A method for obtaining plastid pigments from the biomass of Chlorella microalgae

J. Bazarnova*, Т. Kuznetsova, E. Aronova, L. Popova and E. Pochkaeva

Peter the Great St. Petersburg Polytechnic University, Graduate School of Biotechnology and Food Science, Polytechnicheskaya, 29, RU195251, St. Petersburg, Russia
*Correspondence: j.bazarnova@spbstu.ru

Abstract:

Microalgae are distinguished from land plants by the high content of plastid pigments and the biodiversity of carotenoids. The aim of this study is to develop a technology for extracting a pigment complex from the biomass of the microalgae of the genus Chlorella and to determine the extracted pigments’ composition. To obtain biomass, a crude cell suspension of microalgae was used, which was obtained under laboratory conditions for pre-culture cultivation of C. sorokiniana (strain 211-8k). The extraction of plastid pigments from air-dry biomass after disintegration of cell membrane was performed in the 40 kHz mode. It was found that the highest pigment content in ethanol extracts was observed after 30 min (870.0 ± 27.1 mg L^-1) at 45−50 °C. The pigments’ composition in the resulting total extracts was determined by spectrophotometry and the Reverse Phase HPLC method. The established content of chlorophyll a in the obtained extracts was 537.5 ± 10.0 mg L^-1, the content of chlorophyll b was 182.5 ± 27.5 mg L^-1; the maximum output of the amount of carotenoids in extracts was 150.0 ± 10.0 mg L^-1. Thus, the main identified forms of carotenoids in extracts from the biomass of microalgae C. sorokiniana were xanthophylls: lutein and fucoxanthin (18.6 and 4.7% of the amount of pigment in extract, respectively) and β-carotene (1.8% of the amount of pigment). It is planned to further fractionate the obtained total extracts of the pigment complex to obtain various forms of chlorophylls and carotenoids to study the spectrum of physiological activity of plastid pigments.

Key words:

carotenoids, Chlorella microalgae, chlorophyll, disintegration, extraction, pre-culture cultivation

The temperature changes of barley malt during its disintegration on a two roller mill

P. Vaculik*, L. Chladek, M. Prikryl, A. Smejtkova and P. Brany

Czech University of Life Sciences Prague, Faculty of Engineering, Department of Technological Equipment of Buildings, Kamýcká 129, CZ 165 21 Prague 6-Suchdol, Czech Republic; *Correspondence: vaculik@tf.czu.cz

Abstract:

This article discusses the change of temperature during disintegration on two roller mill. The production of barley and its treatment to malt is first step of beer brewing. The malt is the produced in malt plants. Crushing the malt is realized in only the brewery and is a core activity of brewing technology. This operation is performed both in craft breweries and in industrial brewery. This article therefore is focused on the theory of crashing solid phase with a respect of development of heat. Grinding barley malt is realised using mills of various designs or disintegrators. They are widely used mills with 2, 4, 5, 6 grinding cylinders. These roller mills are used in many other applications, not only in industrial food or drink production. For next treatment solid phase should be broken into smaller pieces (comminuted). The greater the extent of comminution, the large the surface area for impact on next treatment. The amount of mechanical energy converted to heat energy depends on the principle of the process disintegration and other parameters, i.e. distance of grinding gap, capacity, mechanical properties of crashing material etc. For these reasons, it is important to pay attention to the temperature change of barley malt during its disintegration on a mill.

Key words: