阅读说明：本技术 一种油炸型胶原肠衣的制备方法 (Preparation method of fried type collagen casing ) 是由 刘飞 张婷 钟芳 于哲 李强 陈茂深 夏熠珣 徐菲菲 于 2021-07-14 设计创作，主要内容包括：本发明公开了一种油炸型胶原肠衣的制备方法,包括如下步骤：将原料皮通过浸水清洗、浸灰脱毛、一次浸酸、绞碎打浆、可食用大分子物质分散、复配、二次浸酸、均质过滤、挤出固化、水洗塑化和干燥加湿制得可食用油炸型胶原肠衣。本发明还可以搭配戊二醛交联步骤使用,本发明中提供的制备肠衣有着改善机械性能,不改变化学特性,能够根据肠衣的性能要求采取合适的制备方法并且能够在不使用戊二醛的情况下使得制得的油炸型胶原肠衣有着良好的机械性能。(The invention discloses a preparation method of a fried type collagen casing, which comprises the following steps: the raw skin is soaked in water for cleaning, liming for unhairing, primary pickling, mincing and pulping, dispersing edible macromolecular substances, compounding, secondary pickling, homogenizing and filtering, extruding and solidifying, water washing for plasticizing, drying and humidifying to obtain the edible fried collagen casing. The invention can also be used in combination with a glutaraldehyde crosslinking step, the prepared casing provided by the invention has improved mechanical properties, does not change chemical characteristics, can adopt a proper preparation method according to the performance requirement of the casing, and can ensure that the prepared fried type collagen casing has good mechanical properties under the condition of not using glutaraldehyde.)

1. A preparation method of a fried type collagen casing is characterized in that: the method comprises the following steps:

soaking and cleaning: washing the raw material peel with clear water;

liming for unhairing: mixing the raw leather, sodium sulfide and water, and then soaking in ammonium sulfate;

slicing: cutting the raw material skin;

primary pickling: soaking the sliced leather in acid;

mincing and pulping: mincing the skin pieces in a meat mincer;

edible macromolecular substance dispersion: emulsifying the edible macromolecules to obtain edible macromolecule dispersion liquid;

compounding: mixing and compounding the edible macromolecular dispersion liquid and the wood pulp cellulose;

secondary pickling: mixing the skin slurry in an acidizing fluid, and expanding to obtain a collagen cluster;

homogenizing and filtering: homogenizing the collagen clusters in a homogenizer, and filtering after homogenization;

extrusion curing: extruding the collagen clusters to prepare a casing, and then shaping and curing under the condition that certain pressure exists in the casing;

washing and plasticizing: washing and plasticizing the casing;

drying and humidifying: drying and rewetting the casing to obtain the finished product of the fried collagen casing.

2. A method of preparing a fried type collagen casing according to claim 1 characterized in that: and a glutaraldehyde step is also included between the extrusion curing and the water washing plasticizing, and the glutaraldehyde crosslinking is to perform glutaraldehyde crosslinking on the cured casing.

3. A method of preparing a fried type collagen casing as claimed in claim 1, characterized in that: the edible macromolecular substance is dispersed by emulsifying the edible macromolecular substance, adding ice water mixture, and emulsifying in emulsifier to obtain macromolecular substance dispersion liquid.

4. A method of preparing a fried type collagen casing as claimed in claim 1 or 3, characterized in that: the edible macromolecular substance comprises one or more of corn starch, acetate tapioca starch, curdlan, high amylose corn starch, acetate corn starch, flaxseed gum, gum arabic, guar gum and xanthan gum.

5. A method of preparing a fried type collagen casing as claimed in claim 1, characterized in that: in the drying and humidifying process, the drying process is a three-section drying process, and the three-section drying process is specifically set as follows: the first-stage drying temperature is 80-95 ℃, and the time is 5-10 min; the second-stage drying temperature is 65-80 ℃, and the time is 4-8 min; the three-section drying temperature is 65-80 ℃, and the time is 1-5 min.

6. A method of preparing a fried type collagen casing as claimed in claim 2, characterized in that: in the crosslinking, the mass concentration of the glutaraldehyde crosslinking solution is 0-50 ppm.

7. A method of preparing a fried type collagen casing as claimed in claim 4, characterized in that: the edible macromolecular substance is curdlan.

8. A method of preparing a fried type collagen casing as claimed in claim 4, characterized in that: the edible macromolecular substance is acetate cassava starch.

9. A method of preparing a fried type collagen casing as claimed in claim 1, characterized in that: in the water washing plasticization, the plasticizing liquid is a mixed liquid obtained by mixing glycerol and carboxymethyl cellulose.

10. The method for producing a fried type collagen casing according to claim 1, wherein the crosslinking treatment is carried out for 5 to 30 min.

Technical Field

The invention relates to the technical field of processing of collagen casings, in particular to a preparation method of a fried type collagen casing.

Background

The sausage casing is used as a food packaging material and has important effects on maintaining the quality of meat products and prolonging the shelf life. Before 1925, natural casings are used at home and abroad to contain and shape minced meat products, the demands for the casings are correspondingly increased along with the expansion of the market demands of the sausage products, and the natural casings are in short supply, so that the opportunity is provided for the appearance and development of artificial casings. The artificial casing is a tubular film prepared by edible or non-edible materials through a series of processing, and mainly comprises a plastic casing, a cellulose casing and a collagen casing.

The artificial edible casing produced in the market at present is mainly a collagen casing. The artificial collagen casing is superior to a natural casing in the aspects of edibility, resource stability, food safety and the like, has a very large market prospect, and can be applied to almost all meat products at present, including cooking sausages (such as Frankfurs and Vienna sausages), frying sausages (such as breakfast sausages and Chinese Taiwan baked sausages), Chinese sausages, fermented sausages, fresh sausages and the like. For sausage products needing to be fried before eating, in order to prevent phenomena such as shoulder slipping, rod falling and the like during sausage filling in the production process, glutaraldehyde crosslinking modification treatment is needed to improve the mechanical performance, and the most outstanding problems in the application process are that the collagen sausage casing cannot resist high-temperature frying, is tough in taste and difficult to chew, has poor heat shrinkage and meat viscosity in the high-temperature frying process, is easy to break, peel and seriously deforms in appearance, influences the quality and attractiveness of sale, and cannot meet the practical application.

Disclosure of Invention

This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. In this section, as well as in the abstract and the title of the invention of this application, simplifications or omissions may be made to avoid obscuring the purpose of the section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.

The present invention is proposed in view of the above and/or the existing preparation method of edible fried type collagen casing and the technical blank of edible fried type collagen casing.

Therefore, the invention aims to solve the defects in the prior art and provide a preparation method of an edible fried type collagen casing.

In order to solve the technical problems, the invention provides the following technical scheme: a preparation method of a fried type collagen casing comprises the following steps:

soaking and cleaning: washing the raw material peel with clear water;

liming for unhairing: mixing the raw leather, sodium sulfide and water, and then soaking in ammonium sulfate;

slicing: cutting the raw material skin;

primary pickling: soaking the sliced leather in acid;

mincing and pulping: mincing the skin pieces in a meat mincer;

edible macromolecular substance dispersion: emulsifying the edible macromolecules to obtain edible macromolecule dispersion liquid;

compounding: mixing and compounding the edible macromolecular dispersion liquid and the wood pulp cellulose;

secondary pickling: mixing the skin slurry in an acidizing fluid, and expanding to obtain a collagen cluster;

homogenizing and filtering: homogenizing the collagen clusters in a homogenizer, and filtering after homogenization;

extrusion curing: extruding the collagen clusters to prepare a casing, and then shaping and curing under the condition that certain pressure exists in the casing;

washing and plasticizing: washing and plasticizing the casing;

drying and humidifying: drying and rewetting the casing to obtain the finished product of the fried collagen casing.

As a preferable embodiment of the method for producing an edible fried type collagen casing of the present invention, wherein: and a glutaraldehyde step is also included between the extrusion curing and the water washing plasticizing, and the glutaraldehyde crosslinking is to perform glutaraldehyde crosslinking on the cured casing.

As a preferable embodiment of the method for producing an edible fried type collagen casing of the present invention, wherein: the edible macromolecular substance is dispersed by emulsifying the edible macromolecular substance, adding ice water mixture, and emulsifying in emulsifier to obtain macromolecular substance dispersion.

As a preferable embodiment of the method for producing an edible fried type collagen casing of the present invention, wherein: the edible macromolecular substance comprises one or more of corn starch, acetate tapioca starch, curdlan, high amylose corn starch, acetate corn starch, flaxseed gum, gum arabic, guar gum, and xanthan gum.

As a preferable embodiment of the method for producing an edible fried type collagen casing of the present invention, wherein: in the drying humidification, the drying is the syllogic drying, and the specific setting of syllogic drying is as follows: the first-stage drying temperature is 80-95 ℃, and the time is 5-10 min; the second-stage drying temperature is 65-80 ℃, and the time is 4-8 min; the three-section drying temperature is 65-80 ℃, and the time is 1-5 min.

As a preferable embodiment of the method for producing an edible fried type collagen casing of the present invention, wherein: in the crosslinking, the mass concentration of the glutaraldehyde crosslinking solution is 0-50 ppm.

As a preferable embodiment of the method for producing an edible fried type collagen casing of the present invention, wherein: the edible macromolecular substance is curdlan.

As a preferable embodiment of the method for producing an edible fried type collagen casing of the present invention, wherein: the edible macromolecular substance is acetate tapioca starch.

As a preferable embodiment of the method for producing an edible fried type collagen casing of the present invention, wherein: in the water washing plasticization, the plasticizing liquid is a mixed liquid of glycerol and carboxymethyl cellulose.

As a preferable embodiment of the method for producing an edible fried type collagen casing of the present invention, wherein: in the crosslinking, the crosslinking treatment time is 5-30 min.

The invention has the following advantages:

(1) the preparation method of the edible fried collagen casing breaks through the problems that the casing cannot resist high temperature frying and has tough mouthfeel in the current market; the prepared fried edible collagen casing can resist the high temperature of 180 ℃ for frying, and has crisp mouthfeel; innovatively provides that the suitable additives of the fried collagen sausage casing are different under the cross-linking condition of different glutaraldehyde concentrations;

(2) according to the preparation method of the edible fried type collagen casing, the polysaccharide edible macromolecular substances are added, no obvious difference exists in micelle rheological characteristics under the condition of proper addition amount, the size of the spray head is replaceable, the caliber of the casing is adjustable, and the preparation method is suitable for producing collagen casings with various calibers and can better meet the requirements of production and use;

(3) the edible fried collagen casing prepared by the invention has uniform thickness, proper mechanical property and improved tensile strength to a certain extent under the crosslinking condition of different glutaraldehyde concentrations, particularly the mechanical property is obviously improved under the condition of no glutaraldehyde crosslinking, the problems of shoulder slipping, rod dropping and the like of the collagen casing in the current market in the casing process are effectively solved by improving the tensile strength, and the physical property requirement of casing products is met;

(4) the edible fried collagen casing prepared by the invention has better frying shrinkage rate and fried meat viscosity, the added edible macromolecular substances are fried to generate thermal gelation, gelatinization and other phenomena and fully fill collagen network gaps, the casing shrinkage regularity is effectively improved, certain strength is provided, the phenomena of sausage cracking and peeling are obviously improved, the sale quality and the attractiveness of the fried sausage are greatly improved, and the development of the application field of the fried collagen casing is promoted.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:

FIG. 1 is a rheological measurement of micelles with different edible macromolecular substances added;

FIG. 2 is a graph of mechanical property measurements of edible fried type collagen casings with different or no added edible macromolecular substances;

FIG. 3 is a graph comparing the fried state of edible fried collagen casings with different edible macromolecular substances at different glutaraldehyde concentrations;

FIG. 4 is a graph comparing the difference in viscosity between fried meat with edible fried collagen casings prepared during the preparation process and commercially available fried collagen casings;

FIG. 5 is a graph of the effect of different amounts of addition on the performance of collagen casing products in example 6.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention more comprehensible, specific embodiments thereof are described in detail below with reference to examples of the specification.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Furthermore, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

Example 1

The preparation method comprises the following steps of preparing an edible fried type collagen casing added with starch edible macromolecular substances under the condition of 50ppm glutaraldehyde crosslinking, wherein the edible macromolecular substances comprise corn starch, high-amylose corn starch, acetate corn starch and acetate tapioca starch, and the process route of the preparation method comprises the steps of soaking and cleaning raw material skins, liming and unhairing, primary pickling, mincing and pulping, dispersing and compounding the edible macromolecular substances, secondary pickling, homogenizing and filtering, extruding and curing, water washing and plasticizing, glutaraldehyde crosslinking, drying and humidifying to obtain the edible fried type collagen casing.

The method comprises the following specific steps:

(1) soaking and cleaning the raw leather: washing the raw leather with clear water until the leather water is free of sand, soaking in clear water at 15 deg.C for 3 days, and changing water every 6 h.

(2) Liming for unhairing: mixing 5% lime, 3% sodium sulfide and 10% water to obtain paste, uniformly coating on soaked cowhide, and unhairing for 3 hr. Washing cow leather with water for 4 times, soaking in 2% ammonium sulfate for 4 hr, and washing with water until pH is 7.1;

(3) cutting the skin: the leather material is cut into leather blocks with the size of 15cm in a leather cutting machine.

(4) Primary pickling: adding 4 times of clear water, 1% citric acid monohydrate and 2% sodium citrate dihydrate into the leather blocks, soaking for 10h at 15 ℃, stirring once every 2h, controlling the pH to be 4.5, and finally draining and washing for 2 times;

(5) mincing and pulping: the leather blocks are put into a meat grinder to be ground for 3 times, and the diameters of the pore plates of the meat grinder are respectively 18 mm, 8 mm and 1.5 mm. Adding clear water with 10 times of dry weight of the skin material into the minced skin, shearing in a high-speed pulverizer at a shearing rate of 8000rpm for 7min, extracting collagen fiber, adding crushed ice, and controlling the temperature at 13 deg.C;

(6) edible macromolecular substance dispersion: emulsifying edible macromolecular substances, adding an ice-water mixture with the weight 8 times that of the edible macromolecular substances into the edible macromolecular substances, circularly emulsifying in an emulsifying machine at the rotating speed of 2500-3000 rpm for 20-30 min to obtain edible macromolecular substance dispersion, and controlling the temperature of the dispersion to be 10-20 ℃.

(7) Compounding: adding 0.4% hydrochloric acid into water 12 times the weight of the leather to prepare an acidizing solution, adding 0.08 times of wood pulp cellulose and 0.25 times of edible macromolecular dispersion liquid, and stirring and mixing uniformly. The size of the wood pulp cellulose is 50 mu m;

(8) secondary pickling: (5) uniformly mixing the mesocarp mash and the acidizing fluid (7) in equal mass, degassing, and acidizing and expanding for 18-24 hours at the temperature of 10 ℃ to obtain a collagen cluster;

(9) homogenizing and filtering: homogenizing the collagen clusters in a secondary high-pressure homogenizer at 100MPa and 15 deg.C; filtering to remove impurities in the collagen clusters;

(10) extrusion curing: extruding the filtered collagen clusters by adopting an extruding head with internal shearing to obtain a tubular casing, controlling the temperature of the extruding head to be 8 ℃ and the shearing rate to be 200 rpm; after extrusion molding, the tubular casing is conveyed to an ammonia gas atmosphere with the pressure of 20psi at the speed of 2m/s, meanwhile, the inside of the casing is filled with air with the pressure of 20psi for shaping, the temperature is 20 ℃, the casing is solidified in the conveying process, and the solidification time is 1.5 min;

(11) and (3) glutaraldehyde crosslinking: crosslinking the cured casing for 5-30 min by using a crosslinking pool, wherein the mass concentration of glutaraldehyde in the crosslinking pool is 50 ppm;

(12) washing and plasticizing: the crosslinked sausage casing passes through a multi-stage water washing pool to wash off residual salts on the sausage casing, and the water washing time is 10 min; then, the sausage casing passes through a multistage plasticizing pool, and the plasticizing time is 5 min; the plasticizing pool is an aqueous solution containing 4% of glycerol and 1% of carboxymethyl cellulose;

(13) drying and humidifying: three-stage drying is carried out on the casing after washing and plasticizing, wherein the first-stage drying temperature is 90 ℃ and the time is 5 min; the second stage drying temperature is 75 deg.C, and the time is 5 min; the three-section drying temperature is 65 ℃, and the time is 3 min; finally, the sausage casing passes through a moisture recovery device, and the moisture is controlled at 15%.

Example 2

The edible fried type collagen casing is prepared by adding plant gum or microorganism gum edible macromolecules into an edible fried type collagen casing under the condition of 50ppm glutaraldehyde crosslinking, wherein the edible macromolecule substances comprise flaxseed gum, guar gum, gum arabic, curdlan and xanthan gum.

The method comprises the following specific steps:

(1) soaking and cleaning the raw leather: washing the raw leather with clear water until the leather water is free of sand, soaking in clear water at 15 deg.C for 3 days, and changing water every 6 h.

(2) Liming for unhairing: mixing 5% lime, 3% sodium sulfide and 10% water to obtain paste, uniformly coating on soaked cowhide, and unhairing for 3 hr. Washing cow leather with water for 4 times, soaking in 2% ammonium sulfate for 4 hr, and washing with water until pH is 7.1;

(3) cutting the skin: the leather material is cut into leather blocks with the size of 15cm in a leather cutting machine.

(4) Primary pickling: adding 4 times of clear water, 1% citric acid monohydrate and 2% sodium citrate dihydrate into the leather blocks, soaking for 10h at 15 ℃, stirring once every 2h, controlling the pH to be 4.5, and finally draining and washing for 2 times;

(5) mincing and pulping: the leather blocks are put into a meat grinder to be ground for 3 times, and the diameters of the pore plates of the meat grinder are respectively 18 mm, 8 mm and 1.5 mm. Adding clear water with 10 times of dry weight of the skin material into the minced skin, shearing in a high-speed pulverizer at a shearing rate of 8000rpm for 7min, extracting collagen fiber, adding crushed ice, and controlling the temperature at 13 deg.C;

(6) edible macromolecular substance dispersion: emulsifying edible macromolecular substances, adding an ice-water mixture with the weight 8 times that of the edible macromolecular substances into the edible macromolecular substances, circularly emulsifying in an emulsifying machine at the rotating speed of 2500-3000 rpm for 20-30 min to obtain edible macromolecular substance dispersion, and controlling the temperature of the dispersion to be 10-20 ℃.

(7) Compounding: adding 0.4% hydrochloric acid into water 12 times the weight of the leather to prepare an acidizing solution, adding 0.08 times of wood pulp cellulose and 0.025 times of edible macromolecular dispersion liquid, and stirring and mixing uniformly. The size of the wood pulp cellulose is 50 mu m;

(8) secondary pickling: (5) uniformly mixing the mesocarp mash and the acidizing fluid (7) in equal mass, degassing, and acidizing and expanding for 18-24 hours at the temperature of 10 ℃ to obtain a collagen cluster;

(9) homogenizing and filtering: homogenizing the collagen clusters in a secondary high-pressure homogenizer at 100MPa and 15 deg.C; filtering to remove impurities in the collagen clusters;

(10) extrusion curing: extruding the filtered collagen clusters by adopting an extruding head with internal shearing to obtain a tubular casing, controlling the temperature of the extruding head to be 8 ℃ and the shearing rate to be 200 rpm; after extrusion molding, the tubular casing is conveyed to an ammonia gas atmosphere with the pressure of 20psi at the speed of 2m/s, meanwhile, the inside of the casing is filled with air with the pressure of 20psi for shaping, the temperature is 20 ℃, the casing is solidified in the conveying process, and the solidification time is 1.5 min;

(11) and (3) glutaraldehyde crosslinking: crosslinking the cured casing for 5-30 min by using a crosslinking pool, wherein the mass concentration of glutaraldehyde in the crosslinking pool is 50 ppm;

(12) washing and plasticizing: the crosslinked sausage casing passes through a multi-stage water washing pool to wash off residual salts on the sausage casing, and the water washing time is 10 min; then, the sausage casing passes through a multistage plasticizing pool, and the plasticizing time is 5 min; the plasticizing pool is an aqueous solution containing 4% of glycerol and 1% of carboxymethyl cellulose;

(13) drying and humidifying: three-stage drying is carried out on the casing after washing and plasticizing, wherein the first-stage drying temperature is 90 ℃ and the time is 5 min; the second stage drying temperature is 75 deg.C, and the time is 5 min; the three-section drying temperature is 65 ℃, and the time is 3 min; finally, the sausage casing passes through a moisture recovery device, and the moisture is controlled at 15%.

Example 3

In order to highlight the advantages of preparing the fried type collagen casing by adding edible macromolecular substances, the edible macromolecular substance dispersion in the examples 1 and 2 is omitted, and the edible fried type collagen casing without adding the three types of edible macromolecular substances is prepared under the condition of 50ppm glutaraldehyde crosslinking.

The method comprises the following specific steps:

(1) soaking and cleaning the raw leather: washing the raw leather with clear water until the leather water is free of sand, soaking in clear water at 15 deg.C for 3 days, and changing water every 6 h.

(2) Liming for unhairing: mixing 5% lime, 3% sodium sulfide and 10% water to obtain paste, uniformly coating on soaked cowhide, and unhairing for 3 hr. Washing cow leather with water for 4 times, soaking in 2% ammonium sulfate for 4 hr, and washing with water until pH is 7.1;

(3) cutting the skin: the leather material is cut into leather blocks with the size of 15cm in a leather cutting machine.

(4) Primary pickling: adding 4 times of clear water, 1% citric acid monohydrate and 2% sodium citrate dihydrate into the leather blocks, soaking for 10h at 15 ℃, stirring once every 2h, controlling the pH to be 4.5, and finally draining and washing for 2 times;

(5) mincing and pulping: the leather blocks are put into a meat grinder to be ground for 3 times, and the diameters of the pore plates of the meat grinder are respectively 18 mm, 8 mm and 1.5 mm. Adding clear water with 10 times of dry weight of the skin material into the minced skin, shearing in a high-speed pulverizer at a shearing rate of 8000rpm for 7min, extracting collagen fiber, adding crushed ice, and controlling the temperature at 13 deg.C;

(6) compounding: adding 0.4% hydrochloric acid into water 12 times the weight of the leather to prepare an acidizing solution, adding 0.08 times the weight of the wood pulp cellulose into the acidizing solution, and stirring and mixing the mixture uniformly. The size of the wood pulp cellulose is 50 mu m;

(7) secondary pickling: (5) uniformly mixing the mesocarp mash and the acidizing fluid (6) in equal mass, degassing, and acidizing and expanding for 18-24 hours at the temperature of 10 ℃ to obtain a collagen cluster;

(8) homogenizing and filtering: homogenizing the collagen clusters in a secondary high-pressure homogenizer at 100MPa and 15 deg.C; filtering to remove impurities in the collagen clusters;

(9) extrusion curing: extruding the filtered collagen clusters by adopting an extruding head with internal shearing to obtain a tubular casing, controlling the temperature of the extruding head to be 8 ℃ and the shearing rate to be 200 rpm; after extrusion molding, the tubular casing is conveyed to an ammonia gas atmosphere with the pressure of 20psi at the speed of 2m/s, meanwhile, the inside of the casing is filled with air with the pressure of 20psi for shaping, the temperature is 20 ℃, the casing is solidified in the conveying process, and the solidification time is 1.5 min;

(10) and (3) glutaraldehyde crosslinking: crosslinking the cured casing for 5-30 min by using a crosslinking pool, wherein the mass concentration of glutaraldehyde in the crosslinking pool is 50 ppm;

(11) washing and plasticizing: the crosslinked sausage casing passes through a multi-stage water washing pool to wash off residual salts on the sausage casing, and the water washing time is 10 min; then, the sausage casing passes through a multistage plasticizing pool, and the plasticizing time is 5 min; the plasticizing pool is an aqueous solution containing 4% of glycerol and 1% of carboxymethyl cellulose;

(12) drying and humidifying: three-stage drying is carried out on the casing after washing and plasticizing, wherein the first-stage drying temperature is 90 ℃ and the time is 5 min; the second stage drying temperature is 75 deg.C, and the time is 5 min; the three-section drying temperature is 65 ℃, and the time is 3 min; finally, the sausage casing passes through a moisture recovery device, and the moisture is controlled at 15%.

Example 4

In order to research the influence of glutaraldehyde crosslinking on the fried type collagen casing added with edible macromolecular substances, under the conditions of 0ppm, 25ppm and 50ppm of glutaraldehyde crosslinking, the three edible macromolecular substances in the embodiments 1 and 2 are respectively selected to prepare the edible fried type collagen casing added with or without corn starch, acetate cassava starch and curdlan.

The method comprises the following specific steps:

(1) soaking and cleaning the raw leather: washing the raw leather with clear water until the leather water is free of sand, soaking in clear water at 15 deg.C for 3 days, and changing water every 6 h.

(2) Liming for unhairing: mixing 5% lime, 3% sodium sulfide and 10% water to obtain paste, uniformly coating on soaked cowhide, and unhairing for 3 hr. Washing cow leather with water for 4 times, soaking in 2% ammonium sulfate for 4 hr, and washing with water until pH is 7.1;

(3) cutting the skin: the leather material is cut into leather blocks with the size of 15cm in a leather cutting machine.

(4) Primary pickling: adding 4 times of clear water, 1% citric acid monohydrate and 2% sodium citrate dihydrate into the leather blocks, soaking for 10h at 15 ℃, stirring once every 2h, controlling the pH to be 4.5, and finally draining and washing for 2 times;

(5) mincing and pulping: the leather blocks are put into a meat grinder to be ground for 3 times, and the diameters of the pore plates of the meat grinder are respectively 18 mm, 8 mm and 1.5 mm. Adding clear water with 10 times of dry weight of the skin material into the minced skin, shearing in a high-speed pulverizer at a shearing rate of 8000rpm for 7min, extracting collagen fiber, adding crushed ice, and controlling the temperature at 13 deg.C;

(6) edible macromolecular substance dispersion: emulsifying edible macromolecular substances, adding an ice water mixture with the weight 8 times that of the edible macromolecular substances into the edible macromolecular substances, circularly emulsifying in an emulsifying machine at the rotating speed of 2500-3000 rpm for 20-30 min to obtain edible macromolecular substance dispersion liquid, and controlling the temperature of the dispersion liquid to be 10-20 ℃;

(7) compounding: adding 0.4% hydrochloric acid into water 12 times the weight of the leather to prepare an acidizing solution, adding 0.08 times of wood pulp cellulose and 0.025 times or 0.25 times of edible macromolecular dispersion liquid, and stirring and mixing uniformly. The size of the wood pulp cellulose is 50 mu m; adding starch edible macromolecules 0.25 times, and adding plant/microbial gum edible macromolecules 0.025 times;

(8) secondary pickling: (5) uniformly mixing the mesocarp mash and the acidizing fluid (7) in equal mass, degassing, and acidizing and expanding for 18-24 hours at the temperature of 10 ℃ to obtain a collagen cluster;

(9) homogenizing and filtering: homogenizing the collagen clusters in a secondary high-pressure homogenizer at 100MPa and 15 deg.C; filtering to remove impurities in the collagen clusters;

(10) extrusion curing: extruding the filtered collagen clusters by adopting an extruding head with internal shearing to obtain a tubular casing, controlling the temperature of the extruding head to be 8 ℃ and the shearing rate to be 200 rpm; after extrusion molding, the tubular casing is conveyed to an ammonia gas atmosphere with the pressure of 20psi at the speed of 2m/s, meanwhile, the inside of the casing is filled with air with the pressure of 20psi for shaping, the temperature is 20 ℃, the casing is solidified in the conveying process, and the solidification time is 1.5 min;

(11) and (3) glutaraldehyde crosslinking: crosslinking the cured casing for 5-30 min by a crosslinking pool, wherein the mass concentrations of glutaraldehyde in the crosslinking pool are 0ppm, 25ppm and 50ppm respectively;

(12) washing and plasticizing: the crosslinked sausage casing passes through a multi-stage water washing pool to wash off residual salts on the sausage casing, and the water washing time is 10 min; then, the sausage casing passes through a multistage plasticizing pool, and the plasticizing time is 5 min; the plasticizing pool is an aqueous solution containing 4% of glycerol and 1% of carboxymethyl cellulose;

(13) drying and humidifying: three-stage drying is carried out on the casing after washing and plasticizing, wherein the first-stage drying temperature is 90 ℃ and the time is 5 min; the second stage drying temperature is 75 deg.C, and the time is 5 min; the three-section drying temperature is 65 ℃, and the time is 3 min; finally, the sausage casing passes through a moisture recovery device, and the moisture is controlled at 15%.

Example 5

In order to research the influence of the addition amount of starch, vegetable gum or microbial gum edible macromolecular substances on the fried type collagen sausage casing, under the condition of 50ppm glutaraldehyde crosslinking, two edible macromolecular substances in the embodiments 1 and 2 are respectively selected to prepare the edible fried type collagen sausage casing with or without acetate cassava starch and curdlan added, and the process route is that the edible fried type collagen sausage casing is prepared by the steps of raw material skin washing through soaking, liming for unhairing, primary pickling, mincing and pulping, dispersing and compounding the edible macromolecular substances, secondary pickling, homogenizing and filtering, extruding and curing, water washing for plasticizing, drying and humidifying.

The method comprises the following specific steps:

(1) soaking and cleaning the raw leather: washing the raw leather with clear water until the leather water is free of sand, soaking in clear water at 15 deg.C for 3 days, and changing water every 6 h.

(2) Liming for unhairing: mixing 5% lime, 3% sodium sulfide and 10% water to obtain paste, uniformly coating on soaked cowhide, and unhairing for 3 hr. Washing cow leather with water for 4 times, soaking in 2% ammonium sulfate for 4 hr, and washing with water until pH is 7.1;

(3) cutting the skin: the leather material is cut into leather blocks with the size of 15cm in a leather cutting machine.

(4) Primary pickling: adding 4 times of clear water, 1% citric acid monohydrate and 2% sodium citrate dihydrate into the leather blocks, soaking for 10h at 15 ℃, stirring once every 2h, controlling the pH to be 4.5, and finally draining and washing for 2 times;

(5) mincing and pulping: the leather blocks are put into a meat grinder to be ground for 3 times, and the diameters of the pore plates of the meat grinder are respectively 18 mm, 8 mm and 1.5 mm. Adding clear water with 10 times of dry weight of the skin material into the minced skin, shearing in a high-speed pulverizer at a shearing rate of 8000rpm for 7min, extracting collagen fiber, adding crushed ice, and controlling the temperature at 13 deg.C;

(6) edible macromolecular substance dispersion: emulsifying edible macromolecular substances, adding an ice water mixture with the weight 8 times that of the edible macromolecular substances into the edible macromolecular substances, circularly emulsifying in an emulsifying machine at the rotating speed of 2500-3000 rpm for 20-30 min to obtain edible macromolecular substance dispersion liquid, and controlling the temperature of the dispersion liquid to be 10-20 ℃;

(7) compounding: adding 0.4% hydrochloric acid into water 12 times the weight of the leather material to prepare an acidizing solution, adding 0.08 time of wood pulp cellulose and 0.01-0.05 time or 0.05-0.25 time of edible macromolecular dispersion liquid, and stirring and mixing uniformly. The size of the wood pulp cellulose is 50 mu m; adding 0.05-0.25 times of starch edible macromolecules and 0.01-0.05 times of plant/microbial gum edible macromolecules;

(8) secondary pickling: (5) uniformly mixing the mesocarp mash and the acidizing fluid (7) in equal mass, degassing, and acidizing and expanding for 18-24 hours at the temperature of 10 ℃ to obtain a collagen cluster;

(9) homogenizing and filtering: homogenizing the collagen clusters in a secondary high-pressure homogenizer at 100MPa and 15 deg.C; filtering to remove impurities in the collagen clusters;

(10) extrusion curing: extruding the filtered collagen clusters by adopting an extruding head with internal shearing to obtain a tubular casing, controlling the temperature of the extruding head to be 8 ℃ and the shearing rate to be 200 rpm; after extrusion molding, the tubular casing is conveyed to an ammonia gas atmosphere with the pressure of 20psi at the speed of 2m/s, meanwhile, the inside of the casing is filled with air with the pressure of 20psi for shaping, the temperature is 20 ℃, the casing is solidified in the conveying process, and the solidification time is 1.5 min;

(11) and (3) glutaraldehyde crosslinking: crosslinking the cured casing for 5-30 min by a crosslinking pool, wherein the mass concentrations of glutaraldehyde in the crosslinking pool are 0ppm, 25ppm and 50ppm respectively;

(12) washing and plasticizing: the crosslinked sausage casing passes through a multi-stage water washing pool to wash off residual salts on the sausage casing, and the water washing time is 10 min; then, the sausage casing passes through a multistage plasticizing pool, and the plasticizing time is 5 min; the plasticizing pool is an aqueous solution containing 4% of glycerol and 1% of carboxymethyl cellulose;

(13) drying and humidifying: three-stage drying is carried out on the casing after washing and plasticizing, wherein the first-stage drying temperature is 90 ℃ and the time is 5 min; the second stage drying temperature is 75 deg.C, and the time is 5 min; the three-section drying temperature is 65 ℃, and the time is 3 min; finally, the sausage casing passes through a moisture recovery device, and the moisture is controlled at 15%.

Example 6

In order to evaluate the advantage of adding edible macromolecular substances in the preparation of fried collagen casings, the indexes of the edible fried collagen casings prepared in the examples and the prepared sausages were compared.

Index measurement:

(1) determination of rheological Properties: measuring rheological properties of micelle added with edible macromolecular substances by using a Discovery DHR-3 rotational rheometer, measuring the change of storage modulus, loss modulus and loss tangent angle of a sample along with angular frequency, wherein the temperature is 25 ℃, the scanning strain value is 1 percent, the oscillation frequency is 0.1-100rad/s, the measurement result is the value of the scanning frequency being 1Hz, and the result is shown in Table 1; measuring the change of the viscosity of the sample along with the shear rate, wherein the scanning range of the shear rate is 0.01-200 s^-1The test temperature is 25 ℃, and the result is shown in figure 1;

(2) and (3) measuring the tensile strength: the collagen casing was cut to a predetermined size, and the tensile strength was measured by selecting a tensile mode using a physical property tester (ta.xt2i, Lloyd instruments, u.k) according to ASTM standard method D882. The results are shown in FIG. 2;

(3) and (3) measuring the frying shrinkage rate: soaking a sausage casing with a certain length in deionized water for 1min, throwing the sausage casing into a frying pan with oil temperature of 180 ℃, frying for 3min, taking out the sausage casing, measuring the length of the sausage casing before and after frying, and using a formula for the shrinkage rate: (L)₀-L₁)/L₀Is represented by L₀And L₁The results are shown in Table 2, which shows the lengths of casings before and after frying;

(4) and (3) frying sensory evaluation: and forming a sensory evaluation group by 20 persons, and scoring the crispness, hardness and crispness of the fried collagen casing, wherein each sensory index score is 10 points, and the specific scoring standard is as follows:

the frying sensory evaluation was as follows:

crisp property: the sensory characteristics comprise that after the teeth act, the sausage casing is continuously crushed, fragments or fragments are small, the best sound is accompanied by small sound, the sausage casing is crushed by slight biting, the sausage casing has granular feeling, and the sound is small and is 8-10 minutes when the sausage casing is crushed; the broken stone is easy to break and loud in sound, and the number of broken pieces is 4-7 min; no fragments exist, the crisp feeling is small, or the crisp property is 1-3 minutes;

brittleness: the sensory characteristics comprise that when the tooth is used for action, sudden fracture is easy to occur, fragments or fragments are large and are broken into two blocks by biting along with large rattling sound, the rattling sound is large for 8-10 minutes when the tooth is broken, the tooth is easy to break, and the sound is small for 4-7 minutes when the tooth is broken; the steel is not easy to break or is difficult to break, and the toughness is 1-3 minutes;

hardness: the sensory characteristics comprise that teeth have certain resistance when the casing is bitten or chewed, and the resistance is 8-10 minutes when the casing is bitten; the resistance is generally 4 to 7 minutes when the sausage casing is bitten and crumbled;

the results of the obtained fried sensory evaluation data are shown in table 2;

(5) measuring the viscosity of the fried meat: the meat viscosity of the casing was evaluated by selecting 10 prepared sausages at random and frying them in a 180 ℃ oil pan, selecting an excellent commercially available fried collagen casing as a control, and recording the casing shrinkage/rupture/peeling phenomena, as shown in fig. 3.

Table 1 shows the results of measurement of the rheological characteristics of the micelles in each example

As can be seen from the measurement results in Table 1, the storage modulus of the micelles prepared in each example is greater than the loss modulus, which indicates that all micelles are in a solid state in the scanning frequency range, and the loss tangent angle of the sample with the corn starch and the high amylose corn starch added therein is slightly reduced, i.e., the elasticity ratio is increased, indicating that the network structure of the micelle gel system is enhanced. The comprehensive addition of the edible macromolecular substances of the various embodiments has no obvious influence on the rheological property of the micelle, and is suitable for normal extrusion and large-scale production of a factory extrusion head.

Table 2 shows the results of measurement of frying index of edible fried type collagen casing in each example

The results of the measurement in table 2 show that the fried collagen casings added with edible macromolecular substances have obviously improved mouthfeel after being fried under different glutaraldehyde crosslinking concentrations, the crispness degree is increased, and the tough mouthfeel of the current casings is effectively improved; secondly, the most suitable added edible macromolecular substances under different glutaraldehyde crosslinking conditions are different, the fried type collagen casing additive substance with the best comprehensive sense is curdlan under the condition of 0ppm, the fried type collagen casing additive substance with the best comprehensive sense is corn starch under the condition of 25ppm, and the fried type collagen casing additive substance with the best comprehensive sense is acetate cassava starch under the condition of 50 ppm; finally, the fried shrinkage of the sausage casing is related to the concentration of glutaraldehyde, the higher the concentration of the glutaraldehyde, the lower the fried shrinkage of the sausage casing is, the difference between the shrinkages of 25ppm series of sausage casing and 50ppm series of sausage casing is smaller, and the fried shrinkage under different cross-linking conditions is represented as follows: 0ppm is more than 25ppm and more than 50ppm, and the proper frying shrinkage can effectively promote the sausage casing to be better attached to the meat stuffing during frying, and improve the meat viscosity.

The tensile property of the fried type collagen casings prepared by adding different biological macromolecular substances is measured, and the measured data is recorded in figure 1, and the result shows that the mechanical property of the edible fried type collagen casings added with edible macromolecular substances produced by the corresponding preparation method is proper, the tensile strength is improved to a certain extent compared with the tensile strength of the collagen casings without adding edible macromolecular substances, the tensile strength improvement effect is more obvious under the condition of no glutaraldehyde crosslinking, and the production requirements and the practical application can be met;

according to fig. 2, the different results show that the collagen micelles with added edible macromolecular substances produced under the respective preparation methods have the properties of pseudoplastic fluids, manifested by shear thinning; the viscosity changes of examples 1 and 2 were substantially consistent with those of the micelle sample of example 3, indicating that the addition of these three edible macromolecular substances had no significant effect on the flowability of the micelle under the corresponding preparation methods.

Through the graph 3, the fried collagen casings which are prepared by adding different macromolecular biological substances and are added with edible macromolecular substances and prepared under the cross-linking conditions of 0ppm, 25ppm and 50ppm of glutaraldehyde are fried to be tubular, and the regularity is obviously improved compared with that of blank collagen casings without the edible macromolecular substances, and the result shows that the fried regularity of the casings can be obviously improved by adding the edible macromolecular substances, so that the phenomena of opening breakage and peeling caused by uneven shrinkage can be effectively prevented, and the practical application is met; in addition, compared with a blank collagen casing, the collagen casing added with the acetate tapioca starch has more and fine air holes on the fried surface, is similar to a puffed food, has a plurality of small air bubbles on the fried surface after the fried surface is added with the natural casing, has less air holes and air bubbles relative to the other two after the fried casing added with the corn starch, and reduces the quantity and the size of the air holes and the air bubbles along with the increase of the concentration of glutaraldehyde.

According to the figure 4, taking 0ppm glutaraldehyde crosslinking condition added edible fried collagen casings with corn starch, acetate tapioca starch and curdlan as examples, respectively randomly selecting ten casings, then adding the fried collagen casings with curdlan without the phenomenon of crevasse peeling, only one of the fried collagen casings with corn starch has small crevasses, only two of the fried collagen casings with acetate starch has small crevasses, all blank collagen casings have the phenomenon of crevasses and have large crevasses, and all ten commercially available collagen casings have the phenomenon of crevasses and have crevasses, which shows that the moderate collagen casings with edible macromolecular substances can obviously improve the viscosity of fried meat, increase the attaching degree of casings and meat, and effectively improve the sale quality and sense of the fried sausage.

According to the influence of different adding amounts of edible macromolecular substances on the mechanical property of the edible fried type collagen sausage casing in the graph of 5, the fried type collagen sausage casing added with curdlan produced under the corresponding preparation method has better mechanical property when the adding amount is 0.025 times of the weight of the coating; the fried type collagen sausage casing added with the acetate cassava starch has better mechanical property when the addition amount is 0.0125 times of the weight of the casing.

The invention provides a method for preparing fried collagen sausage casing with different glutaraldehyde concentrations by crosslinking and matching with different types and addition of used biological macromolecules, which can adapt to the preparation of any fried collagen sausage casing with mechanical strength, fried shrinkage rate, brittleness, hardness and crispness, and can prepare the fried collagen sausage casing with certain mechanical strength, fried shrinkage rate and good brittleness, hardness and crispness under the condition of not using glutaraldehyde. The invention provides a collagen casing prepared by using curdlan without using glutaraldehyde.

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.