Effect of electron beam irradiation pretreatment on the structural, physicochemical properties of potato starch-fatty acid complexes and the proliferation of Bifidobacterium adolescentis.

Abstract

The effects of different electron beam irradiation doses (5 KGy, 10 KGy, 20 KGy) on the complexation of potato starch with four saturated fatty acids with different chain lengths, i.e., lauric acid (LA), myristic acid (MA), palmitic acid (PA), and stearic acid (SA), were investigated, including structural properties, physicochemical properties, digestive properties, and the effect of Bifidobacteria proliferation. The complexing index increased significantly with increasing irradiation dose and showed the following order: 20 KGy > 10 KGy > 5 KGy > native starch. At irradiation dose of 20 KGy, PA (88.75 %) showed the highest complexing index, followed by MA (87.40 %), SA (82.95 %) and LA (72.33 %). The results of microstructure, relative crystallinity, gelatinization enthalpy, contact angle, and resistant starch content in starch-fatty acid complexes were consistent with the complexing index. In vitro digestion indicated that at irradiation dose of 20 KGy, the addition of PA yielded the highest content of resistant starch (50.35 %), followed by MA (49.25 %), SA (47.05 %) and LA (44.72 %). The four complexes were eventually assessed for their effects on Bifidobacteria's proliferation, with PA exerting the strongest proliferative effects, followed by MA, SA and LA. Overall, electron beam irradiation exhibited good application prospects in the field of starchy food processing and functional foods development.