Search

The effect of Auricularia auricula aqueous extract (AAE) on the survival of Lactobacillus acidophilus La-5 and Bifidobacterium bifidum Bb-12, and on chemical and sensory properties of yogurt was investigated during 28 days of storage at 4°C. The use of 0.05% of AAE improved the survival of L. acidophilus La-5 and B. bifidum Bb-12 about 0.35 and 0.58 log CFU/g, respectively. However, AAE in 0.1% concentration enhanced the survival of L. acidophilus La-5 and B. bifidum Bb-12 about 0.43 and 0.51 log CFU/g, respectively. Moreover, 0.1% concentration of AAE drastically increased antioxidant activity and total phenolic content to 115.30 mg BHT eq./kg and 1,057.6 mg Gallic acid/kg after 28 days, respectively. Addition of AAE to the yogurt significantly decreased sensorial acceptance while increased syneresis compared to the control group (p

Among the main biodegradable food packaging materials, poly-lactic acid (PLA) is a commercially successful polymer used notably in the food packaging industry. In this study, active PLA films containing different percentage of anise essential oil (AE) (0, 0.5, 1 and 1.5% v/v) were developed, and characterized by physical, mechanical and antibacterial analysis. Based on physical examinations, thermal stability of PLA/AE films was greater than the neat PLA film, and the minimum water vapor permeability (WVP) was recorded for PLA/0.5AE film (1.29 × 10 11 g/m s), while maximum WVP was observed for PLA/1.5AE (2.09 × 1011 g/m s). Moreover, the lightness and yellowness of the composites were decreased by the addition of AE. For the PLA composites with 1.5% AE, the tensile strength decreased by 35% and the elongation break increased by 28.09%, comparing to the pure PLA. According to the antibacterial analysis, the minimum inhibitory concentrations of PLA/AE film were 5 to 100 mg/mL and the active composite could create visible inhibition zones of 14.2 to 19.2 mm. Furthermore, the films containing AE inhibited L. monocytogenes and V. parahaemolyticus in a concentration-dependent manner. The confirmation of the success of the incorporation of EOs into the PLA films was further evaluated using principal component analysis, where positive results were obtained. In this context, our findings suggest the significant potency of AE to be used as an antibacterial agent in active food packaging.

Aflatoxin M1 (AFM1) is a 2B Group human carcinogens agent and introduces into the human diet by milk consumption. In the present study 257 raw, 143 pasteurized and 61 UHT milk samples were collecte...

Fresh proteinaceous products with animal origin have a short shelf life. Therefore, this study was done to evaluate the effects of novel films based on the combination of gelatin and nanochitosan incorporated with different concentrations of Zataria multiflora Boiss. essential oil (ZMEO) (0, 0.3, 0.6 and 0.9 % v/v) against two food borne pathogens including Listeria monocytogenes and Salmonella Typhimurium. Afterwards, the effect of films on the microbial, chemical, and organoleptic properties of chicken breast meat was evaluated during refrigerated storage for a period of 14 days. Based on the in vitro findings, the pure gelatin-nanochitosan (GNC) film or GNC film containing different concentration of ZMEO had antibacterial activity against L. monocytogenes, whilst only GNC films containing 0.6 or 0.9 % ZMEO showed antibacterial activity against S. Typhimurium. Also, results showed that the microbial population of chicken breast meat wrapped with GNC films containing ZMEO decreased at least 2 log CFU/g compared to control (P

Rye ( Secale cereale ) is one of a number of cereal species that grow wild in the northwest of Iran, Turkey, and Central Asian countries. It is revealed that sprouts possess higher vitamins, antioxidant, flavonoids and fiber than grains. For evaluation of the potential prebiotic activity of rye sprout extract (RSE), the grains were soaked in water, germinated and dried by a freeze-dryer. The in-vitro viability and relative growth ratio (RGR) of probiotic bacteria, as well as their antimicrobial activities and their retention in synbiotic yogurt during 56 days cold storage in presence of RSE, were investigated. The sensory properties (odor, color, texture, taste and overall acceptance) of symbiotic yogurt with different amounts of RSE in comparison with control group were evaluated. The results showed that adding various concentrations of RSE increased the viability of both Lactobacillus acidophilus and Bifidobacterium animalis (p B. animalis was better than L. acidophilus . Comparison of RGR of treated samples indicated that adding RSE even 0.25% can increase the growth and survival of probiotic in comparison with control. The results also showed that adding of RSE promoted the antimicrobial activities of probiotics. In synbiotic yogurt, probiotic populations remained higher than the minimum recommended therapeutic dose for an extended period of cold storage. There was no significant difference between sensory parameters of control specimens and synbiotic yogurt. According to our results, the synbiotic effect of RSE and probiotics highlights the potential application of RSE as a prebiotic in dairy and other functional products.

In this study, the antibacterial properties of Pimpinella anisum essential oil (PAO) were evaluated against six food‐related bacteria. Afterward, the effects of different concentrations of PAO on microbial, chemical, and organoleptic properties of minced beef were evaluated during refrigerated storage. Based on the findings, PAO was effective against all of the tested strains, where minimum inhibitory concentration of Listeria monocytogenes was 0.015% (v/v) and this value was 0.12% (v/v) for Vibrio parahaemolyticus and Salmonella typhimurium. At the end of storage time, the microbial population of samples treated with 0.5% v/w PAO was decreased approximately 1–2 log CFU/g compared to control (p

The present study aimed to isolate lactic acid strains from 105 camel milk samples from 6 provinces of Iran to investigate their probiotic, technological, and antioxidant properties. Seven identified lactic acid bacteria strains by 16S rRNA gene sequence analysis were Enterococcus faecium MN994352, Lactococcus lactis MN994342, and MT032418, Leuconostoc mesenteroides MT032416, MN994377, MN994378, and MT032415. The results showed that the studied strains successfully met all of the criteria. It has also been observed that bovine milk has a positive effect on the survival of lactic acid strains in the simulated gastric fluid. Great ability in co-aggregation with pathogens was observed in the auto-aggregation capable strains. Among the investigated food pathogens, Staphylococcus aureus was the most susceptible pathogen to the tested probiotic strains. The results also showed that all strains had strong antioxidants, lipolytic, and proteolytic activity, as well as a great ability to produce exopolysaccharide. According to technological analysis, the isolated strain could be used as a starter or co-culture to improve the rheological properties of food products, to enhance the total antioxidant status, and to reduce oxidative stress markers.

Major databases were searched until January 2019 and 77 eligible studies were included in the meta-analysis to estimate the overall mean of AFM1 in milk in Iran. The mean of AFM1 levels was obtained 55.97 ng/kg (95% CI: 50.09–61.84). However, the pooled estimated mean of AFM1 levels in milk were 94.58 (95% CI: 70.24–118.92), 59.19 (95% CI: 51.84–66.54) and 35.23 ng/kg (95% CI: 31.53–38.92), considering 4, 55 and 18 TLC, ELISA and HPLC-based studies (including 354, 9224 and 2606 samples), respectively. Also, there is a wide variation of AFM1 levels among different geographical regions which were the highest in northern (88.77 ng/kg). The AFM1 contamination of milk taken from the areas with humid climate was higher than the arid climate. AFM1 Levels were the highest in winter (48.70 ng/Kg). The level of AFM1 in pasteurized, raw, and UHT milk were 49.76, 55.08 and 94.81 ng/kg, respectively.

Zataria multiflora Boiss., known as Avishan-e-Shirazi in Iran, is a member of the Lamiaceae family. Oxygenated monoterpenic compounds, mainly thymol and carvacrol, are major components of the essential oil (EO) of this plant. The derivatives of this plant, especially its EO, have been long used in folk medicine and healthcare as a decoction, infusion, or vapor. New potential areas of application of this EO in modern medicine have emerged due to increasing attention to different pharmaceutical effects of this EO demonstrated by many experiments. Although it is traditionally used as flavoring agent in a variety of foods, it is now well evident from numerous studies by many food science researchers that this EO possesses different biological effects including antibacterial, antifungal, antioxidant, and antiinsect properties. These findings introduce Z. multiflora Boiss EO as a promising food preservative to improve the safety and quality of food commodities.

In the present work, the effects of Zataria multiflora Boiss. essential oil (EO) against growth and citrinin production by Penicillium citrinum ATCC 1156 were evaluated in culture media and mozzarella cheese. The growth was completely inhibited at 200 ppm on potato dextrose agar, and minimum fungicidal concentration of the EO was estimated at 400 ppm. EO strongly suppressed the growth and citrinin formation in media with a dose-dependent manner. At 200 ppm in yeast extract sucrose (broth) flasks, mycelial dry weight and citrinin production significantly reduced by 87.5 and 92.4%, respectively (P

In this study, the effect of Cuminum cyminum L. essential oil (EO) and Lactobacillus acidophilus (a probiotic) on growth of Staphylococcus aureus in white brined cheese was evaluated. The experiment included different levels of EO (0, 7.5, 15 and 30 µL/100 mL milk) and L. acidophilus (0 and 0.5%) to assess their effects on S. aureus count during the manufacture, ripening and storage of Iranian white brined cheese for up to 75 days. The significant (P

The effects of different concentrations of Zataria multiflora Boiss. essential oil (EO: 0, 5, 15 and 30 μl 100 ml −1 ) and nisin ( N : 0, 0.25 and 0.5 μg ml −1 ), temperatures ( T : 25 and 8 °C), and storage times (up to 21 days) on growth of Salmonella typhimurium and Staphylococcus aureus in a commercial barley soup were evaluated in a factorial design study. The growth of S. typhimurium was significantly ( P N concentrations at 8 °C. For S. aureus , the viable count was significantly ( P N concentrations and their combinations, incubated at both storage temperatures. The mechanism of the antimicrobial action of EO, N , and their combinations against cell membranes of the tested organisms were also studied by measurement of the release of cell constituents and by the electronic microscopy observations of the cells. The significant increase of the cell constituents’ release of both organisms was observed as a result of treatments with EO and EO in combination with N . Electronic microscopy observations revealed that the cell membranes of S. typhimurium treated by EO and EO in combination with N were significantly damaged, while cells treated with only N looked similar to untreated cells. The electron micrographs of treated cells of S. aureus with EO, N , and their combination also showed important morphological damages and disrupted membranes.

UNLABELLED The effect of Zataria multiflora Boiss. (Z. multiflora) essential oils (EO) on biogenic amines (BAs) production and microbial counts in Gouda cheese has been investigated. Zataria multiflora was added to milk in different concentrations (0·05, 0·1, 0·2 and 0·4% (v/v)). The BAs (tyramine and histamine) were measured by RP-HPLC, following extraction from the cheese. Various microbiological analyses (aerobic mesophilic bacteria, enterococci, mesophilic lactobacilli, Enterobacteriaceae, lactococci and yeasts) were performed during ripening using the viable plate count method on specific culture media. The overall acceptability of cheeses was investigated by seven panellists. All the samples containing different concentrations of EO were acceptable to the panellists. Also, Gouda cheeses with 0·2% Z. multiflora EO showed the highest acceptability among all the samples. At the end of maturation period, 0·1, 0·2 and 0·4% Z. multiflora EO reduced tyramine and histamine significantly to 5%, 22% and 44% for tyramine and 14%, 29% and 46% for histamine, respectively, when compared to the control group. The increase of Z. multiflora EO concentrations led to further decrease in BAs content and microbial counts. The maximum microbiological reduction was observed in yeasts, and minimum microbiological reduction was seen in Enterobacteriaceae counts. Zataria multiflora EO could be used for reduction of BAs and also as a flavouring agent in Gouda cheese and could contribute to consumers' health. SIGNIFICANCE AND IMPACT OF THE STUDY The presence of biogenic amines in cheese has a serious impact on public health. Besides, there is growing concern about the use of chemical preservatives and the food industry is looking for new natural preservation methods. Zataria multiflora Boiss. essential oil is well known for its antimicrobial effects, and we attempted to reduce biogenic amines formation in Gouda cheese using Z. multiflora Boiss. essential oil as a natural additive. Furthermore, the desirable organoleptic qualities such as flavour, odour, texture and colour were achieved by adding Z. multiflora Boiss. to cheese.

The effect of different concentrations of Zataria multiflora Boiss. essential oil (EO; 0%, 0.005%, and 0.015%), nisin (0, 0.125, and 0.25 microL/mL), and their combinations on the production of staphylococcal enterotoxin C (SEC) and alpha-hemolysin (alpha-toxin) by Staphylococcus aureus at different inoculation levels (10(3), 10(4), and 10(5) cfu/mL) in brain heart infusion broth during storage at 35 degrees C for up to 43 days was evaluated. The SEC production was significantly (p < 0.05) inhibited and the hemolysis due to alpha-toxin was significantly (p < 0.05) reduced by EO concentration at levels 0.015% and 0.005%, respectively. Significant (p < 0.05) inhibitory effect of EO on SEC production at level 0.005% was observed when it was used in combination with nisin = 0.125 microL/mL. The significant (p < 0.05) synergistic effect of EO = 0.005% and nisin = 0.125 microL/mL was also observed as more reduction of hemolysis due to alpha-toxin than EO = 0.005% alone. Further, EO significantly (p < 0.05) prevented SEC production by S. aureus during the manufacturing process of a traditional Iranian white brined cheese (as a food model) even at its lowest concentration (5 microL/100 mL), in this study.