Open Access Original Research Article

Simultaneous Determination of Erythromycin A in Giant Prawn and Tilapia in Mekong Region by Stripping Square Wave Voltammetry

Nguyen Phuoc Minh, Tran Bich Lam, Nguyen Trong Giao

European Journal of Nutrition & Food Safety, Page 1-14

Erythromycin A (EA) is now one of antibiotics limited in seafood products in general and in giant freshwater prawns (Macrobrachium rosenbergii) and tilapia (Oreochromis niloticus) in particular while exporting to the US, EU, Japan, Canada. There are many methods used for analyzing this antibiotic in these aqua species such as ELISA, HPLC, LC-MS/MS, GC-MS, etc. A new sensitive analytical approach for determination of erythromycin A using stripping square wave voltammetry at the slowly dropping mercury electrode was primarily developed and validated to quantify this antibiotic with simple and short time analysis, not too pure analytical solutions, not high price equipments. Electrochemical signals were measured at potential wave -1430 mV. The optimal experimental parameters for the method were: supporting electrolyte ammonium acetate 0.1 M, pH 8.0, the solvents for dissolving erythromycin standard: acetonitril, Vstart = -400 mV, Vstop = -1700 mV, Vstep = 6 mV, Vpulse = 40 mV, Tdrop = 5000 ms , Velctrolise = -1100 mV, Telectrolyse = 5 s. The method showed high recovery (85.07 ÷ 96.50 %), high sensitivity (lower limit of detection, LoD = 0.57 µg kg-1 in giant prawn and LoD = 0.52 µg kg-1 in tilapia) and high precision (RSD 0.91 ÷ 2.1 %) as well as excellent linearity (r2adjusted ≥ 0.99999).

Open Access Original Research Article

African Breadfruit (Treculia africana) Seed as Adjunct in Ethanol Production

T. U. Nwabueze, C. B. Uchendu

European Journal of Nutrition & Food Safety, Page 15-22

African breadfruit seeds have the potentials as carbon source for ethanol production with a carbohydrate value of 72.19%. On malting the seeds at 28±2oC for 9 days it yielded a 96% germination capacity and total malting loss of 25.70%. Grain dormancy was broken by the second day of malting. Malted breadfruit seeds were ground and defatted to 0.78% fat content. Full fat breadfruit and defatted breadfruit flours were used as adjuncts in the ratio of 3:5 (adjuncts: barley). Fermentation parameters such as wort fermentable sugar, specific gravity, extract yield and ethanol were measured over the 9 days of fermentation. Extract yields were 12.59, 9.66 and 11.23% while ethanol production was 5.79, 6.39 and 6.10% for wort from defatted breadfruit, full fat breadfruit and maize, respectively.