CN1028109C - Method for extracting melanin from black sesame - Google Patents

Abstract

The invention relates to a method for extracting melanin from black sesame. The key point is that the melanin in the black sesame is leached by alkaline solution, the alkaline leaching solution is acidified to flocculate the melanin, the melanin is dissolved in sodium carbonate after filter pressing, and the water-soluble melanin is prepared by evaporation. The method adopts a non-toxic process, has simple equipment, less investment, good product quality, easy water dissolution and convenient use. The sesame after pigment extraction can still produce sesame oil, thereby achieving the purposes of comprehensive utilization, cost reduction and economic benefit improvement.

Description

Extraction of melanin from black sesame

The present invention relates to a kind of is the method that raw material adopts nonpoisonous craft process extraction of natural melanin with the Semen Sesami Nigrum.

The Semen Sesami Nigrum sweet property of distinguishing the flavor of is flat, nontoxic, have invigorating the liver and kidney, benefiting essence-blood, ease constipation dry, promote the production of body fluid, different physiological roles such as hair care, be a kind of traditional effective nourishing food, motherland's medical science is very high to the evaluation of effect of Semen Sesami Nigrum.It is main relevant with its melanochrome that many physiological functions of Semen Sesami Nigrum are different from white sesame.In addition, raising along with science and technology development and human living standard, natural black pigment will be more and more widely be used for that medicine is painted, fields such as makeup and foodstuff additive, to substitute synthesis of melanin, very few in occurring in nature melanochrome kind, so the extraction of natural black pigment is more urgent and needs.At present, extract melanic method by Semen Sesami Nigrum and be not seen in document as yet.

The objective of the invention is to seek a kind of is raw material with the Semen Sesami Nigrum, adopt the method for nonpoisonous craft process extraction of natural melanin, the sesame melanochrome that present method is extracted can make tinting material and other occasions are used, and the sesame substance behind the extraction melanochrome still can be produced sesame oil, the effect that can reach the comprehensive utilization agricultural resource, reduces cost, increases economic efficiency.

Present method technology is simple, less investment, and quality product is excellent, can be water-soluble, easy to use.

The objective of the invention is to realize through the following steps: choosing Semen Sesami Nigrum is raw material, and washing is clean, adds NaOH or Na that concentration is 0.5-5% by a certain percentage ₂CO ₃Solution soaked 8-24 hour at 25-100 ℃, obtained filtrate after the filtration; Soak again once with similarity condition, merge filtrate twice, its filter residue is cleaned the back oven dry for oil expression usefulness with less water, and filtrate and washings are merged, and adds hydrochloric acid or sulfuric acid and makes it to be acidified to pH value 1-4, at this moment melanochrome flocculation, leave standstill and made its sedimentation in 8-24 hour, drop removes the brown clear liquid in upper strata, and the throw out press filtration is separated, with the less water washing, throw out is dissolved in an amount of Na ₂CO ₃In the solution, be evaporated to the dried finished product melanochrome that just gets, its productive rate is 1%, the sesame melanochrome that adopts present method to extract is that black has glossy crystalline solid, and is soluble in water, contains As≤2ppm and contain Pb≤5ppm, its absorption spectrum does not have absorption peak in the 400-760nm scope, measure its absorbancy, E at 500nm ¹⁹⁰ _Cm〉=20.

The sesame melanochrome powder produced under distance 40W ultraviolet lamp 10cm place illuminate condition, is taken by weighing after 50mg is mixed with the 250ml aqueous solution, measure wavelength 500nm, the variation of measuring absorbancy sees Table 1, with the stability of expression sesame melanochrome to light.

Table 1

Irradiation time 024 12 18 24

(hour)

Solution extinction 0.75 0.74 0.72 0.75 0.72 0.72

The variation of degree

Get 50mg sesame melanochrome, be mixed with the aqueous solution of 250ml, the pH value is 7.85, and constant temperature was measured wavelength 500nm after 1 hour under assigned temperature, measures absorbancy and sees Table 2, with the stability of expression sesame melanochrome to heat; And through further confirmation of thermal weight loss experiment, its extrapolation decomposition temperature reaches 232,2 ℃.

Table 2

Temperature does not heat 42 ℃ 61 ℃ 78 ℃ 98 ℃

Absorbancy 0.70 0.68 0.70 0.70 0.72

Choose sesame melanochrome 50mg and be mixed with the 250ml aqueous solution, the pH value is 8.10, measures wavelength 500nm, and the placement different time is surveyed its absorbancy and seen Table 3, to represent sesame melanochrome aqueous solution prolonged preservation at room temperature.

Table 3

Place fate 0 60 120 150

Absorbancy 0.82 0.81 0.79 0.80

Example 1

The Semen Sesami Nigrum of water intaking wash clean is by Semen Sesami Nigrum and Na ₂CO ₃Solution adds 1%Na by 1: 3 amount ₂CO ₃Solution at room temperature soaked 17 hours, solution is leached the reservation filter residue use 1: 2 amount to add 1%Na again ₂CO ₃Solution soaking 6 hours leaches reservation with solution, and filter residue leaches solution and keeps with 1: 1 amount cold water washing, merge three times filtrate, add hcl acidifying, the melanochrome that is settled out was left standstill 12 hours to pH1～4, make its layering, absorb behind the supernatant liquid suction filtration again, throw out is dissolved in 1～5%Na ₂CO ₃In the solution, the filtering insolubles, pulverize the oven dry back, promptly gets product.

Example 2

The Semen Sesami Nigrum of water intaking wash clean, amount by Semen Sesami Nigrum and NaOH solution 1: 3～5 adds 0.25～1%NaOH solution, under 30～60 ℃ temperature, soaked 4～12 hours, leach solution and keep, filter residue added 0.25～1%NaOH solution soaking 4～12 hours by 1: 2 amount again, leached the solution reservation, filter residue adds 30～60 ℃ water washing again in 1: 1 ratio, leach solution and keep, merge three times filtrate, be acidified with acid to pH1～4.The melanochrome that is settled out left standstill made its layering in 12 hours, inhale remove supernatant liquid after, press filtration is again washed with a small amount of water purification, according to a certain percentage throw out is dissolved in 1～5%Na ₂CO ₃In the solution, the elimination insolubles, pulverize the oven dry back, promptly gets product.

Sesame substance behind the extraction pigment washes with water to nearly neutrality, and oven dry is used for squeezing sesame oil.

Claims (2)

1, a kind of is that raw material adopts the nonpoisonous craft process to extract the melanic method of sesame with the Semen Sesami Nigrum, it is characterized in that getting the Semen Sesami Nigrum washing totally, and in 1: it is NaOH or the NaCO of 0.5-5% that the ratio of 3-5 adds concentration ₃Solution soaked 8-24 hour at 25-100 ℃, filtrate was added hydrochloric acid or sulfuric acid makes it to be acidified to pH value 1-4, and at this moment melanochrome flocculates, leave standstill and made its sedimentation in 8-24 hour, drop removes the brown clear liquid in upper strata, and the throw out press filtration is separated, with the less water washing, throw out is dissolved in the NaCO of 1-5% ₃In the solution, the elimination insolubles, the oven dry back is pulverized and is just got finished product melanochrome.

2, according to claim 1ly extract melanic method, it is characterized in that the melanochrome productive rate is 1% with Semen Sesami Nigrum, soluble in water, contain As≤2ppm, contain pb≤5ppm, measuring its absorbancy in 500nm wavelength condition is E _10m20, the extrapolation decomposition temperature reaches 232.2 ℃.