The Recent study aimed to identify the optimum conditions for inulin extraction from jerusalem artichoke tuber (JAT) powder using microwave assisted extraction method, and partially hydrolysis of purified inulin for producing fructooligosaccharide (FOS) using citric acid & microwave energy. The extraction conducted at different temperature (90 – 95) C˚ at (700 W/5min, 450w/8 min and 350w/14 min). The extracted inulin was concentrated to (50 – 60) % of original volume using rotary evaporator, and purified by lime method. The purified inulin extract was concentrated to 32 brix and mixed with acetone (3:1 acetone : extract), kept for 24 h at 4 C˚, then centrifuged at 10000g / 15 min., the precipitate dried at 55 ˚C. Acid hydrolysis of purified inulin carried out at different pH values (1.5, 2.5 & 3.0) at (90 ±2) ˚C. Aliquot of inulin hydrolysate were taken after (5, 10, 15, 20, 25 & 30) min. and subjected to qualitative analysis by RP-HPLC and TLC. The obtained results indicated that the microwave assisted extraction at 700 W/ 5 min. / 95 ˚C was superior as compared to the rest. The yield of extracted inulin was about 39.61 % and the extraction efficiency was 94.31 %, while the optimum condition for inulin acid hydrolysis appeared to be at 90 ˚C/ 15 min at pH 2.5 and 450 W. The qualitative analysis using (RP-HPLC & TLC) showed that the DP of inulin units ranged from (2 - 35) and for FOS ranged from      (2 – 9) unit.

The objective of this study was to produce fructooligosaccharide (FOS) from fresh jerusalem artichoke (JAT) inulin which was extracted by conventional method (hot water extraction) at two different temperature (80˚C & 90˚C\ 90 min). JAT slices were mixed with distilled water at (1 : 5) (w : v) ratio, the obtained extract purified and concentrated to 32˚Brix, then mixed with acetone (1 : 3) (v : v), kept at 4˚C for 24 h., centrifuged at 10000g/ 15 min., and the precipitate dried at 55˚C. Acid hydrolysis of the dried inulin was carried out at three different pH values being (1.5, 2.5 & 3.0) at 85˚C using citric acid (10 %), aliquot of inulin hydrolysate were taken after (5, 10, 15, 20, 25 & 30) min. for qualitative analysis using TLC and RP-HPLC. The results revealed that there were no significant differences in the yield of extracted inulin (33.86, 33.67 %) and extraction efficiency (80.62, 80.17 %) between the extraction at 80˚C and 90˚C\ 90 min. respectively. The optimum condition for acid hydrolysis of the obtained inulin was at pH 2.5 after 15 min at 85˚C. The qualitative analysis for hydrolysate using TLC and RP-HPLC showed that the degree of polymerization (DP) of inulin ranged from (2 - 35) unit and for FOS ranged from (2 – 9) units.