DIFFERENT APPROACHES IN ANALYZING CHYMOSIN PURITY

Chymosin is a specific proteolytic enzyme found in rennet, and is the key enzyme in cheese production classified in the aspartic endopeptidases (EC 3.4.23.4). The aim of this study was to determine the purity of different commercially available chymosins and its equivalents using electrophoretic and chromatographic techniques. Chymosins produced by the company Chr. Hansen, CHY-MAX 200 and CHY-MAX Plus, CHY-MAX PowderExtra NB, as well as Maxiren 1800 Granulate from the company DSM, Sirnik from SZR – Travnik, Kraljevo and Planika from Mikroprocessing, Bileca were used as materials for this study. The purity level of the commercially available enzymes was analyzed using electrophoretic (sodium dodecyl sulfate polyacrylamide gel electrophoresis or SDS-PAGE) and chromatographic (Rapid Resolution Liquid Chromatography or RRLC) techniques. Results showed no presence of undeclared protein fractions due to inappropriate purification process in the samples except for CHY-MAX М 200 which had two protein fractions, most likely as a result of a polymorphism. All the CHY-MAX and Maxiren samples have chymosin as the active component (36 kDa), except for Planika and Sirnik which have a natural protease from R. miehei. Chromatographic analysis showed that beside the active component (chymosin), the preservative sodium benzoate was present in varying concentrations in all but CHY-MAX PowderExtra NB

The Variability of Fruit Characteristics of Traditional Pear Karamanka in Different Ecological Conditions

In this paper, we present the results of the phenological characteristics (flowering and ripening time), fruit characteristics (fruit mass, fruit length, fruit width, fruit hardness, length of fruit stalk and number of seeds in fruit) and chemical characteristics of fruits (soluble dry matter, total sugar and total acids) of a traditional pear variety ‘Karamanka’. For this study, a survey was undertaken in different ecological regions of Macedonia i.e. Skopje, Kumanovo, Kratovo, Kriva Palanka and Resen. The ‘Karamanka’ pear flowers in the first half of April. The period of fruit ripening starts in the second half of August and lasts until the first half of September. The earliest time of flowering and ripening was found to be in the regions of Skopje and Kumanovo. The pear ‘Karamanka’ has medium-sized fruits and the largest fruits were detected in the regions of Kumanovo and Resen. These differences in reference to the fruit mass were statistically significant. It was found that fruits contained 14.2% of soluble dry matter, 13.5% of total sugar and 0.13% of total acids. The highest values of soluble dry matter and total sugar were found in the fruits from the Kriva Palanka region. These values were statistically significant. The fruits from the regions of Skopje and Kratovo were characterized with poor quality and with the highest amount of stone cells