Investigation of Biogenic Amine Levels and Microbiological Activity as Quality Markers in Some Dairy and Fish Products in Food Markets in the Kingdom of Saudi Arabia.

This study aimed to verify the presence of biogenic amines (BAs) and evaluate the microbiological activity of some food samples collected from retail stores in the Kingdom of Saudi Arabia. A total of thirty-five dairy and fish products were collected and analyzed for BAs, including putrescine (PUT), cadaverine (CAD), spermidine (SPE), histamine (HIS), spermine (SPR), and tyramine (TYR), as well as for total colony count (TCC), lactic acid bacteria (LAB), Enterobacteriaceae, yeast and mold (Y and M), coliforms, and aerobic sporulation count (ASF). The thin layer chromatography (TLC) method was used in the analytical methodology to identify the BAs. The results showed the presence of BAs in all dairy products, but their concentration did not exceed the maximum permissible limit, which in contrast was established by the Food and Drug Administration (FDA) at 10 mg/100 g. The amounts of BAs in fish products varied significantly. All fish product samples contained levels of BAs below the permissible limit. Results of an independent study also indicated potential toxicity at levels of BAs (>10 mg/100 g) in Egyptian herring. Enterobacteriaceae and the coli group were present in higher concentrations in the Egyptian herring samples, whereas other samples (particularly frozen shrimp) showed increased TCC levels with a higher concentration of histamine-producing bacteria. From a consumer safety perspective, this study also indicated that food samples generally contained acceptable levels of BAs. In conclusion, there is a need to improve and standardize food quality and hygiene practices during production and storage to ensure human safety and prevent HIS formation.

Application of Nanocomposites from Bees Products and Nano-Selenium in Edible Coating for Catfish Fillets Biopreservation.

Bee products, e.g., chitosan and propolis (Pro), have extraordinary importance in many disciplines including food biopreservation. Fish meat is highly susceptible to vast spoilage, especially catfish (Clarias gariepinus) products. The current work involved the extraction of bees' chitosan nanoparticles (BCht), Pro, Pro-mediated SeNPs and their composites, to evaluate them as potential antimicrobial and preservative nano-compounds, for the preservation of catfish fillets and augment their quality. BCht was extracted from bees (Apis mellifera) corpses and had a 151.9 nm mean particle diameter. The Pro was used for biosynthesis of SeNPs, which had 11.2 nm mean diameters. The entire compounds/composites exhibited powerful antibacterial acts against Escherichia coli, Staphylococcus aureus and Salmonella typhimurium, where S aureus had the uppermost resistance. BCht/Pro/SeNPs were the most forceful toward all bacterial strains. The constructed edible coatings (ECs) from produced compounds/composites (BCht, Pro, Pro/SeNPs, Pro/BCht and BCht/Pro/SeNPs) had elevated efficiency for preserving catfish fillets during cold storages for 7 days. The microbiological (total counts, psychrophilic bacteria, yeast and molds), spoilage chemical parameters (TVB-N, TBARS) and sensorial attributes (appearance, odor, color, overall quality) of ECs-treated fillets indicated the nanocomposite's efficiency for protecting the fish from microbial growth, the progress of chemical spoilage indicators and maintaining the sensorial quality of treated stored fillets. The most effective nanocomposite for maintaining the entire fillet's quality was the BCht/Pro/SeNP. The based ECs on BNCt, Pro/SeNPs and their nanocomposites could be endorsed for prospective employment in the biopreservation of various seafoods.

Exploring the Antifungal Activity and Action of Saussurea costus Root Extracts against Candida albicans and Non-albicans Species.

The isolation and assessment of the active constituents in polar and non-polar crude extracts of Saussurea costus roots as antifungal agents, against Candida albicans and non-C. albicans (NAC) species, was the aim of this current investigation. The SEM "Scanning electron microscopy" imaging provided potential action modes of n-hexane extract (nhhE) toward Candida spp., whereas the TLC-DB "Thin layer chromatography-direct bioautography" was employed for detecting the anticandidal compounds. nhhE had the greatest biocidal activity against all strains and clinical isolates of Candida spp. with maximum zones of inhibition. SEM revealed the occurrence of irregular, dense inclusions of C. albicans cell walls after treatment with nhhE for 12 h. Complete morphological distortions with lysed membranes and deterioration signs appeared in most treated cells of C. parapsilosis. The most effectual compound with anticandidal activity was isolated using TLC-BD and identified as sesquiterpene by GC/MS analysis. The infra-red analysis revealed the presence of lactone ring stretching vibrations at 1766.72 cm-1. The anticandidal activity of nhhE of S. costus roots was confirmed from the results, and the treated cotton fabrics with nhhE of S. costus possessed observable activity against C. albicans. Data could recommend the practical usage of S. costus extracts, particularly nhhE, as influential natural bioactive sources for combating pathogenic Candida spp.

Comparison of the Efficiency of Lepidium sativum, Ficus carica, and Punica granatum Methanolic Extracts in Relieving Hyperglycemia and Hyperlipidemia of Streptozotocin-Induced Diabetic Rats.

BACKGROUND: Diabetes mellitus (DM) is a metabolic disorder characterized by high blood glucose levels that occurs either due to insufficient insulin production or mounting resistance to its action. The purpose of this study was to investigate if methanolic extracts of Lepidium sativum seeds, Ficus carica, and Punica granatum leaves had any effect on blood sugar levels in normal and streptozotocin (STZ) diabetic rats, as well as to explore the most effective extract. METHOD: Healthy male albino rats weighing 185-266 g were divided into nine groups of eight rats each: normal control, diabetic control, diabetic rats with dietary supplements of L. sativum, F. carica, and P. granatum methanolic extracts, and diabetics treated with insulin. All of the rats were fed on ordinary diet with nutritional pellets and were given water ad libitum. To induce diabetes, all animals were administered with STZ intraperitoneal injection at a dose of 60 mg/kg body weight. For five weeks, the crude plant extracts were given orally to various groups of rats at doses of one hundred and two hundred mg/kg body weight. After that, animal groups were sacrificed and blood samples were taken. RESULTS: Phytochemical analysis revealed that the highest amounts of polyphenolic compounds were present in L. sativum seeds and P. granatum leaves, while leaves of F. carica showed the highest amounts of alkaloid and flavonoid content compared to other extracts. Oral administration of F. carica and L. sativum extracts at the dosage of 100 and 200 mg/kg significantly reduced glucose, lipid profile, kidney, and liver enzyme levels. A significant increase in HbAlc levels was also observed with L. sativum extract at a dose of 200 mg/kg compared to diabetic controls. Mellitus rats supplemented with 100 and 200 mg/kg methanolic extracts of P. granatum had higher serum triglycerides and lower serum low-density lipoprotein cholesterol (LDL-C) than normal control rats. F. carica extract is more effective than L. sativum and P. granatum extracts in the prevention and control of type 2 diabetes mellitus (T2DM) and its consequences.

Pharmacological Activities and Characterization of Phenolic and Flavonoid Compounds in Methanolic Extract of Euphorbia cuneata Vahl Aerial Parts.

Euphorbia cuneata Vahl. (Euphorbiaceae) is a plant used in folk medicine for the treatment of pain and inflammation, although the biological basis for these effects has not been thoroughly investigated. The goal of this study was to investigate the pharmacological properties and characterization of phenolic and flavonoid compounds present in the aerial parts of E. cuneata. E. cuneata aerial parts were tested for antioxidant activity (DPPH), antibacterial activity, cell viability and cytotoxic effects, and anti-inflammatory activity. Phenolic and flavonoid contents (HPLC), and volatile constituents (GC-MS) were also characterized. The methanol extract had the highest antioxidant activity, while the ether extract had the lowest. The antioxidant activity of E. cuneata extract increased from (21.11%) at a concentration of 10 µg/mL to (95.53%) at a concentration of 1280 µg/mL. S. aureus was the most sensitive organism with the highest zone of inhibition and lowest MIC, with acetone extract; whereas C. tropicalis was the most resistant, with the lowest inhibition zone. MTT assay revealed that the methanol extract of E. cuneata had significant cytotoxic effects on the A549, Caco-2, and MDA-MB-231 cell lines, respectively. Lower concentrations of methanolic extract gave anti-inflammatory activity, and those effects were compared with indomethacin as a positive control. Pyrogallol was the most abundant phenolic acid, followed by caffeic, p-coumaric, ferulic, syringic, and gallic acids, respectively. The 7-hydroxyflavone and rutin flavonoids were also found in the extract. GC-mass analysis showed that aerial parts of E. cuneata were rich in methyl 12-hydroxy-9-octadecenoate. The volatile components were also composed of considerable amounts of hexadecanoic acid, methyl ester, (9E,12E)-octadeca-9,12-dienoyl chloride, and methyl octadeca-9,12-dienoate as well as a little amount of hexanal dimethyl acetal. It can be concluded that methanolic extract of E. cuneata could be used as an available source of natural bioactive constituents with consequent health benefits.

Paecilomyces variotii xylanase production, purification and characterization with antioxidant xylo-oligosaccharides production.

Paecilomyces variotii xylanase was, produced in stirred tank bioreactor with yield of 760 U/mL and purified using 70% ammonium sulfate precipitation and ultra-filtration causing 3.29-fold purification with 34.47% activity recovery. The enzyme purity was analyzed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) confirming its monomeric nature as single band at 32 KDa. Zymography showed xylan hydrolysis activity at the same band. The purified enzyme had optimum activity at 60 °C and pH 5.0. The pH stability range was 5-9 and the temperature stability was up 70 °C. Fe2+and Fe3+ exhibited inhibition of xylanase enzyme while Cu2+, Ca2+, Mg2+ and Mn2+ stimulated its activity. Mercaptoethanol stimulated its activity; however, Na2-EDTA and SDS inhibited its activity. The purified xylanase could hydrolyze beechwood xylan but not carboxymethyl cellulose (CMC), avicel or soluble starch. Paecilomyces variotii xylanase Km and Vmax for beechwood were determined to be 3.33 mg/mL and 5555 U/mg, respectively. The produced xylanase enzyme applied on beech xylan resulted in different types of XOS. The antioxidant activity of xylo-oligosaccharides increased from 15.22 to 70.57% when the extract concentration was increased from 0.1 to 1.5 mg/mL. The enzyme characteristics and kinetic parameters indicated its high efficiency in the hydrolysis of xylan and its potential effectiveness in lignocellulosic hydrolysis and other industrial application. It also suggests the potential of xylanase enzyme for production of XOS from biomass which are useful in food and pharmaceutical industries.

In vitro and in vivo hypolipidemic properties of the aqueous extract of Spirulina platensis, cultivated in colored flasks under artificial illumination.

BACKGROUND: Spirulina is blue-green algae that grows mainly in tropical and subtropical lakes and is commonly used due to its nutritional features including high concentrations of protein, vitamins, mineral salts, carotenoids and antioxidants. This study aimed to investigate the anti-hypercholesterolemic potential of aqueous extract of Spirulina platensis cultivated in different colored flasks under artificial illumination; in vitro and in the diet induced hypercholesterolemic Swiss albino mice. METHODS: Spirulina platensis was cultivated in red, blue, green and colorless Erlenmeyer flasks containing Zarrouk's medium under aerobic conditions, with incessant illumination by artificial cool white fluorescent with light intensity of 2500 lux (35 µmol photon m-2 s-1). Chlorophyll a and total carotenoid contents were estimated using colorimetric methods, fatty acids composition was determined by GC-Mass, in vitro and in vivo anti-cholesterol assays were used in assessing the anti-hypercholesterolemia potential of obtained Spirulina cells. RESULTS: The results showed that the highest cell dry weight, chlorophyl a, and carotenoid of S. platensis were observed in colorless flasks and that the lowest values were recorded with the green colored flasks. Also, the hot water extract of S. platensis obtained from colorless flasks at a concentration of 15 mg/mL after 60 min of incubation exhibited the greatest reduction of cholesterol level. Gas chromatography-mass spectrometry analysis of S. platensis methanolic extract showed 15 bioactive compounds were identified and grouped according to their chemical structures. An experimental model of hypercholesterolemic mice had been examined for impact of S. platensis individually and combined with atorvastatin drug. All S. platensis groups resulted in a remarkable decrease in plasma total cholesterol, triglycerides and low density lipoprotein; and increase in high density lipoprotein. CONCLUSION: The present study concluded that the hot aqueous extract of S. platensis developed in colorless flasks is recommended as a natural source for bioactive compounds, with anti-cholesterol and antioxidant potentialities.

Antibacterial activity of fusion from biosynthesized acidocin/silver nanoparticles and its application for eggshell decontamination.

Bacteriocins from lactic acid bacteria (LAB) are useful to control the persistent development of pathogenic microorganisms in food and medicine fields. The bacteriocin acidocin was extracted from Lactobacillus acidophilus M1 that was isolated from fermented milk, purified using ammonium sulphate fractionation, and gel filtration column chromatography using Sephadex matrix and applied as a potential antibacterial agent. The molecular weight of the purified acidocin was estimated using SDS-PAGE to be 6.6 kDa. The acidocin was compared with silver nanoparticles (SNPs), biosynthesized by Aspergillus brasiliensis (niger) ATCC 16404, against two bacterial strains Bacillus cereus ATCC 14579 and Staphylococcus aureus ATCC 25923. Both acidocin and SNPs showed significance antibacterial effects using disc and well diffusion methods; the maximum antibacterial activity was proved against B. cereus from acidocin/SNPs composite using a ratio of 1/1 from each agent. The application of acidocin/SNPs composite as immersion solution, for disinfecting chicken eggshells, resulted in remarkable reduction in microbial load on the shells of 5.53 log10 CFU/eggshell. Results could provide an eco-friendly approach for potential antimicrobial composites to be used in food preservation and other health protection researches.

Production of fungal chitosan from date wastes and its application as a biopreservative for minced meat.

Raw and processed meat contaminated with pathogenic microorganisms is a continuing worldwide problem facing health and industry overseers. Fungal chitosan was extracted, purified and characterized from Aspergillus brasiliensis (niger) ATCC 16404 grown in date syrup (dips) and applied as a potential meat biopreservative. The main features of produced chitosan were a deacetylation degree of 81.3%, a molecular weight of 31,000Da, 96% solubility in 1% acetic acid solution and a harmonized IR-spectrum to standard commercial chitosan. The application of fungal chitosan, as a natural and safe biopreservative for minced meat, was conducted in comparison with potassium sorbate, as a commercial meat preservative. Treated meat samples with 0.02% chitosan was the least trials in microbial contents, i.e. total count, coliforms, ß-glucuronidase-positive Escherichia coli, Enterobacteriaceae, yeasts and molds, Staphylococcus aureus and coagulase positive staphylococci. The antimicrobial activity of fungal chitosan was considerably greater than that of potassium sorbate or their combination at 0.01% from each. Sensory characteristics, e.g. color, odor and texture, of treated meat with chitosan, were higher than those of control and potassium sorbate treated samples. Fungal chitosan, however, could be recommended as a powerful, natural and eco-friendly alternative for meat preservation and overall quality maintenance.