This study aimed to evaluate the effects of variables on the process of lipases production by Aspergillus niger C by submerged fermentation (SmF). The production assays were performed in shake flasks for 72 hours at 150 rpm and 32°C. First, a fractional factorial design 2 5-1 (FFD) was carried out to evaluate the effect of the following process variables: sucrose, ammonium sulphate, soybean oil, yeast extract concentration and pH. After the selection of the variables that significantly influenced the lipase production, a central composite rotational design 2 2 (CCRD) was used, aiming to find the most favorable operational conditions. The selected assay condition (15.0 g.L-1 sucrose, 4.0 g.L-1 HIGHLIGHTS • Lipase was production by A. niger using sucrose and soybean oil as carbon source. • Experiment design was an efficient tool in improving A. niger lipase production. • Lipase production kinetics indicated good yield levels in a short fermentation time.
The purpose of this study was to characterize, isolate and chemically modify tiger nut (Cyperus sculentus L.) starch with octenyl succinic anhydride. The efficiency of the chemical modification was 0.04. Chemical composition, particle morphology (SEM), particle size, X-ray diffraction, infrared analysis, thermogravimetric analysis, differential scanning calorimetry and swelling and solubility power were determined for characterization of the native and modified starch. Both showed similar chemical composition and amylose and amylopectin contents, as well as absorption spectra in the infrared region without modification of the molecular structure and A-type crystalline pattern. The particles of both had an oval and spherical shape. The modified starch was more resistant to temperature and the gelatinization process occurred at 67.52 °C. These results suggest that tiger nut starch has a great industrial potential.
Sequential experimental design strategy was applied in order to investigate the best conditions for tiger nut milk extraction process taking into account performance and physicochemical features, simultaneously. Protein, lipid, starch, calcium and total sugar composition were considered for this optimization. The tested factors were: sodium metabisulphite concentration (X 1 ), soaking time (X 2 ), soaking temperature (X 3 ) and water proportion (X 4 ). From the 2 4-1 fractional factorial design all independent variables were found to be statistically significant (p <0.1) and X 1 , X 2 and X 3 were chosen for the central composite design as water proportion was already in the minimum value. The best operational conditions, obtained by desirability function, were: 8 h of soaking time, 22° C for soaking temperature, 0.20% (w/v) of sodium metabisulphite and 1:1 tuber (g): water (ml) proportion. In those conditions a 78% yield was obtained for a tiger nut milk with 2.60% protein, 3.7% total sugar and 8.72% starch. The high yield obtained and the great nutritional value shows that this milk has a great potential for application in the food industry.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.