Artificial neural networks in modelling osmotic dehydration of foods

Artificial neural network (ANN) models for water loss (WL) and solid gain (SG) were evaluated as potential alternative to multiple linear regression (MLR) for osmotic dehydration of apple, banana and potato. The radial basis function (RBF) network with a Gaussian function was used in this study. The RBF employed the orthogonal least square learning method. When predictions of experimental data from MLR and ANN were compared, an agreement was found for ANN models than MLR models for SG than WL. The regression coefficient for determination (R2) for SG in MLR models was 0.31, and for ANN was 0.91. The R2 in MLR for WL was 0.89, whereas ANN was 0.84.Osmotic dehydration experiments found that the amount of WL and SG occurred in the following descending order: Golden Delicious apple > Cox apple > potato > banana. The effect of temperature and concentration of osmotic solution on WL and SG of the plant materials followed a descending order as: 55 > 40 > 32.2C and 70 > 60 > 50 > 40%, respectively.

Triterpenoid saponins from the cytotoxic root extract of Sideroxylon foetidissimum, an endemic Yucatecan medicinal plant

The flora of the Yucatan peninsula (Mexico) includes approximately 3000 plant species. Sideroxylon foetidissimum Jacq. subsp. gaumeri (Sapotaceae) is an endemic plant to the Yucatan peninsula; its fruit is edible and local people use the plant for medicinal purposes, although no details on its preparation or application are available [1,2]. A preliminary cytotoxic evaluation of the ethanolic root extract of S. foetidissimum revealed a potent activity against murine macrophage like cell line RAW 264.7 (IC50=39.54±4.11µg/mL). The systematic bioassay-guided fractionation of the extract resulted in the identification of the active saponin-containing fraction (IC50=33.69±6.19µg/mL). Four new triterpenoid saponins and a 1:1 mixture of two saponins were isolated from the active saponin- containing fraction. The evaluation of their cytotoxic activity revealed no activity for the tested pure saponins; however, the 1:1 mixture of saponins showed a potent activity (IC50=11.91±1.49µg/mL). The isolation of the saponins was carried out using semi-preparative HPLC. The structural assignments of the pure saponins were based on 1D (1H and 13C and DEPT-135) and 2D (COSY, HMBC, HSQC and TOCSY) NMR and mass spectrometry analyses. In this presentation, the isolation, identification and cytotoxic activity of the isolated compounds is discussed in more detail.