Volume 13 (2020): Issue 1 (October 2020)

Carrot (Daucus carota L.) is one of the main root vegetables rich in bioactive compounds with appreciable health-promoting properties, largely consumed in Algeria. In the current study, the storage effect (at 4 °C throughout 12 days) on bioactive compound stability and the antioxidant activity of two Algerian orange carrot varieties (Supermuscade and Touchon) were investigated. Total phenolic content of samples was determined by the Folin–Ciocâlteu method. Antioxidant capacity was determined spectrophotometrically, based on the evaluation of Free Radical Scavenging Activity (FRSA) using DPPH radical and Ferric Reducing Power (FRP). The results showed that the Touchon variety is richer in phenolics, flavonoids, and carotenoids and presents higher antioxidant activity in comparison with the Supermuscade variety. At the end of storage, the bioactive compound content and antiradical activity increased significantly (p < 0.05). Also, an extremely significant correlation (p < 0.001) was observed between the antioxidant contents and the antioxidant capacities of aqueous carrot extracts.

The physico-chemical and sensory qualities of pupuru analogues produced from co-fermented cassava and breadfruit blends were investigated. Cassava and breadfruit were processed separately and cofermented at different proportions to produce pupuru and pupuru analogues. Seven different samples were produced with the ratios of 100:0, 90:10, 80:20, 50:50, 20:80, 10:90, and 0:100 cassava:breadfruit respectively. The proximate composition, bulk density, hydrogen cyanide, pH, TTA, and sensory properties of the sample were determined using standard methods. The results showed that the protein (2.86–6.41%), fat (0.43–2.05%), ash (0.36–1.17%), crude fibre (0.68–2.83%), and energy values (393.84 to 399.38 kcal/100 g) increased together with breadfruit substitution. The bulk density, pH, total titratable acidity, and hydrogen cyanide content of the sample was in the ranges of 0.47–0.60 g/ml, 4.30–5.30, 0.18–0.31%, and 0.56–1.68 mg/100 g respectively. The pupuru analogues had lower hydrogen cyanide content than pupuru. The pupuru analogues up to 50% breadfruit substitutions had acceptable sensory attributes, comparable to pupuru. The study concluded that pupuru analogues of acceptable quality can be produced from co-fermented cassava and breadfruit; this entails increasing the utilization of breadfruit.

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.

Pyrolysis technology facilitates the heating of organic waste biomass in a very low oxygen environment to temperatures over 400 °C. The high carbon content and surface area of the char produced via slow pyrolysis makes it suitable for a range of purposes that would sequester the carbon it contains. For example, there is a growing interest in its use as a soil amendment, which enhances plant growth and nutrient use efficiency.

Romania has many mineral water sources due to its geological features. In the present study, bottles of 26 Romanian mineral water brands were purchased from the market to make a characterization based on the pH, conductivity, and fixed residue content. Focusing on the total fixed residue, the distribution of low, medium, and highly mineralized water was 43.9%, 41.46%, and 14.63% respectively. The mean of fixed residue concentration was 763.3 mg/L, ranging from 40.37 mg/L to 2,603 mg/L. The pH values of the still mineral waters varied between 6.86 and 7.91, while the pH values of the sparkling mineral waters were the lowest (4.7). The conductivity was strongly related to the concentration of the ions, so the maximum measured conductivity for the still waters was 573 μS/cm, for the partially sparkling waters 2,133 μS/cm, and for the sparkling mineral waters 3,079 μS/cm. The chemical composition of the mineral waters was highly dependent on the rock types. Using the hierarchical cluster analysis, two different clusters were detected according to the main characteristics of mineral waters.

Aflatoxins are fungal toxins produced by Aspergillus species, which, due to increasing temperature and climate change in the temperate zone, appeared in the most important feeding plant and food ingredients. The most toxic of them is aflatoxin B1 (AFB1), which hydroxylates to aflatoxin M1 in the body of dairy animals and humans, and excretes in the milk. With the development of analytical methods, researchers are now able to detect toxins with a concentration of ng/kg. It was found that in most countries in Europe both breast milk and cow’s milk may contain AFM1, and therefore increased attention should be paid to the toxin content of milk, and that those above the limit should be excluded from consumption. In addition to cow’s milk, the AFM1 toxin content of breast milk can also be significant, the precursors of which are introduced into the mother’s body with food. Aflatoxins are highly resistant to physical, chemical, and microbiological effects, so the detoxification of foods, especially milk, is almost impossible. The best solution appears to be feeding the animals with toxin-free feeds or feeds containing toxins below the permitted limit, without giving opportunity to the toxins to enter the milk from the feed and from there into the human body.

Acidification in lactic-fermented foods is realized by lactic acid bacteria as an added starter culture or by autochthonous strains. These microbial strains possess different prominent features that define the technological, organoleptic, nutritional, and microbial safety aspects of the product. The bioprotective effect of the bacterial strains may be related to antagonistic properties against food spoilage and/or pathogenic strains. The aim of the present study is to determine the antimicrobial properties of three different food-grade lactic acid bacteria in order to use them as bioprotective cultures. Our findings show that the Lactobacillus pentosus, Enterococcus faecalis, and Pediococcus parvulus exerted a bacteriostatic effect on Escherichia coli and Bacillus cereus, whereas the Saccharomyces cerevisiae growth was not inhibited, which made them susceptible agent for co-culture systems.

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.