TITLE:
Physicochemical properties of lacquer berries and decolorization of lacquer wax by physical adsorption and UV irradiation
AUTHORS:
Chengzhang Wang, Yanhe Dong, Hongxia Cheng, Yuanfeng He, Jianzhong Ye, Hao Zhou
KEYWORDS:
T. vernicifera; Lacquer Berries; Lacquer Wax; Physical Decolorization; UV Irradiation
JOURNAL NAME:
Advances in Biological Chemistry,
Vol.3 No.3,
June
25,
2013
ABSTRACT: Physicochemical properties of No.1 - No.6 lacquer
berries were investigated from different origins. The Japan Showafuku (No.1) was the best cultivar of Rhus
succedaneum, the size of the berry of
it was near 3 -4 folds, which was bigger than the Chinese cultivars (No.4 - No.6) of Rhus vernicifera et al. It had more than 5% ~ 10% of lacquer wax in
pericard, and contained less than 6% - 8% of lacquer oil in seed. No.1
had lower acid value (A.V) and iodine value (I.V); the key factors for this were
cultivar and its growing environment. The principal constituents of lacquer
waxes of No.1- No.6 were triglycerides of fatty acids with total saturated
fatty acids (TSFA) of 75% - 82.7%, total unsaturated fatty acids (TUSFA) of 15.1% - 20%, and total dibasic acids (TDBA) of 5%. The CIEL a b system and Hunter
whiteness formula were used to evaluate the bleaching effect on lacquer wax by
physical adsorption and ultraviolet (UV) irradiation. The optimal conditions of
physical decoloration were determined for activated carbon: kieselguhr = 3:2 (g/g)
as adsorbent, a ratio of 1:20 (g/mL) for lacquer wax to petroleum ether, bleaching
30 min at 80?C. UV light achieved a good bleaching effect irradiated at 60?C
for 60 hrs. UV irradiation definitely changed relative contents of fatty acids,
TUSFA and TDBA decreased from 19.617% to 11.022% and 4.379% to 2.017% respectively,
while TSFA could be raised from 76.462% to 86.077%, however, the mechanism of
UV irradiation was still unclear and should be investigated in the future.