Method for processing Pachyrhizus juice concentrate with good taste and stable color value

Abstract

Disclosed is a method for processing Pachyrhizus juice concentrate with good taste and stable color value, with the steps as follows: (1) pretreatment of raw materials; (2) high-temperature enzymolysis: adding the high-temperature amylase for enzymolysis 30 min at 95 C.; (3) juicing; (4) pasteurization; (5) acidity adjustment; (6) enzymolysis: adding raw materials of glucoamylase 747 ml/T pectinase 50 ml/T, activated carbon 3 kg/T, bentonite 1 kg/T to the Pachyrhizus juice after acidity adjustment; (7) secondary pasteurization: cooling to 53 C.; (8) filtration; filtering through 0.45 um twice; (9) acidity adjustment, concentrating and cardboard filtration to obtain the finished product. The method for processing Pachyrhizus juice concentrate provided herein is proved through experiments that, the conventional method for color protection by adding VC is not applicable for Pachyrhizus juice concentrate, without adding VC, the browning during the product processing is significantly reduced, and the color value of final samples is well controlled; therefore, the method in the invention is simple, suitable for industrial production.

Claims

1. A method for making concentrated clear Pachyrhizus erosus juice, comprising the following steps: pretreating raw material, wherein the raw material comprises undamaged Pachyrhizus erosus, and the pretreating comprises cleaning the undamaged Pachyrhizus erosus in magnetized water, the magnetized water comprising 5-15 wt % flocculent aluminum chloride and 5-15 wt % hydrogen peroxide; and introducing ozone and UV irradiation to the magnetized water while cleaning; thoroughly removing residual substances on the surface of the cleaned Pachyrhizus erosus using a conveyor belt that sprays water, and then weighing the Pachyrhizus erosus and then juicing the Pachyrhizus erosus with a juicer to form Pachyrhizus erosus crude juice and debris; and collecting the Pachyrhizus erosus crude juice and debris; performing high temperature enzymolysis by adding to the Pachyrhizus erosus crude juice and debris: clean water and 300 mL of high-temperature amylase per ton of the raw material to form a mixture, and then performing enzymolysis for 30 min at 95 C. on the mixture; juicing the enzymolysis treated mixture with a belt-press filter, to obtain filtered Pachyrhizus erosus juice; debitterizing and anti-oxidation treating the filtered Pachyrhizus erosus juice by passing the filtered Pachyrhizus erosus juice through a magnetization duct with the magnetic field strength of 6,000-10,000 gauss, and then pasteurizing the debittered and anti-oxidized Pachyrhizus erosus juice at 100 C.4 C. for 20-30 seconds; adjusting the acidity of the pasteurized Pachyrhizus erosus juice using citric acid; adding 750 mL of glucoamylase per ton of the raw material, 60 mL of pectinate per ton of the raw material, 2 kg of activated carbon per ton of the raw material, and 1 kg of bentonite per ton of the raw materials, to the Pachyrhizus erosus juice after acidity adjustment, then performing enzymolysis for 110 min; performing a secondary pasteurization at 100 C.4 C., for 20-30 seconds on the second enzymolysis treated Pachyrhizus erosus juice, and then cooling the Pachyrhizus erosus juice to room temperature; performing ultrafiltration on the cooled Pachyrhizus erosus juice using a microfiltration membrane; concentrating the ultrafiltered Pachyrhizus erosus juice to 40-45 Bx, and then holding the Pachyrhizus erosus juice still at room temperature for 24 hours, wherein the concentrated Pachyrhizus erosus juice has a total acid content of 0.7-0.9 wt. %; filtering the concentrated Pachyrhizus erosus juice to obtain the finished product.

2. The method according to claim 1, wherein a rated pore size of the microfiltration membrane is 0.001-0.02 m.

3. The method according to claim 1, wherein for the magnetization duct, wires are twined around an outer edge of a metallic duct, and current is introduced inside the wire, with an electromagnetic direction opposite to a liquid flow direction.

4. The method according to claim 1, wherein the step of cleaning the undamaged Pachyrhizus erosus further comprises ultrasonic cleaning.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(1) The invention is further described in combination with the specific embodiments. The following embodiments are illustrative rather than restrictive, which cannot restrict the scope of protection of the invention.

Embodiment 1

(2) A method for processing Pachyrhizus juice concentrate with good taste and stable color value, comprises the following steps:

(3) (1) pretreatment of raw materials: selecting uandamaged mature Pachyrhizus, cleaning in magnetized water; adding 5%-15 wt % flocculent aluminum chloride, 5-15 wt % hydrogen peroxide to the magnetized water, and introducing ozone and UV irradiation to the cleaning pool while cleaning; and ultrasound can also be added.

(4) There are many fissures on the surface of Pachyrhizus, and the sand in the gap is difficult to remove. The existing method cannot clean them thoroughly. Adding flocculants and hydrogen peroxide to the magnetized water can achieve two purposes: firstly, the flocculants can bring out the sand in the gap to achieve thorough removal of sand. The hydrogen peroxide can kill the bacteria in the water and on the surface of the Pachyrhizus, to ensure cleanliness of raw material, and together with the ozone and ultraviolet light, it can achieve thorough sterilization.

(5) (2) thoroughly removing the residual substances on the surface of the Pachyrhizus using a conveyor belt that can spray water; filtering the water and weighing, juicing the Pachyrhizus with a juicer, and collecting the debris and Pachyrhizus crude juice in a unified manner.

(6) (3) high-temperature enzymolysis: adding 1.8 kg of clean water to the above debris and Pachyrhizus juice, adding high-temperature amylase, then performing enzymolysis for 30 min at 95 C.;

(7) (4) juicing: juicing with a belt-press filter, to obtain the Pachyrhizus juice;

(8) (5) debitterizing anti-oxidation treatment of juice: passing the Pachyrhizus juice through a magnetization duct with the magnetic field strength of 6000-10000 gauss;

(9) Pachyrhizus juice is in a transparent color and tastes slightly sweet. After pasteurization and acidity adjustment, the color becomes yellow and it tastes slightly bitter, mainly because the phenols in the Pachyrhizus juice is oxidized into anthraquinone, and the biological activity decreases, the antioxidant activity decreases; the tests have shown that after magnetization, the color and taste basically maintain unchanged in the subsequent process.

(10) (6) pasteurization: 100 C.4 C., 20-30 s; cooling down to 53 C., to obtain the original juice 5.5 kg, 7.7BX;

(11) (7) acidity adjustment: adding 23,540 g citric acid:

(12) (8) enzymolysis: adding raw materials of glucoamylase 747 ml/T, pectinase 50 ml/T, activated carbon 3 kg/T, bentonite 1 kg/T to the Pachyrhizus juice after acidity adjustment, then performing enzymolysis for 110 min;

(13) (9) secondary pasteurization: 100 C.4 C., 20-30 s; cooling to 53 C.;

(14) (8) filtration: filtering twice through a microfiltration membrane of 0.45 m;

(15) (10) acidity adjustment: adjusting the acidity to 3.54%@60BX;

(16) (11) concentration: concentrating to 50BX-60BXBX, standing still at room temperature for 24 h:

(17) (12) filtering through a cardboard to obtain the finished product.

Embodiment 2

(18) A method for processing Pachyrhizus juice concentrate with good taste and stable color value, comprises the following steps:

(19) (1) pretreatment of raw materials: selecting undamaged mature Pachyrhizus, cleaning in magnetized water; adding 5%-15 wt % flocculent aluminum chloride, 5-15 wt % hydrogen peroxide to the magnetized water, and introducing ozone and UV irradiation to the cleaning pool while cleaning; and ultrasound can also be added.

(20) There are many fissures on the surface of Pachyrhizus, and the sand in the gap is difficult to remove. The existing method cannot clean them thoroughly. Adding flocculants and hydrogen peroxide to the magnetized water can achieve two purposes: firstly, the flocculants can bring out the sand in the gap to achieve thorough removal of sand. The hydrogen peroxide can kill the bacteria on the water and the surface of the Pachyrhizus, to ensure cleanliness of raw material, and together with the ozone and ultraviolet light, it can achieve thorough sterilization.

(21) (2) thoroughly removing the residual substances on the surface of the Pachyrhizus using a conveyor belt that can spray water; filtering the water and weighing, juicing the Pachyrhizus with a juicer, and collecting the debris and Pachyrhizus crude juice in a unified manner;

(22) (3) high-temperature enzymolysis: adding 0.3-0.5 time of clean water to the above debris and Pachyrhizus juice, adding high-temperature amylase of about 300 ml/T raw material, then performing enzymolysis for 30 min at 95 C.;

(23) (4) juicing: juicing with a belt-press filter, to obtain the Pachyrhizus juice;

(24) (5) debitterizing anti-oxidation treatment of juice: passing the Pachyrhizus juice through a magnetization duct with the magnetic field strength of 6000-10000 gauss;

(25) Pachyrhizus juice is in a transparent color and tastes slightly sweet. After pasteurization and acidity adjustment, the color becomes yellow and it tastes slightly bitter, mainly because the phenols in the Pachyrhizus juice is oxidized into anthraquinone, and the biological activity decreases, the antioxidant activity decreases; the tests have shown that after magnetization, the color and taste are basically maintain unchanged in the subsequent process.

(26) (6) pasteurization: 100 C.4 C., 20-30 s;

(27) acidity adjustment adjusting the acidity to teal acid being 0.9%@45BX using citric acid;

(28) (7) enzymolysis: adding raw materials of glucoamylase 750 ml/T, pectinase 60 ml/T, activated carbon 2 kg/T, bentonite 1 kg/T to the Pachyrhizus juice after acidity adjustment, then performing enzymolysis for 110 min;

(29) (8) secondary pasteurization: 100 C.4 C., 20-30 s; cooling to temperature;

(30) (9) ultrafiltration: performing ultrafiltration of the Pachyrhizus juice cooled in step (7) with a microfiltration membrane of 0.45 m; (the rated pore size of the microfiltration membrane is in range of 0.001-9.02 m)

(31) (10) concentration: concentrating to 40-45BX, standing still at room temperature for 24 h;

(32) Filtering through a cardboard to obtain the finished product.

(33) Various indicators of finished products shall meet the following requirements:

(34) TABLE-US-00001 Total Sugar acidity Index Degree @45BX pH A410 T625 Turbidity Value 40-45BX 0.7-0.9% 4.6-4.8 0.1 95% 3