RESUMO
The present study is designed to study the efficiency of plant-based hydrocolloids for the efficient clarification of sugarcane juice and subsequent production of non-centrifugal sugars (NCSs). NCSs are generally produced with lime or other inorganic solids as a clarification agent, often leading to products with a bland taste and dark color. This work is a first of its kind, where plant-based hydrocolloids such as starch, xanthan gum, and guar gum are used for clarification studies. Clarification efficiency was evaluated in terms of separation efficiency, turbidity removal, sucrose content, color transmittance, and rheology studies. Preliminary studies revealed that starch showed a better separation efficiency of 78% compared to other hydrocolloids, and further rheology studies of starch-clarified juice showed a favourable shear-thickening (dilatant, n = 1.382) behaviour, whereas the other two hydrocolloids showed an unfavourable shear-thinning (pseudo plastic, n < 0.9) behaviour. Eventually, starch was found to be a better clarification agent and is proposed as an alternative to lime-based clarification. Solidification studies were performed with starch at various concentrations (0.02-0.04%), pH (6.8-7.2), and temperature (80 °C-100 °C), and it was found that NCSs produced via starch clarification showed superior properties compared with traditional lime-based clarification processes.
Assuntos
Compostos de Cálcio , Bengala , Coloides , Óxidos , Coloides/química , Polissacarídeos Bacterianos/química , Amido/química , Reologia , ViscosidadeRESUMO
Cholesterol enrichment of vascular smooth muscle cells, as occurs under conditions of hypercholesterolemia and atherosclerosis, is accompanied by specific changes in cholesterol metabolism and in intracellular cholesterol trafficking. Sterol-carrier protein-2 (SCP2), an intracellular lipid binding protein, enhances the activation of enzymes involved in cholesterol metabolism. It may also enhance cholesterol efflux by regulating the size of the "fast" cholesterol pool available for efflux to high density lipoproteins. However, a definitive role for SCP2 in arterial cholesterol metabolism is unclear. Therefore, we examined the expression of SCP2 (13.1 kD), SCPx (58 kD), and p30 (30.8 kD) in cultured arterial smooth muscle cells under conditions of cholesterol enrichment. We found that SCP2, SCPx, and p30 are localized principally in the cytosolic fraction, with lesser amounts associated with the nuclear/peroxisomal fraction; the expression of SCP2 protein and mRNA, but not SCPx, is increased after exposure of smooth muscle cells to cationized LDL. In contrast to the increased expression of SCP2, the expression of p30 decreases after cholesterol enrichment of smooth muscle cells. Coupled with previous studies demonstrating enhanced cholesterol efflux from cholesterol-enriched smooth muscle cells in response to high density lipoproteins, our results suggest that increased expression of SCP2 may partly mediate the cholesterol trafficking process.