciens spores suspended in PBS buffer (0.01 M, pH 7.0), low fat milk (1.5%, pH 6.7) and whole milk (3.5%, pH 6.7) at initial concentration of ~106 CFU/mL were subjected to UHPH treatments at 200, 300 and 350 MPa with an inlet temperature at ~80 °C. Thermal inactivation kinetics of B. amyloliquefaciens spores in PBS and milk were assessed with thin wall glass capillaries and modeled using first-order and Weibull models. The residence time during UHPH treatments was estimated to determine the contribution of temperature to spore inactivation by UHPH. No sublethal injury was detected after UHPH treatments using sodium chloride as selective component in the nutrient agar medium. The inactivation profiles of spores in PBS buffer and milk were compared and fat provided no clear protective effect for spores against treatments. Treatment at 200 MPa with valve temperatures lower than 125 °C caused no reduction of spores. A reduction of 3.5 log10 CFU/mL of B. amyloliquefaciens spores was achieved by treatment at 350 MPa with a valve temperature higher than 150 °C. The modeled thermal inactivation and observed inactivation during UHPH treatments suggest that temperature could be the main lethal effect driving inactivation. © 2015 Dong, Georget, Aganovic, Heinz and Mathys.


Guo X.,China Agricultural University | Guo X.,Liaocheng University | Guo X.,Key Laboratory of Fruits and Vegetables Processing | Guo X.,National Engineering Research Center for Fruits and Vegetables Processing | And 15 more authors.
Food Hydrocolloids | Year: 2014

In the previous studies, two novel methods for pectin extraction, using high hydrostatic pressure (HHP) and high-speed shearing homogenization (HSHE), were developed with higher efficiency, less time and energy consumptions than traditional thermal extraction (THE); however, many functional properties of these pectins are still unknown. To explore the influence of extraction methods (HHP, HSHE and THE) and pH on the emulsion stabilizing properties of these pectins, many parameters, including zeta potential, apparent viscosity, light microscopy, and particle mean diameters of pectins or their emulsions (1% pectin with 42.8% refined soybean oil), were firstly determined compared with those of two commercial pectins (AP and SP). The results revealed that extraction methods have important influence on viscosities of pectins and their emulsions. The emulsions prepared by HHP extracted pectin have the smallest particle mean diameters (8.96-11.02μm) and best emulsifying stability (100%) after centrifugation assay or 3 weeks of storage at 4°C with the pH in the range of 3-5. The emulsions prepared by HSHE and THE extracted pectins have a similar particle mean diameters and emulsifying stabilities better than those made with AP and SP. The molecular weight distributions and morphological features, determined by HPSEC-RID and AFM, then indicated their difference at molecular level and their interactions. From the results, it could be concluded that emulsion stabilizing properties of pectin were greatly influenced by their physicochemical properties, including viscosity, molecular size and their interactions. © 2013 .


Zhao M.,National Engineering Research Center for Fruits and Vegetables Processing | Zhao M.,China Agricultural University | Wang P.,National Engineering Research Center for Fruits and Vegetables Processing | Wang P.,China Agricultural University | And 8 more authors.
Journal of Functional Foods | Year: 2015

The intervention effects of blueberry anthocyanins extract (BAE) on the acrylamide (AA)-induced general toxicity, genotoxicity and reproductive toxicity were investigated in a mice model. Compared to the AA group, BAE restored the AA-induced alteration in haematology and serum chemistry, markedly decreased the DNA damage in lymphocyte and liver cells, as well as micronucleus formation in bone marrow cell. Meanwhile, BAE improved sperm motility levels and decreased abnormal sperm rate. Furthermore, BAE inhibited the AA-induced ROS accumulation and glutathione (GSH) depletion, ameliorated the activities of glutathione peroxidase (GPx) and glutathione-S-transferase (GST), improved the protein expression of GPx, GST and gamma-glutamyl cysteine synthase (γ-GCS), and inhibited the cytochrome P4502E1 (CYP2E1) protein expression. Thus, the intervention mechanism of BAE on the AA-induced toxicity possibly attributed to the prevention of AA-induced oxidative stress and CYP2E1 activation. BAE would have potential application for the chemoprevention of the AA toxicity as a nutraceutical or a dietary supplement. © 2015 Elsevier Ltd.


Long F.,National Engineering Research Center for Fruits and Vegetables Processing | Long F.,Northwest Agriculture and Forestry University | Yang X.,Northwest Agriculture and Forestry University | Wang R.,National Engineering Research Center for Fruits and Vegetables Processing | And 2 more authors.
Innovative Food Science and Emerging Technologies | Year: 2015

Crustacean allergy is a significant health problem worldwide, and tropomyosin (TM) is the major allergen found in crustaceans. Therefore, this study aimed to determine whether high pressure and thermal treatments could reduce the allergic properties of TM. Shrimp protein extracts were treated with high pressure and/or thermal treatment, and the allergenicity of TM was analyzed by competitive inhibition enzyme-linked immunosorbent assays using pooled sera from eight patients with shrimp specific IgE. Compared to the boiling treatment, a reduction with 73.59% in immunoglobulin E (IgE) binding was observed when the samples were treated at 55 °C, 500 MPa for 10 min. Furthermore, in a BALB/c mouse model of allergy, significant reductions in specific IgE titers were observed in mice fed with TM treated with high pressure and heat (TMH), accompanied by reduced histamine levels in serum. Similarly, real-time reverse transcription polymerase chain reaction revealed the decrease in mRNAs encoding interferon-γ, interleukin (IL)-4, and IL-10 in jejunum tissues. TMH had almost no allergenicity in the BALB/c mouse model of TM allergy. Industrial relevance High hydrostatic pressure (HHP) processing can inactivate microorganisms and enzymes, leaving sensory and nutritional quality almost unchanged. Furthermore, HHP could alter allergen conformation and hence decrease allergenic activity in rice, fish, milk and celery that were reported. As a health concern, shrimp allergies have been studied in this work. This study was conducted to determine whether high pressure and heat could reduce the allergic properties of shrimp allergen tropomyosin (TM). In addition, the effects on the allergenicity of TM treated with high pressure and heat (TMH) were characterized using a BALB/c mouse model of allergy. The results showed that TMH has great potential for industrialization to eliminate or decrease allergenicity of food protein. © 2015 Elsevier Ltd.


Zhang F.,National Engineering Research Center for Fruits and Vegetables Processing | Dong P.,National Engineering Research Center for Fruits and Vegetables Processing | Feng L.,National Engineering Research Center for Fruits and Vegetables Processing | Chen F.,National Engineering Research Center for Fruits and Vegetables Processing | And 3 more authors.
Food and Bioprocess Technology | Year: 2012

Textural changes of yellow peach in pouches (YPP) treated by high hydrostatic pressure (HHP) and thermal processing during storage at 4 ± 1 °C and 25 ± 1 °C for 180 days were studied. Hardness, syrup viscosity, pectin compositions, and cell structure of YPP samples were evaluated in this study. The hardness of YPP stored at 4 ± 1 °C exceeded 50-70 % as compared to those stored at 25 ± 1 °C. Moreover, the higher flesh hardness and lower syrup viscosity were obtained at longer pressure-holding time of HHP processing. Water-soluble pectin (WSP), sodium carbonate-soluble pectin (NSP), and total pectin contents in flesh decreased, while chelate-soluble pectin (CSP) in flesh and water-soluble pectin in syrup (WSPS) increased after 180 days storage. The texture degradation in YPP was mainly caused by solubilization and depolymerization of WSP and NSP. The temperature of 4 ± 1 °C inhibited pectin degradation and delayed the softening of flesh and the increase of syrup viscosity more effectively than 25 ± 1 °C. Comparing with the flesh tissue microstructure of HHP-processed YPP stored at 25 ± 1 °C, better cell structures of YPP were retained during storage at 4 ± 1 °C. Since the breakdown of intercellular cementing pectin was obviously delayed at lower storage temperature, thus cell wall loosening and distortion were prevented. © 2012 Springer Science+Business Media, LLC.

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