Fatty Acid Composition of Cultured Butter with Probiotic Lbc. Acidophilus La-5 Produced in Winter Time
The objective of our study was to determine the fatty acid composition of sweet butter (SB) and cultured butter (CB) after Lbc. acidophilus was added to the starter. Control butter was churned from sweet cream (SB). Starters Flora Danica (Lac. lactis, Lac. cremoris, Leu. cremoris, Lac. diacetilactis and Lbc. acidophilus La-5), provided by Chr. Hansen, were used. Four groups of CB were produced: group 1 – cream fermented at 30ºC for 6 hours by Flora Danica (CB1), 1:1 Flora Danica and La-5 (CB2) and La-5 (CB3); group 2 – cream fermented at 37ºC for 6 hours by Flora Danica (CB4), 1:1 Flora Danica and La-5 (CB5) and La-5 (CB6); group 3 (Alnarps Winter method) – left for 2 hours at 8°Ñ, heated up to 20°Ñ and starter Flora Danica (CB7), 1:1 Flora Danica and La-5 (CB8) and La-5 (CB9) were added and fermented for 8 hours, then cooled down to 12°Ñ and left for 10 hours; group 4 –starter Flora Danica (CB10), 1:1 Flora Danica and La-5 (CB11) and La-5 (CB12) were added to the butter grain. The experiment was replicated 3 times. Butter samples were stored at 20ºC before the fatty acid analysis by GLC. The FAME were separated in a chromatography column (Hewlett Packard 6890, 100 m × 0,25 mm × 0,2 µm [HP-88] 88%-cyanopropyl aryl-polysilixane, Agilent Technologies). The total content of the trans-9 isomers was 1.22 g in SB, whereas in CB2 the value was the lowest, i.e. 1.02 g/100 g of fatty acids. The total content of trans-11 isomers was the highest in CB2 (7.92 g/100 g) vs. 7.56 g/100 g of fatty acids in the SB (p <0.05). Trans-11 C18:1 content increased from 5.19 in SB to 5.28-5.41% in the CB, the highest value observed for CB2 (p < 0.05). The percentage of cis-9,trans-11 CLA was the highest for CB2, CB5, CB6, CB8, when Flora Danica was combined with La-5, and for pure La-5 at 37°C (the optimal inoculation temperature for this strain). The total percentage of unpaired and branched-chain fatty acids was the same for all samples, but the percentage of medium-chain saturated fatty acids (C12-C16) slightly decreased from 37.34% in the SB to 37.0% in CB7 and CB9. CB1 and CB2 possessed the best taste, flavour and texture. Thus, adding La-5 into starter for cultured butter stimulates the 11-trans isomerisation of fatty acid and provides probiotic properties of cultured butter.
butter, cultured butter, La-5, fatty acid