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Azlin Mustapha

Bio: Azlin Mustapha is an academic researcher from University of Missouri. The author has contributed to research in topics: Salmonella & Silver nanoparticle. The author has an hindex of 38, co-authored 86 publications receiving 5034 citations. Previous affiliations of Azlin Mustapha include University of Nebraska–Lincoln & University of Minnesota.


Papers
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Journal ArticleDOI
Yang Liu1, Lili He1, Azlin Mustapha1, Hao Li1, Zhiqiang Hu1, Mengshi Lin1 
TL;DR: To investigate antibacterial activities of zinc oxide nanoparticles (ZnO NP) and their mode of action against an important foodborne pathogen, Escherichia coli O157:H7.
Abstract: Aims: To investigate antibacterial activities of zinc oxide nanoparticles (ZnO NP) and their mode of action against an important foodborne pathogen, Escherichia coli O157:H7. Methods and Results: ZnO NP with sizes of 70 nm and concentrations of 0, 3, 6 and 12 mmol l−1 and NP-free solutions were used in antimicrobial tests against E. coli O157:H7. ZnO NP showed increasing inhibitory effects on the growth of E. coli O157:H7 as the concentrations of ZnO NP increased. A complete inhibition of microbial growth was achieved at the concentration level of 12 mmol l−1 or higher. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy were used to characterize the changes of morphology and cellular compositions of bacterial cells treated with ZnO NP and study the mode of action of ZnO NP against E. coli O157:H7. The intensity of lipid and protein bands in the Raman spectra of bacterial cells increased after exposure to ZnO NP, while no significant changes in nucleic acid bands were observed. Conclusions: ZnO NP were found to have antibacterial activity against E. coli O157:H7. The inhibitory effects increase as the concentration of ZnO NP increased. Results indicate that ZnO NP may distort and damage bacterial cell membrane, resulting in a leakage of intracellular contents and eventually the death of bacterial cells. Significance and Impact of the Study: These results suggest that ZnO NP could potentially be used as an effective antibacterial agent to protect agricultural and food safety.

735 citations

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TL;DR: Results show that ZnO NPs at concentrations greater than 3 mmol l(-1) can significantly inhibit the growth of B. cinerea and P. expansum, and suggest that the substance could be used as an effective fungicide in agricultural and food safety applications.

717 citations

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TL;DR: Results of this work show that ActiVin and Pycnogenol are promising additives for maintaining the quality and safety of cooked beef.

366 citations

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TL;DR: In this article, surface enhanced Raman spectroscopy (SERS) was used to detect 0.1% melamine in wheat gluten, 0.05% in chicken feed and 0.07% in noodles.
Abstract: Melamine, a nitrogen-rich chemical, was implicated in pet and human food recalls in 2007, which caused enormous economic losses to the food industry. In this study, melamine concentration in wheat gluten, chicken feed, and processed foods (that is, cake and noodle) was measured by surface enhanced Raman spectroscopy (SERS) in combination with SERS-active substrates. SERS was able to rapidly detect 0.1% melamine in wheat gluten, 0.05% in chicken feed, 0.05% in cakes, and 0.07% in noodle, respectively. A partial least squares (PLS) model was established for the quantification of melamine in foods by SERS: R= 0.90, RMSEP = 0.33. In addition, SERS results were verified by HPLC analysis based on a simplified FDA method. Compared with HPLC, the SERS method is much faster and simpler, requires minimum sample preparation, but still yields satisfactory qualitative and quantitative results. These results demonstrate that it is an applicable approach to use SERS to screen foods, eliminate presumptive negative samples of melamine contamination from the sample population, and then verify presumptive positive samples using HPLC protocols. Combining these 2 methods could provide a more rapid and cost-effective way for monitoring melamine contamination in increasingly large numbers of imported foods and feed products.

287 citations

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TL;DR: Microencapsulation appears to increase the viability of bifidobacterium longum B6 and B. longum ATCC 15708 in yogurt during refrigerated storage for 30 d and consumers judged the nonencapsulated treatment as the most sour, which was likely due to the higher acetic acid content.

246 citations


Cited by
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TL;DR: Toxicity data exist for only a few bacteriocins, but research and their long-time intentional use strongly suggest that bacteriOCins can be safely used.

1,782 citations

Journal ArticleDOI
01 Nov 2011
TL;DR: Several applications of nanomaterials in food packaging and food safety are reviewed, including polymer/clay nanocomposites as high barrier packaging materials, silver nanoparticles as potent antimicrobial agents, and nanosensors and nanomMaterial-based assays for the detection of food-relevant analytes.
Abstract: In this article, several applications of nanomaterials in food packaging and food safety are reviewed, including: polymer/clay nanocomposites as high barrier packaging materials, silver nanoparticles as potent antimicrobial agents, and nanosensors and nanomaterial-based assays for the detection of food-relevant analytes (gasses, small organic molecules and food-borne pathogens). In addition to covering the technical aspects of these topics, the current commercial status and understanding of health implications of these technologies are also discussed. These applications were chosen because they do not involve direct addition of nanoparticles to consumed foods, and thus are more likely to be marketed to the public in the short term.

1,568 citations

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TL;DR: The main purpose of this review is to elaborate the mechanical and physical properties that affect PLA stability, processability, degradation, PLA-other polymers immiscibility, aging and recyclability, and therefore its potential suitability to fulfill specific application requirements.

1,557 citations

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TL;DR: This review summarizes emerging efforts in combating against infectious diseases, particularly using antimicrobial NPs and antibiotics delivery systems as new tools to tackle the current challenges in treating infectious diseases.

1,493 citations

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TL;DR: An overview of natural antioxidants, their mechanisms of action, and potential applications can be found in this article, where the authors provide an overview of the potential applications of these natural antioxidants.
Abstract: While use of synthetic antioxidants (such as butylated hydroxytoluene and butylated hydroxyanisole) to maintain the quality of ready-to-eat food products has become commonplace, consumer concern regarding their safety has motivated the food industry to seek natural alternatives. Phenolic antioxidants can inhibit free radical formation and/or interrupt propagation of autoxidation. Fat-soluble vitamin E (α-tocopherol) and water-soluble vitamin C (L-ascorbic acid) are both effective in the appropriate matrix. Plant extracts, generally used for their flavoring characteristics, often have strong H-donating activity thus making them extremely effective antioxidants. This antioxidant activity is most often due to phenolic acids (gallic, protocatechuic, caffeic, and rosmarinic acids), phenolic diterpenes (carnosol, carnosic acid, rosmanol, and rosmadial), flavonoids (quercetin, catechin, naringenin, and kaempferol), and volatile oils (eugenol, carvacrol, thymol, and menthol). Some plant pigments (anthocyanin and anthocyanidin) can chelate metals and donate H to oxygen radicals thus slowing oxidation via 2 mechanisms. Tea and extracts of grape seeds and skins contain catechins, epicatechins, phenolic acids, proanthocyanidins, and resveratrol, all of which contribute to their antioxidative activity. The objective of this article is to provide an overview of natural antioxidants, their mechanisms of action, and potential applications.

1,393 citations