Compositional evaluation of hot-pressed rapeseed cake for the purpose of bioplastic production

K. Jõgi¹*, D. Malenica¹, I. Jõudu¹² and R. Bhat¹

¹ERA-Chair for Food (By-) Products Valorisation Technologies of the Estonian University of Life Sciences (VALORTECH), Estonian University of Life Sciences, Fr.R. Kreutzwaldi 1, EE51006 Tartu, Estonia
²Chair of Food Science and Technology, Institute of Veterinary Medicine and Animal Sciences, Estonian, University of Life Science, Fr.R. Kreutzwaldi 56/5, EE51006 Tartu, Estonia
*Correspondence: katrin.jogi@student.emu.ee

Abstract:

Rapeseed is widely cultivated for biodiesel or food-grade oil production. As the oil production process generates huge amounts of wastes and by-products (e.g. oil press cake and meal) that have relatively high crude protein content, valorisation as input material for protein-based bioplastics has a lot of potential. There is a limited number of studies undertaken on using rapeseed cake directly (without prior protein extraction) for biomaterial production, but the initial results have been very promising. As rape and turnip rapeseeds are also some of the most harvested crops in Estonia, the rapeseed oil press cake as a by-product is also available from local food-grade rapeseed oil production. In this regard, we investigated locally available rapeseed oil press cake for chemical composition and explored suitability for bioplastic production. The results indicate suitability for direct biomaterial production, meaning properties for biomaterial formation could be further explored.

Key words:

Optimization of cattle by-products amino acid composition formula

O. Zinina¹*, S. Merenkova¹, M. Rebezov², D. Tazeddinova¹, Z. Yessimbekov³ and V. Vietoris⁴

¹South Ural State University (National Research University), Lenin Avenue 76, RU454080 Chelyabinsk, Russia
²Ural State Agrarian University, Karl Liebknecht 42, RU620075 Ekaterinburg, Russia
³Shakarim State University of Semey, Glinki street 20a, KZ071400 Semey, Kazakhstan
⁴Slovak University of Agriculture in Nitra, Hlinku 2, SK94901 Nitra, Slovakia
*Correspondence: zininaov@susu.ru

Abstract:

The aim of this research was to develop optimal formulations of by-product mixtures in terms of biological value using MS Excel Solver standard software application. The objects of study were underutilized cattle by-products as tripe, ears, lips, lungs, and heart. Physical and chemical studies were carried out to compile a database of the by-products used. As a result, the protein content was 14.3% in tripe, 24.6% in lips, 24.9% in ears, 15.2% in lungs, and 16.8% in heart (P < 0.05). The content of essential amino acids in various by-products, determined by high-performance liquid chromatography, did not have significant differences compared with the results obtained by other researchers. While conducting optimization of the by-product formulation, focused on the physiologically-based content of the essential amino acids in the ‛ideal’ protein according to the Food and Agriculture Organization of the United Nations and the World Health Organization (FAO/WHO). Essential amino acids index (EAAI) was chosen as the goal function. In the process of optimization, indicators such as chemical score, EAAI, biological value, and coefficient of amino acid score differences (CAASD) were calculated. Several variants of the formulations with high biological value were obtained as a result of the optimization. According to the results of the research it was found that more balanced ratio of the essential amino acids was in the following formulations: 1 – tripe (4.9%), ears (28.4%) and heart (66.7%) or 2 – ears (25.4%), lips (8.9%) and heart (65.7%). According to the results, the highest in vitro protein digestibility was in compositions number 1 and 2 (78.2% and 76.8%), which correlated with the calculated biological value. Thus, the use of computer modeling allowed obtaining the formulations of the by-products composition with the highest possible biological value by varying the content of the various by-products.

Key words:

amino acid, biological value, by-product, optimization