Physicochemical Properties of Lacquer Berries and Decolorization of Lacquer Wax by Physical Adsorption and UV Irradiation
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Advances in Biological Chemistry, 2013, 3, 329-337 ABC http://dx.doi.org/10.4236/abc.2013.33037 Published Online June 2013 (http://www.scirp.org/journal/abc/) Physicochemical properties of lacquer berries and decolorization of lacquer wax by physical adsorption and UV irradiation Chengzhang Wang1,2,3*, Yanhe Dong1,2, Hongxia Cheng1,2, Yuanfeng He1,2, Jianzhong Ye1,2, Hao Zhou1,2,3 1Institute of Chemical Industry of Forest Products, CAF, Nanjing, China 2Key and Open Laboratory on Forest Chemical Engineering, SFA, Nanjing, China 3Institute of New Technology of Forestry, CAF, Beijing, China Email: *[email protected] Received 17 March 2013; revised 3 May 2013; accepted 17 May 2013 Copyright © 2013 Chengzhang Wang et al. This is an open access article distributed under the Creative Commons Attribution Li- cense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT Keywords: T. vernicifera; Lacquer Berries; Lacquer Wax; Physical Decolorization; UV Irradiation Physicochemical properties of No.1 - No.6 lacquer berries were investigated from different origins. The Japan Showafuku (No.1) was the best cultivar of 1. INTRODUCTION Rhus succedaneum, the size of the berry of it was Lacquer tree belongs to the family of Anacardiaceae. near 3 - 4 folds, which was bigger than the Chinese There are more than 73 general kinds and more than 600 cultivars (No.4 - No.6) of Rhus vernicifera et al. It had different species of lacquer trees all over the world. Most more than 5% ~ 10% of lacquer wax in pericard, and of them grow in the subtropical regions of southeast Asia. contained less than 6% - 8% of lacquer oil in seed. [1,2]. Rhus succedanea L. is a cultivated tree, it was No.1 had lower acid value (A.V) and iodine value originally introduced to Japan from China at the end of (I.V); the key factors for this were cultivar and its the 16th century AD via Ryukyu islands. About 30 spe- growing environment. The principal constituents of cies among these trees can produce as much as 1.5 mil- lacquer waxes of No.1 - No.6 were triglycerides of lion tons of lacquer berry per year, which contain large fatty acids with total saturated fatty acids (TSFA) of amounts of wax, while lacquer berry has not been proc- 75% - 82.7%, total unsaturated fatty acids (TUSFA) essed and utilized until now [3]. of 15.1% - 20%, and total dibasic acids (TDBA) of Lacquer wax has a wide range of applications such as 5%. The CIEL a b system and Hunter whiteness food, cosmetics, medicines, electronic photography toner, formula were used to evaluate the bleaching effect on etc. it has been used as edible vegetable oil in China min- lacquer wax by physical adsorption and ultraviolet ority, which can prevent stomach diseases, it is also the (UV) irradiation. The optimal conditions of physical excellent nutrition for puerpera. Japanese scholars de- decoloration were determined for activated carbon: velop a kind of coffee drinks of lacquer berry by baking kieselguhr = 3:2 (g/g) as adsorbent, a ratio of 1:20 lacqer seed, which is a benefit for digestion. (g/mL) for lacquer wax to petroleum ether, bleaching Lacquer wax is an important fatty resource from the 30 min at 80˚C. UV light achieved a good bleaching mesocarp of the berries of lacquer tree, i.e., T. verni- effect irradiated at 60˚C for 60 hrs. UV irradiation ciflua, T. sylvestris Sieb and rhus trichocarpa in China. definitely changed relative contents of fatty acids, Its principal constituents are triglycerides of fatty acids, TUSFA and TDBA decreased from 19.617% to long-chain aliphatic alcohol and pigments, and compared 11.022% and 4.379% to 2.017% respectively, while with the Japan wax, it has a similar physical properties TSFA could be raised from 76.462% to 86.077%, and chemical constituents in the main fatty acids par- however, the mechanism of UV irradiation was still ticularly. Japan wax is made from the berry of Rhus unclear and should be investigated in the future. succedanea L (hazenoki in Japanese). The difference lies in the cultivars and planting environment. For containing *Corresponding author. a special ingredient which is known as “Japan acid”, OPEN ACCESS 330 C. Z. Wang et al. / Advances in Biological Chemistry 3 (2013) 329-337 Japan wax, as a kind of high-grade fatty acid, exhibits its 10 h in the oven. The dried fruit, with less than 7.0% of excellent properties, such as tackiness, releasability, and water, were crushed to remove the husks and seed kernel, low iodine value as well as 100% natural in origin and the remained pulp was grounded into powder and stored nontoxic to human body [4-6], however lacquer wax in dryness and darkness. from China might have a much lower content than the Standard of methyl ethers of fatty acids were pur- Japan acid [7]. chased from Shanghai An Pu Chemical Reagent Co. As pigments are the key factors to involve the quality Ltd. Activated carbon, kieselguhr and solvents were of lacquer wax, more researches focus on the discolora- purchased from Nanjing chemical industries company, tion of lacquer seed oils and lacquer wax recently. Ad- Ltd. sorbents or chemical agents are used to decolorize and bleach lacquer wax, activated charcoal or acid clay is 2.2. Preparation of Lacquer Wax added directly to molten crude wax and then the ad- The pulp powder from No.5 sample was extracted by sorbent is separated by filtration. But research has found using petroleum ether (60˚C - 90˚C) with solid-liquid that activated carbon had poor bleaching, what’s more, ratio of 1:20 (g/mL), at 80˚C for 60 min, twice then to powdered activated carbon was very difficult to filtrate combinate the extraction solution, filtered and condensed [8]. A traditional method to produce Japan wax is to re- in vacuum, the residue yielded raw lacquer wax with move the pigments with the aid of sun’s ray [9,10], green color. however, it wholly depends on weather conditions and time-consuming. Due to its low yield and labor-inten- 2.3. Physical Discoloration of Lacquer Wax siveness, this old-fashioned method is uneconomical and 4 inefficient. Single factors experiments and L9 (3 ) orthogonal experi- It is suggested that UV ray irradiation may serve as an ments of three factors (ratio of raw wax to solvent alternative and effective decoloration method without (g/mL), discolor temperature and times) were designed. depending on weather conditions. Meguro S et al. had 10 g of raw wax was dissolved in petroleum ether each investigated physical properties, major fatty acid con- time, water was added for keeping a special temperature. tents and seasonal variations of some chemical consti- After filtrating, the filtrate was condensed under vacuum, tuents of the Japan wax [11-13], however, very few the residue was cooled and obtained solid of lacquer wax. literatures reported the bleaching effection of physical The whiteness of the lacquer wax was then measured by adsorption and UV light on lacquer wax, particularly in Hunter completely whiteness formula. physico-chemical properties of lacquer wax. The aim of this paper was to investigate the physicochemical prop- 2.4. UV Irradiation of Lacquer Wax erties of different species and discoloration process of 10 g of raw lacquer wax from sample 5 was placed in a lacquer wax from lacquer berries via physical adsorption petri dish (6 cm inside diameter (ID) × 1.1 cm height and UV irradiation. (H)), and irradiated under a UV lamp of 400 W at 360 nm. The irradiated time change from 10 to 80 h at 50˚C, 2. MATERIALS AND METHODS 60˚C and 70˚C, respectively, the whiteness of the sam- 2.1. Lacquer Berries and Chemicals ples was measured after solidification by Hunter com- pletely whiteness formula. No.1 - No.6 samples are the berries of lacquer tree. No.1 sample was collected from japan native Showafuku cul- 2.5. Detection Method of Whiteness tivar of Rhus succedanea L, grafted over 10 years in Kyushu area in japan. No.2 sample was from the intro- Under the Huntersystem, WSC-S colorimeter was pre- duced Showafuku cultivar of Rhus succedanea L from heated for 30 min. As the chromaticity of L, a, b of japan, grafted about 3 - 4 years in Lindu county, Jiangxi lacquer wax was measured, the hunter whiteness could province, No.3 sample also from the introduced Showa- be calculated by using Hunter completely whiteness fuku cultivar, but seeded about 8 - 10 years in the same formula. 12 plantation in Jiangxi province. No.4 sample was from W = 100 100 L2 a22 b local cultivar of T. vernicifera seeded over 25 years in Enshi area, Hubei province, No.5 sample was from local W—Hunter whiteness of the sample; L—Hunter cultivar of T. sylvestris Sieb seeded over 20 years in lightness index; a, b—Hunter chromaticity. Ankang area, Shanxi province, and No.6 sample was WSC-S colorimeter was used to characterize the dis- from local cultivar of rhus trichocarpa seeded over 20 coloration effect of the lacquer wax, while chromaticity years in Lujiang area, Yunnan province. All samples values were used to represent the change of the pig- were collected in November, 2012, then dried at 45˚C for ments. Copyright © 2013 SciRes. OPEN ACCESS C. Z. Wang et al. / Advances in Biological Chemistry 3 (2013) 329-337 331 2.6. Determination of Chemical Constituents of than local seeded cultivars in china, but also had more Fatty Acids of Lacquer Wax 5% ~ 10% of lacquer wax in pericard, and contained less 6% ~ 8% of lacquer oil.