CN1147238C - Refined edible lac and its preparing method - Google Patents

Abstract

The present invention relates to a refined edible lac and a preparation method and an application thereof. Natural lac granules are completely dissolved by water under the conditions of pH of 6 to 8 and temperature of 60 DEG C to 100 DEG C. A bleaching agent which is compounded from chlorine dioxide, ozone, sodium chlorite, sodium hypochlorite and sodium citrate is adopted. Bleaching temperature is from 20 DEG C to 60 DEG C, and bleaching time is from 30 to 60 minutes. Then, a stabilizer is added to be stabilized for 30 to 60 minutes. Filtration and dewaxing are carried out by a molecular sieve, acetate fiber and polysulfone fiber. A powder product which is the refined edible lac is obtained from a lac solution after being dewaxed by crystallisation, resolution, washing, centrifugal dewatering, waterproof pulverization and hot air drying. The existing bleaching time is shortened from 20 hours to less than one hour by the present invention. The total cost of the bleaching agent is lowered by 20% more or less. The storage period of a product is enhanced from 3 to 6 months to 24 months.

Description

A kind of refined edible lac and preparation method thereof

Affiliated technical field

The present invention relates to a kind of lac, more particularly, the present invention relates to a kind of lac of food grade, the invention still further relates to the preparation method of described lac simultaneously.

Background technology

Natural lac (shellac) claim shellac or Shellac again.A kind of natural resin.Suck and digest juice behind the myron drying of on branch, condensing and form by parasitizing tachardia lacca on the shellac tree.Red-purple.Natural lac is a kind of excellent property, comprehensive natural resin, contains sclerolac and a spot of shellac wax, lac pigment etc., the brown or white flake lac of yellowly after making with extra care.Lac after refining has become a kind of important industrial raw material, obtains widespread use in more than 200 industries such as papermaking, printing, food and furniture manufacturing.But, according to prior art purified lac, remaining in unstable product quality, the shelf-time is too short.Bleaching time is long, and the SYNTHETIC OPTICAL WHITNER consumption is big, and the high deficiency of production cost presses for improvement.

Bleaching glue is destroyed coloring matter contained in the lac with SYNTHETIC OPTICAL WHITNER, makes the product of lac light colorization, and the SYNTHETIC OPTICAL WHITNER of using at most is Naclo, and it is put into the NaCO that is dissolved with the raw material lac ₃In the aqueous solution, behind the elimination impurity, acidifying, be settled out bleaching glue, through washing, drying, promptly become product again.But this bleaching method has a fatal weakness, promptly bleach and contain the combined chloride that is connected on the molecular resin in the glue, the combined chloride instability, the form that can bleach again in drying or the storage process with HCl breaks away from resin, the catalytic resin polymerization, make the product staging life very short, cause bleach product to lose use value very soon.

" development of bleaching processing technology and the situation in Guangdong " (" the Guangzhou chemical industry " of Kazakhstan Cheng Yong etc., 1996.23 (2)) summarized each link of bleaching glue processing technology, comprise raw material, SYNTHETIC OPTICAL WHITNER, system pH, acidifying with sour, the selection of aftertreatment and product storage requirement, point out that the period of storage of bleaching glue at present in the world also can only reach half a year, though the stability of domestic bleaching glue increases, period of storage is two years of less than still.

Summary of the invention

In order to overcome shortcomings such as existing white shellac period of storage is too short, the invention provides the refined edible lac of bringing up to a kind of storage period more than 2 years.

Simultaneously, the present invention also provides a kind of preparation method of refined edible lac.

Technical scheme

Refined edible lac provided by the invention can be prepared by following method: water is dissolving fully under 60 ℃～100 ℃ with natural lac particle in temperature, and water and natural lac particulate weight ratio are 4: 1; Add SPC-D or Sodium peroxoborate or yellow soda ash the pH value is adjusted to 6～8.Adopt the mixed bleach agent that lac liquid is bleached, described mixed bleach agent is made up of A, B two portions, and wherein the weight percentage partly formed of A is: water 94.5%, Textone 2.0%, clorox 3.0%, Trisodium Citrate 0.5%; The weight percentage that B partly forms is: water 90.5%, dioxide peroxide 9.0%, ozone 0.5%; A component and B component mix by 3: 1 weight ratio then, are mixed bleach agent of the present invention.Mixed bleach agent consumption and natural lac particulate weight ratio are 0.6～1.2: 1,20 ℃～60 ℃ of bleaching temperatures, bleaching time 30～60 minutes.Add stablizer then, stabilizing treatment 30～60 minutes.Again through molecular sieve and cellulose acetate, polysulfone fibre filter take off cured.The shellac solution that takes off after cured is refined edible lac through the powder-like product that crystallization parsing, washing, centrifuge dehydration, wet pulverization and warm air drying obtain.

Wherein the consumption of mixed bleach agent is to adopt test method to determine the bleaching index, and is bigger according to the different difference of lac raw materials quality.Because of the raw material lac is divided into superfine, the I level, the II level, the III level, five grades such as IV level, the consumption that reaches the requirement of bleaching color with test method is a coefficient, promptly bleaches index, determines the production add-on then.

The invention provides a kind of preparation method of refined edible lac, this method comprises the step of following order:

(1) water is dissolving fully under 60 ℃～100 ℃ with natural lac particle in temperature, and water and natural lac particulate weight ratio are 4: 1, adds SPC-D the pH value is adjusted to 6～8;

(2) shellac solution is cooled to below 60 ℃, with the mixed bleach agent lac liquid is bleached, described mixed bleach agent is made up of A, B two portions, wherein the weight percentage partly formed of A is: water 94.5%, Textone 2.0%, clorox 3.0%, Trisodium Citrate 0.5%; The weight percentage that B partly forms is: water 90.5%, dioxide peroxide 9.0%, ozone 0.5%; A component and B component mix by 3: 1 weight ratio then, are mixed bleach agent of the present invention; Mixed bleach agent consumption and natural lac particulate weight ratio are 0.6～1.2: 1,20 ℃～60 ℃ of bleaching temperatures, bleaching time 30～60 minutes;

(3) add the stablizer that accounts for whole slurry weight 0.5%～1.5%, stabilizing treatment 30～60 minutes then;

(4) filter dewaxing through molecular sieve and cellulose acetate, polysulfone fibre;

(5) the shellac solution dilute with water after will dewaxing, measuring refractive index with refractometer is 8～10, carries out crystallization and resolves, and the pH value is controlled at 2.5～5, and temperature is controlled at 20 ℃～60 ℃;

(6) be washed with water to neutrality, centrifuge dehydration, wet pulverization is 25 ℃～28 ℃ following warm air dryings in temperature, product is required refined edible lac.

Among the above-mentioned preparation method, add stablizer in step (3), described stablizer is selected from a kind of in sodium borohydride, POTASSIUM BOROHYDRIDE, Sodium Pyrosulfite, the Sulfothiorine or their mixture.

Beneficial effect: the present invention adopts the mixed bleach agent to bleach natural lac, and bleaching time was foreshortened in 1 hour from existing 20 hours, and the consumption of SYNTHETIC OPTICAL WHITNER reduces 50%.Molecular sieve filtration is adopted in dewaxing, and wax content is dropped to below 0.1% from 5%, reclaims shellac wax simultaneously.With the dioxide peroxide decolouring, the lac color index drops to below No. 1.Product is handled through stability, and 170 ℃ ± 1 heat embrittlement time was brought up to more than 4 minutes.The period of storage of product was brought up to more than 2 years, had successfully solved this technical barrier that this area exists for a long time.

The invention will be further described below by specific embodiment, but content of the present invention is not limited to shown in the embodiment.

Embodiment 1

Water is dissolving fully under 85 ℃ with natural lac particle in temperature, and water and natural lac particulate weight ratio are 4: 1; Add SPC-D or Sodium peroxoborate or yellow soda ash and regulate pH value to 7; Slurry is cooled to 50 ℃, adopts the mixed bleach agent that lac liquid is bleached, described mixed bleach agent is made up of A, B two portions, and wherein the weight percentage partly formed of A is: water 94.5%, Textone 2.0%, clorox 3.0%, Trisodium Citrate 0.5%; The weight percentage that B partly forms is: water 90.5%, dioxide peroxide 9.0%, ozone 0.5%; A component and B component mix by 3: 1 weight ratio then.Mixed bleach agent consumption and natural lac particulate weight ratio are 0.8: 1.Dioxide peroxide and ozone produce with the BTT-100-200DA producer.50 ℃ of bleaching temperatures, bleaching time 45 minutes.The sodium borohydride that adds slurry weight 1% then is as stablizer, stabilizing treatment 45 minutes.Again through molecular sieve and cellulose acetate, polysulfone fibre filter take off cured.The shellac solution that takes off after cured is refined edible lac through the powder-like product that crystallization parsing, washing, centrifuge dehydration, wet pulverization and warm air drying obtain.Through the test of Kunming product quality supervision and testing institute, the quality product contrast is as shown in table 1.

The quality synopsis of table 1. product of the present invention

Cl content	/	/	1.5 3.0	1.0 1.0	/
						170 ℃ of seconds heat embrittlement time.(heat life)≤	60	/	//	//	300-400
Storage period.Month	3～6	3～6	33	3～6	24
						Edibility	Food grade	Food grade	Not	Not	Food grade

Annotate: domestic existing dechlorination bleaching glue product does not also reach food grade, and the national standard of relevant dewaxing, decolouring still under study for action.The determination data of table 1 clearly illustrates that every technical indicator of the present invention all is in international most advanced level, especially reaches 2 years the storage period of product, transportation, preserves all easily, makes product have wide development application prospect more.

Embodiment 2～embodiment 4

Except stablizer was selected a kind of in POTASSIUM BOROHYDRIDE or Sodium Pyrosulfite or the Sulfothiorine respectively, other process was with embodiment 1.

Embodiment 5

II level raw material lac particulate mass analysis (weight %) is as follows: moisture content 2.5, hot ethanol insolubles 4.0, the water solubles 1.0, wax content 4.2; Color index is No. 11.With refined edible lac check analysis result such as the table 2 that obtains after the method processing of this raw material lac particle by embodiment 1.

Table 2.

Sequence number	Project	Analytical results
			1	Moisture content (weight %)	4.0
2	Hot ethanol insolubles (weight %)	0.06
			3	The U.S.'s 15% chlorine method solubility property	Transparent nothing precipitation
4	U.S.'s ammonia process color number	5
			5	Wax content (weight %)	0.07
6	Acid number KOH Mg/g	86
			7	Iodine number	3

8	Ash (weight)	0.13
			9	170 ℃ of heat embrittlement times (second)	300″

Annotate: the present invention judges bleaching exponential method, goes to measure color according to U.S.'s ammonia and is standard numbers No. 7, contrasts Chinese color measurenent method and be to be equivalent to U.S.'s ammonia process No. 0.5 and to measure No. 7, color.With Chinese color measurenent method (iodine method) preparation standard color solution color number is No. 1,0.8 number, 0.5 number, No. 0.3, put into four colorimetric cylinders respectively, the contrast colorimetric, color is to when in 0.5 the time, i.e. mixed bleach agent add-on is to terminal point, the mixed bleach dosage that is consumed, be the lac particulate bleaching index of this batch raw material, instruct with this and produce with mixed bleach agent consumption.

Claims (2)

1. refined edible lac is to be prepared by following method: water is dissolving fully under 60 ℃～100 ℃ with natural lac particle in temperature, and water and natural lac particulate weight ratio are 4: 1; Add SPC-D or Sodium peroxoborate or yellow soda ash the pH value is adjusted to 6～8; Adopt the mixed bleach agent that lac liquid is bleached, described mixed bleach agent is made up of A, B two portions, and wherein the weight percentage partly formed of A is: water 94.5%, Textone 2.0%, clorox 3.0%, Trisodium Citrate 0.5%; The weight percentage that B partly forms is: water 90.5%, dioxide peroxide 9.0%, ozone 0.5%; A component and B component mix by 3: 1 weight ratio then; Mixed bleach agent consumption and natural lac particulate weight ratio are 0.6～1.2: 1,20 ℃～60 ℃ of bleaching temperatures, bleaching time 30～60 minutes; Add stablizer then, described stablizer is selected from a kind of in sodium borohydride, POTASSIUM BOROHYDRIDE, Sodium Pyrosulfite, the Sulfothiorine or their mixture; Stabilizing treatment 30～60 minutes; Again through molecular sieve and cellulose acetate, polysulfone fibre filter take off cured; The shellac solution that takes off after cured is refined edible lac through the powder-like product that crystallization parsing, washing, centrifuge dehydration, wet pulverization and warm air drying obtain.

2. the preparation method of a refined edible lac, this method comprises the step of following order:

(1) water is dissolving fully under 60 ℃～100 ℃ with natural lac particle in temperature, and water and natural lac particulate weight ratio are 4: 1, adds SPC-D the pH value is adjusted to 6～8;

(2) shellac solution is cooled to below 60 ℃, with the mixed bleach agent lac liquid is bleached, described mixed bleach agent is made up of A, B two portions, wherein the weight percentage partly formed of A is: water 94.5%, Textone 2.0%, clorox 3.0%, Trisodium Citrate 0.5%; The weight percentage that B partly forms is: water 90.5%, dioxide peroxide 9.0%, ozone 0.5%; A component and B component mix by 3: 1 weight ratio then, are mixed bleach agent of the present invention; Mixed bleach agent consumption and natural lac particulate weight ratio are 0.6～1.2: 1,20 ℃～60 ℃ of bleaching temperatures, bleaching time 30～60 minutes;

(3) add the stablizer account for whole slurry weight 0.5%～1.5% then, described stablizer is selected from a kind of in sodium borohydride, POTASSIUM BOROHYDRIDE, Sodium Pyrosulfite, the Sulfothiorine or their mixture; Stabilizing treatment 30～60 minutes;

(4) filter dewaxing through molecular sieve and cellulose acetate, polysulfone fibre;

(5) the shellac solution dilute with water after will dewaxing, measuring refractive index with refractometer is 8～10, carries out crystallization and resolves, and the pH value is controlled at 2.5～5, and temperature is controlled at 20 ℃～60 ℃;

(6) be washed with water to neutrality, centrifuge dehydration, wet pulverization is 25 ℃～28 ℃ following warm air dryings in temperature, product is required refined edible lac.