Abstract:

The content change of soybean lecithin was investigated during storage under various illuminations. Results indicated that illumination had a significant effect on the peroxide value of soybean lecithin. Fluorescent lamp, ultraviolet lamp and incandescent lamp exhibited an effect on acid the value of soybean lecithin from strong to weak. After the dark storage for 60 h, the peroxide value and acid value of soybean lecithin were 21.10 mmol/kg and 38.83 mgKOH/g, respectively. Meanwhile, the effect of different packaging materials on soybean lecithin was also investigated under the identical illumination condition. The packaging materials with better photopathy could result in the smaller peroxide value of soybean lecithin. The preservative effect on soybean lecithin exhibited an order as follows: aluminum foil membrane ＞ composite film ＞ polyester film ＞ olypropylene film. The peroxide value of soybean lecithin packaged by aluminum foil membrane under illumination for 60 h with fluorescent lamp was still as low as 21.18 mmol/kg.

Key words: soybean lecithin powder, peroxide value, acid value, p-anisidine value, storage stability