Food-borne pathogenic bacteria cause infection and death in humans, and impose great economic losses in the food industry worldwide annually. Therefore, researchers have turned to the use of different types of antimicrobials to control pathogenic bacteria in foods. Due to the side effects of synthetic antimicrobials, much attention has recently been paid to natural ones. Endolysins, enzymes coded by bacteriophages, and their derivatives have been known as natural and safe antimicrobials which may be used to eliminate or reduce pathogenic bacteria in foods and their processing environments. Endolysins are remarkably stable under different conditions, and therefore they may have broader use in the food industry. In addition to describing the structure and production of endolysins, this review provides almost comprehensive information on using endolysins as antimicrobials against food-borne pathogens in vitro and in food models, and against their biofilms. According to the results of published studies, endolysins can be considered as a very suitable alternative to synthetic antimicrobials. The use of endolysins to control food-borne pathogens and increase food safety assurance level have been emphasized due to the rapid and specific action of the endolysins, their good stability, and lack of resistance development to endolysins in bacteria.
Abstract This study aimed to prepare an inhibitory edible coating for Gouda cheese based on whey protein containing lactoperoxidase system ( LPOS ) and Bunium persicum essential oil ( EO ) in order to control postpasteurization contamination. Using a full factorial design, the effects of LPOS and EO on microbiological characteristics and chemical indices of manufactured Gouda cheeses were evaluated during 90 days of storage time. Listeria , lactic acid bacteria , Enterobacter , Escherichia , and Pseudomonas species were considered as potential pathogenic and spoilage indicators of produced Gouda cheese samples. Chemical properties of cheeses were assessed using the free fatty acid, peroxide value, and thiobarbituric acid experiments. The results showed that bacteria counts remained constant in cheese samples coated with EO and also EO – LPOS . However, the survival of gram‐positive lactic acid bacteria and Enterobacter spp. was more pronounced in LPOS ‐based coating. The most effective treatments on oxidation stability parameters in cheese samples were EO ‐ and EO – LPOS coatings. By the addition of B. persicum EO and LPOS , further inhibition of the lipid oxidation of the cheese samples was achieved. Lipolysis, as a result of lipid degradation, was more pronounced in the control, whey‐coated, and whey– LPOS ‐coated samples in comparison with whey– EO ‐ and whey– EO – LPOS ‐coated samples during the final days of storage time. These results indicate that antibacterial, lipid oxidation, and oxygen barrier properties of the coatings were developed by the addition of B. persicum EO and LPOS .
Pomegranate juice (PJ) and its products are directly used in foods due to their pleasant taste and palatability as well as preservative effects. In spite of useful effects of essential oils such as zataria multiflora Boiss essential oil (ZEO) on prolonging shelf-life of foods, their application is restricted due to their vigorous taste and aroma. In the present study, physicochemical characteristics, chemical compositions and antioxidative activities of two Iranian native plants, PJ (Rabbab-e-Neyriz cultivar) and ZEO were investigated. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and reducing power tests were used for measuring antioxidant activity. The level of total phenolic of them were also determined. Total soluble solids content, pH value, titratable acidity content and total anthocyanins content of PJ were also measured. Chemical compositions of ZEO were determined using gas-chromatography, mass-spectrometry (GC-MS). The results of antioxidative tests indicated that the ZEO was significantly more potent (p < 0.05) than PJ. Also the phenolic content in ZEO (262.52 mg per g) was significantly higher (p < 0.05) than PJ (154.90 mg per 100g). Chemical compositions analysis of ZEO indicated that its major components were carvacrol (59.17%), linalool (23.67%), trans-caryophyllene (3.07%) and carvacrol methyl ether (2.44%). In the present study, physicochemical and antioxidative characteristics of Rabbab-e-Neyriz PJ were determined for first time. It was aslo found that ZEO in comparison with PJ had higher antioxidative activity and total phenolic content.
Abstract Four hundred and fifty one-day-old male broiler chicks (Ross 308) in 9 groups of 50 each (3 × 3 factorial experiment) were randomly allocated to investigate the effects of different dietary levels of 0, 30 and 60 mg/kg Zinc (Zn) and 0, 300 and 600 mg/kg magnesium (Mg) on thigh meat colour, nutrient composition and lipid peroxidation value in broiler chickens under heat stress. The birds were kept under a high temperature (32±1°C) for 24 h/day for the first until the final day. At the end of the experiment (day 42), five birds per treatment were slaughtered. Then two pieces of the right thigh muscle per bird (upper part of the thigh muscle) were immediately collected for assessing the meat quality indices. The results of the present experiment showed that addition of Zn and Mg did not influence the ash, dry matter (DM) and ether extract (EE) contents of thigh meat (P>0.05), whereas the crude protein (CP) content of the thigh meat was increased when diet was supplemented with Zn (P<0.05). Addition of Zn and Mg in diet did not change the mean lightness (L) and redness (a) value in the thigh meat (P>0.05). Thigh yellowness (b) value was increased by inclusion of 30 mg/kg Zn alone or along with 600 mg/kg Mg (P<0.05). Furthermore, inclusion of 30 mg/kg Zn in diet (at any level of Mg) decreased the thigh thiobarbituric acid reactive substances (P<0.05)
There is a strong inclination and attention toward consumption of functional
foods due to their bioprotection in preventing health problems and conferring health benefits beyond
their nutritional content. The aim of this study was to evaluate L. casei potential as bioprotection and
probiotic agent to inhibit s. Typhimurium.
Material & Methods: For this purpose, firstly, the antibacterial capacities towards s. Typhimurium
were determined in an agar spot test. Secondly, in macrodilution method, several dose of L. casei was
evaluated for its effects on the growth and survival of s. Typhimurium inoculated onto mixture broth
media (LB+ MRS broth).
Result: In Agar spot test, inhibition zone diameter of s. Typhimurium in encounter with 6.6 and 2.6
log of L.casei for the first and third day were 23.96, 15.74 , 25.78, and 17.19 (mm) respectively. At 8-
10 and 37 °C, initial counts of s. Typhimurium in the mixture broth media treated with 8 log of L.
casei decreased from ~5 to 2 and undetected level (<1 log CFU/ml) respectively at final day. With 5
log of L.casei, it reached from ~5 to 5.5 and below the detection level (
The present study was conducted to extend the shelf life of Lyoner-type sausages during 40 days of storage at 4 8C with individual and combinational use of natural preservatives including cinnamon essential oil (CEO) and grape seed extract (GSE). The samples were analyzed for physicochemical properties (pH, aw, and color changes), lipid oxidation (thiobarbituric acid reactive substances [TBARS]), microbial quality (Lactic acid bacteria count, total viable count, psychrotrophic count, mold and yeast count, and fate of inoculated Clostridium perfringens), and sensorial characteristics (taste, odor, color, texture, and overall acceptability) at 10-day intervals. Results indicated that using GSE and CEO had higher DE (.55–1.56), a* (13.03–13.91), and lower L* (65.10–66.82), b* (15.40–16.65), whiteness index (59.45–60.60), TBARS values (2.91–3.28), and microbial counts than control at the end of storage time. Samples containing CEO .04%1 GSE .16% showed the best antimicrobial activity against C. perfringens (reduction of 1.72 log10 CFU/g at the end of storage time). Results also indicated that CEO addition and GSE addition improved odor and color scores of the samples, respectively. Therefore, use of CEO and GSE, especially in combination, is recommended to be applied in meat products.
Practical applications
Nowadays, because of the adverse effects of chemical preservatives, application of multipurpose natural preservatives in small quantities is a more preferred approach. Therefore, to increase the shelf-life and quality characteristics of meat products, new ingredient systems that are associated with natural and organic foods, are applied. The results of the present study showed the synergistic effects of combined use of CEO and GSE in maintaining the quality of fresh meat products as well as preventing their undesirable impacts on sensory attributes and physicochemical properties. Thus, combinational use of CEO and GSE due to extending the shelf life and safety of meat products can practically profit both producers and consumers.
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