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This study investigated the effects of the aqueous extracts of Aframomum danielli, Turmeric and Clove in sprouting of yam (Dioscorea rotundata) and sweet potato (Ipomoea batatas). The sliced tubers were dipped into the aqueous extracts of A. danielli, turmeric and Clove, each at concentrations of 5%, 10% and 15%. The tubers were allowed to stand in the solution for 5 and 10 minutes. Distilled water was used in the control samples. The yam slices were air dried after removal from the liquids, placed in paper boxes and incubated at room temperature (28.9 ± 4.0°C) and Relative Humidity of 44.6 ± 18.4 % for a period of six weeks (Bibah, 2014). Weight loss was determined by finding the difference between the initial and final weights and expressed as percentage weight loss. The results indicated that Turmeric treatments at different concentrations of 5%, 10% and 15% were more effective in reducing sprouting index at 5 minutes treatment time with values of 1.79%; 3.00% and 3.02% respectively. Clove treatment at 15%, 10% and 15% A. danielli treatment were more effective in controlling sprouting at 10 minutes treatment time for the yam tubers. There was no clear

Antioxidative and flavouring effects of Aframomum danielli seed crude ethanolic extract on biscuits were studied. The degree of oxidation during storage was monitored by determining the acidity of the extracted fat from the biscuit samples using the standard method. Biscuits were baked with A. danielli seed extract at the following levels of addition: 100, 200, 300, 400, 500 ppm and a sample using butylated hydroxytoluene (BHT) at a level of 200 ppm, with a synthetic flavour (vanilla) added at a level of 50 ppm. A control sample was baked without the inclusion of A. danielli, BHT or synthetic flavour. The crude ethanolic extract of A. danielli seed at a concentration of 400 ppm was very effective as an antioxidant in the biscuit samples within the period of10 weeks of monitoring at a temperature of 25°C. Based on taste, aroma and acceptability scores, the flavour of A. danielli extract was not noticeable in biscuit until it was 500 ppm.

Selenium is an essential micronutrient for all mammals and plays an important role in maintaining human physiological functions. Selenium nanoparticles (SeNPs) have been shown to demonstrate antioxidant and antimicrobial activity. The objective of this study was to explore whether SeNPs have the potential to be used as food preservatives with which to reduce food spoilage. SeNPs were synthesized through ascorbic acid reduction of sodium selenite (Na2SeO3) in the presence of bovine serum albumin (BSA) as a capping and stabilizing agent. The chemically synthesized SeNPs had a spherical conformation with an average diameter of 22.8 ± 4.7 nm. FTIR analysis confirmed that the nanoparticles were covered with BSA. We further tested the antibacterial activity of these SeNPs against ten common food-borne bacteria. A colony-forming unit assay showed that SeNPs exhibited inhibition on the growth of Listeria Monocytogens (ATCC15313) and Staphylococcus epidermidis (ATCC 700583) starting at 0.5 µg/mL, but higher concentrations were required to slow down the growth of Staphylococcus aureus (ATCC12600), Vibrio alginolyticus (ATCC 33787), and Salmonella enterica (ATCC19585). No inhibition was observed on the growth of the other five test bacteria in our study. Our data suggested that the chemically synthesized SeNPs were able to inhibit the growth of some food-borne bacteria. The size and shape of SeNPs, method of synthesis, and combination of SeNPs with other food preservatives should be considered when SeNPs are to be used for the prevention of bacteria-mediated food spoilage.