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Volume 13, Issue 2, 2024
Online ISSN: 2182-1054
Volume 13 , Issue 2, (2024)
Published: 18.10.2024.
Open Access
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Contents
18.10.2021.
Original scientific paper
Tetracycline resistance in enterococci and Escherichia coli isolated from fresh produce and why it matters
The contamination of fresh produce with antibiotic-resistant bacteria is of particular concern as they are often eaten raw and can be a source for foodborne diseases. Tetracyclines have been largely used in humans, animals and plants which might have accelerated microbial resistance to them. Enterococci and Escherichia coli can be used as indicators to monitor contamination of the fresh produce with tetracycline-resistant bacteria. The investigation related to this issue is very scarce in Oman. This study aimed at identifying tetracycline-resistant enterococci and E. coli in fresh produce at the market place. Thirty-one enterococci and ten E. coli were isolated from local (Oman) and imported fruits and vegetables (N= 105). Using the standard Kirby-Bauer disc diffusion method, resistance to tetracycline was found in 6 (19 %) enterococci, isolated from cucumber, lettuce and radish, and 5 (50 %) E. coli, obtained from cabbage, lettuce and radish. Genetic analysis revealed the presence of tetracycline resistance genes, tet(A) and tet(K), in E. coli and tet(K), tet(L) and tet(M) in enterococci, including Enterococcus sulfureus, Enterococcus mundtii, Enterococcus casseli avus and Enterococcus faecalis. The integron integrase IntI 1 gene, which is known to facilitate the dissemination of antibiotic resistance genes among bacteria, was detected in 2 isolates of E. coli. These results demonstrated the capability of fresh produce to act as a potential source for disseminating tetracycline or possibly other antibiotic-resistant bacteria through the food chain. Thus, control strategies are needed to reduce exposure of the public to such microorganisms.
Zahra Al-Kharousi, Nejib Guizani, Abdullah M. Al-Sadi, Ismail M. Al-Bulushi
18.05.2021.
Original scientific paper
Influence of Raw Meat Content on 3D-Printing and Rheological Properties
The aim of this study was to investigate the influence of raw chicken meat content on the rheological properties and 3D printability of minced meat mixtures using different concentrations of raw and cooked chicken meat. The meat mass contained yolk, crushed ice, lean raw meat and cooked meat with a high concentration of connective tissue. The concentrations of raw meat added to cooked meat as a percentage of the total weight of meat were 0; 30; 40; 50; 60; 70 and 100. To determine the rheological properties, amplitude sweep and frequency sweep were carried out with a Rheostress RS 300 (Thermo Fisher Scientific Inc.). Cubes were printed, and the printability and optical impression were evaluated using grades from 1-5. The results showed that rheological properties had a strong influence on the printability of meat mass and it is necessary for G' (storage modulus) at the LVR (linear viscoelastic region) to be higher than 7000 Pa. The complex viscosity |η*| should be higher than 170 Pa, at a shear stress τ = 10 Pa, and a frequency f = 10 Hz used to guarantee sufficient solidity.
Marius Herold, Sören Morick, Oliver Hensel, Uwe Grupa
18.10.2021.
Original scientific paper
Response surface analysis and process optimization of non-cereal (elephant foot yam, taro and water chestnut) snacks
The present study was conducted to develop non-cereal starch extruded products. The effects of feed moisture (15-21%), temperature (130-170 °C) and screw speed (120-160 rpm) were evaluated on the physical and functional properties of extruded snacks using response surface methodology. Feed moisture and screw speed increased the bulk density and hardness of extruded snacks. Significant decreases in water absorption index and increases in water solubility index were observed with increases in extrusion temperature. The best conditions were determined by numerical optimization. The optimized value for non-cereal snacks for feed moisture is 18.22%, temperature 155.96 °C, screw speed 142.75 rpm and, desirability is 0.75. Verification of results showed decent agreement between the responses of experimental values at certain optimum conditions and the predicted values.
Anuj Saklani, Ravinder Kaushik, Krishan Kumar
18.04.2021.
Original scientific paper
Reduced Meat Consumption: from Multicriteria Argument Modelling to Agent-Based Social Simulation
A second nutrition transition seems to be emerging towards more plant-based diets, curbing meat consumption in developed countries at the beginning of the 21st century. This shift suggests that rational arguments tend to influence an increasing number of individuals to adopt vegetarian diets. This work aimed to understand and simulate the impact of different types of messages on the choice to change food diets at the individual level, and the impact of the diffusion of opinions at the collective level. It provided two results: (1) a network of arguments around vegetarian diets is modelled using an abstract argumentation approach. Each argument, formalized by a node, was connected with other arguments by arrows, thus formalizing relationships between arguments. This methodology made it possible to formalize an argument network about vegetarian diets and to identify the importance of health arguments compared to ethical or other types of arguments. This methodology also identified key arguments as a result of their high centrality in being challenged or challenging other arguments. The results of constructing this argument network suggested that any controversy surrounding vegetarian diets will be polarized around such high centrality arguments about health. Even though few ethical arguments appeared in our network, the health arguments concerning the necessity or not of animal products for humans were indirectly connected with ethical choices towards vegetarian diets; (2) an agent-based simulation of the social diffusion of opinions and practices concerning meat consumption is then introduced. The purpose of this simulation was to capture the balance of vegetarian vs. meat-based diets. It contributes to modelling consumer choices by exploring the balance between individual values and external influences such as social pressure, communication campaigns and sanitary, environmental or ethical crises.
Rallou Thomopoulos, Nicolas Salliou, Carolina Abreu, Vincent Cohen, Timothée Fouqueray
18.10.2021.
Original scientific paper
Effects of addition of swine skin on the technological characteristics of mortadella produced in an industrial unit
The aim of this work was to evaluate the effects of the addition of swine skin on the technological characteristics of mortadella formulations produced on industrial scale. The effects of concentrations of swine skin (1.5 to 5.5 %) and sodium chloride (2 to 3 %) on total protein, total fat, starch, moisture, water activity, sodium, pH and texture profile (hardness, adhesiveness, elasticity, cohesiveness and chewiness) were evaluated and compared to a mortadella formulation without swine skin addition. The mortadella formulations with addition of 3.5 to 5.5 % swine skin and 2 to 2.5 % sodium chloride are in accordance with Brazilian legislation and provided an increase of approximately 12 % in protein content, a decrease of 14 % in sodium content and a water activity less than 0.9488. The swine skin and sodium chloride provided stability to the mortadella and influenced its texture, mainly in hardness, elasticity and chewiness.
Karem Muraro, Jamile Zeni, Rogério Luis Cansian, Juliana Steffens, Eunice Valduga, Geciane Toniazzo Backes
18.05.2021.
Original scientific paper
Production and characterization of emulsified fish mortadella from Nile tilapia (Oreochromus niloticus)
This study produced fish mortadella from Mechanically Separated Meat (MSM) of Nile tilapia added with animal fat. Three formulations were developed: M1 (MSM - 89 % and 5 % pork fat), M2 (MSM - 84 % and 10 % pork fat) and M3 (MSM - 79 % and 15 % pork fat). The elaborated products were tested for technological, physical, physico-chemical, microbiological and sensory parameters. The results showed that the fish mortadella were microbiologically stable with a particular texture for an emulsified meat product, attractive colour and characteristic flavour. All formulations met the expected identity and quality requirements. They also achieved good acceptance by the judges, in which formulation M1 may be highlighted for presenting an emulsion stability of 97 %, higher protein content (18.09 %) and lower lipids (16.31 %). In addition, it also reached higher mean scores for texture attributes and purchase intent. Therefore, it is possible to prepare fish mortadellas from tilapia MSM using less animal fat.
Heloísa Maria Ângelo Jerônimo, Maria Elieidy Gomes de Oliveira, Carlos Eduardo Vasconcelos de Oliveira, Natália Ferrão Castelo Branco Melo, Alex Poeta Casali, Antônio Rosendo da Costa, Aryane Ribeiro da Silva, Ricácia de Sousa Silva, Tânia Stamford
18.10.2020.
Original scientific paper
Quality of postharvest strawberries: comparative effect of fungal chitosan gel, nanoparticles and gel enriched with edible nanoparticles coatings
This study compared, for the first time, the postharvest conservative action of edible fungal chitosan coatings (gel, nanoparticles and gel-nanoparticle) on the physico-chemical, sensorial and microbiological characteristics of strawberries. The nanoparticles were prepared by an ionic gelation method and characterized by dynamic light scattering and scanning electron microscopy. The antioxidant (DPPH* and ABTS*) activity of the edible coatings and the antimicrobial (macrodilution method) action against phytopathogenic fungi were verified. The nanoparticles had a size of 331.1 nm and a zeta potential of+ 34 mV. The gel, nanoparticles and gel+nanoparticles exhibited minimum inhibitory concentration values ranging from 4 to 5, 1.5 to 2.5 and 1.0 + 0.5 to 2.0 + 1.5 g.L-1, respectively. All the edible coatings exhibited antifungal action. All the coatings had high scavenging activity, especially the gel edible coating. The coatings, especially the gel+nanoparticles, decreased the weight loss, microbiological growth, soluble solids, maturity index and moisture loss of the strawberry and preserved the pH values, anthocyanin content, titratable acidity and sensory characteristics. Therefore, the use of chitosan edible coating containing nanoparticles can be a promising strategy to improve the post-harvest quality of strawberries.
Natália Melo, Maria Manuela Estevez Pintado, José Alberto da Costa Medeiros, André Galembeck, Margarida Angélica da Silva Vasconcelos, Viviane Lansky Xavier, Marcos Antônio Barbosa de Lima, Tânia Lucia Montenegro Stamford, Thatiana Montenegro Stamford–Arnaud, Miguel Angel Pelágio Flores, Thayza Christina Montenegro Stamford
18.10.2020.
Original scientific paper
Estimation of the dietary exposure of polycyclic aromatic hydrocarbons in Syria and their health risks assessment
In this work, the exposure of people, through their diet, to polycyclic aromatic hydrocarbons (PAHs) has been assessed for the urban, rural, and general populations in Syria. The food categories consumed have been divided into major groups, and the health risk assessment on dietary exposure of PAHs determined in each food category. For this purpose, two approaches were used: incremental lifetime cancer risk (ILCR) and margin of exposure approach (MOE). The results showed that each of the following food categories: oils and fats, meat and meat products, vegetables, and cereals dominantly contribute in the dietary exposure of PAHs. Also their MOE values are the lowest. Additionally, they have higher ILCR values. Therefore, these groups are a main risk source to health. On the other hand, the dietary exposure of PAHs in each of urban, rural and general populations was of low health concern, whereas their ILCR values reached to 10E-05 in total food categories, nevertheless it remains lower than serious risk level (ILCR>10E-04). This work is the first study that is dealing with dietary exposure of PAHs and their health risk assessment in Syria.
Hour KRAJIAN
18.10.2020.
Original scientific paper
Biodegradable film development by nisin Z addition into hydroxypropylmethylcellulose matrix for mozzarella cheese preservation
Currently, improvement of food preservation has been a substantial challenge for industries to increase shelf-life of products and to maintain food quality during storage. These goals are often tied to the sustainable tendency for use of eco-friendly packaging to store these products without loss of the packaging features. Therefore, the aim of this study was to produce biodegradable antimicrobial films by the incorporation of nisin Z peptide under different concentrations (0 %, 5 %, 10 %, 15 % and 20 % wt.) into hydroxypropylmethylcellulose (HPMC) matrices. The active film properties were evaluated in terms of their antimicrobial capacity in vitro, mechanical performance and microscopic characteristics. Hence, active films containing 10 % (wt.) of nisin Z and control films were placed in contact with sliced mozzarella cheese for eight days, and microbiological growth was monitored during storage. Nisin Z’s antimicrobial effects were observed against the Gram-positive microorganisms such as Staphylococcus aureus and Listeria innocua, regardless if the compound was free as a suspension or incorporated into HPMC matrices. However, the expected low action of nisin Z against Gram-negative bacteria, as reported in literature, was not observed since Salmonella enterica Choleraesuis’s growth was inhibited. Moreover, active films with added nisin Z (10 % wt.) were more effective than the control film to inhibit mesophilic microorganisms in mozzarella cheese during 8 days of storage. The mechanical properties of the films were not influenced by nisin Z incorporation, since the addition of the compound enhanced the active function without the loss of mechanical properties required for a good food packaging. These results suggest that biodegradable films produced by nisin Z addition into HPMC matrix are an excellent biomaterial for mozzarella cheese preservation.
Pedro Augusto de Freitas, Rafael R. A. Silva, Taíla V. de Oliveira, Raquel R. A. Soares, Nilda F. F. Soares
18.10.2020.
Original scientific paper
Research, development and capacity building for food and nutrition security in sub-Saharan Africa
This paper focuses on research, development, and capacity building in relation to food and nutrition security (FNS) in sub-Saharan Africa (SSA). It looks at human capacity, education, teaching and learning, women empowerment, research, innovation and technology, research, indigenous knowledge (IK), institutional aspects, infrastructure, information and communication technologies (ICT), policies and finance. Professional bodies exist in many countries and the extent to which they engage in FNS awareness creation differs. Food and nutrition insecurity continues to affect people in Africa’s 54 nations where the population is expected to double by 2050 with the expected doubling of food production to keep pace with population growth. Within the continent there is a substantial number of human capacity professionals who are global leaders in food, nutrition and related professions. Some research organisations in the continent directly or indirectly benefit from grants administered by developed economies but a challenge exists with brain drain and ageing of qualified and experienced experts. Increasing educational need, coupled with the growing population necessitates attention to ensuring a sustained supply of highly trained, adequately equipped and qualified professionals in the relevant fields of food and nutrition sciences. Higher educational institutions exist in especially those that fall within the 500 in world universities ranking. Research activities take place in the continent along with the translation of research outputs into commercialisable products. Research towards transforming agriculture for improved livelihoods is taking place in different parts of the continent. Education, governance, gender and rural development are the key challenges. Income growth and the impacts of climate change on food production have contributed to food insecurity. ICTs can play an important role for FNS. Strengthening research, development, capacity building and industry cooperation are critical for FNS in Africa.
Afam I. O. Jideani