CN113558202B - Preparation method of sulfur-free and browning-free konjak dry slices - Google Patents

Preparation method of sulfur-free and browning-free konjak dry slices Download PDF

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CN113558202B
CN113558202B CN202110641013.7A CN202110641013A CN113558202B CN 113558202 B CN113558202 B CN 113558202B CN 202110641013 A CN202110641013 A CN 202110641013A CN 113558202 B CN113558202 B CN 113558202B
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konjak
slices
microwave
free
slice
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CN113558202A (en
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李秉正
黄纪民
黄志民
吴钊龙
陈先锐
胡文进
师德强
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Guangxi Zhongke Microwave Advanced Manufacturing Industry Technology Research Institute
Nanning Zhongke Microwave Advanced Manufacturing Industry Technology Research Institute
Guangxi Academy of Sciences
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Guangxi Zhongke Microwave Advanced Manufacturing Industry Technology Research Institute
Nanning Zhongke Microwave Advanced Manufacturing Industry Technology Research Institute
Guangxi Academy of Sciences
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    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L19/00—Products from fruits or vegetables; Preparation or treatment thereof
    • A23L19/10—Products from fruits or vegetables; Preparation or treatment thereof of tuberous or like starch containing root crops
    • A23L19/115—Konjak; Konntaku
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
    • A23L5/20—Removal of unwanted matter, e.g. deodorisation or detoxification
    • A23L5/21—Removal of unwanted matter, e.g. deodorisation or detoxification by heating without chemical treatment, e.g. steam treatment, cooking
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
    • A23L5/20—Removal of unwanted matter, e.g. deodorisation or detoxification
    • A23L5/27—Removal of unwanted matter, e.g. deodorisation or detoxification by chemical treatment, by adsorption or by absorption
    • A23L5/276—Treatment with inorganic compounds
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
    • A23L5/30—Physical treatment, e.g. electrical or magnetic means, wave energy or irradiation
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
    • A23L5/30—Physical treatment, e.g. electrical or magnetic means, wave energy or irradiation
    • A23L5/34—Physical treatment, e.g. electrical or magnetic means, wave energy or irradiation using microwaves
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23L—FOODS, FOODSTUFFS, OR NON-ALCOHOLIC BEVERAGES, NOT COVERED BY SUBCLASSES A21D OR A23B-A23J; THEIR PREPARATION OR TREATMENT, e.g. COOKING, MODIFICATION OF NUTRITIVE QUALITIES, PHYSICAL TREATMENT; PRESERVATION OF FOODS OR FOODSTUFFS, IN GENERAL
    • A23L5/00—Preparation or treatment of foods or foodstuffs, in general; Food or foodstuffs obtained thereby; Materials therefor
    • A23L5/40—Colouring or decolouring of foods
    • A23L5/41—Retaining or modifying natural colour by use of additives, e.g. optical brighteners
    • A—HUMAN NECESSITIES
    • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
    • A23V—INDEXING SCHEME RELATING TO FOODS, FOODSTUFFS OR NON-ALCOHOLIC BEVERAGES AND LACTIC OR PROPIONIC ACID BACTERIA USED IN FOODSTUFFS OR FOOD PREPARATION
    • A23V2002/00—Food compositions, function of food ingredients or processes for food or foodstuffs
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P60/00—Technologies relating to agriculture, livestock or agroalimentary industries
    • Y02P60/80—Food processing, e.g. use of renewable energies or variable speed drives in handling, conveying or stacking
    • Y02P60/85—Food storage or conservation, e.g. cooling or drying

Abstract

The invention discloses a preparation method of a sulfur-free and browning-free konjak dry slice, which comprises the steps of removing soil from fresh konjak, washing the konjak, heating the konjak in a microwave drying oven, peeling the konjak, cutting off surface pulp, slicing the konjak, placing the konjak slice in an ozone sterilizer for ozone fumigation, placing the konjak slice under ultraviolet light for irradiation for 20-30 min, and drying the konjak slice by microwaves for 60-80 min to reduce the final moisture content of a wet base of the konjak dry slice to below 8%, thus obtaining the sulfur-free and browning-free konjak dry slice. The method has the advantages of no sulfur fumigation, maintaining the color of konjak, effectively reducing nutrition loss of konjak, improving production efficiency, solving the problems of browning, poor quality and the like in the konjak sheet drying process, and realizing deep processing comprehensive utilization of konjak raw materials.

Description

Preparation method of sulfur-free and browning-free konjak dry slices
Technical Field
The invention belongs to the field of agricultural product processing technology, and particularly relates to a preparation method of sulfur-free and browning-free konjak dry slices.
Background
The konjak is called as mill konjak and ghost konjak, belongs to the konjak genus of Araceae family, is an important plant resource in China, has important medical, edible and industrial values, and is the only economic plant containing glucomannan. The dextran is a nonionic polysaccharide with high molecular weight, and excellent dietary fiber, called seventh nutrient, is a health food in the new century. Has effects in reducing blood lipid, blood sugar, and cholesterol, regulating endocrine, and preventing obesity. However, since konjak contains a large amount of polyphenols and polyphenol oxidase, the polyphenol oxidase oxidizes the polyphenols under the action of oxygen in the air to produce brown pigment, which causes blackening of konjak slices, severely reduces the content of glucomannan, and affects the whiteness grade of konjak itself and deep processed products (such as konjak coarse powder, konjak gum and the like), thereby affecting the color and appearance of konjak flour. The konjak slice can be browned to a certain extent, so that the quick enzyme deactivation treatment is needed, and how to control the konjak browning is a main problem of fresh konjak drying processing. In order to prevent browning, sulfur fumigation is usually adopted to protect color when konjak is dried, and the sulfur-fumigated konjak slices can keep white color, but in the sulfur fumigation process, sulfur content is not easy to control, and sulfur content is difficult to remove in the later period, so that potential safety hazards such as exceeding of sulfur content exist, the existing method is difficult to meet the development requirement of konjak industry, and development of a new processing technology is needed to further process konjak, so that the added value of a product is further improved.
Disclosure of Invention
Aiming at the defects, the invention discloses a preparation method of sulfur-free and browning-free konjak dry slices, solves the problems of browning, poor quality and the like in the konjak slice drying process, and realizes the deep processing comprehensive utilization of konjak raw materials.
The invention is realized by adopting the following technical scheme:
a preparation method of sulfur-free and browning-free konjak dry slices comprises the following steps:
(1) Cleaning: removing soil from fresh konjak, and washing;
(2) Microwave pretreatment: heating konjak treated in the step (1) in a microwave drying oven with the microwave frequency of 915MHz and the microwave power of 7-10 KW for 27-52 s;
(3) Pretreatment: peeling the konjak processed in the step (2) and cutting off surface pulp, wherein the thickness of the surface pulp is 4.5-5.5 mm;
(4) Slicing: slicing the konjak processed in the step (3) to obtain konjak slices, wherein the thickness of the konjak slices is 2-5 mm;
(5) Ozone fumigation: placing the konjak slices obtained in the step (4) into an ozone sterilizer, and fumigating for 20-30 min under the condition that the ozone concentration value is 450-550 PPM;
(6) Ultraviolet irradiation: the konjak slices treated in the step (5) are irradiated for 20 to 30 minutes under ultraviolet light with the intensity of 0.5 to 1.5mW/cm 2 ；
(7) Microwave drying: and (3) drying the konjak slices treated in the step (6) by adopting microwaves with the microwave frequency of 2450MHz and the microwave power of 0.2-1.5 kW for 60-80 min, so that the final moisture content of the wet base of the konjak slices is reduced to below 8%, obtaining the konjak dry slices with no sulfur and low browning, and then filling nitrogen into the konjak dry slices for packaging and storing.
Further, the heating temperature in the step (1) is 63.7-74.8 ℃.
Further, in the ozone fumigation step, the spreading density of the konjak slices is 0.4-0.6 g/cm 2 。
Further, in the ultraviolet irradiation step, the spread density of the konjak sheet is 0.4 to 0.6g/cm 2 . The density of the spreading material is controlled, which is favorable for ensuring that the ultraviolet irradiates the konjak slices uniformly and improving the ultraviolet irradiation effect.
Further, in the microwave drying step, the spread density of the konjak sheet is 0.4 to 0.6g/cm 2 . The spreading density is strictly controlled, because the larger the spreading density is, the smaller the evaporation amount of water in the material is, and the drying efficiency is low.
Further, in the step (7), the konjak slices are subjected to microwave drying treatment in two stages, firstly, the konjak slices are continuously heated for 1-3 min under the conditions that the microwave power is 1.0kW and the microwave frequency is 2450MHz, the konjak slices are quickly heated to the drying temperature, then, the konjak slices are continuously heated for 60-80 min under the conditions that the microwave power is 0.3kW and the microwave frequency is 2450MHz, and the final moisture content of the wet base of the konjak dry slices is reduced to below 8%. The konjak slices are subjected to microwave drying treatment in two sections, the temperature of the konjak slices is quickly increased by using higher microwave power in the early stage, a large amount of moisture is evaporated, and the moisture is uniformly distributed in the konjak slices again by using lower microwave power in the later stage, so that local coking caused by overheating is avoided.
Further, in the step (7), the temperature of the microwave drying is 65 to 75 ℃.
Compared with the prior art, the technical scheme has the following beneficial effects:
1. the traditional konjak drying produces heat by burning wood and coal, has long drying time, large energy consumption, low quality after drying and serious environmental pollution, and the current industrial product of the domestic konjak dried product is dried by a hot air drying box, and has better efficiency than the traditional processing method, but the konjak slices have better color and luster, worse quality and more nutrient loss.
The process of the invention adopts the integration of microwave, ozone and ultraviolet technology, and compared with the crisp chips prepared by the traditional process, the nutrition and the crunchiness of the dried product are improved to a certain extent, the color and luster are uniform, the quality is excellent, no special requirement is required for drying equipment, the investment cost is low, the process is simple, no waste water is generated, and the popularization and the application are convenient.
2. According to the invention, the konjak browning can be effectively inhibited by adopting a treatment method combining microwave irradiation and ozone fumigation, firstly, the konjak corms are passivated by using the high penetrability of 915MHz microwaves under the precondition of no peeling, then, the sliced konjak slices are subjected to secondary enzyme deactivation by using ozone fumigation, the obtained enzyme deactivation effect is good, and then, the konjak slice products with no sulfur, no other chemical color fixative residues and high whiteness can be obtained after drying. Because of the unique heating characteristics and drying mechanism of microwave drying, microwave heating is an ideal sterilization and enzyme deactivation method, 915MHz microwaves have a larger penetration depth of the material than 2450MHz microwaves, and thicker and larger-sized materials can be processed. The microwave heating has the characteristics of high heating speed, small heat loss, convenient operation and the like, can shorten the process time, improve the production efficiency, reduce the cost, improve the product quality, enable the inside and outside of the material to be heated simultaneously, tend to obtain better enzyme deactivation effect than the traditional method, better keep the original color, aroma and taste of the material to be dried, have less nutrition loss, and the dried product has natural color, attractive appearance, better drying quality, and can obviously improve the drying speed and reduce the energy consumption.
3. The konjac is peeled and then cut to a certain thickness of the surface pulp because the pulp is easily blackened during the drying process near the surface portion. In addition, since konjak contains a large amount of polyphenol substances and polyphenol oxidase, the thickness of konjak slices needs to be strictly controlled in the drying process, and if the slice thickness is too small, the drying rate is too high, so that the konjak slices are locally overheated to form scorched paste; the slice thickness is too large, the drying rate is slow, the drying degree of each part is uneven, and the inside is easy to overheat to cause blackening.
Detailed Description
The invention is further illustrated by the following examples, which are not intended to be limiting. The specific experimental conditions and methods not specified in the following examples are generally conventional means well known to those skilled in the art, the chromaticity adopts a color difference meter with the model of CR-400 to measure the color of the konjak dry sheet, a standard ceramic whiteboard is used as a standard sample, an international lighting association CIE L a b uniform color space color system is applied, and L is the brightness of the color; a is red-green, a is "+" represents red, and a is "-" represents green; b is yellow Lan Sedu, b is "+" represents yellow, and b is "-" represents blue. In the measurement process of this embodiment, the value of L is used, and if L is greater, it indicates that the whiteness of the konjak dry sheet is high.
Example 1:
a preparation method of sulfur-free and browning-free konjak dry slices comprises the following steps:
(1) Cleaning: removing soil from fresh konjak, and washing;
(2) Microwave pretreatment: heating konjak treated in the step (1) in a microwave drying oven with microwave frequency of 915MHz, microwave power of 8KW, heating time of 52s and heating temperature of 68.5 ℃;
(3) Pretreatment: peeling the konjak treated in the step (2) and cutting off surface pulp, wherein the thickness of the surface pulp is 5.0mm;
(4) Slicing: slicing the konjak processed in the step (3) to obtain konjak slices, wherein the thickness of the konjak slices is 4mm;
(5) Ozone fumigation: placing the konjak slices obtained in the step (4) into an ozone sterilizer, and carrying out ozone fumigation for 30min under the condition that the ozone concentration value is 450-550 PPM, wherein the spreading density of the konjak slices is 0.45g/cm 2 ；
(6) Ultraviolet irradiation: irradiating the konjak slices treated in the step (5) under ultraviolet light for 30min, wherein the spreading density of the konjak slices is 0.55g/cm 2 The ultraviolet intensity was 1.5mW/cm 2 ；
(7) Microwave drying: dividing the konjak slices treated in the step (6) into two sections, and adopting microwave drying treatment, wherein the microwave drying temperature is 70 ℃, and the spreading density of the konjak slices is 0.45g/cm 2 Firstly, continuously heating for 3min under the conditions that the microwave power is 1.0kW and the microwave frequency is 2450MHz, so that the konjak slice is quickly heated to a drying temperature, then continuously heating for 75min under the conditions that the microwave power is 0.3kW and the microwave frequency is 2450MHz, so that the final moisture content of the wet base of the konjak slice is reduced to below 8%, obtaining the konjak slice without sulfur and with low browning, and then filling nitrogen into the konjak slice for packaging and storing.
The final moisture content of the obtained konjak dry sheet is 6.55%, the L is 84.44, and the konjak dry sheet has uniform color and no chromatic aberration.
Example 2:
a preparation method of sulfur-free and browning-free konjak dry slices comprises the following steps:
(1) Cleaning: removing soil from fresh konjak, and washing;
(2) Microwave pretreatment: heating konjak treated in the step (1) in a microwave drying oven with the microwave frequency of 915MHz, the microwave power of 9KW, the heating time of 52s and the heating temperature of 65.4 ℃;
(3) Pretreatment: peeling the konjak treated in the step (2) and cutting off surface pulp, wherein the thickness of the surface pulp is 4.8mm;
(4) Slicing: slicing the konjak processed in the step (3) to obtain konjak slices, wherein the thickness of the konjak slices is 3mm;
(5) Ozone fumigation: placing the konjak slices obtained in the step (4) into an ozone sterilizer, and carrying out ozone fumigation for 25min under the condition that the ozone concentration value is 450-550 PPM, wherein the spreading density of the konjak slices is 0.5g/cm 2 ；
(6) Ultraviolet irradiation: irradiating the konjak slices treated in the step (5) under ultraviolet light for 25min, wherein the spreading density of the konjak slices is 0.55g/cm 2 The ultraviolet intensity is 0.5-1.5 mW/cm 2 ；
(7) Microwave drying: dividing the konjak slices treated in the step (6) into two sections, and adopting microwave drying treatment, wherein the microwave drying temperature is 68 ℃, and the spreading density of the konjak slices is 0.5g/cm 2 Firstly, continuously heating for 2min under the conditions that the microwave power is 1.0kW and the microwave frequency is 2450MHz, so that the konjak slice is quickly heated to the drying temperature, then continuously heating for 60-80 min under the conditions that the microwave power is 0.3kW and the microwave frequency is 2450MHz, so that the final moisture content of the wet base of the konjak slice is reduced to below 8%, obtaining the konjak slice with no sulfur and low browning, and then filling nitrogen into the konjak slice for packaging and storing.
The final moisture content of the obtained konjak dry sheet is 6.82%, the L is 84.32, and the konjak dry sheet has uniform color and no chromatic aberration.
Example 3:
a preparation method of sulfur-free and browning-free konjak dry slices comprises the following steps:
(1) Cleaning: removing soil from fresh konjak, and washing;
(2) Microwave pretreatment: heating konjak treated in the step (1) in a microwave drying oven with microwave frequency of 915MHz, microwave power of 10KW, heating time of 27s and heating temperature of 74.8 ℃;
(3) Pretreatment: peeling the konjak treated in the step (2) and cutting off surface pulp, wherein the thickness of the surface pulp is 5.2mm;
(4) Slicing: slicing the konjak processed in the step (3) to obtain konjak slices, wherein the thickness of the konjak slices is 2mm;
(5) Ozone fumigation: placing the konjak slices obtained in the step (4) into an ozone sterilizer, and carrying out ozone fumigation for 20min under the condition that the ozone concentration value is 450-550 PPM, wherein the spreading density of the konjak slices is 0.4g/cm 2 ；
(6) Ultraviolet irradiation: irradiating the konjak slices treated in the step (5) under ultraviolet light for 20min, wherein the spreading density of the konjak slices is 0.6g/cm 2 The ultraviolet intensity was 0.7mW/cm 2 ；
(7) Microwave drying: dividing the konjak slices treated in the step (6) into two sections, and adopting microwave drying treatment, wherein the microwave drying temperature is 72 ℃, and the spreading density of the konjak slices is 0.5g/cm 2 Firstly, continuously heating for 2min under the conditions that the microwave power is 1.0kW and the microwave frequency is 2450MHz, so that the konjak slice is quickly heated to a drying temperature, then continuously heating for 80min under the conditions that the microwave power is 0.3kW and the microwave frequency is 2450MHz, so that the final moisture content of the wet base of the konjak slice is reduced to below 8%, obtaining the konjak slice without sulfur and with low browning, and then filling nitrogen into the konjak slice for packaging and storing.
The final moisture content of the obtained konjak dry sheet is 6.32%, the L is 83.98, and the konjak dry sheet has uniform color and no chromatic aberration.
Example 4:
a preparation method of sulfur-free and browning-free konjak dry slices comprises the following steps:
(1) Cleaning: removing soil from fresh konjak, and washing;
(2) Microwave pretreatment: heating konjak treated in the step (1) in a microwave drying oven with microwave frequency of 915MHz, microwave power of 7KW, heating time of 45s and heating temperature of 70.9 ℃;
(3) Pretreatment: peeling the konjak treated in the step (2) and cutting off surface pulp, wherein the thickness of the surface pulp is 4.8mm;
(4) Slicing: slicing the konjak processed in the step (3) to obtain konjak slices, wherein the thickness of the konjak slices is 5mm;
(5) Ozone fumigation: placing the konjak slices obtained in the step (4) into an ozone sterilizer, and carrying out ozone fumigation for 25min under the condition that the ozone concentration value is 450-550 PPM, wherein the spreading density of the konjak slices is 0.4g/cm 2 ；
(6) Ultraviolet irradiation: irradiating the konjak slices treated in the step (5) under ultraviolet light for 25min, wherein the spreading density of the konjak slices is 0.4g/cm 2 The ultraviolet intensity was 0.5mW/cm 2 ；
(7) Microwave drying: dividing the konjak slices treated in the step (6) into two sections, and adopting microwave drying treatment, wherein the microwave drying temperature is 65 ℃, and the spreading density of the konjak slices is 0.4g/cm 2 Firstly, continuously heating for 1min under the conditions that the microwave power is 1.0kW and the microwave frequency is 2450MHz, so that the konjak slice is quickly heated to a drying temperature, then continuously heating for 60min under the conditions that the microwave power is 0.3kW and the microwave frequency is 2450MHz, so that the final moisture content of the wet base of the konjak slice is reduced to below 8%, obtaining the konjak slice without sulfur and with low browning, and then filling nitrogen into the konjak slice for packaging and storing.
The final moisture content of the obtained konjak dry sheet is 7.57%, the L is 83.38, and the konjak dry sheet has uniform color and no chromatic aberration.
Example 5:
a preparation method of sulfur-free and browning-free konjak dry slices comprises the following steps:
(1) Cleaning: removing soil from fresh konjak, and washing;
(2) Microwave pretreatment: heating konjak treated in the step (1) in a microwave drying oven with the microwave frequency of 915MHz, the microwave power of 8KW, the heating time of 40s and the heating temperature of 72.4 ℃;
(3) Pretreatment: peeling the konjak treated in the step (2) and cutting off surface pulp, wherein the thickness of the surface pulp is 4.5mm;
(4) Slicing: slicing the konjak processed in the step (3) to obtain konjak slices, wherein the thickness of the konjak slices is 3mm;
(5) Ozone fumigation: placing the konjak slices obtained in the step (4) into an ozone sterilizer, and carrying out ozone fumigation for 20min under the condition that the ozone concentration value is 450-550 PPM, wherein the spreading density of the konjak slices is 0.6g/cm 2 ；
(6) Ultraviolet irradiation: irradiating the konjak slices treated in the step (5) under ultraviolet light for 20min, wherein the spreading density of the konjak slices is 0.55g/cm 2 The intensity of the ultraviolet light is 1.2mW/cm 2 ；
(7) Microwave drying: drying the konjak slices treated in the step (6) by microwaves at the temperature of 75 ℃ and the spreading density of the konjak slices of 0.6g/cm 2 The microwave frequency is 2450MHz, the microwave power is 0.2kW, the microwave drying time is 80min, the final moisture content of the wet base of the konjak slice is reduced to below 8%, the konjak dry slice with no sulfur and low browning is obtained, and then the konjak dry slice is packaged by filling nitrogen and then stored.
The final moisture content of the obtained konjak dry sheet is 7.92%, the L is 82.63, and the konjak dry sheet has uniform color and no chromatic aberration.
Example 6:
a preparation method of sulfur-free and browning-free konjak dry slices comprises the following steps:
(1) Cleaning: removing soil from fresh konjak, and washing;
(2) Microwave pretreatment: heating konjak treated in the step (1) in a microwave drying oven with the microwave frequency of 915MHz, the microwave power of 9KW, the heating time of 35s and the heating temperature of 66.9 ℃;
(3) Pretreatment: peeling the konjak treated in the step (2) and cutting off surface pulp, wherein the thickness of the surface pulp is 5.5mm;
(4) Slicing: slicing the konjak processed in the step (3) to obtain konjak slices, wherein the thickness of the konjak slices is 4mm;
(5) Ozone fumigation: placing the konjak slices obtained in the step (4) into an ozone sterilizer, and performing ozone fumigation for 30min under the condition that the ozone concentration value is 450-550 PPMThe mat density of (C) was 0.6g/cm 2 ；
(6) Ultraviolet irradiation: irradiating the konjak slices treated in the step (5) under ultraviolet light for 30min, wherein the spreading density of the konjak slices is 0.6g/cm 2 The ultraviolet intensity is 0.8mW/cm 2 ；
(7) Microwave drying: drying the konjak slices treated in the step (6) by microwaves at the temperature of 66 ℃ and the spreading density of the konjak slices of 0.6g/cm 2 The microwave frequency is 2450MHz, the microwave power is 1.5kW, the microwave drying time is 60min, the final moisture content of the wet base of the konjak slice is reduced to below 8%, the konjak dry slice with no sulfur and low browning is obtained, and then the konjak dry slice is packaged by filling nitrogen and then stored.
The final moisture content of the obtained konjak dry sheet is 6.62%, the L is 82.12, and the konjak dry sheet has uniform color and no chromatic aberration.
Comparative example 1:
the process differs from that described in example 1 only in that the ozone fumigation and uv irradiation steps were omitted, the resulting konjak dry piece had a brownish black surface, a dark color, poor quality, a final moisture content of 6.34% in the wet base, and L74.22.
Comparative example 2:
the difference from the method in embodiment 1 is that the ozone fumigation in step (5) is to put the treated konjak slices into an ozone sterilizer, and subject the konjak slices to ozone fumigation for 30min under the condition that the ozone concentration value is 250-350 PPM, and the obtained konjak dry slices are darker in color and poor in quality, and the final moisture content of a wet base is 6.13% and L is 74.31. Because the concentration of ozone is too low and enzyme can not be effectively killed, the color of the konjak dry sheet is darkened and darkened due to browning, the ozone concentration is reasonably improved, ozone fumigation is carried out under the limited fumigation time and spreading density conditions, the enzyme can be rapidly and effectively killed, and the konjak nutritional ingredients can not react and deteriorate due to long-time ozone fumigation, so that the loss of the nutritional ingredients is increased.
Comparative example 3:
the difference from the method of embodiment 1 is that the step (7) of microwave drying is to dry the processed konjak pieces by microwave with a microwave frequency of 2450MHz, a microwave power of 0.3kW and a continuous heating time of 90min, and the obtained konjak dried pieces are darker in color, uneven in drying of the konjak pieces, have individual carbonization points, have scorched smell, have a large loss of nutrients, and have a final moisture content of 7.26% and l× 70.91.
Experimental example 1:
dried konjak pieces were prepared according to the method described in this example 1, and in the step (4) of slicing, konjak was cut into pieces having a thickness of 1mm, 1.5mm, 2mm, 4mm, 5mm, 6mm, 7mm, 8mm, and then subjected to steps of ozone fumigation, ultraviolet irradiation, microwave drying, etc. in the same manner, the color of the obtained dried konjak pieces was observed, and the moisture content of the dried konjak pieces was simultaneously examined, and specific results are shown in Table 1.
TABLE 1 color and Water content of konjak Dry sheet detection results
As can be seen from the data in the table, when the thickness of the konjak slice is smaller than 1.5mm, the obtained konjak dry slice has less water content, but uneven color and black carbonization points, and because the thickness of the konjak slice is too small, the drying rate is too fast, the konjak slice is locally overheated to form scorched, and the nutrition loss is increased; when the thickness of the konjak sheet is larger than 6mm, the water content of the konjak dry sheet obviously rises, and the drying degree of each part is uneven due to slower drying speed, so that the internal part is overheated and blackened, and the surface part is darkened.
Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims (2)

1. A preparation method of sulfur-free and browning-free konjak dry slices is characterized by comprising the following steps: the method comprises the following steps:
(1) Cleaning: removing soil from fresh konjak, and washing;
(2) Microwave pretreatment: heating konjak treated in the step (1) in a microwave drying oven with the microwave frequency of 915MHz and the microwave power of 7-10 kW for 27-52 s and the heating temperature of 63.7-74.8 ℃;
(3) Pretreatment: peeling the konjak processed in the step (2) and cutting off surface pulp, wherein the thickness of the surface pulp is 4.5-5.5 mm;
(4) Slicing: slicing the konjak processed in the step (3) to obtain konjak slices, wherein the thickness of the konjak slices is 2-5 mm;
(5) Ozone fumigation: placing the konjak slices obtained in the step (4) into an ozone sterilizer, and fumigating for 20-30 min under the condition that the concentration value of ozone is 450-550 ppm, wherein the spreading density of the konjak slices is 0.4-0.6 g/cm 2 ；
(6) Ultraviolet irradiation: the konjak slices treated in the step (5) are irradiated for 20 to 30 minutes under ultraviolet light with the intensity of 0.5 to 1.5mW/cm 2 The spreading density of the konjak slice is 0.4-0.6 g/cm 2 ；
(7) Microwave drying: the konjak slices processed in the step (6) are divided into two sections and are subjected to microwave drying treatment, firstly, the konjak slices are continuously heated for 1 to 3 minutes under the conditions that the microwave power is 1.0kW and the microwave frequency is 2450MHz, the konjak slices are quickly heated to the drying temperature, then, the konjak slices are continuously heated for 60 to 80 minutes under the conditions that the microwave power is 0.3kW and the microwave frequency is 2450MHz, and the spreading density of the konjak slices is 0.4 to 0.6g/cm 2 The final moisture content of the wet base of the konjak dry slice is reduced to below 8%, the konjak dry slice without sulfur and with low browning is obtained, and then the konjak dry slice is packed with nitrogen and stored.
2. The method for preparing sulfur-free and browning-free konjak dried slices according to claim 1, which is characterized by comprising the following steps: in the step (7), the temperature of microwave drying is 65-75 ℃.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1370439A (en) * 2002-03-04 2002-09-25 关时瑜 Microwave enzyme killing and drying process for konjaku
CN102657369A (en) * 2012-05-03 2012-09-12 重庆市彭水县天娇农业开发有限公司 Anaerobic enzyme suppression microwave drying method for konjak cake
CN109869986A (en) * 2017-12-05 2019-06-11 贺州学院 A kind of method of fresh ginger slice vacuum microwave drying

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7258882B2 (en) * 2002-03-07 2007-08-21 Thomas R. Hankinson System for maintaining fresh quality and safe food attributes of minimally processed produce

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1370439A (en) * 2002-03-04 2002-09-25 关时瑜 Microwave enzyme killing and drying process for konjaku
CN102657369A (en) * 2012-05-03 2012-09-12 重庆市彭水县天娇农业开发有限公司 Anaerobic enzyme suppression microwave drying method for konjak cake
CN109869986A (en) * 2017-12-05 2019-06-11 贺州学院 A kind of method of fresh ginger slice vacuum microwave drying

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"臭氧对鲜切莲藕酶促褐变的影响";张永清;《湖北农业科学》;第56卷(第13期);摘要，第2502右栏 *

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