Evaluation of the antioxidant and antimicrobial activities of the spent coffee extracts and their applications as natural food preservatives of chicken fillets

The present study aimed at evaluating the phytochemical composition, antioxidant, and antimicrobial potentials of spent coffee extracts (SCE) to use these extracts as natural preservatives of food. The effectiveness of SCE in postponing the oxidation and extending the shelf life of chicken fillets through delaying the microbial growth were investigated. Spent coffee was collected and extracted using water and ethanol. The extracts were analyzed for their bioactive components using Gas chromatography-mass spectrometry (GC/MS) and antioxidant properties using different spectrophotometric assays. The detected bioactive components were mainly fatty acids (80 %), flavonoids, terpenoids and caffeine (5.4 %). Spent coffee ethanolic extract was richer in its active components than the aqueous one. Additionally, the in vitro antibacterial efficacy of the extracts against several food-borne bacterial strains revealed that spent coffee ethanolic extract was effective against all the tested bacteria with inhibitory percentages ranging from 34.62 to 66.69 %, whereas the aqueous extract expressed an inhibitory effect only against Salmonella typhimurium (35.82 %). To assess the practical utility of SCE as food preservatives, chicken fillets were treated with SCE at two levels (0.1 % and 0.2 %) and butylated hydroxytoluene (BHT, 0.02 %) was used as a synthetic preservative. The antioxidant and microbiological attributes of the SCE treated chicken fillets were investigated at 3 d intervals for 15 d. The results showed that inclusion of SCE enhanced the chicken fillets antioxidant properties and microbiological characteristics. Furthermore, the chicken fillets treatments succeeded in stopping the rise of the total bacterial count, with no Salmonella sp. or fungal contamination, and additionally, the overall total coliform was less than 102 cfu/ g; indicating their safety for human consumption. In conclusion, this study proved that spent coffee-treated chicken fillets exhibited extended shelf life through delaying the microbial spoilage and maintaining the antioxidant quality

Phytochemical, Antioxidant and Antibacterial Activities of Golden berry (Physalis Peruviana L.) Extract and its Effects on the Storage Stability of Tomato Paste

This study focused on the phytochemical, antioxidant, and antimicrobial activities of the ethanol extracts of golden berry calyx and fruits. The phytochemical analysis of calyx and fruit extracts revealed high total phenols and flavonoids. High antioxidant capacity was recorded for fruit extracts. Fruit extracts also gave the highest antibacterial activity against Pseudomonas fluorescens, Escherichia coli, and Salmonella typhimurium. Furthermore, tomato paste was prepared using sodium benzoate and golden berry extract as food preservatives. The incorporation of golden berry extract and chemical preservatives maintained the paste quality indicators over the control samples. A rapid decline in total antioxidant capacity was also observed in control samples (21.6%) as compared with the treated samples (15.21% and 15.41% for sodium benzoate and golden berry extract, respectively) after 30 days of storage. This study demonstrated that dried fruit extract with high phytochemical and antimicrobial properties could be used as a natural food preservative

Magnetic activated carbon nanocomposite from Nigella sativa L. waste (MNSA) for the removal of Coomassie brilliant blue dye from aqueous solution: Statistical design of experiments for optimization of the adsorption conditions

The present work was carried out to evaluate the removal of Coomassie brilliant blue dye by adsorption onto a magnetized activated carbon nanocomposite (MNSA) prepared from Nigella sativa L. (NS) waste. Different techniques, including infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption/desorption, were used to characterize MNSA to investigate its adsorption properties. Adsorption experiments were carried out by simultaneously optimizing four variables that usually present a strong effect in adsorption studies. A full 24 factorial design with 3 central points was used. The four independent variables were the initial pH of the dye solution (pH), the initial dye concentration (Co), the adsorbent mass (m), and the contact time (t). The sorption capacity (q) of the adsorbent and the percentage of dye removal (% Rem) from an aqueous solution were used as the responses of the factorial design. The results indicated that pH, Co, and m were essential factors for the overall optimization of both responses (q and % Rem) and that several interactions of two, three and four factors occurred. Based on the design of the experiments (DOE), the optimized conditions for adsorption were pH = 2.00, Co = 40.0 mg L−1, m = 30.0 mg, and t = 3.0 h. Under these conditions, both responses, q and % Rem, were maximized, with a desirability of 85.54%. The findings of this study could be useful for industrial wastewater treatment systems. Keywords: Nigella sativa L. waste, Nanocomposite, Coomassie brilliant blue, Central composite design, Adsorptio

Water: Analysis, Treatment, and Reuse [Editorial]

Editoria

Effects of Dietary Bioactive Lipid Compounds of <i>Acacia nilotica</i> Bark on Productive Performance, Antioxidant Status, and Antimicrobial Activities of Growing Rabbits under Hot Climatic Conditions

This study aimed to evaluate the efficacy of dietary Acacia nilotica bark bioactive lipid compounds (ANBBLCs) as novel feed additives on the growth performance, carcass criteria, antioxidants, and antimicrobial activities of growing male rabbits. A total of 100 California male weanling rabbits aged 35 days were divided into four nutritional treatments, each of which contained ANBBLCs at concentrations of 0 (control group), 50, 100, and 150 mg/kg diet (n = 25 per treatment, each replication consisting of one animal). The average body weight of the animals was 613 ± 14 g. The experiments lasted for 56 days. Dietary ANBBLC levels linearly improved (p p Lactobacillus increased and Staphylococcus decreased (p < 0.05) in comparison to the control group when ANBBLC levels were added to the diets of rabbits. Rabbit diets supplemented with ANBBLCs increased dressing percentages and decreased abdominal fat. This study shows that ANBBLCs can be used as a feed additive to enhance the growth performance, carcass criteria, antioxidant, and antibacterial properties of growing rabbits