NAROSSA® International Conference for Renewable Resources and Plant Biotechnology 18th conference, NAROSSA® 2012 in Magdeburg, Germany, June 4–5, 2012
UNIVERSITY OF FOOD TECHNOLOGIES Bulgaria, 4002 Plovdiv, 26, bulv. “Maritza“
O
O
O
NEW FATTY ACID ESTERS OF SOLUBLE DIETARY FIBERS WITH EMULSIFYING PROPERTIES
CH2
NADEZHDA PETKOVA*, MINA TODOROVA*, NIKOVSKA KREMENA**, PANTELEY DENEV*
O
O
*University of Food Technologies, Department of Organic Chemistry and Microbiology, 26 Maritza Blvd., Plovdiv, Bulgaria, **University of Food Technologies, Departament of Catering and Tourism, 26 Maritza Blvd., Plovdiv, Bulgaria,
CH2
E-mail address:
[email protected],
[email protected] C=O (ester groups)
FT-IR specta of inulin and inulin starate (DS 0,33)
O
80
–OH alcohol groups
40
25
1556.80
50
free –OH groups
0 40 00
35 00
30 00
25 00
20 00
15 00
20
10
2917.17
3373.58
10
1031.20
1132.31
15
5
CH 2
0
10 00
50 0
40 00
597.40 719.76
936.76 987.86
O
1033.19
O
CH 2
2849.52
30
20
1439.03
1742.63
60
1469.80
30
936.09
2930.43
35
599.31
40
70
%T
1417.63
45
3330.54
820.06
1646.54
50
1421.21
80
55
1171.58
60
1197.86
90
1215.49
65
10 0
1379.73
70
11 0
3773.05
75
%T
Abstract Fatty esters of carbohydrates constitute an interesting group of non-ionic surfactants. These compounds are environmentally friendly, with low toxicity and present interest in agriculture, pharmaceuticals, cosmetic and food industry. Inulin and fructooligosaccharides esters were synthesized by reacting these carbohydrates with methyl esters of saturated fatty acids (C12 to С18). The esterification reaction was performed in presence of catalyst NaOMe and absence of solvent. A new method for synthesis with the ultrasonic influence has been developed and applied. The fructooligosaccharides esters and modified inulin have been characterized by measurement of melting point, water activity, thin-layer chromatography (TLC) and FT-IR. A preliminary study of their emulsifying and stabilizing properties was analyzed. The rheological properties, dispersion and emulsion stability of oil-in-water emulsions (O/W) prepared with different concentration of inulin esters as emulsifier were investigated.
O
35 00
30 00
W aven umb ers (c m-1)
Successful esterification 25 00
20 00
15 00
O
O
10 00
50 0
W aven umb ers (c m-1)
Figure 3. FT-IR spectrum of inulin
Figure 4. FT-IR spectrum of synthesized inulin stearate
CH2 O O
Emulsion study
inulin backbone
Introduction Fatty esters of carbohydrates constitute an interesting group of non-ionic surfactants. These compounds present a good biodegradability and a low toxicity, which confer to them a particular interest in pharmaceutical, cosmetic, food industry and agriculture. Polymeric surfactants attract considerable attention as dispersants for solid in liquid medium and as emulsifiers. In recent years, the interest to surfactants that are based on polysaccharides via the grafting of alkyl chains increased dramatically. Inulin is a polydisperse linear polysaccharide, member of fructan family and serves as a reserve carbohydrate in underground part of the Compositae plants. Inulin consists mainly of β-(2→1) fructosyl fructose units (Fm), and usually but not always the chain contains a terminal α-glucopyranose unit (1→2) (GFn) at the reducing end (Figure 1). A small percentage of inulin molecules have a terminal fructoside unit found primarily in the pyranose form in aqueous solution. The degree of polymerization (DP) of inulin varies from 2 to 70 and depends on plant species, harvesting time and post-harvest conditions. Molecules with DP
