Tag Archives: Antioxidant

1361–1371 Z. Kruma, L. Tomsone, R. Galoburda, E. Straumite, A. Kronberga and M. Åssveen
Total phenols and antioxidant capacity of hull-less barley and hull-less oats
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Total phenols and antioxidant capacity of hull-less barley and hull-less oats

Z. Kruma¹*, L. Tomsone¹, R. Galoburda¹, E. Straumite¹, A. Kronberga² and M. Åssveen³

¹Latvia University of Agriculture, Department of Food Technology, Rigas iela 22, LV-3004 Jelgava, Latvia
²Institute of Agricultural Resources and Economics, Zinatnes iela 2, LV-4126 Priekuli, Latvia
³Norwegian Institute of Bioeconomy Research, Fredrik A. St. Dahls 20, 1432 Ås, Norway
*Correspondence: zanda.kruma@llu.lv

Abstract:

 Grain products are the main source of carbohydrates but they also contain other bioactive substances such as phenolic compounds. Content of phenolic compounds differ among cereal types, varieties, and farming methods. The aim of the current study was to assess total phenolic content and radical scavenging activity in different oats and barley varieties compared to hulled ones. In the experiment hull-less varieties / lines were analysed: three barley (line ‘GN 03386’, from Norway and ‘Kornelija’, ‘Irbe’ from Latvia) and three oats varieties (‘Bikini’, ‘Nudist’, from Norway and ‘Stendes Emilija,’ from Latvia). One hulled variety of barley and oats from each country was included in the experiment for comparison. For the isolation of phenolic compounds ultrasound assisted extraction was used. For all extracts the total phenol content and DPPH, ABTS+ radical scavenging activity were determined spectrophotometrically. Overall, the highest content of total phenols was detected in hull-less barley samples. The barley variety with the highest content was line ‘GN 03386,’ followed by varieties ‘Kornelija’, ‘Irbe,’ and hulled Norwegian barley variety ‘Tyra’. High DPPH and ABTS+ radical scavenging activity was recorded in barley line ‘GN 03386’. Generally, there was strong correlation between total phenol content and ABTS˙+radical scavenging activity and moderate correlation between total phenol content and DPPH radical scavenging activity. In conclusion, the barley varieties had generally higher content of bioactive substances than oats and the barley line ‘GN 03386’ seems to be one of the best.

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407-416 K. Sirviö,, S. Niemi, V. Vauhkonen and E. Hiltunen
Antioxidant studies for animal-based fat methyl ester
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Antioxidant studies for animal-based fat methyl ester

K. Sirviö¹,*, S. Niemi¹, V. Vauhkonen² and E. Hiltunen¹

¹University of Vaasa, Faculty of Technology, PL 700, FIN-65101 Vaasa, Finland; *Correspondence: Katriina.Sirvio@uwasa.fi 2UPM Research Center, FI-53200 Lappeenranta, Finland

Abstract:

The aim of this study was to test an antioxidant, BioSineox, for animal-based fat methyl ester, AFME, in order to determine the optimal concentration of this antioxidant for meeting the six-hour oxidation stability requirement as set in the EN 14214:2010 standard. Oxidation stability was measured using a Biodiesel Rancimat 873, which meets the requirements of the EN 14112 standard. The variety of raw materials used in the production of methyl esters, i.e. biodiesels, renders a variety of fatty acid profiles. Consequently, the reaction of biodiesels with various antioxidants must be individually tested for each combination. Before the antioxidant is added during the manufacturing process, it must be tested in laboratory conditions. As the main result of this study it can be stated that the process requires a relatively high (2,000 ppm) BioSineox concentration in order for the biodiesel to meet the six-hour oxidation stability requirement. In March 2013, the standard EN 14214:2010 was replaced by the EN 14214:2012. One of the changes was an increase in the oxidation stability requirement from 6 hours minimum to 8 hours minimum. To reach this target, the concentration of the antioxidant must be further increased.

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