فهرست مطالب
Journal of Food Quality and Hazards Control
Volume:9 Issue: 4, Dec 2022
- تاریخ انتشار: 1401/11/02
- تعداد عناوین: 8
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Pages 181-189Background
Lemongrass (Cymbopogon citratus) is an aromatic herb; rich source of citric, vitamin C, and phenolic compounds used as natural antioxidant and antibacterial agents in food processing. This study aimed to evaluate the effect of lemongrass extract on the quality properties of chicken burger during frozen storage.
MethodsLemongrass extract was prepared with three levels (0.5, 1.0, and 1.5%) in the formulation of chicken burger and its effect was studied on some chemical, physical, and microbiological quality characteristics during frozen storage at -20 °C for 90 days. Data were analyzed using statistical analysis system (SAS, 2000).
ResultsChicken burger treated with different levels of lemongrass extract exhibited the lowest pH values than control one. L* values (the lightness) of treated chicken burger showed a gradually decrease as the level of lemongrass increased. Significant increase (p<0.05) was found in a* value (the redness) of chicken burger formulated with 1.5% lemongrass after 30 days of storage and remained constant during frozen storage period 90 days. Significant differences (p<0.05) were found in b* value (the yellowness) during frozen storage of chicken burger treated with different levels of lemongrass extract. Chicken burger formulated with 1.5% lemongrass extract exhibited a significant decreased (p<0.05) in Thiobarbituric Acid (TBA) value at the end of frozen storage period 90 days.
ConclusionUsing different levels of lemongrass extract in the formulation of chicken burger resulted in delaying the lipid oxidation, improved the color stability, and reduced the bacterial count during frozen storage.
Keywords: Cymbopogon, Chickens, Food Quality, Food Storage, Freezing -
Pages 190-198Background
Microbial and fungal contamination of agricultural produce has been a health challenge over the years. The present study surveyed microbial and aflatoxin contamination in groundnut, maize, and cowpea collected from Port Harcourt, Nigeria.
MethodsNinety samples of maize, groundnut, and cowpea were purchased from six major markets in Port Harcourt, Nigeria. The samples were first examined for insect pest infestation, then Moisture Content (MC), microbial, and aflatoxin contamination. Characterization of bacterial isolates was determined based on their morphological and cultural characteristics. Statistical analyses were performed using SPSS 20.0
ResultsData showed that 50% of groundnut samples and 33.33% of maize samples had total aflatoxins levels above World Health Organization (WHO) acceptable limits of 0.5-15 µg/kg. MC for groundnut, maize, and cowpea samples significantly ranged from 2.48-5.55%, 9.00-11.25%, and 9.50-12.48%, respectively. The mean bacterial count for groundnut, maize, and cowpea samples ranged from 0.7×108-1.7×108 Colony Forming Unit (CFU)/g, 0.3×108-1.7×108 CFU/g, and 0.7×108-1.9×108 CFU/g, respectively. Bacterial isolates, including Pseudomonas sp., Streptococcus sp., and Clostridium sp. were isolated from groundnut while Bacillus sp., Staphylococcus sp., Proteus sp., and Escherichia coli were isolated from maize and cowpea. Fungal isolates, including Aspergillus flavus and A. niger were isolated from groundnut and maize.
ConclusionThis study revealed the health risk exposure of consumers of the assayed staples in Port Harcourt of Nigeria, especially groundnut which had very high aflatoxin levels in most of the markets.
Keywords: Aflatoxins, Mycotoxins, Arachis, Zea mays, Vigna, Nigeria -
Pages 199-214Background
Bacteriocins are small peptides which are ribosomally synthesized and have been shown to have wide range of antimicrobial activity. The aim of this study was to optimize the production of L. paracasei MG847589 bacteriocin. Furthermore, the potential antibacterial properties of the novel bacteriocins were characterized and evaluated against Staphylococcus aureus.
MethodsThe present study optimized the growth media constituents of Lactobacillus paracasei MG847589 to improve bacteriocin yield by applying One-Factor-at-a-Time (OFAT) and Response Surface Methodology (RSM) methods.
ResultsAt OFAT, two-fold activity increased against Staphylococcus aureus in the presence of whey (22.5 g/L) as nitrogen source and sucrose (30 g/L) as carbon source. RSM tool was performed with media compounds using design expert 12.0.1.0. Whey (22.5 g/L), sucrose (30 g/L), temperature (30 ºC), and pH (6.5) condition yielded 25,600 AU/ml of bacteriocin against S. aureus. Bacteriocin was stable at pH range of 2.0 to 8.0 for one h and at 60 ºC for 15 min. The produced antimicrobial peptide is a novel bacteriocin with molecular mass of 2,611.122 Da.
ConclusionBacteriocin of L. paracasei MG847589 isolated from traditional Egyptian cheese (Kareish) showed great antimicrobial activity and could be applied as food preservative in food manufacturing.
Keywords: Bacteriocins, Peptides, Lactobacillales, Lacticaseibacillus paracasei, Anti-Bacterial Agents, Staphylococcus aureus -
Multidrug Resistance and Virulence Factors of Enterococci Isolated from Milk and Some Dairy DessertsPages 215-225Background
Enterococci spp. bacteria especially Enterococcus faecalis and E. faecium have the ability to acquire antibiotic-resistance pattern and causing life-threatening hospital-acquired infections. So, the aim of this study was to count and isolate of E. faecalis and E. faecium from milk and dairy desserts consumed in Assiut city, Egypt.
MethodsA total of 100 raw milk, ice cream, mehallabia, and milk rice samples were collected from dairies shop in Assiut city, Egypt and were bacteriologically examined for the presence and count of Enterococcus spp. Then, identification of enterococci isolates by conventional and Polymerase Chain Reaction (PCR) methods, performance of antibiotic sensitivity assay, and some virulence genes in the Multi Drug Resistant (MDR) isolates were identified.
ResultsThe prevalence of counted Enterococcus spp. in raw milk, ice cream, mehallabia, and milk rice samples were 76, 44, 20, and 32%, respectively. The prevalence of E. faecalis in raw milk, ice cream, mehallabia, and milk rice samples were 64, 0, 0, and 8%, while for E. faecium were 12, 44, 20, and 24%, respectively. E. faecalis isolates were resistant to vancomycin, ciprofloxacin, gentamicin, erythromycin, and tetracycline with the rate of 72.2, 88.9, 88.9, 94.4, and 77.8%, respectively, while for the resistance rates of E. faecium were 16, 40, 16, 84, and 20%, respectively. E. faecalis and E. faecium were MDR in rate of 88.9 and 32%, respectively.
ConclusionThis study revealed that milk, ice cream, mehallabia, and milk rice could be a source of enterococci to consumers in Assiut, Egypt. Moreover, E. faecalis had higher MDR and Resistant Index (RI) than E. faecium.
Keywords: Milk, Dairy Products, Enterococcus, Drug Resistance, Microbial, Egypt -
Pages 226-233Background
Edible film is a food packaging that can be eaten directly and have protection function of outside contamination. The purpose of this research is to know how about the effect of using a glycerol plasticizer to film whey-konjac edible films that enriched with clove essential oil.
MethodsA completely randomized design was used by different clove essential oil including P10, 0% clove essential oil; P10C1, 5% clove essential oil; P10C2, 10% clove essential oil; and P10C3, 15% clove essential oil. The present study investigated the physical characteristics, including tensile strength, elongation, Water Vapour Transmission Rate (WVTR), and microstructur film. Data were statistically evaluated using an Analysis of Variance (ANOVA) in Statistical Program for Social Science (SPSS) 16.0.
ResultsResults showed that the addition of glycerol plasticizer enriched with clove essential oil had no significant difference (p>0.05) to value of tensile strength, elongation, and WVTR of whey- konjac edible film. The value of tensile strength with the addition of clove essential oil at doses of 0, 5, 10, and 15% were 9.16, 7.9, 7.1, and 6.52 N, respectively. The concentration of 5% clove essential oil resulted in the best physical properties of film with a tensile strength 7.90 N, elongation 64.0%, and WVTR 8.12 g/mm2/day.
ConclusionUse of clove essential oil with different concentrations had no effect on tensile strength, elongation, and WVTR; but the addition of clove essential oil had promising potential to improve the physical characteristic of whey-konjac edible films.
Keywords: Syzygium, Oils, Volatile, Whey, Edible Films, Food Packaging, Glycerol -
Pages 234-240Background
The intestinal tract of human can be infected by protozoan parasites. In this short communication, the stool samples were collected from patients with diarrhea referred to Kut hospital, Iraq, and then the parasites (Giardia lamblia, Entamoeba histolytica, Cryptosporidium parvum) were considered for molecular identification.
MethodsStool samples were collected from 69 patients with diarrhea and then transferred to laboratory. Protozoan parasites were evaluated by Polymerase Chain Reaction (PCR) and phylogenetic tree analysis. Small subunit 18S rRNA region was amplified in the sizes of 514 bp, 409 bp, and 507 pb for G. lamblia, E. histolytica, and C. parvum, respectively.
ResultsThe results of phylogenetic tree analysis showed that G. lamblia had 99% identity to G. lamblia with accession number of DQ157272.1 (and total genetic changes of 0.002%); E. histolytica also had 99% identity to E. histolytica with accession number of GQ423748.1 (total genetic changes of 0.0005%); and C. parvum had 99% identity to C. parvum with accession number of AJ539197.1 (total genetic changes of 0.05%).
ConclusionGastrointestinal symptoms in the individuals with the studied protozoan parasites can be diagnosed directly by molecular detection and phylogenetic tree analysis with satisfying results. As well as, it can be utilized like a target for therapeutic intervention for these enteric protozoans.
Keywords: Giardia lamblia, Entamoeba histolytica, Cryptosporidium parvum, Phylogeny, Diarrhea, Iraq