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PP-23

Total fructan contents in common Thai fruits

1, 2 2, 3 1, 2
Jiradej Manosroi , Abubakar Gidado , Aranya Manosroi
1
Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand, 50200.
2
Natural Products Research and Development Center (NPRDC), Science and Technology Research Institute, Chiang Mai
University, Chiang Mai, Thailand, 50200.
3
Biochemistry Department, Faculty of Science, University of Maiduguri, Maiduguri, Nigeria.

Rationale: Fructans are oligo- and polysaccharides consisting of short chain of fructose units with a
single D-glucosyl unit at the non-reducing end. They include the fructooligosaccharides (FOS) and the inulins.
They are widely distributed in fruits and vegetables and are reported to be very effective in improving the
functions of the intestines, preventing constipation and diarrhea, lowering blood cholesterol and increasing the
bodyûs immunity.
Objective: The objective of this work is to establish the presence of fructans in Thai fruits and determine

their contents. The Thai fruits selected for this study include Longan (Dimorcarpus longan Linn), Long kong
(Angaia sp), Lychee (Litchi chinensis Sonn), Mangosteen (Garcinia mangostana L.), Persimmon (Diospyros kaki
Linn), Rambutan (Nephelium lappaceum L), Java apple (Syzygium samarangense), Star fruit (Averrhoa carambola)
and Sala (Salacca sp).
Methodology: The total fructan contents of the fruits were extracted using the hot water extraction
method according to Muir et al (2007). Fructose contents were assayed using the method of Sadasivam and
o
Manickam (1997). Briefly, fresh fruits were first blended to a homogenous mixture. Hot water (80 ml, 80 C) was
then added to 1g of the blended fruit mixture and heated on a magnetic stirrer for 15 minutes. The extract was
cooled to room temperature and quantitatively transferred to a 100 ml volumetric flask and the volume was

adjusted with water. The extract was then filtered and the fructose contents assayed by spectrophotometry.
Results: All fruits contained the fructans ranging between 1.72 - 2.30% of the total fructan. Lychee (Litchi
chinensis Sonn) showed the highest concentration of 2.30 ± 0.30 %, while Sala (Salacca sp) gave the least
content of 1.72 ± 0.03% of the total fructan.
Conclusion: The results have suggested that Thai fruits contain high content of fructans. The information
from this study will be used for further development of fructan from Thai common fruits for food supplements.
Keywords: Fructans; Fructooligosaccharides (FOS); Thai fruits.

Selected references:

Muir, J.G., Shepherd, S.J., Rosella, O., Rose, R., Barrett, J.S. and Gibson, P.R. (2007). Fructan and free
fructose content of common Australian vegetables and fruit. J. Agric. Food Chem. 55: 6619-6627
Sadasivam, S. and Manickam, A. (1997). Determination of fructose and inulin, In: Biochemical Methods,
Accredited Business, New York, pp: 15-17.