Co-reporter:Shunshan Jiao;Wenyun Sun;Tiankui Yang;Yanping Zou
Food and Bioprocess Technology 2017 Volume 10( Issue 4) pp:781-788
Publication Date(Web):2017 April
DOI:10.1007/s11947-017-1865-8
Many studies showed that radio frequency (RF) holds great potential to control insects in grains, while a few more technical issues need to be addressed to further make this technology ready for industrial application. Therefore, the effect of RF heating rate on rice fissure ratio and broken rate, RF heating lethality on immature rice weevils, and RF disinfestation treatment on cooking and eating quality of milled rice was investigated in this study. Results indicated that RF heating rate had no significant influence on rice broken rate, while fast RF heating rate (>7.2 °C/min) had adverse effects on rice fissure ratio, and mild RF heating rate (<5.8 °C/min) had no significant influence on fissure ratio of milled rice. RF treatment (50 °C, 5 min) could completely control immature rice weevils in rough, brown, and milled rice. Even though RF disinfestation treatment (50 °C, 5 min) influenced the cooking quality (water absorption, adhesive strength) of milled rice, it had no significant effect on overall sensory quality. This study provided valuable information for considering the application of RF energy in milled rice process to control insects.
Co-reporter:Virginia P. Gouw, Jooyeoun Jung, John Simonsen, Yanyun Zhao
Composites Part A: Applied Science and Manufacturing 2017 Volume 99(Volume 99) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.compositesa.2017.04.007
Fruit pomace (FP) as a source of fiber partially replaced recycled newspaper (NP) to create molded pulp boards (FPBs). Blueberry (BP), cranberry (CP), and apple pomace (AP) with different fiber compositions and morphologies were studied for their compatibility with NP. Cellulose nanofiber (CNF) was used to improve adhesion between FP and NP. FP/NP ratio and CNF concentration were optimized via central composite design to create FPBs with lower water absorption, and similar flexural strength and strain to 100% newspaper board (NPB). Lignocellulosic composition and fiber morphology of FP affected its compatibility with NP. Incorporating CNF reduced water absorption and increased flexural strength and strain of FPBs, but the amount of required CNF varied among the types of pomace. This study demonstrated that FP can partially substitute NP to create FPBs with better or similar properties to 100% NPB.
Co-reporter:Zilong Deng, Jooyeoun Jung, John Simonsen, Yanyun Zhao
Food Chemistry 2017 Volume 232(Volume 232) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.foodchem.2017.04.028
•Cellulose nanofiber (CNF) emulsion coating was developed and characterized.•CNF emulsion coating had superior hydrophobicity and wettability onto banana surface.•CNF emulsion coating controlled postharvest physiological activity of bananas.•CNF emulsion coating modified banana surface morphology and provided uniform coverage.•CNF emulsion coating reduced ripening and enhanced storability of bananas.Cellulose nanomaterials (CNs)-incorporated emulsion coatings with improved moisture barrier, wettability and surface adhesion onto fruit surfaces were developed for controlling postharvest physiological activity and enhancing storability of bananas during ambient storage. Cellulose nanofiber (CNF)-based emulsion coating (CNFC: 0.3% CNF/1% oleic acid/1% sucrose ester fatty acid (w/w wet base)) had low contact angle, high spread coefficient onto banana surfaces, and lower surface tension (ST, 25.4 mN/m) than the critical ST (35.2 mN/m) of banana peels, and exhibited good wettability onto banana surfaces. CNFC coating delayed the ethylene biosynthesis pathway and reduced ethylene and CO2 production, thus delaying fruit ripening. As the result, CNFC coating minimized chlorophyll degradation, weight loss, and firmness of bananas while ensuring the properly fruit ripening during 10 d of ambient storage. This study demonstrated the effectiveness of CNF based emulsion coatings for improving the storability of postharvest bananas.
Co-reporter:Hongcai Zhang, Jooyeoun Jung, Yanyun Zhao
Food Hydrocolloids 2017 Volume 69(Volume 69) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.foodhyd.2017.01.029
•Different types of essential oils (EOs) were loaded into β-chitosan (CS) beads.•EOs loaded β-CS beads were incorporated into cellulose nanocrystals (CNCs) film.•Antibacterial and mechanical properties of CNCs films depend on the type of EOs.•CNCs could serve as stable film matrix and stabilizer for EOs loaded β-CS beads.Essential oils (EOs), including clover (CL), cinnamon bark (CB), and lemongrass (LG) oils, were loaded into β-chitosan (β-CS) beads using a simple two-step method: oil/water emulsion and ionic gelation with sodium tripolyphosphate. EOs loaded β-CS beads were then incorporated into cellulose nanocrystals (CNCs) for producing films. CL, CB, and LG loaded β-CS beads had particle size of 272, 191 and 775 nm, polydispersity index of 0.312, 0.382, and 0.012, and encapsulation efficacy of 54.12, 54.16, and 55.41%, respectively. Mechanical and antibacterial properties of CNCs films were enhanced by incorporating EOs loaded β-CS beads. Depending on the type of loaded EOs, incorporating β-CS beads might alter structural and morphological properties of CNCs films. This study validated that β-CS beads can be used as stable loading system for EOs while CNCs as film forming material and stabilizer for distributing EOs loaded β-CS beads in film matrix for creating antibacterial packaging material.Download high-res image (106KB)Download full-size image
Co-reporter:Virginia P. Gouw, Jooyeoun Jung, Yanyun Zhao
LWT - Food Science and Technology 2017 Volume 80(Volume 80) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.lwt.2017.02.015
•Amount of dietary fibers and polyphenols varied among different fruit pomace (FP).•Bound polyphenols in FP were liberated in simulated gastrointestinal digestion.•FP possessed high oil-adsorption and water-holding capacities.•Distinguished fiber characteristics among FP impacted their functional properties.•FP can be selectively utilized in various food applications.Apple (AP), blueberry (BP), red raspberry (RP), and cranberry pomace (CP), were evaluated for their physicochemical and functional properties and bioactive compounds (i.e. dietary fibers and phenolics) as potential functional food ingredients. Bound phenolics in AP, BP, and CP could be liberated through simulated gastrointestinal digestion (SGD). Among all tested fruit pomace (FP), RP contained the highest total phenolic content based on both chemical extraction and SGD. AP contained the highest soluble dietary fiber obtained from AOAC method and SGD, while it presented the lowest insoluble dietary fiber in comparison with BP, RP, and CP. Total dietary fiber content of RP and CP from SGD was significantly (P < 0.05) higher than that from AOAC method. AP exhibited a high water-holding capacity (9.27 g water/g dry weight (DW)) and swelling ability (6.51 mL/g DW), while BP and CP showed high oil-adsorption capacity (1.96 g oil/g DW and 1.97 g oil/g DW, respectively). The differences in the functional properties of the tested FP could be due to their distinguished fiber compositions and structures. This study demonstrated the potential of using FP as fiber-rich and antioxidant functional ingredient that can be selectively utilized in various food applications.
Co-reporter:Zilong Deng, Jooyeoun Jung, Yanyun Zhao
LWT - Food Science and Technology 2017 Volume 83(Volume 83) pp:
Publication Date(Web):15 September 2017
DOI:10.1016/j.lwt.2017.05.013
•Most compatible polysaccharides with cellulose nanofiber (CNF) was identified.•Chitosan (CH) incorporated CNF films were fully characterized.•CH reduced water solubility and enhanced antibacterial activity of CNF film.•CH molecular weight and concentration impact functionality of CNF-CH film.•CNF-CH films exhibited success to package food with wet surfaces.Compatibility of CNF with three polysaccharides having different surface charges and backbones (chitosan, methyl cellulose, and carboxymethyl cellulose) was investigated. Chitosan (CH) incorporation reduced water absorption (WA) of CNF films (P < 0.05). CH molecular weight (Mw) (68, 181, 287 kDa) and amount (10 and 20 g/100 g CNF in dry basis) impacted moisture barrier, mechanical, antibacterial, thermal, and structural properties of CNF films. Regardless of Mw, CH incorporation (20 g/100 g CNF) decreased (P < 0.05) WA of CNF films, and high Mw (287 kDa) CH (20 g/100 g CNF) incorporation resulted in lower film water solubility while increasing film water vapor permeability compared with low Mw CH (68 kDa) incorporation (P < 0.05). CNF film with low Mw CH (20 g/100 g CNF) exhibited antibacterial activity against L. innocua and E. coli. Interaction mechanisms between CH and CNF were investigated through thermal, structural, and morphology analyses using DSC, FTIR, and SEM, respectively. CNF films with low or high Mw CH incorporation (20 g/100 g CNF) were further validated as surface contact films for fresh beef patties, showing effectiveness to prevent moisture transfer between the layered patties. This study demonstrated the potential of using CNF-CH composite films as water resistant and antibacterial packaging for foods with high moisture surfaces.
Co-reporter:Yifeng Zhang, Bona Dai, Yun Deng, Yanyun Zhao
Food Chemistry 2016 Volume 203() pp:258-266
Publication Date(Web):15 July 2016
DOI:10.1016/j.foodchem.2016.02.072
•Antioxidant and anti-inflammatory activity and protein quality of squids were studied.•Two-cycle 600 MPa HHP gave the highest in vitro protein digestibility, 84.42%.•HHP resulted in significantly higher anti-inflammatory values compared to control.•Anti-inflammatory 1H NMR ranges affected by HHP were 3.00–3.19 and 3.60–3.79 ppm.•HHP modified the characteristic NMR spectra with food property changes.This study investigated the in vitro anti-inflammatory and antioxidant properties, protein quality, and other related characteristics obtained by the single-cycle and two-cycle high hydrostatic pressure (HHP at 200, 400 and 600 MPa) treatment of squids (Todarodes pacificus). The soluble protein nitrogen content and in vitro protein digestibility increased significantly (p < 0.05) after all HHP treatments, and the two-cycle 600 MPa HHP treatments yielded the highest values, 7.59% and 84.42%, respectively. The estimated protein efficiency ratios, and antioxidant and anti-inflammatory properties of squids significantly increased by all HHP treatments. 1H nuclear magnetic resonance (NMR) showed that the main spectral changes associated to the anti-inflammatory properties of proteins following HHP treatment were in the range of 3.00–3.19 and 3.60–3.79 ppm. This indicates that the HHP treatments modified the protein and functional properties of squids and gave the relevant chemical shifts in NMR signals, either migrated or disappeared.
Co-reporter:Hongcai Zhang, Jooyeoun Jung, Yanyun Zhao
Carbohydrate Polymers 2016 Volume 137() pp:82-91
Publication Date(Web):10 February 2016
DOI:10.1016/j.carbpol.2015.10.036
•Catechins (CAT) or CAT–Zn was encapsulated by β-chitosan nanoparticles (β-CS NPs).•CAT–Zn complex loaded β-CS NPs had particle sizes of 208–590 nm.•CAT–Zn loaded β-CS NPs of smaller particle sizes had higher antibacterial activity.•Samples had stronger antibacterial activity against L. innocua than against E. coli.•CAT or CAT–Zn complex loaded β-CS NPs solutions had good stability at pH 2.0–4.5.This study used β-chitosan nanoparticles (β-CS NPs) of different particle sizes to encapsulate catechins (CAT) or CAT–Zn complex by ionic gelation technology. The antibacterial activity of CAT or CAT–Zn complex loaded β-CS NPs against Escherichia coli and Listeria innocua were investigated based on bacterial growth curve, minimum inhibitory concentration (MIC), and minimum bacterial concentration (MBC). Fourier transform infrared spectrometer (FT-IR) was employed to study the incorporation of CAT or CAT–Zn complex into β-CS NPs. The CAT–Zn complex loaded β-CS NPs had particle size of 208–591 nm, polydispersity index (PDI) of 0.377–0.395, and positive Zeta-potential of 39.17–45.62 mV. The CAT–Zn complex loaded β-CS NPs of smaller particle sizes showed higher antibacterial activity than that of larger particle size ones. The MIC and MBC of CAT–Zn complex loaded β-CS NPs of the smallest particle size against L. innocua and E. coli were 0.031 and 0.063 mg/mL, and 0.063 and 0.125 mg/mL, respectively. This study suggested that encapsulation of CAT–Zn complex in β-CS NPs improved the antibacterial activity of CAT and CAT–Zn complex, and the encapsulators have great potential to be used as antibacterial substances for food and other applications through either direct addition or incorporation into packaging materials.
Co-reporter:Shunshan Jiao;Didi Zhu;Yun Deng
Food and Bioprocess Technology 2016 Volume 9( Issue 2) pp:308-319
Publication Date(Web):2016 February
DOI:10.1007/s11947-015-1624-7
Roasting is a critical step in processing peanut snack foods. The conventional roasting using hot air ovens has drawbacks of low production rate, poor product quality, and high energy cost. This study investigated the feasibility of using hot air-assisted radio frequency (RF) to roast dried salted peanuts. Physicochemical properties, volatile compounds, and sensory quality of the roasted peanuts were determined. The quality changes and shelf-life of vacuum-packaged roast peanuts stored under an accelerated shelf-life testing (ASLT) trial conducted at 20 and 50 °C were also evaluated. After 45 min roasting, moisture content of the salted peanuts reduced from initial 7.7 to 3.1 % and acid and peroxide values were 0.26 ± 0.02 mg/g and 2.46 ± 0.10 meq/kg, respectively, all in the levels associating with good quality of roasted peanuts. Sensory evaluation further validated the good quality of the roasted peanuts. Totally, 69 volatile compounds were identified in the roasted peanuts, in which 3 new volatiles were produced after about 13 weeks of storage. During the storage, relative concentrations of the favorable volatile compounds (mainly pyrazines and furan compounds) decreased in a certain degree, while the relative concentrations of some undesirable flavor compounds increased. The roasted peanuts had 31 weeks of shelf-life based on the industrial standard on the peroxide value. This study demonstrated that hot air-assisted RF roasting can produce high-quality roasted peanuts with prolonged shelf-life, thus, a new technology for the peanut roasting industry.
Co-reporter:Yun Deng, Yali Luo, Yuegang Wang, Yanyun Zhao
Food Chemistry 2015 Volume 171() pp:168-176
Publication Date(Web):15 March 2015
DOI:10.1016/j.foodchem.2014.09.002
•Squid fillets were dried by freeze- (FD), hot air- (AD) and heat pump-drying (HPD).•FD retained the highest protein quality and digestibility, followed by HPD and AD.•AD caused the severest damage of myosin secondary or tertiary structure.•232 volatile compounds were firstly detected in fresh squid by GC × GC–TOFMS.•HPD samples had the highest total numbers and contents of volatiles.The impacts of freeze drying (FD), hot-air drying (AD), and heat pump drying (HPD) on myosin structure, amino acid composition, protein digestibility and volatile compounds of squid (Todarodes pacificus) fillets were evaluated. Freeze-dried squids showed similar amino acid composition to that of raw squids, but differed from that of AD and HPD samples. The percentage of in vitro digestibility followed the order of FD (76.81%) > HPD (70.51%) > raw (67.99%) > AD (61.47%) samples. AD caused more damage to squid myosin structure than HPD, while FD effectively retained the myosin integrity. Drying decreased total number of volatile compounds, but increased the content of total volatile compounds based on GC × GC–TOFMS results. HPD and AD samples had the highest and lowest total numbers and contents of volatiles, respectively. In general, FD provided squids with the best quality, followed by HPD. Considering the production cost and product quality, HPD demonstrated the potential for industrial application.
Co-reporter:Jooyeoun Jung, George Cavender, John Simonsen, and Yanyun Zhao
Journal of Agricultural and Food Chemistry 2015 Volume 63(Issue 11) pp:3031-3038
Publication Date(Web):March 10, 2015
DOI:10.1021/acs.jafc.5b00616
This study investigated the mechanisms of anthocyanin pigment retention using Fe3+–anthocyanin complexation and cellulose nanofiber (CNF)/sodium alginate (SA) layer-by-layer (LBL) coatings on thermally processed blueberries in aqueous media. Anthocyanin pigments were polymerized through complexation with Fe3+ but readily degraded by heat (93 °C for 7 min) in the aqueous media because of poor stability. CNF/SA LBL coating was successful to retain anthocyanin pigments in thermally processed blueberries. Fruits coated with CNF containing CaCl2 followed by treatment in a SA bath formed a second hydrogel layer onto the CNF layer (LBL coating system) through cross-linking between Ca2+ and alginic acid. Methyl-cellulose-modified CNF improved the interactions between CNF, the fruit surface, and the SA layer. This study demonstrated that the CNF/SA LBL coating system was effective to retain anthocyanin pigments on thermally processed whole blueberries, whereas no combined benefit of complexation with coating was observed. Results explained the mechanisms of the new approaches for developing colorful and nutritionally enhanced anthocyanin-rich fruit products.
Co-reporter:Jooyeoun Jung;George Cavender
Journal of Food Science and Technology 2015 Volume 52( Issue 9) pp:5568-5578
Publication Date(Web):2015 September
DOI:10.1007/s13197-014-1680-4
This study aimed to evaluate impingement drying (ID) as a rapid drying method to dry wet apple pomace (WAP) and to investigate the fortification of dried apple pomace flour (APF) or WAP in bakery and meat products. ID at ~110 °C reduced the moisture content of apple pomace from 80 % (wet basis) to 4.5 % within 3 h, compared with 24 h to 2.2 % using 40 °C forced-air drying and ~60 h to 2.3 % using freeze drying. Furthermore, ID enhanced the extractable phenolic compounds, allowing for a 58 % increase in total phenolic content (TPC) compared with wet pomace, a 110 % and 83 % higher than TPC in forced-air dried and freeze dried samples, respectively. The 15–20 % APF-fortified cookies were found to be ~44–59 % softer, ~30 % more chewy, and ~14 % moister than those of the control. WAP-fortified meat products had significantly higher dietary fiber content (0.7–1.8 % vs. 0.1–0.2 % in control) and radical scavenging activity than that of the control. These results suggest that impingement drying is a fast and effective method for preparing dried APF with highly retained bioactive compounds, and apple pomace fortified products maintained or even had improved quality.
Co-reporter:Qian Bingjun;Jooyeoun Jung
Applied Biochemistry and Biotechnology 2015 Volume 175( Issue 6) pp:2972-2985
Publication Date(Web):2015 March
DOI:10.1007/s12010-014-1413-1
This study investigated the effects of acidity and metal ion on the antibacterial activity of α- and β-chitosan at different molecular weights (Mw, 22–360 kDa) against Escherichia coli and Listeria innocua through agar well diffusion assay. Spectrophotometric, electrophoretic, and confocal fluorescence microscopy analysis were further employed to evaluate the antibacterial mechanisms probably involved. Increasing pH from 4.0 to 5.0 weakened the antibacterial ability of chitosan as shown by the decreased bacteria growth inhibition zone (BGIZ) from 0.63 to 0.57 cm for β-chitosan (61 kDa) and from 0.62 to 0.57 cm for α-chitosan (30 kDa) against E. coli. All β- and α-chitosan samples showed antibacterial activity against L. innocua, in which 22 kDa β-chitosan and 30 kDa α-chitosan at pH 4.0 had the highest antibacterial activity with BGIZ of 1.22 and 0.98 cm, respectively. Interactive effect between pH and Mw on the antibacterial activity of β-chitosan was observed, but not of α-chitosan. Adding Co2+ and Ni2+ significantly improved the antibacterial activity of chitosan, while adding K+, Na+, and Li+ significantly weakened the antibacterial activity of some β- and α-chitosan samples (P < 0.05), and different Mw and forms of chitosan showed different metal ion absorption capacities. Results indicate that chitosan might insert into the groove of bacterial DNA double helix structure to induce DNA degradation and permeate through bacteria cell membranes and combine with genomic DNA to induce its dysfunction, providing evidences for the antibacterial mechanisms of chitosan.
Co-reporter:Jooyeoun Jung, Yanyun Zhao
Food Chemistry 2014 Volume 152() pp:355-362
Publication Date(Web):1 June 2014
DOI:10.1016/j.foodchem.2013.11.165
•β-Chitin converted to α-chitin after 3 h in 40% NaOH and 1–3 h in 40% HCl.•Alkali treatment destroyed crystallites and decreased CI in α- and β-chitin.•Acid treatment induced less impact on structural modification than alkali treatment.•α-Chitin converted from β-chitin had higher reactivity than native α-chitin.Alkali- or acid-induced structural modifications in β-chitin from squid (Dosidicus gigas, d’Orbigny, 1835) pens and their moisture absorption ability (MAA) and deacetylating reaction were investigated and compared with α-chitin from shrimp shells. β-Chitin was converted into the α-form after 3 h in 40% NaOH or 1–3 h in 40% HCl solution, and α-chitin obtained from NaOH treatment had higher MAA than had native α-chitin, due to polymorphic destructions. In contrast, induced α-chitin from acid treatment of β-chitin had few polymorphic modifications, showing no significant change (P > 0.05) in MAA. β-Chitin was more susceptible to alkali deacetylation than was α-chitin, and required a lower concentration of NaOH and shorter reaction time. These results demonstrate that alkali- or acid-treated β-chitin retained high susceptibility toward solvents, which in turn resulted in good biological activity of β-chitosan for use as a natural antioxidant and antimicrobial substance or application as edible coatings and films for various food applications.
Co-reporter:Hongcai Zhang, Shoufeng Yang, Jiyang Fang, Yun Deng, Danfeng Wang, Yanyun Zhao
Carbohydrate Polymers 2014 Volume 101() pp:57-67
Publication Date(Web):30 January 2014
DOI:10.1016/j.carbpol.2013.09.015
•Bioconversion of chitin to chitosan by R. japonicus fermentation was studied.•Fermentation conditions for CDA production were optimized statistically.•Chitosan from bioconversion had superior quality than that of chemically extracted.To improve the production of chitin deacetylase (CDA) for the bioconversion of chitin to chitosan with desirable functionality, the effect of the nutritional requirement on the CDA production from Rhizopus japonicus M193 fermentation was investigated under submerged conditions. Nutritional elements including glucose (g/L), inoculum level (%), and MgSO4·7H2O (g/L), as well as culture time (d) were identified as the most critical factors for the CDA production based on the results from Plackett–Burman design (PBD). Taguchi design with orthogonal array was further employed to optimize R. japonicus M193 fermentation conditions based on the results from PBD, in which 2.5% chitin, 5 g/L glucose, 5% inoculum level, 0.6 g/L MgSO4·7H2O, and 5 d culture time were identified as the optimal fermentation conditions. Under this condition, the maximum CDA production, DDA and MM of produced chitosan were 547.38 ± 12.06 U/L, 78.85 ± 1.68%, and 125.63 ± 3.74 kDa, respectively. Obtained chitosan displayed similar physicochemical and structural properties to those of commercial chitosan extracted using chemical method based on the results from Fourier transform infrared spectrometer (FT-IR), thermogravimetric analysis (TGA)–differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR) assays, while the use of chemical reagents was significantly reduced.
Co-reporter:Angela Tseng, Yanyun Zhao
Food Chemistry 2013 Volume 138(Issue 1) pp:356-365
Publication Date(Web):1 May 2013
DOI:10.1016/j.foodchem.2012.09.148
Wine grape pomace (WGP) as a source of antioxidant dietary fibre (ADF) was fortified in yogurt (Y), Italian (I) and Thousand Island (T) salad dressings. During the 3 weeks of storage at 4 °C, viscosity and pH of WGP-Y increased and decreased, respectively, but syneresis and lactic acid percentage of WGP-Y and pH of WGP-I and WGP-T were stable. Adding WGP resulted in 35–65% reduction of peroxide values in all samples. Dried whole pomace powder (WP) fortified products had dietary fibre content of 0.94–3.6% (w/w product), mainly insoluble fractions. Total phenolic content and DPPH radical scavenging activity were 958–1340 mg GAE/kg product and 710–936 mg AAE/kg product, respectively. The highest ADF was obtained in 3% WP-Y, 1% WP-I and 2% WP-T, while 1% WP-Y, 0.5% WP-I and 1% WP-T were mostly liked by consumers based on the sensory study. Study demonstrated that WGP may be used as a functional food ingredient for promoting human health and extending shelf-life of food products.Highlights► Wine grape pomace was fortified in yogurt and salad dressing. ► Fortified products had increased dietary fibre and polyphenol contents. ► Fortified products had delayed lipid oxidation during refrigeration storage. ► Fortified products were acceptable by consumers based on sensory study.
Co-reporter:Jooyeoun Jung and Yanyun Zhao
Journal of Agricultural and Food Chemistry 2013 Volume 61(Issue 37) pp:8783-8789
Publication Date(Web):August 2, 2013
DOI:10.1021/jf4018965
The polymeric structure characteristics of β-chitosan from jumbo squid (Dosidicus gigas) pens and α-chitosan from shrimp shells during deploymerization by cellulase hydrolysis at different degrees of deacetylation (DDA) (60, 75, and 90%) were investigated by using Fourier transform infrared spectroscopy and X-ray diffraction. Antibacterial activity of β-chitosan against Escherichia coli and Listeria innocua was compared with that of α-chitosan at similar Mw and degrees of deacetylation (DDA) by studying inhibition ratio and minimal inhibition concentration (MIC) and was coordinated with the structural characteristics of the two forms of chitosan. β-Chitosan was more reactive to cellulase hydrolysis than α-chitosan due to its relatively lower crystallinity (CI) and loose crystal property, and the 75% DDA chitosan was more susceptible to cellulase than the 90% DDA ones with the 75% DDA of β-chitosan mostly reactive. Both forms of chitosan showed more inhibition against E. coli than against L. innocua, and no difference against L. innocua between the two forms of chitosan was observed. However, the two forms of chitosan exhibited different levels of antibacterial activity against E. coli, in which 75% DDA/31 kDa β-chitosan demonstrated significantly higher inhibition (lower MIC) than that of 75% DDA/31 kDa α-chitosan, whereas 90% DDA/74–76 kDa α-chitosan had a higher inhibition ratio than that of 90% DDA/74–76 kDa of β-chitosan. This result may be explained by the impact of the different structural properties between α- and β-chitosan on chitosan conformations in the solution. This study provided new information about the biological activities of β-chitosan, a bioactive compound with unique functionalities and great potential for food and other applications.
Co-reporter:Hongcai Zhang, Yafang Jin, Yun Deng, Danfeng Wang, Yanyun Zhao
Carbohydrate Research 2012 Volume 362() pp:13-20
Publication Date(Web):15 November 2012
DOI:10.1016/j.carres.2012.09.011
Shrimp shell powders (SSPs) were fermented by successive two-step fermentation of Serratia marcescens B742 and Lactobacillus plantarum ATCC 8014 to extract chitin. Taguchi experimental design with orthogonal array was employed to investigate the most contributing factors on each of the one-step fermentation first. The identified optimal fermentation conditions for extracting chitin from SSPs using S. marcescens B742 were 2% SSP, 2 h of sonication time, 10% incubation level, and 4 d of culture time, while that of using L. plantarum ATCC 8014 fermentation was 2% SSP, 15% glucose, 10% incubation level, and 2 d of culture time. Successive two-step fermentation using identified optimal fermentation conditions resulted in chitin yield of 18.9% with the final deproteinization (DP) and demineralization (DM) rate of 94.5% and 93.0%, respectively. The obtained chitin was compared with the commercial chitin from SSP using scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR) and X-ray diffraction (XRD). Results showed that the chitin prepared by the successive two-step fermentation exhibited similar physicochemical and structural properties to those of the commercial one, while significantly less use of chemical reagents.Graphical abstractHighlights► Chitin was extracted from SSPs using Serratia marcescens and Lactobacillus plantarum fermentation. ► Successive two-step fermentation was more effective than single step. ► Ultrasonic treatment was firstly introduced into microbial fermentation of SSPs. ► Prepared chitin has similar functional properties to the commercial one.
Co-reporter:Jooyeoun Jung, Yanyun Zhao
Bioorganic & Medicinal Chemistry 2012 20(9) pp: 2905-2911
Publication Date(Web):
DOI:10.1016/j.bmc.2012.03.020
Co-reporter:Jooyeoun Jung, Yanyun Zhao
Carbohydrate Research 2011 Volume 346(Issue 13) pp:1876-1884
Publication Date(Web):27 September 2011
DOI:10.1016/j.carres.2011.05.021
This study evaluated the deacetylation characteristics of β-chitin from jumbo squid (Dosidicus gigas) pens by using strongly alkaline solutions of NaOH or KOH. Taguchi design was employed to investigate the effect of reagent concentration, temperature, time, and treatment step on molecular mass (MM) and degree of deacetylation (DDA) of the chitosan obtained. The optimal treatment conditions for achieving high MM and DDA of chitosan were identified as: 40% NaOH at 90 °C for 6 h with three separate steps (2 h + 2 h + 2 h) or 50% NaOH at 90 °C for 6 h with one step, or 50% KOH at 90 °C for 4 h with three steps (1 h + 1 h + 2 h) or 6 h with one step. The most important factor affecting DDA and MM was temperature and time, respectively. The chitosan obtained was then further depolymerized by cellulase or lysozyme with cellulase giving a higher degradation ratio, lower relative viscosity, and a larger amount of reducing-end formations than that of lysozyme due to its higher susceptibility. This study demonstrated that jumbo squid pens are a good source of materials to produce β-chitosan with high DDA and a wide range of MM for various potential applications.
Co-reporter:Yan Jiang;John Simonsen
Journal of Applied Polymer Science 2011 Volume 119( Issue 5) pp:2834-2846
Publication Date(Web):
DOI:10.1002/app.32961
Abstract
Biocomposite boards from red wine grape pomace (WGP; Pinot Noir) or white WGP (Morio Muscat) were investigated on the basis of crosslinking and thermal compression mechanisms. We used an orthogonal experimental design to optimize the formulations by examining the effects of binder type, pomace-to-binder (P/B) ratio, and hydrophobic and crosslinking agents on the mechanical properties, water sensitivity, and biodegradability of the board. The optimized formulations were as follows: (1) for red WGP boards, soy flour (SF) or soy protein isolate (SPI) and poly(vinyl alcohol) (PVA; 1 : 1) as binders at a P/B ratio of 19 : 1 with 1% stearic acid (SA) and 1% epichlorohydrin and (2) for white WGP boards, SF or SPI–PVA (1 : 1) as binders, with a P/B ratio of 4 : 1, and 1% SA. The red WGP boards showed a high break strength and modulus of elasticity with a moderate percentage strain value, whereas the white WGP boards had a high flexibility and biodegradability. After burial in soil for 30 days, the red and white WGP boards degraded by about 50 and 80%, respectively. Microstructure studies indicated that the use of binders and other functional agents resulted in a compact fracture surface of the WGP biocomposite boards. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Jingyun Duan, Gita Cherian, Yanyun Zhao
Food Chemistry 2010 Volume 119(Issue 2) pp:524-532
Publication Date(Web):15 March 2010
DOI:10.1016/j.foodchem.2009.06.055
The 3% chitosan solutions incorporating 10% fish oil (w/w chitosan, containing 91.2% EPA and DHA) with or without the addition of 0.8% vitamin E were prepared. Fresh lingcod (Ophiodon elongates) fillets were vacuum-impregnated in coating solution at 100 mm Hg for 10 min followed by atmospheric restoration for 15 min, dried, and then stored at 2 °C or −20 °C for 3-weeks and 3-months, respectively, for physicochemical and microbial quality evaluation. Chitosan–fish oil coating increased total lipid and omega-3 fatty acid contents of fish by about 3-fold, reduced TBARS values in both fresh and frozen samples, and also decreased drip loss of frozen samples by 14.1–27.6%. Chitosan coatings resulted in 0.37–1.19 and 0.27–1.55 log CFU/g reductions in total plate and psychrotrophic counts in cold stored and frozen stored samples, respectively. Chitosan–fish oil coatings may be used to extend shelf-life and fortify omega-3 fatty acid in lean fish.
Co-reporter:Jingyun Duan, Yan Jiang, Gita Cherian, Yanyun Zhao
Food Chemistry 2010 Volume 122(Issue 4) pp:1035-1042
Publication Date(Web):15 October 2010
DOI:10.1016/j.foodchem.2010.03.065
Chitosan solutions (3%) incorporating 20% krill oil (w/w chitosan) with or without the addition of 0.1 μl/ml cinnamon leaf essential oil were prepared. Fresh lingcod (Ophiodon elongates) fillets were vacuum-impregnated with the coating solutions, vacuum or modified atmosphere (MA) (60% CO2 + 40% N2) packaged, and then stored at 2 °C for up to 21 days for physicochemical and microbial quality evaluation. Chitosan-krill oil coating increased total lipid and omega-3 fatty acid contents of the lingcod by about 2-fold. The combined chitosan coating and vacuum or MA packaging reduced lipid oxidation as represented in TBARS, chemical spoilage as reflected in TVBN, and microbiological spoilage as reported in total plate count (2.22–4.25 Log reductions during storage). Chitosan-krill oil coating did not change the colour of the fresh fillets, nor affect consumers’ acceptance of both raw and cooked fish samples. Consumers preferred the overall quality of chitosan-coated, cooked lingcod samples over the control, based on their firm texture and less fishy aroma.
Co-reporter:Su-Il Park;Yan Jiang;John Simonsen
Journal of Applied Polymer Science 2010 Volume 115( Issue 1) pp:127-136
Publication Date(Web):
DOI:10.1002/app.30951
Abstract
In this study, we investigated the feasibility of creating biocomposite boards from berry fruit pomaces on the basis of a crosslinking mechanism. Blueberry, cranberry, and wine grape pomaces were ground, dried, and mixed with soy flour (SF) or pectin and xanthan gum mixture at a ratio of 1 : 1 and with the addition of 15% glycerol (w/w of pomace and SF). Blueberry pomace (BP) was also blended with NaOH-modified soy flour (MSF) at pomace/MSF ratios of 1 : 1, 4 : 1, and 9 : 1 and with 5, 10, or 15% glycerol. The mixtures were compression-molded at 130–140°C into biocomposite boards to evaluate their mechanical and thermal properties, water absorption and solubility, and microstructure. Among the three pomaces, the BP board was the stiffest, whereas the wine grape pomace board was the most flexible. The breaking strength and modulus of elasticity of the BP/MSF boards increased with increasing MSF concentration but decreased with increased glycerol concentration. Mixing the pomace and glycerol into SF shifted the endothermic peaks and initial degradation to lower temperatures compared to that of SF alone. Increasing the glycerol concentration decreased the water absorption but increased the water solubility of the BP/MSF board. The pomace/MSF ratio in the board did not affect (P > 0.05) the water absorption, but the water solubility increased with increasing pomace concentration. Glycerol addition in the BP/MSF board smoothed the fracture surface, as shown by scanning electron microscopy images. This study may provide an approach to reducing fruit pomace disposal through the development of new value-added biodegradable products for industrial applications, such as nursery pots and egg cartons. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Yun Deng, Yanyun Zhao
Journal of Food Engineering (March 2008) Volume 85(Issue 1) pp:84-93
Publication Date(Web):1 March 2008
DOI:10.1016/j.jfoodeng.2007.07.016
The influence of pulsed-vacuum (PV) and ultrasound on the osmodehydration kinetics and microstructure of apples (Fuji) was investigated. Apple cylinders (15 mm height × 15 mm diameter) immersed in a 60% (w/w) high-fructose corn syrup solution were subjected to shaking (55 rpm), PV (13 MPa vacuum for 5 min + atmospheric pressure for 5 min + same vacuum for 5 min, then atmospheric pressure), or ultrasound treatment (50/60 Hz and 185 W) for 3 h. Changes in water loss, solid gain, and firmness of apples were measured, and the data were fitted using Weibull and Peleg models. In addition, microstructure was observed using scanning electronic microscopy (SEM). The high regression coefficients (R2 > 0.96) and low percent mean relative deviations (E < 6.37%) indicated the acceptability of Weibull model for predicting both water loss and solid gain under all treatments. The Peleg model well described the sample firmness changes with a R2 ∼ 0.98 and E ∼ 3.24–6.14%. PV resulted in the lowest shape parameter α value (0.74) for solid gain and the greatest rate constant k1 (40.98 s) for firmness loss, indicating the largest amount of solid gain (3.02%) and the least firmness loss of samples, while ultrasound led to the lowest α value (0.45) for water loss and k1 value (33.42 s) for firmness loss: the highest water and firmness losses (56.3% and 22.3%, respectively) in samples among three treatments. SEM showed that cell deformation and cell structure collapse were the most severe in ultrasound treated samples, but moderate in PV samples. SEM also revealed a larger amount of solute uptake in the cells of PV and ultrasound treated samples.
Co-reporter:Connie L. Fisk, Alissa M. Silver, Bernadine C. Strik, Yanyun Zhao
Postharvest Biology and Technology (March 2008) Volume 47(Issue 3) pp:338-345
Publication Date(Web):1 March 2008
DOI:10.1016/j.postharvbio.2007.07.015
Limited information exists regarding the ripening physiology of hardy kiwifruit (Actinidia arguta (Siebold & Zucc.) Planch. ex Miq) or the ideal packaging and storage conditions for optimum quality and storage life. In this study, the physicochemical properties (total soluble solids, titratable acidity, pH, firmness, color, weight loss, and respiration) of hardy kiwifruit cv. Ananasnaya were monitored at harvest and during storage from 2003 to 2005. Fruit were packaged in low- or high-vent clamshell containers and stored under room (22 ± 1 °C, 45% RH) or refrigerated (2 °C, 88% RH) conditions. Calcium caseinate, chitosan, PrimaFresh® 50-V, and Semperfresh™ edible coatings were investigated for their potential to enhance the quality and extend the storage life of the fruit. Semperfresh™-coated and uncoated fruit were evaluated by a sensory consumer panel using a hedonic scale in the third season. Low-vent packaging reduced weight loss. Refrigerated storage delayed ripening and extended storage life of fresh fruit compared to un-refrigerated fruit to 7–10 weeks depending on the specific packaging and other storage conditions. Coatings provided an attractive sheen to the fruit surface and did not impair ripening. The consumer test indicated that both coated and uncoated fruit were well liked. These results provide important information regarding the ripening physiology of ‘Ananasnaya’ hardy kiwifruit and indicate that edible coatings may be an alternative to costly low-vent packaging for reducing moisture loss and extending storage life of fresh fruit.
Co-reporter:Jingyun Duan, Ruyi Wu, Bernadine C. Strik, Yanyun Zhao
Postharvest Biology and Technology (January 2011) Volume 59(Issue 1) pp:71-79
Publication Date(Web):1 January 2011
DOI:10.1016/j.postharvbio.2010.08.006
The effects of edible coatings, Semperfresh™ (SF), acid-soluble chitosan (ACH), water-soluble chitosan (WCH), calcium caseinate (CC), and sodium alginate (SA) on the fruit quality of fresh blueberries during storage was studied in 2006 and 2008. Fruit were washed in 200 μL L−1 chlorinated water before applying coatings, packaged in vented or non-vented clam-shell containers, and then stored at 2 °C for 1 week, followed by storage at room temperature (20 °C) for up to 15 d for quality evaluation. The ACH, WCH, and WCH + SA coatings helped reduce the decay rate of ‘Duke’ or ‘Elliott’ fruit during room temperature storage. Results from 2006 showed that SF coating decreased weight loss of ‘Duke’ after 6 d of room temperature storage, CC-coated ‘Elliott’ fruit had delayed fruit ripening as evidenced by higher TA, lower pH, and greater firmness than control during storage, and washing and coating did not significantly affect antioxidant capacity and total phenolics content of ‘Duke’ and ‘Elliott’. Fruit in non-vented containers had reduced weight loss and increased firmness than those in vented containers as demonstrated in 2008 study. Our results suggest that edible coatings have potential for retaining quality of pre-washed, ready-to-eat fresh blueberries under commercial storage conditions, when appropriate coating material, container, and method of applying the coatings are used.
Co-reporter:Zixuan Lian, Yifeng Zhang, Yanyun Zhao
Innovative Food Science & Emerging Technologies (February 2016) Volume 33() pp:145-153
Publication Date(Web):1 February 2016
DOI:10.1016/j.ifset.2015.10.008
•Nano-TiO2 particle and HHP were used to improve functionality of PVA–CHI films.•HHP changed layered microstructure of films into homogeneous and compact structure.•HHP improved water vapor, gas barrier and mechanical properties of films.•Nano-TiO2 gave PVA–CHI films with better antibacterial and mechanical properties.•Nano-TiO2 migrated from 200 to 400 MPa treated films into olive oil was < 4.20 × 10− 3‰.This study investigated the impact of nano-TiO2 and high hydrostatic pressure (HHP) treatment on microstructure, water vapor and gas barrier, antibacterial and mechanical properties of polyvinyl alcohol (PVA)–chitosan (CHI) biodegradable films and determined the migration behavior of TiO2 nanoparticles from the films to food simulants. Apart from the effect of filler, TiO2 nanoparticles also could improve the antibacterial activity of the films and play a role as a plasticizer in the films. HHP treatment promoted the interaction between PVA and chitosan molecules, resulting in the formation of more compacted network structures in PVA–CHI films. The migration of TiO2 from the films was investigated in food simulants including distilled water, acetic acid, ethanol and olive oil, in which the trace amount of TiO2 (< 4.20 × 10− 3‰) was only detected in olive oil. HHP treatment at 200–400 MPa significantly reduced migration of TiO2 nanoparticles from the films.Industrial relevanceResults from this study provide a new application direction of high hydrostatic pressure (HHP) in the field of food packaging materials for improving the functionality of materials. Due to the non-thermal characteristic, HHP in combination with nano-TiO2 not only improved the mechanical and barrier properties of the biodegradable PVA–CHI composite films (polyvinyl alcohol and chitosan based materials), but also enhanced the antibacterial activity of the films. The HHP treated PVA–CHI–TiO2 films are very stable in food simulants, such as olive oils. Therefore, the utilization of HHP and nano-TiO2 is promising in the preparation of food packaging materials with desirable functionalities.
Co-reporter:Jooyeoun Jung, Zilong Deng, John Simonsen, Richard M. Bastías, Yanyun Zhao
Scientia Horticulturae (8 March 2016) Volume 200() pp:161-169
Publication Date(Web):8 March 2016
DOI:10.1016/j.scienta.2016.01.016
•CFN coating for preventing cherry rain-cracking was developed and validated.•Amount of surfactant in coating was a critical factor affecting coating performance.•CNF coating containing glycerol and surfactant had high wettability and elasticity.•CNF coating reduced cherry rain-cracking without detrimental effect on fruit quality.This study was aimed to systematically develop and validate cellulose nanofiber (CNF)-based hydrophobic coatings (Innofresh™) for reducing cherry rain-cracking through a lab-scale optimization study and the preliminary field validation trials. The base coating formulation consist of 0.5% CNF (w/w) and 0.5% potassium sorbate (KSb) (w/w). For optimizing the coating formulations with desired water resistance, wettability and elasticity, three different types of plasticizer (glycerol, PEG 400, and sorbitol) and their concentrations (0, 0.05, and 0.1% (w/w)), as well as surfactant mixture (1:1 ratio of Tween 80 and Span 80) at 0.05, 0.1, and 0.2% (w/w) were evaluated as additional functional substances in the base coating formulation. It was found that 0.5% CNF/0.5% KSb based coatings containing 0.1% glycerol and 0.1% or 0.2% surfactant mixture provided high wettability and elasticity along with superior water resistance. The effectiveness of the optimized coating formulations on reducing cherry rain-cracking was validated through two field studies conducted in Chile and the United States during November–December, 2014 and May–June, 2015, respectively. The 0.5% CNF/0.5% KSb/0.1% glycerol coating containing 0.1% or 0.2% surfactant mixture resulted in significant reduction in cherry rain-cracking (∼31.18–44.60%) (P < 0.05), while no any detrimental effect on fruit firmness, size, soluble sugar, pedicel/fruit retention force, and color was observed in comparison with non-coated cherries. Therefore, the simple, but versatile CNF-based coatings incorporated with an appropriate amount of glycerol and surfactant was effective to reduce cherry rain-cracking without impacting fruit growth and quality.
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![(2R)-2-AMINO-1-PHENYL-PROPAN-1-OL; (E)-4-(4-BROMOPHENOXY)-4-OXO-B<WBR />UT-2-ENOIC ACID; N,N-DIMETHYL-3-(2-PYRIDYL)PROPAN-1-AMINE; 3-[(1R<WBR />)-1-HYDROXY-2-METHYLAMINO-ETHYL]PHENOL; DIHYDROCHLORIDE](http://img.cochemist.com/ccimg/400/320-77-4_b.png)
