Probabilistic health risk assessment of potentially toxic elements in the traditional and industrial olive products.

Iran is recognized as one of the top olive producers globally, and it forms an integral part of the countries agriculture, particularly in Zanjan province. This study measured Hg, As, Pb, Cd, and Zn concentrations and evaluated probabilistic health risk in olive products. Results showed that Zn had the highest concentration (traditional and industrial table olive, Parvardeh, and olive oil: 4.912 ± 3.957 and 9.181 ± 6.385; 16.139 ± 6.986 and 18.330 ± 8.700; 41.385 ± 7.480 and 46.043 ± 15.773 µg g-1, respectively) compared to other potentially toxic elements (PTEs). Additionally, Cd in table olive (traditional: 0.137 ± 199 and industrial: 0.059 ± 0.041 µg g-1) and Parvardeh (traditional: 0.014 ± 0.009 and industrial: 0.019 ± 0.006 µg g-1), and As in olive oil (traditional: 0.025 ± 0.006 and industrial: 0.026 ± 0.009 µg g-1) had the lowest concentrations, respectively. As and Hg in table olive (0.224 ± 0.214 and 1.158 ± 0.974 µg g-1) and Hg in Parvardeh (0.210 ± 0.213 µg g-1) samples were significantly higher in traditional than industrial products (p < 0.05). Cd in Parvardeh (0.019 ± 0.006 µg g-1) and Zn in table olive (9.181 ± 6.385 µg g-1) samples were substantially more in industrial than traditional products (p < 0.05). Results suggest that industrially processed olive products are more likely to introduce higher levels of PTEs into the body. Nevertheless, based on the health risk assessment criteria, industrial products' hazard index (HI) values were lower than traditional types due to high Hg concentrations (HI = 0.01227 and 0.2708, respectively). Adults' total carcinogenic risk (TCR) in traditional olive products was higher than in industrial (sum TCR = 0.00016 and 0.00007, respectively). In conclusion, the results indicated that the consumption of olive products in the study area offered an increased non-carcinogenic and cancer risk to the population of this region owing to PTEs exposure, especially Hg.

The effect of Arabic gum on frozen dough properties and the sensory assessments of the bread produced.

The use of hydrocolloids in frozen dough has become frequent as bread improvers due to their anti-staling effect. Nevertheless, the impact of both different frozen storage and Arabic gum level in non-prefermented flat dough with following thawing procedure have not been studied. This work intended to study the effect of three different ratio of Arabic gum on rheological properties of 1, 7, and 30 days of frozen storage and the quality of the bread made from. In order to gain the least detrimental effects on gluten network, we used rapid rate freezing and microwave heating in thawing stage. Rheological results showed that the unfrozen samples to which Arabic gum had been added rendered the highest resistance to extension. The resistance of gum fortified samples were less than fresh dough, however the decline was not significant in 3.0% Arabic gum dough kept in a month storage (p > .05). The similar findings were obtained for extensibility and adhesiveness; in which the maximum incorporation of Arabic gum lessen the destructive impact of long freezing storage. Addition of 3% gum could be able to retard staling through an increment in hydrophilic bonds between water molecules and amylose during thawing (p < .05). The overall rating of Arabic gum enriched samples was similar with bread made from non-frozen dough, even after 30 days of storage as indicated by the sensory evaluation of breads. PRACTICAL APPLICATIONS: Producing a chapatti-like fermented bread without long fermentation period. Formulation a frozen dough without using chemical additives. Introducing a proper use of a new defrosting method with the aim of achieving a better texture. Improvement in retarding staling by the use of Gum Arabic after 7 days.

Some biological activities of pigments extracted from Micrococcus roseus (PTCC 1411) and Rhodotorula glutinis (PTCC 5257).

The importance of replacing synthetic pigments with natural types is increasing day by day in the food industry due to the harmful effects of some synthetic pigments. Microorganisms are a major source of natural pigments, which nowadays have attracted the attention of researchers. In this study, carotenoid pigments were produced by Micrococcus roseus and Rhodotorula glutinis, and some of their biological properties such as antimicrobial, antioxidant, anticancer, and anti-inflammatory activities were evaluated. Given the results, bacteria, especially gram-positive bacteria, had higher sensitivity to the pigments extracted from M. roseus (PEM) and R. glutinis (PER) compared to molds so that Bacillus cereus and Alternaria citri had the highest and the lowest sensitivity, respectively. PER showed a higher antioxidant activity compared with PEM in the various methods of measuring antioxidant activity. In vitro and in vivo anti-tumor-promoting activities of PER were measured significantly more than PEM (P <0.05). Both pigment extracts remarkably inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation, so that ID50 (50% inhibitory dose) of PEM and PER were 0.22 and 0.09 mg/ear, respectively.

Generation of a Uracil Auxotroph Strain of the Probiotic Yeast Saccharomyces boulardii as a Host for the Recombinant Protein Production.

BACKGROUND: Saccharomyces boulardii (S. boulardii) is the best known probiotic yeast. The genetic engineering of this probiotic strain requires the availability of appropriate mutants to accept various gene constructs carrying different selection markers. As the auxotrophy selection markers are under focus, we have generated a ura3 auxotroph mutant of S. boulardii for use in further genetic manipulations. METHODS: Classical UV mutagenesis was used for the generation of auxotroph mutants. The mutants were selected in the presence of 5-FOA (5-Fluoroorotic acid), uracil and uridine. Uracil auxotrophy phenotype was confirmed by the ability of mutants to grow in the presence of uracil and the lack of growth in the absence of this compound. To test whether the uracil auxotrophy phenotype is due to the inactivation of URA3, the mutants were transformed with a plasmid carrying the gene. An in vitro assay was used for the analysis of acid and bile resistance capacity of these mutants. RESULTS: Three mutants were found to be ura3 auxotroph as they were able to grow only in the presence of uracil. When the URA3 gene was added, these mutants were able to grow normally in the absence of uracil. Further in vitro analysis showed that the acid and bile resistance capacity of one of these mutants is intact and similar to the wild type. CONCLUSION: A uracil auxotroph mutant of the probiotic yeast, S. boulardii, was generated and characterized. This auxotroph strain may have potential applications in the production and delivery of the recombinant pharmacuetics into the intestinal lumen.

Effect of Zataria multiflora Boiss. essential oil on colony morphology and ultrastructure of Aspergillus flavus.

The mode of inhibitory action of Zataria multiflora Boiss. essential oil (EO) on the fungus, Aspergillus flavus, was studied by colony morphology examination, light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The EO at concentrations used in this study suppressed the size of the colony as well as sporulation. SEM of mycelia treated with given concentrations of EO showed morphological alterations ranging from loss of turgidity and uniformity of mycelia at low concentrations of EO to evident destruction of the hyphae at higher concentration of EO. Semi-thin sections of mycelia exposed to different concentrations of EO were analysed by light microscopy and revealed that the major change at level as low as 50 ppm of EO was limited to vacuolisation of cytoplasm resulting in cell swelling, while at higher concentrations, detachment of the cell membrane from the cell wall, deformation of mycelia and shedding the cytoplasm from the cell were the main alterations. These damages were well documented by TEM, which showed that the main sites of action of EO were the plasma membrane and cell wall. In conclusion, morphological and structural changes observed in this study may be one of the mechanisms involved in growth inhibition of the fungi and reducing aflatoxin production.