The production methods of selenium nanoparticles

In recent years, the application of selenium nanoparticles has been increasing in medicine, agriculture, engineering, and food science. Therefore, researchers are converting inorganic selenium sources into nano form by various methods. Particularly both probiotics and pathogenic bacterial strains have the ability to synthesize selenium nanoparticles under aerobic and anaerobic conditions. Amazingly, dose-dependent selenium nanoparticles have antibacterial activity against their own pathogenic producer, even when added externally. Also, plant extracts and conventional chemical reducing agents continue to make a significant contribution to the production of selenium nanoparticles in an economic, eco-friendly, simple, and rapid way. Biological and chemical methods are suitable for the biological applications of selenium nanoparticles such as functional food or nutritional supplements and nanomedicine.

Physiological benefits of a honeydew-based functional food fortified with selected bioactive agents justified by trials

Honey is a consumer-preferred, highly esteemed natural product with a broad variety of distinct bioactive components. In recent days, the consumption of high-added-value, honey-based products are increasingly coming to the forefront of interest, and thus huge efforts are being made by researchers/developers to elaborate honey variants with fortified biological value. Relevant human clinical trials have scarcely been accomplished; thus, the biological impact of honey and its derivatives has not been thoroughly revealed. In this work, we present our experiments on the development of a novel honey-based prototype and its plausible physiological impacts certified via human clinical trials. The investigated product was a newly elaborated honeydew-based prototype fortified with pumpkin, sea buckthorn, and inulin, which was subjected to a 13-week-long, double-blind, placebo-controlled human clinical trial. The prototypes were applied to 20 adult volunteers to establish the complex impact of the newly developed product. Conclusions drawn at the end of the trial were based on results of blood tests taken at diverse phases of the study. The positive physiological effects of consumption of the investigated products are underpinned by the fact that no significant elevations have been measured in terms of the blood glucose level and parameters featuring long-term blood sugar levels. Slight decrease of both LDL and HDL cholesterol levels were also experienced.

Nutritional status and dietary behaviours of Northern Algeria university students

The present study tries to assess the nutritional status and dietary behaviours in a group of undergraduate students in order to characterize their food habits and assess the quality of their diet. A cross-sectional study was conducted with 220 undergraduate university students (110 male and 110 female) aged between 19 and 24 years from the Food Department of Saad Dahlab Blida 1 University (Algeria). The data collection and nutritional evaluation were carried out using DIAL nutritional software. Male participants had significantly (P < 0.005) higher body mass index (BMI) when compared to females. Significantly higher percentages of female students (P < 0.005) had tried a low-fat diet (P = 0.0075) and a low-carbohydrate diet (P < 0.005). The prevalence of overweight was higher among males compared to females. In contrast, a greater percentage of underweight students were observed in the group of female subjects. Related to micronutrient intake, a significant difference by sex was observed for vitamin A, C, folic acid, iron, calcium, and sodium intakes. However, females consumed more food containing vitamins C and A, whereas males’ intake of calcium, sodium, folic acid, and iron was higher than the corresponding values observed in females. To conclude, these students reported a diet characterized by a high variety of cereal products and a moderate amount of vegetables, milk and dairy products, meat, fish and eggs, dietary fats and beverages, whereas the consumption of fruits was highly infrequent.

Influence of milk used for cheese making on microbiological aspects of Camembert-type cheese

Camembert-type cheeses are surface mould-ripened soft cheeses obtained with Penicillium camemberti. Soft cheeses are more frequently associa ted with foodborne disease outbreaks than hard and semi-hard cheeses. During our work, three Camembert-type cheeses were prepared on a pilot/small industrial scale. The first cheese was made from bulk milk and pasteurized at 74 °C for 15 seconds. The second and third cheese were prepared from one type of milk and were heat-treated at 72 °C for 60 seconds. The microbial contamination with Salmonella spp. and Staphylococcus aureus of the three Camembert-type cheeses was evaluated. The food-related stress survival of Salmonella spp. and S. aureus isolates originated from the cheese samples was assayed. The antibiotic suscep tibility of the bacterial isolates was determined by the disk diffusion method, using 12 and 16 different antibiotics respectively. Based on the results, the first cheese sample contained the highest number of Salmonella bacteria; S. aureus was detected only in the first sample. According to the results of antibiotic susceptibility of the Salmonella, isolates showed susceptibility to the majority of assayed antibiotics and resistance to trimethoprim, chloramphenicol, amikacin, and cefotaxime. The S. aureus isolates showed resistance to trimethoprim and displayed intermediate resistance to levofloxacin and ciprofloxacin.

The comparative analysis of some Hungarian and Moldovan wines: The promise of protected geographical indication

Hungary and Moldova are excelling in unique wines and alcoholic beverages that could qualify for the protected geographical indication (PGI) by emphasizing parameters attributable to the geographical area, production or processing methods. In this study, we have assessed some parameters of wine and brandy samples looking for specificities. The studied samples were of Moldovan and Hungarian Cabernet Sauvignon red wines, Hungarian Furmint white wines, and Moldovan wine distillate/brandy called Divin. The assessed samples were evaluated for: total polyphenol and flavonoid, ethanol, malic, citric, lactic, tartaric acids, reducing sugar, glycerol, carbon dioxide, total and free SO2 content as well as for total acidity, volatile acidity, pH, and wine density. Our results indicate that despite the relatively close geographical vicinity of Hungary and Moldova, the wines produced in the two countries have specific composition, antioxidant activity, and sensorial properties. Thus, the registration of such wines as PGI is clearly justified, and such a label itself does represent a competitive advantage worth promoting.

Antioxidant capacity of blackcurrant (Ribes nigrum L.) leaves and buds

The antioxidant capacity is the combined free radical scavenging effect of all antioxidant compounds found in the studied system. There is a growing need for accurate, numerical determination of this capacity (for easier comparison), so there are many analytical procedures, methods, and measurement systems available to researchers. Neither one is able to model the totality of real, naturally occurring reactions; therefore, conclusions about the antioxidant power of the studied sample can be drawn only after using several methods. In this work, the total phenolic content (TPC) of blackcurrant leaves and buds was determined, and the antioxidant capacity was tested using the DPPH and FRAP assays. 80% methanol was the most effective in the extraction of phenolics followed by 80% ethanol, while for the antioxidant capacity the acetone (50%)/water/acetic acid (2%) mixture proved to be the best. Significant differences were observed between cultivars and sampling dates, but the pattern of variation during the harvest period was similar for all cultivars.

The role of r esistant starch in human nutrition

In this paper, we examine the role and effect of resistant starch (RS) in human nutrition; further, the structure and properties of RS, the food sources based on resistance to digestion in the colon, and the physiological effects of RS are described. The nutritional value of RS, the effect of RS on short-chain fatty acid (SCFA) production, the relationships between RS and colon function, and the relationships between food starch, dietary fibre, and RS content and colon cancer development are reviewed. It has been shown that the use of RS in foods may have some benefits. Resistant starch, digestion of resistant-starch-containing foods have a number of health benefits for colon function but appear to have less effect on lipid-glucose metabolism. It has a positive effect on colon bacterial activity, promotes the growth of beneficial microbes, and reduces the activity of enzymes that are harmful to the digestive system. Under the influence of RS, increased SCFA production lowers the pH of the colon and stimulates bile acid secretion. The decreased pH protects against colon cancer and inhibits the conversion of primary and secondary bile acids, which are cytotoxic to intestinal cells. At the end of the review article, the relationships between RS and the colon microflora, its use as a prebiotic, and the relationship between RS and glucose metabolism are analysed. It was found that the use of RS in the diet might have benefits as it shortens the time it takes food to pass through the colon and increases the amount of stool. It was also found that the physicochemical properties of foods can directly affect the amount of RS and thereby the blood glucose levels and insulin response.

Some aspects of plate number estimation of plate heat exchangers (PHEs). A case study

For the proper estimation of the plate number (N) of a plate heat exchanger (PHE) – in addition to the flow rates and thermophysical properties of fluids –, an appropriate correlation is needed for convective heat transfer coefficient (α) calculation. When one does not have a criterial equation for the corresponding plate shape, we propose a selecting method for α. With the suggested relationships from literature, we calculate the plate number of a geometrically known, similar heat duty PHE and choose those relationships that give the same plate number with the known heat exchanger. In our case study, the plate number determined by any of the screened equations for whole milk preheating has almost the same value (n = 10 ± 1) regardless of the method used to solve the PHE model (plate efficiency and Nconverg or Kconverg convergence methods). For liquids’ thermophysical property estimation, we recommend averaging the values given by equations from literature, followed by equation fitting.

Functional and pasting characteristics of pupuru and pupuru analogues from cassava (Manihot esculenta) and breadfruit (Artocarpus altilis) blends

Pupuru and pupuru analogues are fermented, smoked food products usually produced from cassava or cassava substituted with a varying ratio of breadfruit. This study aims at determining and comparing the functional and pasting characteristics of pupuru and pupuru analogues with a view to expanding the utilization of breadfruit as pupuru analogue. The functional properties (water absorption capacity (%), swelling power (g/g), solubility (%)) and pasting characteristics were determined using standard methods. The results showed that the yield of the products ranged between 24.66 and 29.65%, and it was not affected by the amount of breadfruit substituted. The water absorption capacities of the pupuru and pupuru analogues ranged between 216.0 and 449.0%; this parameter increased with temperature increase. Both swelling power and solubility had a rapid increase from 80 °C to 90 °C. Pasting temperature ranged between 73.15 and 83.66 °C, with peak time between 4.58 and 5.33 min. The final viscosity ranged between 94.08 and 391.83 RVU, and it decreased with increase in breadfruit substitution. The study concluded that adding breadfruit to cassava in pupuru analogue production improved some of the functional and pasting properties of the product.

Antibacterial activity of plant extracts against Listeria monocytogenes isolated from ready-to-eat salads

Ready-to-eat salads are becoming more and more popular. However, due to their ingredients, they represent a suitable growth environment for different microbes. In the prevention of foodborne diseases, hygienic food preparation and appropriate storage conditions are very important. During this study, ten different ready-to-eat salads were analysed for the presence of Listeria monocytogenes. Five different selective agar mediums were used for the enumeration and isolation of Listeria monocytogenes. The isolated bacterial strains were subjected to morphological and biochemical confirmation tests. The antibacterial effects of five different freshly squeezed vegetable juices (carrots, celery, beets, horseradish, and onions) and of five essential oils (dill, thyme, oregano, lemongrass, and sage) were determined against Listeria monocytogenes, Listeria innocua, and L. monocytogenes strains isolated from ready-to-eat salads. Based on the results obtained from fresh vegetable juices, carrot juice exerted the highest antibacterial effect, while the others showed no or slight inhibitory effect (horseradish, beets, onions) against Listeria species. Among the essential oils, thyme, lemongrass, and oregano showed the strongest antibacterial effect against the studied Listeria species.