5 research outputs found
Method development for measurement of elements in Hungarian red wines by inductivelvy coupled plasma optival emission spectrometry (ICP-OES)
ICP-OES (inductively coupled plasma optical emission spectrometry) was used to determine the element content of red wines. Development of the method involves various procedures of sample handling as well as repeatability and reproducibility measurements. Measurements were made for the following 16 elements: Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, P, Sr and Zn. The relative standard deviation of repeatability ranged from 0.41% (potassium) to 27% (cadmium) and that of reproducibility varied between 0.73% (boron) to 52% (cobalt). Recovery of the elements was determined by standard addition with results ranging from 90.6% (phosphorus) to 116.2% (boron). After that, 15 red wine samples were measured. Significant differences were found in the Al, B, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, P, Sr and Zn (P<0.001) concentration of wine samples. Correlation studies revealed parallel changes in phosphorus-potassium, phosphorus-magnesium and zinc-manganese concentrations (r=0.857, 0.875, 0.838). According to principal component analysis, measurements of zinc-, sodium-, boron-, copper- and strontium content gave almost the same results as obtained with 16 different elements. According to a two dimensional non-linear map of absolute values of principal component analysis, wines from Szekszárd and Eger could be differentiated, whereas the analysis of wines from Villány, the Mátra Mountains and Lake Balaton showed overlapping results
Optimization of various extraction methods for quercetin from onion skin using response surface methodology
Optimization of a Solid-Phase Extraction Method Using Copolymer Sorbents for Isolation of Phenolic Compounds in Red Wines and Quantification by HPLC
Oleoresins from Capsicum spp.: Extraction Methods and Bioactivity
Capsicum spp. fruit is one of the most produced vegetables around the world, and it is consumed both as fresh vegetable and as a spice like a food additive for their characteristic red color and, in many cases, its pungency. In addition to its economic importance, the bioactivity of some important compounds such as capsaicinoids and carotenoids has promoted its research. The use of Capsicum oleoresins has been increased due to its advantages comparing with the traditional dry spice. These include obtaining higher quality products with the desired content of bioactive and flavored substances. The wide diversity of extraction methods including water extraction, organic solvent extraction, microwave-assisted extraction, and ultrasound assisted extraction as well as supercritical fluid extraction among others are discussed in the present review. Moreover, pretreatments such as chemical treatments, osmotic dehydration, sun and oven drying, and freeze-drying commonly used before the extraction are also presented. Due to its importance, Capsicum oleoresins produced with “green” solvents and the improvement of fractional extraction techniques that allow to obtain separately the various bioactive fractions will continue under research for further development