Carboxymethyl Cellulose Coatings Research Articles

Effect of ultrasound combined with chemical pretreatment as an innovative non-thermal technology on the drying process, quality properties and texture of cherry subjected to radio frequency vacuum drying

To obtain high-quality cherry products, ultrasound (US) combined with five chemical pretreatment techniques were used on cherry prior to radio frequency vacuum drying (RFV), including carboxymethyl cellulose coating (CMC), cellulase (CE), ethanol (EA), isomaltooligosaccharide (IMO), and potassium carbonate + ethyl oleate (PC + AEEO). The effect of different pretreatments (US-CMC, US-CE, US-EA, US-IMO, US-(PC + AEEO)) on the drying characteristics, quality properties, texture, and sensory evaluation of cherries was evaluated. Results showed that the dehydration time and energy consumption were decreased by 4.17 − 20.83 % and 3.22 − 19.34 %, respectively, and the contents of individual sugars, soluble solid, total phenolics (TPC), natural active substances, total flavonoids (TFC), and antioxidant properties (DPPH, ABTS and FRAP) were significantly increased after US combined with five chemical treatments (P < 0.05). Moreover, the pretreatment played important role in improving texture properties and surface color retention in the dried cherries. According to the sensory evaluation analysis, the dehydrated cherries pretreated with US-CMC exhibited the highest overall acceptance, texture, crispness, color, and sweet taste showed lower off-odor, bitter taste and sour taste compared to control and other pretreatments. The findings indicate that US-CMC pretreatment is a promising technique for increasing physicochemical qualities and dehydration rate of samples, which provides a novel strategy to processing of dried cherry.

Layer by layer application of chitosan and carboxymethyl cellulose coatings delays ripening of mango fruit by suppressing cell wall polysaccharides disassembly

Mango is a climacteric fruit that ripens quickly after harvest due to its climacteric nature. Edible coatings have been reported to delay the ripening of various harvested fruit. The efficacy of the applied edible coatings could be improved by using in combination as a layer-by-layer (LBL) approach. So, the influence of LBL application of chitosan (CH) and carboxymethyl cellulose (CMC) was studied on mangoes during postharvest storage at 15 °C for 20 days. Mangoes were coated with monolayers of CH (1 % w/v) and CMC (1 % w/v) as well as LBL application of CH and CMC and were compared with control. The treatment of mangoes with CH and CMC-based LBL treatment resulted in lower decay percentage and weight loss along with higher total chlorophyll pigments and suppressed total carotenoid accumulation. The LBL application of CH and CMC showed lower activity of chlorophyll degrading such as chlorophyllase (CPS), pheophytinase (Phe), Mg-dechalatase (MGD) and chlorophyll degrading peroxidase (Chl-POD) enzymes as well as reduced changes in b*, a* and L* along with a suppressed increase in ethylene (EP) and CO2 production (CPR) rates having higher antioxidant such as catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and superoxide dismutase (SOD) enzymes activity. In addition, mangoes coated with LBL treatment of CH and CMC exhibited lower water-soluble pectin (WSP) and higher protopectin (PP) having higher concentrations of chelate soluble (CSP) and sodium carbonate-soluble pectin (SCP). Similarly, LBL-coated mangoes showed significantly higher hemicellulose (HCLS) and cellulose (CLS) contents in contrast with control. It was observed that mangoes coated with CH and CMC-based LBL coating exhibited higher flesh firmness and showed suppressed cellulase (CS), pectin methylesterase (PME), polygalacturonase (PG) and β-galactosidase (β-Gal) enzymes activity. The concentrations of total soluble solids and ripening index were markedly lower and titratable acidity was higher in the LBL-based coating treatment in comparison with control. In conclusion, LBL treatment based on CH and CMC coatings could be used for the delay of ripening and softening of harvested mangoes.

The hydrophobicity and swelling of methyl cellulose coating synergistically enhancing the inkjet printing qualities of cotton fabric

Textile coated by natural polymer is an industrial method for enhancing the inkjet printing qualities. However, the hydrophobic modified polymer coating has been rarely reported. Here, the effect of hydrophobic methyl cellulose (MC) coating on the inkjet printing qualities of cotton fabric was investigated and compared with commonly used sodium alginate (SA) and sodium carboxymethyl cellulose (CMC) coatings. The results show that all three polymers could improve the sharpness and color depth of inkjet printing. However, the effect of the MC coating was far better than the SA and CMC coatings, which results from the different functional groups of the three polymers. Methyl groups make MC coating hydrophobic, while the SA and CMC coatings exhibit hydrophilicity. The hydrophobicity and swelling of the MC coating could synergistically reduce the spreading and penetrating of ink droplets. SA and CMC coatings rarely reduced the flow of ink droplets and only preserved part of ink by the swelling property. This work reveals the action mechanism of the polymer coating. And it is confirmed that the hydrophobic natural polymer coating is more effective than the hydrophilic coating to enhance the inkjet printing qualities.

Impact of a Carboxymethyl Cellulose Coating Incorporated with an Ethanolic Propolis Extract on the Quality Criteria of Chicken Breast Meat.

Recently, the demand for composite edible coatings has increased significantly as a new trend to confront the serious processing and storage problems that always arise regarding chicken meat. We aim to develop a carboxymethyl cellulose (CMC) coating containing various concentrations (0, 1, 2, 3, and 4%) of an ethanolic propolis extract (EPE) to maintain the quality and extend the shelf life of chicken breast meat stored at 2 °C for 16 days. The influence of the CMC and EPE coating on the physicochemical and microbiological quality parameters of chicken breast meat, e.g., pH, color, metmyoglobin (MetMb), lipid oxidation (thiobarbituric acid reactive substance, TBARS), and microbiological and sensory analyses, was studied. Significantly lower weight loss and pH (p ≤ 0.05) were noted in the coated samples compared with the uncoated samples (control) over the storage period. MetMb content was significantly reduced (p ≤ 0.05) in the coated samples compared to the control. Additionally, the addition of EPE to CMC was more effective in inhibiting microbial growth, preventing lipid oxidation, and keeping the overall acceptability of coated chicken breast meat compared to the control. This work presents CMC and EPE as alternative preservatives to produce active packaging coatings.

Postharvest Biopreservation of Fresh Blueberries by Propolis-Containing Edible Coatings Under Refrigerated Conditions

Propolis is a complex honey bee product known for its antioxidant potential and antimicrobial activity, widely used as a food biopreservative and food additive. The object of the current research was to investigate the effects of carboxymethyl cellulose (CMC) edible coatings applied alone and in combination with a propolis extract on the quality parameters and storage life of fresh blueberries during refrigerated storage for 20 days. For this purpose, three experimental groups were prepared: blueberries without coating (control group), blueberries with 1% CMC coatings and blueberries with 1% CMC coatings + 1% propolis extract (CMC+P). During the storage, the physicochemical and microbiological parameters of the experimental groups were evaluated. The use of CMC and CMC+P coatings reduced the weight loss by 1.13% and 1.67% in comparison with the control group on the 20-th day of storage. A significant decrease in decay percentage was found, which was in the great extent in the CMC+P coated fruit compared to the CMC coatings and the control fruit. The CMC and CMC+P edible coatings did not affect the TSS levels, the decreasing TA and increasing pH values. The application of CMC and CMC+P coatings did not cause a protective effect on the lowering values of total phenolic and anthocyanin contents in both treatments, but exhibited a positive influence on the antioxidant activity in the coated blueberries. During the entire storage period, propolis containing edible coatings (CMC+P) reduced the bacterial, yeasts and fungal counts, visibly expressed by a reduction in decay incidence in comparison with the uncoated and CMC-treated fruit. Therefore, the application of propolis in the composition of edible coatings can be considered as an effective approach for improving the postharvest quality and prolonging the storage life of fresh blueberries.

Effects of carboxymethyl cellulose/pectin coating combined with ultrasound pretreatment before drying on quality of turmeric (Curcuma longa L.)

Turmeric is an herb with multiple bioactive substances and health benefits. Drying is one of the most important steps of its processing and sales. In order to obtain high-quality turmeric products, we used five different pretreatment methods to treat turmeric prior to pulse-spouted microwave vacuum drying (PSMVD), including carboxymethyl cellulose coating (CMC), pectin coating (P), ultrasound (US) and their combination (CMCUS or PUS). The effect of different pretreatments on the drying kinetics, quality attributes and microstructure of turmeric were evaluated. Results showed that the US pretreatment had the shortest drying time (60 min), while coating treatment did not significantly affect drying rate. Dried turmeric with coating pretreatment had lower rehydration ratio and water adsorption capacity compared with individual ultrasound treatment. Carboxymethyl cellulose coating protected bioactive substances better than pectin coating. Moreover, CMCUS pretreatment showed significantly lower total color change, higher curcumin content, total phenols and flavonoid content as well as antioxidant capacity in all dried samples. Microstructure observation showed that the polysaccharide coating covering the surface of turmeric might reduce the degradation of bioactive compounds. Therefore, the CMCUS pretreatment before PSMVD of turmeric was recommended due to the efficiency and quality protections.

Physical, Chemical and Sensory Characterization of Deep-Fried Fresh-Cut Potatoes Coated with Hydrocolloid/Herbal Extracts.

Recently, natural plant extracts have been used to increase the nutritional value of food and to potentially reduce the absorbed fat and the formation of acrylamide in fried foods. Literature data on the use of edible polymers with nettle or olive leaf extracts are scarce. The effect of novel coatings on colour, fat absorption, phenolic and sugar content, and acrylamide formation in deep-fat-fried fresh-cut potatoes was evaluated. Extracts of olive and nettle leaves were incorporated in carboxymethyl cellulose (CMC) and gum arabic, used as coatings for potatoes and applied before frying. This aimed to improve the nutritional quality of deep-fat-fried fresh-cut potatoes. Enrichment of the edible coatings with extracts resulted in a significant change in the visible colour of the potatoes before frying. Significant effect of the extract amount on the sensory characteristics of potatoes was also observed. Most importantly, the perception of characteristic potato odour and taste was not significantly affected by the coating. Although higher amounts of the extract (1.5%) resulted in higher phenolic mass fraction in fried potatoes, the sensory scores decreased. After frying, fat mass fraction in the coated potatoes was reduced by about 15% compared to the uncoated samples. The type of extract affected the total sugar mass fraction in fried potatoes, which was lower in the samples with coatings enriched with olive leaf than in those with nettle leaf. Only gum arabic coating had a reducing effect on acrylamide mass fraction by 17%. Based on all the obtained results, CMC and gum arabic coatings did not influence sensory properties, so they can be recommended as carriers of functional compounds or as a frying pre-treatment for potatoes with favourable effect on fat and acrylamide content. The knowledge obtained in this study can be exploited for preparation of coatings with functional compounds used as a pre-treatment for fried food with favourable effect on fat and acrylamide content.

Impact of Carboxymethyl Cellulose Coating Incorporated with Ethanolic Propolis Extract on the Quality Criteria of Chicken Meat

Impact of Carboxymethyl Cellulose Coating Incorporated with Ethanolic Propolis Extract on the Quality Criteria of Chicken Meat

Assessing the Carboxymethylcellulose Copper-Montmorillonite Nanocomposite for Controlling the Infection of Erwinia carotovora in Potato (Solanum tuberosum L.)

A novel antimicrobial formulation based on carboxymethylcellulose (CMC) spray-coated Cu2+ intercalated montmorillonite (MMT) nanocomposite material was prepared and its morphology, internal structure, and bonding interactions were studied. Meanwhile, the antibacterial efficacy and release behavior of Cu2+ was also determined. PXRD patterns indicated the intercalation of Cu2+, while FTIR spectra and TGA traces confirmed the association of Cu−MMT with CMC. SEM study revealed the improvement of nanocomposites by CMC, without disturbing the clay structure. TEM and EDAX studies indicated the distribution of Cu (copper) throughout the composite. In vitro antibacterial assays performed with Erwinia carotovora revealed effective bacterial growth suppression, indicating the potential of this material in controlling soft rot of potatoes (Solanum tuberosum); also observed was a connection between growth inhibition and concentration of CMC spray coats indicating a positive relationship between Cu2+ release and concentration of the CMC coatings. The activity pattern of the nanocomposite displayed a significant degree of sustained-release behavior.

Impact of Carboxymethyl Cellulose Coating Incorporated with Rosemary Essential Oil and ‎sodium Acetate on the Quality and Shelf Life of Rainbow Trout Fillet‎

ABSTRACT The objective of the current research was to evaluate the impact of sodium acetate (SA) and rosemary essential oil (REO) on the microbiological and physicochemical characteristics of rainbow trout coated with carboxymethyl cellulose (CMC) and kept for 16 days at 4°C. The CMC coating was supplemented with isolated SA or SA combined with REO (0.5% or 1%). The gas chromatography-mass spectrometry (GC-MS) evaluation indicated that the REO was chiefly composed of 1,8-cineole (25.21%) and α-pinene (22.34%). The microbiological evaluation revealed that the growth of mesophilic bacteria, psychrotrophic bacteria, Pseudomonas spp., lactic acid bacteria, and Enterobacteriaceae was considerably slower in rainbow trout meat coated with CMC, SA, and REO (0.5 or 1%) relative to the control. Such coatings also improved the pH, water-holding capacity, cooking yield index, and sensory characteristics of rainbow trout fillets. The total volatile basic nitrogen content, peroxide value, and amount of thiobarbituric acid reactive substances were significantly lower in the experimental samples relative to the control. Hence, we introduced a novel CMC coating containing SA and REO (0.5 or 1%) that improves the shelf life and quality of refrigerated rainbow trout meat.

Improving the oxidative stability of sunflower seed kernels by edible biopolymeric coatings loaded with rosemary extract

An optimized combination of whey protein concentrate (WPC), glycerol and carboxymethyl cellulose (CMC) was determined by evaluating the mechanical properties of edible films and coating percentage on sunflower seed kernels (SUKs). The optimal coating solutions with/without rosemary extract (RAE) were used to improve oxidative stability of SUKs. Moreover, the efficiency of the coated SUKs was assessed in a sesame-based product, as a food system. The optimized composite coating (CMC 0.6% and WPC 8% by total solution weight, and glycerol 51% by WPC weight) provided the better color features for SUKs stored at elevated temperature compared to WPC coatings (10 and 11%, w/w) with a Maillard-induced red color, and it was more effective than CMC (4%, w/w) coating to improve the oxidative stability of the nuts. The RAE had a positive effect on the color characteristics of the composite and CMC coatings; however, it enhanced the oxidation of SUKs, which could be due to disruption of coating polymer network, and thus increasing the oxygen diffusion into the product. The food system containing the coated nuts exhibited a lower oxidation extent in comparison to the control formulation prepared by uncoated ones. Therefore, using an optimal composite coating, reddening of WPC at high temperatures and less oxidation protection efficiency of CMC were resolved as the kernels with desirable color and oxidative stability properties were produced, applicable in the formulation of products needing thermal processing.

Effect of polysaccharide derived from Osmunda japonica Thunb ‐incorporated carboxymethyl cellulose coatings on preservation of tomatoes

Polysaccharides from Osmunda japonica Thunb (Op) exhibit a wide range of biological activities including antibacterial, anti-inflammatory, antioxidant, and antitumor effects. Carboxymethyl cellulose (CMC) is a type of cellulose derivative that can form dense films. CMC can slow the respiratory transpiration of tomatoes and reduce water evaporation. Coatings of CMC (0.7% concentration) with various levels of Op (0.02%, 0.04%, 0.06%, 0.08%, and 0.1%) were used to preserve tomatoes at room temperature. The treatment, weight loss, hardness, titratable acidity (TA), respiratory intensity, and concentrations of ascorbic acid, polyphenol oxidase, and malondialdehyde (MDA) were evaluated in tomatoes after 0, 5, 10, 15, 20, and 25 days of storage. Compared with untreated tomatoes, the tomatoes with Op-incorporated CMC coatings had reduced respiratory intensity, weight loss and ascorbic acid loss, increased TA, controlled MDA, and inhibited the decay of tomatoes. Therefore, the use of Op-incorporated CMC coatings extended the shelf life and maintained the quality of postharvest tomatoes. Practical applications In the past decades, the use of edible coatings has attracted widespread interest in extending the shelf life of particularly perishable foods. Currently, applications of edible coatings have been proven to be promising as a tool to improve the quality and extend the shelf life of various fruits. But there have been no reports on the effect of Op-incorporated CMC treatment on the postharvest quality of tomatoes during storage. The purpose of this work is to investigate the efficiency of Op-incorporated CMC treatment to extend shelf life and provide theoretical guidance for the preservation of tomatoes.

The effects of novel bioactive carboxymethyl cellulose coatings on food-borne pathogenic bacteria and shelf life extension of fresh and sauced chicken breast fillets

The aims of the present study were to evaluate the effects of carboxymethyl cellulose (CMC) coatings containing Ziziphora clinopodioides (ZEO; 0, 0.25 and 0.5%) and Mentha spicata (MEO; 0 and 0.5%) essential oils on pathogenic bacteria (i.e. Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7, Salmonella typhimurium and Campylobacter jejuni) and shelf life extension of fresh and sauced chicken breast fillets under refrigerated condition for two weeks. The order of bacterial spoilage population (i.e. total viable count, psychrotrophic count, Pseudomonas spp., P. fluorescens and Enterobacteriaceae), survival of pathogenic bacteria and lipid oxidation of coated samples are as follows: CMC > CMC + MEO 0.5% > CMC + ZEO 0.25% > CMC + ZEO 0.5% > CMC + ZEO 0.25% + MEO 0.5% > CMC + ZEO 0.5% + MEO 0.5%. Our findings indicated that application of CMC coatings containing ZEO in combination with MEO can reduce the number of test pathogens and increase the shelf life of fresh and sauced chicken breast fillets.

Quality preservation of walnut kernels using edible coatings

The objective of this work was to evaluate the performance of various edible coatings for preserving the quality of walnut kernels (W) during storage. Three edible coatings based on carboxymethyl cellulose (CMC), methyl cellulose (MC) and whey protein isolates (WP) were prepared. Coated and uncoated walnuts (WC) were stored for 210 days at room temperature (23±2 °C). After 210 days, WC presented the highest peroxide value (PV = 3.06 meqO2/kg), conjugated dienes (CD = 3.01) and trienes (CT = 0.31), pentanal, nonanal, hexanal, and decane, 5,6-bis (2,2-dimethylpropylidene) contents. Meanwhile, WMC showed the lowest PV (1.20 meqO2/kg), CD (2.26) and CT (0.17) and the lowest decrease in carotenoid content (0.60 mg/kg). The L* value measured in walnut oil decreased in all samples. MC, CMC and WP coatings showed protection on walnuts against the deterioration process. MC coating displayed the best performance.

Application of carboxymethyl cellulose and chitosan coatings containing Mentha spicata essential oil in fresh strawberries

The aim of the present study was to investigate the effects of carboxymethyl cellulose (CMC) and chitosan (CH) coatings containing Mentha spicata essential oil (MSO 0.1 and 0.2%) on survival of Listeria monocytogenes, and physicochemical (weight loss, titratable acidity and pH), microbial (total viable count, psychrotrophic bacteria as well as yeasts and molds) and sensory (appearance, color, texture and overall acceptability) properties of fresh strawberries during refrigerated storage. The treatments of fruits with CH+MSO 0.2% and CMC+MSO 0.2% resulted in the best microbial, physicochemical and organoleptic properties after 12days storage. The final population of L. monocytogenes in treated samples was decreased by 3.92–3.69 compared to control groups. It can be concluded that CH and CMC coatings enriched with MSO can be used as appropriate active packaging materials to preserve fresh strawberries in the food industry.

Improving quality of fresh‐cut mango using polysaccharide‐based edible coatings

SummaryThis study was aimed at evaluating the effect of coatings with alginate (AL), pectin (PE), carboxymethyl cellulose (CMC) or chitosan (CH) on microbial stability, physicochemical attributes, total phenolics and carotenoids content, antioxidant capacity and sensory properties of fresh‐cut mango during 14 days at 4 ± 1 °C. Coated fresh‐cut mango kept microbial counts below 6 logs CFU g−1, being CH‐coated fresh‐cut mango those that exhibited the lowest microbial counts (1 log CFU g−1) along entire storage. AL, PE and CMC coatings maintained yellow colour of fresh‐cut mango throughout storage. AL and CH coatings, which have different monomers in their chain, improved the content of antioxidant compounds in fresh‐cut mango as related to uncoated. AL‐coated fresh‐cut mangoes were the toughest, among those coated, during 14 days. The highest consumer acceptance was achieved in AL (90.2%) coated fresh‐cut mango. CH would be the most suitable coating to extend the quality of fresh‐cut mango throughout storage.

Effect of different edible coatings on postharvest quality of ‘Kinnow’ mandarin

Coating of fruits is an effective method in the postharvest industry in order to replace natural waxes which are removed during washing and handling. Recently, there is an increasing interest in application of natural edible coatings instead of commercial synthetic waxes due to human health issues and environmental protection. In this research, the effect of different edible coatings on quality of ‘Kinnow’ mandarin was studied. Different coating materials including 1% carboxymethyl cellulose (CMC), 5% gum Arabic (GA), 1% Persian gum (PG), 0.5% beeswax (BW), 1% carnauba wax (CA) (w/v) and commercial wax were applied and the results were compared with those of uncoated (control) fruit. After coating, fruit were stored for 3 weeks at 5 °C and 90–95% RH. At the end of the storage time, fruit firmness, weight loss, total soluble solids (TSS), titratable acidity (TA), pH, and TSS/TA ratio were examined. The results showed that all coatings could reduce the weight loss as compared to the control. GA and CA treatments showed the highest and the lowest pH values, respectively. Samples treated with CMC had the highest TSS/TA. An increase in storage time led to a decrease in the firmness and an increase in the TSS, TA, and weight loss. Glossiness was just observed in CMC and PG coatings; however, they were less effective than the commercial wax coating. Based on the results, PG was the best coating used in this study.

Potential of carboxymethyl cellulose coating and low dose gamma irradiation to maintain storage quality, inhibit fungal growth and extend shelf-life of cherry fruit.

Carboxymethyl cellulose (CMC) coatings alone and in combination with gamma irradiation was tested for maintaining the storage quality, inhibiting fungal incidence and extending shelf-life of cherry fruit. Two commercial cherry varieties viz. Misri and Double after harvest at commercial maturity were coated with CMC at levels 0.5-1.0% w/v and gamma irradiated at 1.2kGy. The treated fruit including control was stored under ambient (temperature 25±2°C, RH 70%) and refrigerated (temperature 3±1°C, RH 80%) conditions for evaluation of various physico-chemical parameters. Fruits were evaluated after every 3 and 7days under ambient and refrigerated conditions. CMC coating alone at levels 0.5 and 0.75% w/v was not found effective with respect to mold growth inhibition under either of the two conditions. Individual treatment of CMC coating at 1.0% w/v and 1.2kGy irradiation proved helpful in delaying the onset of mold growth up to 5 and 8days of ambient storage. During post-refrigerated storage at 25±2°C, RH 70%, irradiation alone at 1.2kGy gave further 4days extension in shelf-life of cherry varieties following 28days of refrigeration. All combinatory treatments of CMC coating and irradiation proved beneficial in maintaining the storage quality as well as delaying the decaying of cherry fruit during post-refrigerated storage at 25±2°C, RH 70% but, combination of CMC at 1.0% w/v and 1.2kGy irradiation was found significantly (p≤0.05) superior to all other treatments in maintaining the storage quality and delaying the decaying of cherry fruit. The above combinatory treatment besides maintaining storage quality resulted in extension of 6days in shelf life of cherry varieties during post-refrigerated storage at 25±2°C, RH 80% following 28days of refrigeration. Above Combination treatment gave a maximum of 2.3 and 1.5 log reduction in yeast and mold count of cherry fruits after 9 and 28days of ambient and refrigerated storage, thereby ensuring consumer safety.

Effects of Rhamnolipid and Carboxymethylcellulose Coatings on Reactivity of Palladium-Doped Nanoscale Zerovalent Iron Particles.

Nanoscale zerovalent iron (NZVI) particles are often coated with polymeric surface modifiers for improved colloidal stability and transport during remediation of contaminated aquifers. Doping the NZVI surface with palladium (Pd-NZVI) increases its reactivity to pollutants such as trichloroethylene (TCE). In this study, we investigate the effects of coating Pd-NZVI with two surface modifiers of very different molecular size: rhamnolipid (RL, anionic biosurfactant, M.W. 600 g mol(-1)) and carboxymethylcellulose (CMC, anionic polyelectrolyte, M.W. 700 000 g mol(-1)) on TCE degradation. RL loadings of 13-133 mg TOC/g NZVI inhibited deposition of Pd in a concentration-dependent manner, thus limiting the number of available Pd sites and decreasing the TCE degradation reaction rate constant from 0.191 h(-1) to 0.027 h(-1). Furthermore, the presence of RL in solution had an additional inhibitory effect on the reactivity of Pd-NZVI by interacting with the exposed Pd deposits after they were formed. In contrast, CMC had no effect on reactivity at loadings up to 167 mg TOC/g NZVI. There was a lack of correlation between Pd-NZVI aggregate sizes and TCE reaction rates, and is explained by cryo-transmission electron microscopy images that show open, porous aggregate structures where TCE would be able to easily access Pd sites.

Potential of carboxymethyl cellulose and γ-irradiation to maintain quality and control disease of peach fruit

Carboxymethyl cellulose (CMC) coatings alone and in combination with gamma irradiation were tested for maintaining the storage quality and control of post-harvest gray and black mold disease of peach. Matured green peaches were CMC coated at levels 0.5–1.0% (w/v) and gamma irradiated at 1.2kGy. The treated fruit including control was stored under ambient (temperature 25±2°C, RH 70%) and refrigerated (temperature 3±1°C, RH 80%) conditions. In fruits treated with individual treatments of 1.0% (w/v) CMC; 1.2kGy irradiation and combination of 1.0% (w/v) CMC and 1.2kGy irradiation, no decay was recorded up to 6, 8 and 14 days of ambient storage. Irradiation alone at 1.2kGy prevented the onset of disease incidence up to 4 days compared to 2 days by 1.0% (w/v) CMC coating following 30 days of refrigeration. Combination of CMC at 1.0% (w/v) and 1.2kGy irradiation prevented disease incidence of peach up to 7 days during post-refrigerated storage at 25±2°C, RH 70% following 30 days of refrigeration. Above combinatory treatment can be of great potential in facilitating the marketing of the fruit, thereby benefiting the growers.