Effect of Zataria multiflora Boiss Essential Oil and Grape Seed Extract on the Shelf Life of Raw Buffalo Patty and Fate of Inoculated Listeria monocytogenes

The present study was conducted to investigate the effect of Zataria multiflora Boiss essential oil (ZEO) and grape seed extract (GSE) on microbial and chemical changes in raw buffalo patty at a temperature of 8C. First, chemical composition and minimum inhibitory concentration of oil against Listeria monocytogenes were identified. Then, ZEO and GSE were added in raw buffalo patties and analyzed for spoilage microorganism count, lipid oxidation, pH, sensory attributes and inoculated L.monocytogenes survival at 8C for 9 days. Results revealed that samples containing 0.1 ZEO+0.2 GSE showed significant decrease in the growth of all tested microbial groups as well as the most decrease in the level of lipid oxidation at the end of storage period. Control and samples with 0.1 ZEO were the most preferred samples by sensory panelist, indicating that ZEO and GSE can be practically applied in food systems especially in meat in order to extend the shelf life. Practical Applications: Buffalo meat is highly prone to microbial and chemical spoilage as they are rich in essential nutrients and putrefying in nature. The adverse effects of various chemical preservatives caused to attract the consumer's attention to natural alternatives. Therefore, in order to increase the shelf life and quality characteristics of meat, new processing technologies and new ingredient systems that are associated with natural and organic foods are applied. These results demonstrate the potential combined use of grape seed extract and Zataria multiflora Boiss essential oil to the meat industry in the development of novel healthy meat products with improved shelf life and superior product quality. © 2015 Wiley Periodicals, Inc

Guaranteed optimal reachability control of reaction-diffusion equations using one-sided Lipschitz constants and model reduction

We show that, for any spatially discretized system of reaction-diffusion, the approximate solution given by the explicit Euler time-discretization scheme converges to the exact time-continuous solution, provided that diffusion coefficient be sufficiently large. By "sufficiently large", we mean that the diffusion coefficient value makes the one-sided Lipschitz constant of the reaction-diffusion system negative. We apply this result to solve a finite horizon control problem for a 1D reaction-diffusion example. We also explain how to perform model reduction in order to improve the efficiency of the method

Simulation-based reachability analysis for nonlinear systems using componentwise contraction properties

A shortcoming of existing reachability approaches for nonlinear systems is the poor scalability with the number of continuous state variables. To mitigate this problem we present a simulation-based approach where we first sample a number of trajectories of the system and next establish bounds on the convergence or divergence between the samples and neighboring trajectories. We compute these bounds using contraction theory and reduce the conservatism by partitioning the state vector into several components and analyzing contraction properties separately in each direction. Among other benefits this allows us to analyze the effect of constant but uncertain parameters by treating them as state variables and partitioning them into a separate direction. We next present a numerical procedure to search for weighted norms that yield a prescribed contraction rate, which can be incorporated in the reachability algorithm to adjust the weights to minimize the growth of the reachable set

Probiotic white cheese production using coculture with Lactobacillus species isolated from traditional cheeses

Aim: The aim of the present study was to investigate the viability of lactic acid bacteria isolated from traditional cheeses and cocultured in Iranian white cheese during ripening. Materials and Methods: A total of 24 samples were isolated from 8 types of traditional cheeses in West Azerbaijan, Iran. Isolated species were cocultured with starter bacteria during the production of Iranian white cheese, and their viability was investigated up to 60 days of the refrigerated storage. Results: Of 118 isolates of Lactobacillus, 73 isolates (62%) were confirmed as facultative heterofermentative and 45 isolates (38%) as obligate homofermentative. Of the facultative heterofermentatives, 28 isolates (24%) were Lactobacillus plantarum, 24 isolates (20%) were Lactobacillus casei, and 21 isolates (18%) were Lactobacillus agilis. Obligate homofermentatives were Lactobacillus delbrueckii (21%), Lactobacillus helveticus (14%), and Lactobacillus salivarius (3%). L. plantarum, L. casei and L. helveticus were found in high enough levels (106 CFU/g). Conclusion: According to the obtained data, it is recommended that complex starters such as L. helveticus, L. plantarum, and L. casei can be used in industrial productions of cheese to obtain exclusive properties of traditional cheeses

Effect of cinnamon essential oil and grape seed extract as functional-natural additives in the production of cooked sausage-impact on microbiological, physicochemical, lipid oxidation and sensory aspects, and fate of inoculated Clostridium perfringens

The present study was conducted to extend the shelf life of Lyoner-type sausages during 40 days of storage at 4 °C 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 ΔE (.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%+ 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. © 2018 Wiley Periodicals, Inc

Application of Honey to Reduce Oxidation in Soybean Oil

Background: The oxidation of unsaturated lipids by free radicals is one of the main causes of food deterioration. The major purpose of the present study was to determine effectiveness of application of honey in order to reduce oxidation in soybean oil. Methods: Six groups were designed, including control (soybean oil emulsion without preservative), positive control (butylated hydroxyl toluene 200 ppm), and soybean oil treatment groups (containing 1, 2.5, 5, and 7.5% honey). Each group was sampled in order to measure peroxide value, thiobarbituric acid-reactive substances and total antioxidant&nbsp;capacity&nbsp; parameters during 5 intervals (0, 1, 3, 5, and 7 days). Data were analyzed by ANOVA using SPSS statistical software. Results: Total phenolic content and radical scavenging activity (IC50 in mg/ml) were&nbsp;estimated to be 74.8&plusmn;0.3 mg gallic acid equivalents/100 g and 23.4&plusmn;0.2 mg/ml, respectively. Totally, the soybean oil samples treated by 2.5 and 5% honey showed higher (p<0.05) antioxidant capacity than control and other treatment groups. Conclusion: The present study demonstrated considerable antioxidant potency of honey in oil emulsion. Owing to economical reasons, it is recommended that 2.5% honey could be applied as an alternative for synthetic antioxidants in oil-rich foods

Effect of different types of active biodegradable films containing lactoperoxidase system or sage essential oil on the shelf life of fish burger during refrigerated storage

The present study aimed to control the spoilage of fish burger of common carp meat kept at refrigerated temperature (4 ± 2 °C) during 20 days storage using active biodegradable films containing lactoperoxidase system (LPS) or sage essential oil (SEO). Fish burgers were prepared from minced common carp meat and were wrapped in chitosan (CH), alginate (AL) and gelatin (ZH) films containing SEO or LPS. Different groups were kept in the refrigerated temperature and samples taken at day 0, 5, 10, 15 and 20 of storage time for determination of Total Viable Count (TVC), psychrotrophic bacterial count (PTC), Pseudomonas spp. (PSC) and Shewanella spp (ShC). Also, TBARS, pH and sensory properties of the groups were checked during refrigeration. Chitosan films containing LPS were the most effective package to significantly suppress the increase of TVC, PTC, Pseudomonas spp. and Shewanella spp and TBARS during 20-day storage at refrigerated condition compared with other treatments (P<0.05). Moreover, the alginate and chitosan films containing LPS and SEO had the higher ultimate pH (P<0.05). The results of this study indicated that the chitosan film containing LPS extend the shelf life of fish burgers in comparison by other treatments and control for 5 days. © 2019 Elsevier Lt

Antibacterial activity and sensory properties of Heracleum persicum essential oil, nisin, and Lactobacillus acidophilus against Listeria monocytogenes in cheese

Aim: The aim of this study was to evaluate the antibacterial and chemical effect of Heracleum persicum essential oil (EO), nisin, Lactobacillus acidophilus, and their combination against Listeria monocytogenes both in vitro and in Iranian white cheese model. Materials and Methods: Chemical compositions of H. persicum EO were analyzed by gas chromatography-mass spectrometry. After production of Iranian white cheese, minimum inhibitory concentration (MIC) and minimum bactericidal concentration of EO and nisin and agar spot test of L. acidophilus against L. monocytogenes were evaluated. Results: Hexyl butanoate (25.98%), octyl isobutyrate (17.82%), methyl butyrate (14.37%), and pentyl cyclopropane (12.77%) were the main components of the EO. MIC of the EO against L. monocytogenes was 2.5 mg/mL. Combination of nisin (5.3 IU/mL) and H. persicum EO (2500 μg/mL) showed increasing effect against L. monocytogenes (fractional inhibitory concentration = 0.9), while a higher concentration of EO and nisin showed undesirable effect on the cheese flavor. Furthermore, a combination of 1012 CFU/g L. acidophilus with H. persicum EO at the concentration of 2.5 mg/mL (T12) showed acceptable sensorial and also antibacterial results in Iranian white cheese. Conclusion: Combination of H. persicum EO, L. acidophilus, and nisin can be recommended as natural preservatives and flavoring agents in cheese

Health Risk Assessment for Human Exposure to Trace Metals and Arsenic via Consumption of Hen Egg Collected from Largest Poultry Industry in Iran

The relative contribution of foodstuffs to intake of heavy metal is still equivocal, and thus, available data are rare. Here, the concentration of ten heavy metals and arsenic were measured in the content of hen egg from five strains of commercial laying hens to evaluate contamination level and potential health risk among local and international consumers in Iran. The estimated daily intake (EDI) of all heavy metals was significantly lower than the provisional tolerable daily intake (PTDI) and respective tolerable daily intake (TDI). The non-carcinogenic and carcinogenic risk values for eating eggs were in the safe range for all consumers, indicating that the no health risk for consumers due to the daily intake of either arsenic or heavy metals. Therefore, intake of heavy metal exposure through the consumption of commercial egg product in Iran is completely safe for both national and international consumers. © 2018, Springer Science+Business Media, LLC, part of Springer Nature

Sintering behavior of an ultrafine alumina powder shaped by pressure filtration and dry pressing

Master sintering curve (MSC) was used as a practical approach to analyse the sintering behavior of an ultrafine alumina powder. Non-isothermal sintering was carried out at three heating rates. The concept of the MSC has been used to investigate the effect of different shaping methods, i.e. dry pressing (DP) and pressure filtration (PF) on the apparent activation energy for sintering. Although no change in the dominant densification mechanism is expected, the interplay between different diffusion mechanisms taking place during the heating ramp may be affected by the shaping method. Values of 605 +/- 15 and 700 +/- 20 kJ/mol were determined for PF and DP samples, respectively. The lower activation energy for PF samples may be explained by the higher green density and homogeneity, smaller pore size in comparison with the DP samples. Furthermore, the mechanical properties (hardness and fracture toughness) of the samples are presented. (C) 2010 Elsevier B.V. All rights reserved