Solmaz Alborzi - Academia.edu (original) (raw)

Papers by Solmaz Alborzi

Research paper thumbnail of Photoirradiated caffeic acid as an antimicrobial treatment for fresh produce

FEMS Microbiology Letters

Research paper thumbnail of Novel sanitization approach based on synergistic action of UV-A light and benzoic acid: Inactivation mechanism and a potential application in washing fresh produce

Research paper thumbnail of Investigation on chlorine-based sanitization under stabilized conditions in the presence of organic load

International journal of food microbiology, 2017

Chlorine, the most commonly used sanitizer for fresh produce washing, has constantly shown inferi... more Chlorine, the most commonly used sanitizer for fresh produce washing, has constantly shown inferior sanitizing efficacy in the presence of organic load. Conventionally this is attributed indirectly to the rapid chlorine depletion by organics leading to fluctuating free chlorine (FC) contents. However, little is known on whether organic load affects the sanitization process directly at well-maintained FC levels. Hereby, a sustained chlorine decay approach was employed to study the inactivation of Escherichia coli O157:H7 under stabilized washing conditions. Chlorine solution was first incubated with organic load for up to 4h, modeling the chlorination in produce washing lines. The FC level was then stabilized at five targeted values for sanitization study. Our study showed decreased sanitizing efficacy as the organic load increased. At 5s residence time and pH6.5, a minimum of 0.5 and 7.5mg/L FC were needed to achieve a 5 log reduction at 0 and 900mg/L chemical oxygen demand (COD), r...

Research paper thumbnail of On mechanism behind UV-A light enhanced antibacterial activity of gallic acid and propyl gallate against Escherichia coli O157:H7

Scientific reports, Jan 16, 2017

Possible mechanisms behind the enhanced antimicrobial activity of gallic acid (GA) and its ester ... more Possible mechanisms behind the enhanced antimicrobial activity of gallic acid (GA) and its ester propyl gallate (PG) in the presence of UV-A light against Escherichia coli O157:H7 were investigated. GA by itself is a mild antimicrobial and has a pro-oxidant ability. We found that the presence of UV-A light increases the uptake of GA by the bacteria. Once GA is internalized, the interaction between GA and UV-A induces intracellular ROS formation, leading to oxidative damage. Concurrently, GA + UV-A also inhibits the activity of superoxide dismutase (SOD), magnifying the imbalance of redox status of E. coli O157:H7. In addition to ROS induced damage, UV-A light and GA also cause injury to the cell membrane of E. coli O157:H7. UV-A exposed PG caused oxidative damage to the cell and significantly higher damage to the cell membrane than GA + UV-A treatment, explaining its higher effectiveness than GA + UV-A treatment. The findings presented here may be useful in developing new antimicrob...

Research paper thumbnail of Release of folic acid from sodium alginate-pectin-poly(ethylene oxide) electrospun fibers under in vitro conditions

LWT - Food Science and Technology, 2014

ABSTRACT The present study evaluated the release behavior of folic acid from ultrafine sodium alg... more ABSTRACT The present study evaluated the release behavior of folic acid from ultrafine sodium alginate-pectin-poly(ethylene oxide) electrospun fibers under in vitro conditions. In aqueous solution, the release of folic acid at pH 1.2 (64%) was significantly higher than at pH 3 (21%). At pH 7.8, the majority of folic acid was released (97%) due to extensive swelling and partial dissolution of the fibers. In simulated gastric juice, the folic acid release profile was similar to that of aqueous solution at pH 1.2. By contrast, using the simulated pH 7.8 intestinal fluid, a lower amount (40%) of folic acid was released as compared with the aqueous alkaline solution. These results showed that the release of folic acid from the alginate fibers is affected by the constituents present in the simulated intestinal fluid, in addition to the pH effect. The in vitro release study showed that the composite alginate electrospun fibers have good potential as a carrier that retains folic acid in acidic food products (pH 3), but selectively releases the micronutrient in the small intestine.

Research paper thumbnail of Electrospinning of Sodium Alginate-Pectin Ultrafine Fibers

Journal of Food Science, 2010

In this study, we investigated the electrospinning process of sodium alginate-pectin fibers inten... more In this study, we investigated the electrospinning process of sodium alginate-pectin fibers intended to be used as a carrier for stabilizing folic acid. Fiber-forming solutions containing 0.01% (w/w) folic acid were prepared by blending low-or medium-viscosity sodium alginate with pectin in a 70 : 30 ratio to form LSAP and MSAP solutions, respectively. Similar to other polysaccharide polymers reported previously, these solutions could not be electrospun. However, the incorporation of poly(ethylene oxide) (PEO) effectively enabled the electrospinning process. Electrospun fibers of different morphologies, ranging from fiber to fiber-bead, were obtained, depending on the blend ratio, concentration, and viscosity of the polymer-PEO solution used. Fibers electrospun from 3% MSAP/PEO (80%/20% w/w) had the smallest diameter (about 40 nm), whereas fibers containing higher PEO contents were larger in diameter. Bead-free fibers were formed when 4% LSAP/PEO (50/50) and 5% LSAP/PEO (80/20 to 50/50) were electrospun. The electrical conductivity and surface tension lowering effects of PEO on the polymer solution were likely the contributing factors for the observed electrospinning behaviors. By adjusting the formulation of the polymer solution, fibers of various morphologies may be obtained to suit different end-use applications. A study is currently ongoing to investigate the effectiveness of these fibers for stabilizing folic acid.

Research paper thumbnail of Aflatoxin M1 contamination in pasteurized milk in Tabriz (northwest of Iran)

Food and Chemical Toxicology, 2009

Aflatoxin M1 (AFM1) appears in milk as a direct result of the ingestion of food contaminated with... more Aflatoxin M1 (AFM1) appears in milk as a direct result of the ingestion of food contaminated with aflatoxin B1 by cattle. The role of milk in human nutrition is well-known. The aim of this study was to evaluate Aflatoxin M1 contamination in pasteurized milk samples in Tabriz city (Iran) by ELISA (Enzyme Linked Immunosorbent Assay). Fifty pasteurized milk samples from different supermarkets in Tabriz city were collected during 6 months (July to December 2008). AFM1 was found in 100% of the examined milk samples. Sixty-two percent of the samples had AFM1 greater than the maximum tolerance limit (50 ng/l) accepted by European Union. It can be concluded that AFM1 levels in the samples purchased in Tabriz city, appear to be a serious public health problem at the moment. To achieve a low level of AFM1 in milk, dairy cows' feed samples from various cows' herds must be controlled periodically for aflatoxin and kept away from fungal contamination as much as possible.

Research paper thumbnail of Encapsulation of folic acid and its stability in sodium alginate-pectin-poly(ethylene oxide) electrospun fibres

Journal of Microencapsulation, 2013

In this study, we investigated the effect of alginate-pectin-poly(ethylene oxide) (PEO) electrosp... more In this study, we investigated the effect of alginate-pectin-poly(ethylene oxide) (PEO) electrospun fibres on the stability of folic acid. Fibre-forming solutions containing folic acid were prepared by blending low- or medium-viscosity alginate with pectin. PEO was added to make the electrospinning process possible. Folic acid encapsulated in electrospun fibres achieved close to 100% retention when stored in the dark at pH 3 after 41 days of storage. By contrast, recovery of unencapsulated folic acid was 0% and 8% within the first day when stored at pH 3 in the presence and the absence of light, respectively. Electrospun fibres produced from the combination of alginate-pectin resulted in higher retention of folic acid compared to that of alginate alone. Nucleic magnetic resonance and FTIR results show that folic acid has been encapsulated in electrospun fibres through physical entrapment.

Research paper thumbnail of Photoirradiated caffeic acid as an antimicrobial treatment for fresh produce

FEMS Microbiology Letters

Research paper thumbnail of Novel sanitization approach based on synergistic action of UV-A light and benzoic acid: Inactivation mechanism and a potential application in washing fresh produce

Research paper thumbnail of Investigation on chlorine-based sanitization under stabilized conditions in the presence of organic load

International journal of food microbiology, 2017

Chlorine, the most commonly used sanitizer for fresh produce washing, has constantly shown inferi... more Chlorine, the most commonly used sanitizer for fresh produce washing, has constantly shown inferior sanitizing efficacy in the presence of organic load. Conventionally this is attributed indirectly to the rapid chlorine depletion by organics leading to fluctuating free chlorine (FC) contents. However, little is known on whether organic load affects the sanitization process directly at well-maintained FC levels. Hereby, a sustained chlorine decay approach was employed to study the inactivation of Escherichia coli O157:H7 under stabilized washing conditions. Chlorine solution was first incubated with organic load for up to 4h, modeling the chlorination in produce washing lines. The FC level was then stabilized at five targeted values for sanitization study. Our study showed decreased sanitizing efficacy as the organic load increased. At 5s residence time and pH6.5, a minimum of 0.5 and 7.5mg/L FC were needed to achieve a 5 log reduction at 0 and 900mg/L chemical oxygen demand (COD), r...

Research paper thumbnail of On mechanism behind UV-A light enhanced antibacterial activity of gallic acid and propyl gallate against Escherichia coli O157:H7

Scientific reports, Jan 16, 2017

Possible mechanisms behind the enhanced antimicrobial activity of gallic acid (GA) and its ester ... more Possible mechanisms behind the enhanced antimicrobial activity of gallic acid (GA) and its ester propyl gallate (PG) in the presence of UV-A light against Escherichia coli O157:H7 were investigated. GA by itself is a mild antimicrobial and has a pro-oxidant ability. We found that the presence of UV-A light increases the uptake of GA by the bacteria. Once GA is internalized, the interaction between GA and UV-A induces intracellular ROS formation, leading to oxidative damage. Concurrently, GA + UV-A also inhibits the activity of superoxide dismutase (SOD), magnifying the imbalance of redox status of E. coli O157:H7. In addition to ROS induced damage, UV-A light and GA also cause injury to the cell membrane of E. coli O157:H7. UV-A exposed PG caused oxidative damage to the cell and significantly higher damage to the cell membrane than GA + UV-A treatment, explaining its higher effectiveness than GA + UV-A treatment. The findings presented here may be useful in developing new antimicrob...

Research paper thumbnail of Release of folic acid from sodium alginate-pectin-poly(ethylene oxide) electrospun fibers under in vitro conditions

LWT - Food Science and Technology, 2014

ABSTRACT The present study evaluated the release behavior of folic acid from ultrafine sodium alg... more ABSTRACT The present study evaluated the release behavior of folic acid from ultrafine sodium alginate-pectin-poly(ethylene oxide) electrospun fibers under in vitro conditions. In aqueous solution, the release of folic acid at pH 1.2 (64%) was significantly higher than at pH 3 (21%). At pH 7.8, the majority of folic acid was released (97%) due to extensive swelling and partial dissolution of the fibers. In simulated gastric juice, the folic acid release profile was similar to that of aqueous solution at pH 1.2. By contrast, using the simulated pH 7.8 intestinal fluid, a lower amount (40%) of folic acid was released as compared with the aqueous alkaline solution. These results showed that the release of folic acid from the alginate fibers is affected by the constituents present in the simulated intestinal fluid, in addition to the pH effect. The in vitro release study showed that the composite alginate electrospun fibers have good potential as a carrier that retains folic acid in acidic food products (pH 3), but selectively releases the micronutrient in the small intestine.

Research paper thumbnail of Electrospinning of Sodium Alginate-Pectin Ultrafine Fibers

Journal of Food Science, 2010

In this study, we investigated the electrospinning process of sodium alginate-pectin fibers inten... more In this study, we investigated the electrospinning process of sodium alginate-pectin fibers intended to be used as a carrier for stabilizing folic acid. Fiber-forming solutions containing 0.01% (w/w) folic acid were prepared by blending low-or medium-viscosity sodium alginate with pectin in a 70 : 30 ratio to form LSAP and MSAP solutions, respectively. Similar to other polysaccharide polymers reported previously, these solutions could not be electrospun. However, the incorporation of poly(ethylene oxide) (PEO) effectively enabled the electrospinning process. Electrospun fibers of different morphologies, ranging from fiber to fiber-bead, were obtained, depending on the blend ratio, concentration, and viscosity of the polymer-PEO solution used. Fibers electrospun from 3% MSAP/PEO (80%/20% w/w) had the smallest diameter (about 40 nm), whereas fibers containing higher PEO contents were larger in diameter. Bead-free fibers were formed when 4% LSAP/PEO (50/50) and 5% LSAP/PEO (80/20 to 50/50) were electrospun. The electrical conductivity and surface tension lowering effects of PEO on the polymer solution were likely the contributing factors for the observed electrospinning behaviors. By adjusting the formulation of the polymer solution, fibers of various morphologies may be obtained to suit different end-use applications. A study is currently ongoing to investigate the effectiveness of these fibers for stabilizing folic acid.

Research paper thumbnail of Aflatoxin M1 contamination in pasteurized milk in Tabriz (northwest of Iran)

Food and Chemical Toxicology, 2009

Aflatoxin M1 (AFM1) appears in milk as a direct result of the ingestion of food contaminated with... more Aflatoxin M1 (AFM1) appears in milk as a direct result of the ingestion of food contaminated with aflatoxin B1 by cattle. The role of milk in human nutrition is well-known. The aim of this study was to evaluate Aflatoxin M1 contamination in pasteurized milk samples in Tabriz city (Iran) by ELISA (Enzyme Linked Immunosorbent Assay). Fifty pasteurized milk samples from different supermarkets in Tabriz city were collected during 6 months (July to December 2008). AFM1 was found in 100% of the examined milk samples. Sixty-two percent of the samples had AFM1 greater than the maximum tolerance limit (50 ng/l) accepted by European Union. It can be concluded that AFM1 levels in the samples purchased in Tabriz city, appear to be a serious public health problem at the moment. To achieve a low level of AFM1 in milk, dairy cows' feed samples from various cows' herds must be controlled periodically for aflatoxin and kept away from fungal contamination as much as possible.

Research paper thumbnail of Encapsulation of folic acid and its stability in sodium alginate-pectin-poly(ethylene oxide) electrospun fibres

Journal of Microencapsulation, 2013

In this study, we investigated the effect of alginate-pectin-poly(ethylene oxide) (PEO) electrosp... more In this study, we investigated the effect of alginate-pectin-poly(ethylene oxide) (PEO) electrospun fibres on the stability of folic acid. Fibre-forming solutions containing folic acid were prepared by blending low- or medium-viscosity alginate with pectin. PEO was added to make the electrospinning process possible. Folic acid encapsulated in electrospun fibres achieved close to 100% retention when stored in the dark at pH 3 after 41 days of storage. By contrast, recovery of unencapsulated folic acid was 0% and 8% within the first day when stored at pH 3 in the presence and the absence of light, respectively. Electrospun fibres produced from the combination of alginate-pectin resulted in higher retention of folic acid compared to that of alginate alone. Nucleic magnetic resonance and FTIR results show that folic acid has been encapsulated in electrospun fibres through physical entrapment.