The utilisation of fatty-acid substrates in triacylglycerol biosynthesis by tissue-slices of developing safflower (Carthamus tinctorius L.) and sunflower (Helianthus annuus L.) cotyledons

Planta ◽  
1988 ◽  
Vol 173 (3) ◽  
pp. 309-316 ◽  
Author(s):  
Gareth Griffiths ◽  
Sten Stymne ◽  
A. Keith Stobart
2012 ◽  
Vol 12 (1) ◽  
pp. 59 ◽  
Author(s):  
Dewa G Katja

KUALITAS MINYAK BUNGA MATAHARI KOMERSIAL DAN MINYAK HASIL EKSTRAKSI BIJI BUNGA MATAHARI (Helianthus annuus L.) ABSTRAK Minyak komersial dan minyak hasil ekstrasi dari biji bunga matahari melalui uji kadar air, kadar asam lemak bebas, bilangan peroksida. Analisis hasil ekstrak biji bunga matahari diperoleh kadar air 0,43%, kadar asam lemak bebas 0,47% dan bilangan persoksida 5,22 mek/kg. analisis minyak komersial diperoleh kadar air 0,21%, kadar asam lemak bebas 0,28% dan bilangan peroksida 4,18 mek/kg. Hasil analisis dengan kromatografi gas kedua sampel menunjukkan kadar asam lemak bebas berbeda.       Berdasarkan uji kualitas yang dilakukan terhadap kedua sampel yang dianalisis terdapat hasil yang diperoleh tidak memenuhi syarat yang ditentukan yakni kadar asam lemak bebas 0,08% dan bilangan peroksida 2 mek/kg. Kata kunci: Asam lemak bebas, bilangan proksida, minyak biji bunga matahari  QUALITY OF COMMERCIAL SUNFLOWER OIL AND OIL EXTRACTION SEEDS SUNFLOWER (Helianthus annuus L.) ABSTRACT Experimental study of analyzing the extract oil from sunflower seed compare with the commercial sunflower seed oil according to the company standard which includes determining of moisture content, free fatty acid content, peroxide value and the fatty acids compositions is reported in this paper. The result show that the moisture content of the extract oil is 0,43%, free fatly acid content is 0,47%, and the peroxide value is 5,22% mek/Kg. For the commercial sunflower seed oil company product that is 0,21% for the moisture, free fatty acid is 0,28% and the peroxide value is 4,89 mek/Kg. The gas chromatography analysis indicated that the most fatty acid from both samples is linoleic acid. The quality of the extract sunflower seed oil has not been improved to conform with the commercial quality according to the company standard, that is 0,08% for the free fatty acid and 2 mek/Kg for the peroxide value. Keywords: Free fatty acid, peroxide value, sunflower seeds oil


2005 ◽  
Vol 56 (415) ◽  
pp. 1297-1303 ◽  
Author(s):  
Rafael Pleite ◽  
Marilyn J. Pike ◽  
Rafael Garcés ◽  
Enrique Martínez-Force ◽  
Stephen Rawsthorne

1984 ◽  
Vol 220 (2) ◽  
pp. 481-488 ◽  
Author(s):  
S Stymne ◽  
A K Stobart

The synthesis of triacylglycerols was investigated in microsomes (microsomal fractions) prepared from the developing cotyledons of sunflower (Helianthus annuus). Particular emphasis was placed on the mechanisms involved in controlling the C18- unsaturated-fatty-acid content of the oils. We have demonstrated that the microsomes were capable of: the transfer of oleate from acyl-CoA to position 2 of sn-phosphatidylcholine for its subsequent desaturation and the return of the polyunsaturated products to the acyl-CoA pool by further acyl exchange; the acylation of sn-glycerol 3-phosphate with acyl-CoA to yield phosphatidic acid, which was further utilized in diacyl- and tri-acylglycerol synthesis; and (3) the equilibrium of a diacylglycerol pool with phosphatidylcholine. The acyl exchange between acyl-CoA and position 2 of sn-phosphatidylcholine coupled to the equilibration of diacylglycerol and phosphatidylcholine brings about the continuous enrichment of the glycerol backbone with C18 polyunsaturated fatty acids for triacylglycerol production. Similar reactions were found to operate in another oilseed plant, safflower (Carthamus tinctorius L.). On the other hand, the microsomes of avocado (Persea americana) mesocarp, which synthesize triacylglycerol via the Kennedy [(1961) Fed. Proc. Fed. Am. Soc. Exp. Biol. 20, 934-940] pathway, were deficient in acyl exchange and the diacylglycerol in equilibrium phosphatidylcholine interconversion. The results provide a working model that helps to explain the relationship between C18- unsaturated-fatty-acid synthesis and triacylglycerol production in oilseeds.


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