Abstract:

The extraction conditions of insoluble dietary fiber (IDF) from apricot kernel skins were optimized using
response surface methodology by modeling extraction yield with respect to three variables including alkali concentration,
ultrasonication time and extraction temperature. Furthermore, factors affecting the water-holding capacity and swelling
capacity of IDF were also studied. The results showed that the optimal extraction conditions were as follows: sodium
hydroxide concentration, 0.70 mol/L; ultrasound-assisted extraction time, 51 min; and extraction temperature, 86 ℃. The
extraction yield of IDF was 49.73% under these conditions. In addition, this study found that the water-holding capacity and
swelling capacity of the IDF were affected less by glucose concentration, but significantly by pH and temperature within the
investigated ranges.

Key words: apricot kernel skin, insoluble dietary fiber, response surface methodology, water-holding capacity, swelling capacity