CN111990655A

CN111990655A - Citrus fiber used in solid food and preparation method and application thereof

Info

Publication number: CN111990655A
Application number: CN202010758556.2A
Authority: CN
Inventors: 吕广; 赵林松; 董晓; 杨晓光
Original assignee: Hebei Lemeng Biotechnology Co ltd
Current assignee: Hebei Lemeng Biotechnology Co ltd
Priority date: 2020-07-31
Filing date: 2020-07-31
Publication date: 2020-11-27

Abstract

The invention discloses citrus fiber used in solid food and a preparation method and application thereof. The fiber finished product obtained by the method has the characteristics of water retention, improved yield, improved product quality and structure, convenient equipment processing and the like when being added into solid food, and has the advantages of water retention, improved yield, improved product quality and the like when the insoluble fiber content (calculated by dry matters) reaches more than 60 percent, the soluble fiber content (calculated by dry matters) reaches 5 to 20 percent, a 5 to 10 percent fiber aqueous solution is solid, the firmness is more than 20g, the hardness is more than 300g S, and the viscosity is less than-10 g/g.

Description

Citrus fiber used in solid food and preparation method and application thereof

Technical Field

The invention belongs to the field of food, and particularly relates to citrus fiber used in solid food as well as a preparation method and application thereof.

Background

Water retention is a very important quality characteristic of solid food products.

For meat products, for example, lower water retention means greater economic losses, including losses due to water loss and losses due to yield reduction. For consumers, the poor water retention can affect the appearance quality of raw meat in the storage and sale processes, and the raw meat has more surface moisture, is usually white in color and gives people a stale feeling.

Common water-retaining agents in meat products are salt, phosphate water-retaining agents, non-phosphate water-retaining agents:

(1) salt

The salt with a certain concentration has the function of increasing the water retention capacity of the meat. This is mainly because salt swells myofibrils. Under the existence of salt with a certain concentration, a large amount of chloride ions are bound among the myofibrils, so that the electrostatic repulsion caused by negative charges is increased, the myofibrils are expanded, and the water retention is enhanced.

(2) Phosphate water-retaining agent

The phosphate can combine magnesium ion and calcium ion in muscle protein to make the hydroxyl of protein be dissociated. The protein structure is relaxed due to the mutual repulsion of negative charges among hydroxyl groups, and the water-retaining property of the meat is improved.

Polyphosphate is an alkaline substance having a buffering action, and when added to meat, it shifts the pH of the meat in the alkaline direction, and myosin and actin in the muscle are dissolved away from the isoelectric point, thereby improving the water retentivity of the meat.

(3) Phosphorus-free water-retaining agent

The traditional water retention agent utilizes a mixed preparation of tripolyphosphate, sodium pyrophosphate and a small amount of hexametaphosphate to improve the water retention capacity of meat products.

However, excessive use of phosphate is detrimental to the flavor of meat products, and causes unpleasant so-called metallic astringency, which results in deterioration of the flavor of the products and a rough texture. While below a certain limit, phosphates have an unpleasant aftertaste in the emulsified product. Alkaline phosphates, when adjusted to pH, tend to reduce meat color and exhibit undesirable appearance. And if the pH value of the meat product is too high, fat decomposition is caused, and the shelf life is shortened.

Citrus fiber belongs to a class of dietary fiber, which has become very popular in the food industry, and about 20% of the annual sales of $ 160 billion instant cereal foods are foods rich in dietary fiber functions. Dietary fiber foods are also popular in Japan as in Europe and America, and in 1996, the sales of dietary fiber foods reaches 100 billion dollars, wherein more than 70% of functional drinks contain dietary fibers. The global dietary fiber food can be more than 600, and the new products launched in recent years can be more than 400. Numerous dietary fiber-supplemented fiber beverages, low-energy chocolate and nutrition bars, sports drinks, lactic acid bacteria beverages, milk tablets, etc. are available in the japanese market. International markets outside japan also emerge with a number of innovative fiber-fortified foods such as low-carbohydrate ice cream, fruit mates, yogurt, cookies, low-energy instant coffee, and the like. Most of these new products are introduced by international famous food companies such as Nestle, Dynence, Kafu, Unitrary, etc. The domestic dietary fiber market is still mainly concentrated in health food, and the share of common food is relatively small. In recent two years, food huge enterprises in China such as Mongolian cattle, illite, Guangming, Wahaha, farmer mountain spring and the like have developed health foods rich in dietary fibers, but most of the food enterprises are concentrated in the field of beverages, and the development of new fiber products is required to be increased in other food fields.

The application of dietary fiber in food is mostly taken as a functional component, and the research on improving the stable state of food is less; and the research on the dietary fiber mostly focuses on the aspects of extraction, content determination and modification research (increasing the content of soluble fiber) of the dietary fiber, and the research on the application of the insoluble dietary fiber is less.

The insoluble fiber in the citrus fiber has water holding capacity and expansibility, can increase the viscosity of a system when being applied to beverages and fermented milk, can provide suspending force in the system due to the thickening and gelling effects of the fiber, reduces the aggregation and sedimentation of protein, and maintains the stability of the system. In addition, the citrus fiber applied to solid food can replace additives, retain water, improve the yield, improve the product quality and structure, facilitate equipment processing and the like.

Researchers comparatively find that the water swelling effect of the citrus fiber is the best among a plurality of insoluble fibers.

Disclosure of Invention

The invention provides citrus fiber for solid food and a preparation method thereof, which have the effects of replacing additives, retaining water, improving the yield, improving the product quality and structure, improving the product fragrance and facilitating equipment processing in solid food by extracting insoluble fiber, physically modifying and controlling the content and the hydrophilic characteristic of the soluble fiber, and have great market prospect.

The technical scheme of the invention is as follows:

a citrus fiber used in solid food contains insoluble fiber more than 60%, soluble fiber 5-20%, and 5-10% fiber water solution in solid state, and has firmness greater than 20g, hardness greater than 300g S, and viscosity less than-10 g/g.

Further, the content of the insoluble fiber and the soluble fiber in the citrus fiber is the corresponding content measured after the water in the citrus fiber is removed.

A method for preparing the citrus fiber comprises the following steps:

step 1, juicing citrus fruits and separating to obtain solid components;

step 2, performing acid treatment on the solid component, specifically, adding the solid component into water to form a water system, then adding acid to adjust the pH of the system to be acidic, preserving the temperature at 70-85 ℃ for 60-180min, and separating to obtain residue I;

step 3, adding the residue I into water to form a water system, then adopting an instantaneous alkali treatment mode, specifically, adjusting the pH of the system to be alkaline by adding alkali once, then continuing stirring for 15-60min to enable the pH of the system to naturally fall back to 3-7, and separating to obtain a residue II;

step 4, adding the residue II into an ethanol water solution, and adjusting the pH value of the system to 2-3 to obtain a solution I;

and 5, adding the solution I into an ethanol system for dehydration, and then drying and crushing to obtain a finished citrus fiber product.

Further, in the preparation method, in the step 1, the citrus fruit includes one or more of orange, lemon, grapefruit and tangerine.

Further, in the preparation method, the mass ratio of the solid component to the added water in the step 2 is 1:20-1: 60.

Further, in the preparation method, the pH value of the system is adjusted to be 1.5-2.5 in the step 2.

Further, in the preparation method, the mass ratio of the residue I in the step 3 to the added water is 1:15-1: 25.

Further, in the preparation method, the pH value of the system is adjusted to 7-10 in the step 3.

Further, in the preparation method, the volume ratio of the residue two to the ethanol solution in the step 4 is 1:1-1: 3.

Further, in the preparation method, the ethanol content in the ethanol water solution in the step 4 is 0-70%.

Further, in the preparation method, the ethanol content is 70-90% when the ethanol system is dehydrated in the step 5.

Further, in the preparation method, an ethanol system is added in the step 5, and the pH value of dehydration is 4-7.

Use of citrus fibre as described above in solid food products.

Further, the application comprises the step of pretreating the citrus fiber before application, specifically, mixing the finished citrus fiber with water according to the weight ratio of 1:5-1:20, uniformly stirring at a high speed by using a stirrer, a shearing machine or a cutting and mixing machine, and adding the mixture into solid food.

Based on the preparation process of the citrus fiber, the invention determines the optimal quality standard and production process of the citrus fiber through the research on the physicochemical properties of insoluble fiber and soluble fiber and the application properties of the insoluble fiber and the soluble fiber in solid food, and the application effect is better than other food additives and food raw materials:

(1) the soluble fiber and the colloid are dissolved in water and combined with the water to retain water, and are in a colloid state after being combined with the water, so that when the soluble fiber and the colloid are applied to solid food, the water retaining effect can be realized, but the original texture of the product can be influenced, the product is softened, and the product is easy to adhere to equipment and is difficult to clean in the processing process; the insoluble fiber has a water absorption mode like a sponge, can play the same water retention effect as an additive when applied to solid food, but can not influence the original texture of a product, realizes the effects of increasing the yield and strengthening the original texture of the product, and makes the product compact in structure and not easy to adhere to equipment in the processing process, thereby facilitating the processing. Meanwhile, the insoluble fiber can absorb water-soluble aroma substances while absorbing water, so that the product is full and rich in aroma when being eaten. According to the invention, the compact fibers are subjected to acidolysis to a certain extent through acid treatment, so that the processing for improving the water absorption effect of the fibers at the later stage is facilitated, and part of soluble components in the citrus fibers are removed, so that the content of insoluble fibers in the citrus fibers reaches more than 60%, and the texture enhancing effect and the fragrance improving effect are better;

(2) although the citrus fiber has better water holding capacity than other fibers, the crystallization degree of insoluble fiber in the citrus fiber is still higher, the citrus fiber cannot have higher water holding capacity and better application effect through simple separation and purification, and the crystalline fiber of the citrus fiber can be further opened through alkali treatment, so that the water absorption swelling capacity of the fiber is effectively improved, and the insoluble fiber with high water holding capacity is obtained. Meanwhile, the alkali treatment can also convert part-COOH structure of pectin in the fiber into-COONa, so that the fiber has better hydrophilicity, further improves the water absorption capacity and water absorption speed of the citrus fiber, and is more beneficial to processing and use. The pectin has ionic structure, and has strong electrostatic repulsion, and can inhibit fiber aggregation during drying and storage, and improve water absorption stability of citrus fiber during drying and storage.

(3) The instant alkali treatment used in the invention can control the pH of the final solution to be weakly acidic when improving the water absorption capacity of the insoluble fiber and the hydrophilic capacity of the pectin, and can reduce the loss of the pectin and the soluble fiber. Before the fibers are dehydrated by using the ethanol solution, the pH value of the fibers is reduced to 2-3, so that the residual pectin and soluble fibers in the fibers can be completely reserved, and the water absorption capacity and the stability of the fibers are further improved. In addition, a certain amount of pectin and soluble fiber are remained in the citrus fiber, and due to the water absorption effect of the insoluble fiber, the pectin and the soluble fiber cannot be combined with too much water to be thinned, so that the quality structure is not influenced; due to the hydrophilic action of pectin and soluble fiber, the insoluble fiber can not absorb water completely and dry, so that the citrus fiber is solid after absorbing water and has a moist surface. The product is applied to solid food, so that the effects of increasing the product yield, improving the moist mouthfeel of the product and not influencing the quality and structure of the product are achieved.

(4) The dispersed citrus fibers are dried under low pH, so that the dispersed fibers can be re-aggregated, the water absorption capacity and the water absorption speed are reduced, and the application effect is poor; finished citrus fibers can be re-aggregated when stored at low pH, obvious water absorption capacity and water absorption speed reduction can be realized within 6 months, and the application effect is further deteriorated. In the preparation process of the citrus fiber, the water absorption capacity and the water absorption speed of the citrus fiber are improved through alkali treatment, a better application effect is achieved, and the water absorption capacity and the water absorption speed of the fiber in the drying process and the quality guarantee period are stable and the application effect is stable through pH control before drying.

(5) The drying speed and drying temperature of the citrus fiber drying link have great influence on the water absorption capacity and application effect of the fibers, and the process control is matched with the dehydration of the organic solvent and the proper drying temperature to ensure that the fiber production reaches the optimal stable state

(6) Through the control of the citrus fiber preparation process, the water absorption capacity and the water absorption speed of the fibers are optimized, more water can be added into a solid food formula without affecting the quality of the product when the fibers are applied, the product quality is stronger, the taste is more moist, the aroma is more intense, the yield is higher, the using amount is lower, the cost is lower, and the citrus fiber preparation process really realizes the substitution of food additives.

(7) The addition of the orange fiber and water in a separate shearing and pulping mode can furthest increase the water content in the product, thereby increasing the product yield without influencing the texture effect. The reason is that the citrus fiber is cut separately from water, so that the citrus fiber absorbs water sufficiently and is added into the product, thereby achieving the best effect of increasing the yield. If the citrus fiber is directly added into the product and then the excessive water is added, the hydrophilic components in the product are more, the water is strived for with the fiber, and the additionally added water is combined by the hydrophilic components to influence the texture, so that the product is softened.

The specific implementation mode is as follows:

the invention is further illustrated by the following comparison of examples in which the performance of citrus fiber prepared is evaluated by the insoluble fiber content, the soluble fiber content, the citrus fiber-water blend texture and the effect of its use in meat products.

1. The content of insoluble dietary fiber and the content of soluble dietary fiber are detected according to GB 5009.88-2014.

2. The texture detection method comprises the following steps: mixing the prepared citrus fiber with water at a weight ratio of 1:10, stirring at high speed with a stirrer, a shearing machine and a chopper mixer, standing for 60min, and detecting the firmness, hardness and viscous force of citrus fiber slurry with an SMS texture analyzer, model TA.XTplus C and probe ABE-45 mm.

Example 1

The embodiment provides a preparation method of citrus fiber, which comprises the following steps:

(1) weighing fruits, juicing, dividing into 100g (calculated on dry matter) of solid components, adding water according to the weight ratio of the dry matter to the water of 1:20, adjusting the pH value to 2, preserving the heat at 70 ℃ for 60min, and separating to obtain residue I;

(2) adding water into the residue I according to the weight ratio of the dry matter to the water of 1:15, adding alkali to adjust the pH value to 7, stirring for 15min, naturally reducing the pH value to 3, and separating to obtain residue II;

(3) mixing the residue II separated in the step (2) with an ethanol aqueous solution with the mass fraction of 70% according to the volume ratio of 1:1, uniformly stirring, and adjusting the pH value to 2 to obtain a solution I;

(4) mixing the solution I obtained in the step (3) with ethanol with the mass fraction of 70% according to the volume ratio of 1:1, adjusting the pH value to 4, and separating and extruding to obtain a solid phase;

(5) and (3) drying the solid phase components separated in the step (4) at 80 ℃ to obtain a semi-finished product of citrus fiber with the water content of 8%, and then crushing to obtain the citrus fiber.

Example 2

(1) weighing fruits, juicing, dividing into 100g (calculated on dry matter) of solid components, adding water according to the weight ratio of the dry matter to the water of 1:40, adjusting the pH value to 2.5, keeping the temperature at 75 ℃ for 90min, and separating to obtain residue I;

(2) adding water into the residue I according to the weight ratio of the dry matter to the water of 1:20, adding alkali to adjust the pH value to 8, stirring for 30min, naturally reducing the pH value to 5, and separating to obtain residue II;

(3) mixing the residue II separated in the step (2) with an ethanol water solution with the mass fraction of 50% according to the volume ratio of 1:2, uniformly stirring, and adjusting the pH value to 2 to obtain a solution I;

(4) mixing the solution I obtained in the step (3) with 80% ethanol by mass according to a volume ratio of 1:2, adjusting the pH value to 5, and separating and extruding to obtain a solid phase;

(5) and (3) drying the solid phase components separated in the step (4) at 80 ℃ to obtain a semi-finished product of citrus fiber with the water content of 7%, and then crushing to obtain the citrus fiber.

Example 3

(1) weighing fruits, juicing, dividing into 100g (calculated on dry matter) of solid components, adding water according to the weight ratio of the dry matter to the water of 1:50, adjusting the pH to 2.3, keeping the temperature at 85 ℃ for 130min, and separating to obtain residue I;

(2) adding water into the residue I according to the weight ratio of the dry matter to the water of 1:25, adding alkali to adjust the pH value to 8, stirring for 50min, naturally reducing the pH value to 5, and separating to obtain residue II;

(3) mixing the residue II separated in the step (2) with an ethanol aqueous solution with the mass fraction of 30% according to the volume ratio of 1:3, uniformly stirring, and adjusting the pH value to 3 to obtain a solution I;

(4) mixing the solution I obtained in the step (3) with ethanol with the mass fraction of 90% according to the volume ratio of 1:2, adjusting the pH value to 6, and separating and extruding to obtain a solid phase;

Example 4

(1) weighing fruits, juicing, dividing into 100g (calculated on dry matter) of solid components, adding water according to the weight ratio of the dry matter to the water of 1:60, adjusting the pH value to 1.5, keeping the temperature at 85 ℃ for 180min, and separating to obtain residue I;

(2) adding water into the residue I according to the weight ratio of the dry matter to the water of 1:25, adding alkali to adjust the pH value to 10, stirring for 60min, naturally reducing the pH value to 7, and separating to obtain residue II;

(3) mixing the residue II separated in the step (2) with water according to the volume ratio of 1:1, uniformly stirring, and adjusting the pH value to 2 to obtain a solution I;

(4) mixing the solution I obtained in the step (3) with 80% ethanol by mass according to a volume ratio of 1:2, adjusting the pH value to 7, and separating and extruding to obtain a solid phase;

Performance tests were performed on citrus fiber samples prepared in examples 1-4 above and the results are shown below:

example 5

The citrus fiber prepared in the embodiment 3 of the invention is adopted to carry out a new Orleans chicken leg steak application test, which specifically comprises the following steps:

the formula, key control points and evaluation method of the new orleand leg steak are as follows:

the formula of the new orleand leg steak is as follows:

ingredients	Dosage per gram	For applicationsAmount per g
			Leg meat	100	260
Ice water	22.00	57.2
			Orleans cure (Heyang)	6.8	17.68
Carrageenan	0.6	1.56
			Water-retaining agent for harmonizing body	0.88	2.288
Salt	0.11	0.286
			White sugar	0.50	1.3
Gourmet powder	0.60	1.56
			Crushed black pepper of 35 meshes	0.1	0.26
Composite phosphate (Heyang)	0.60	1.56
			Pigment oil	0.73	1.898
Modified starch (Soft elastic)	9	23.4
			Isolated soy protein	0.5	1.3
Spreading material	0.2	0.52
			Total of	146.92	381.992

The key control points for the new orleand leg row are:

1. unfreezing the leg row, and then trimming meat: 63g to 68 g. And after finishing repairing, placing and refrigerating for weighing.

2. Weighing materials by using a plastic bag: after the materials of the formula content are added specifically, the mixture is shaken off;

3. putting meat into plastic bag, and rolling and kneading for 30 min;

4. taking out, continuously weighing and adding carrageenan, modified starch, soybean protein isolate and sprinkling material external water retention substances into the plastic bag, and rolling and kneading for 10 min;

5. taking out, refrigerating the plastic bag at 4 deg.C for more than 5 hr, and pickling;

6. taking out, unpacking, and spreading the leg rows in a tray for freezing for at least 2 h;

7. frying at 170 deg.C for 5 min.

Evaluation method of new orleand leg steaks:

and (3) evaluating the yield:

actual weight after freezing/raw meat weight

Sensory taste evaluation:

the new orleans leg steaks were prepared as follows:

(1) unfreezing the leg row, putting the leg row into a plastic bag, and putting the plastic bag into a rolling and kneading machine to roll and knead for 30 min;

(2) continuously weighing the plastic bags in the step (1), adding carrageenan, modified starch, soybean protein isolate and external water retention substances, and rolling and kneading for 10 min;

(3) preserving the plastic bag in the step (2) after refrigerating at 4 ℃ and standing for 5 h;

(4) removing the plastic bag package in the step (3), and flatly paving the leg rows in a tray for freezing for 2 h;

(5) frying the frozen leg steak in the step (4) at 170 ℃ for 5min to obtain a new Orleans leg steak No. 1;

(7) continuously weighing and adding citrus fiber (4g), carrageenan, modified starch, soybean protein isolate and external water retention substances into the plastic bag in the step (1), and rolling and kneading for 10 min;

(8) then, obtaining a new Orleans leg row 2# according to the processing modes from (3) to (5);

(9) stirring and pulping the citrus fiber and water according to the weight ratio of 1: 10;

(10) adding 44g of the citrus fiber pulp obtained in the step (9) into the plastic bag obtained in the step (1), and rolling and kneading for 10 min;

(11) continuously weighing the plastic bags in the step (10), adding carrageenan, modified starch, soybean protein isolate and external water retention substances, and rolling and kneading for 10 min;

(12) and then, obtaining a new Oerlang leg row 3# according to the processing modes from (3) to (5).

Product yield evaluation results:

	raw meat	After being frozen completely	Come out to
				New Orleans leg 1#	263.4	312.2	118.52
New Orleans leg Row 2#	264.2	314.8	119.15
				New Orleans leg 3#	263	327.8	124.64

Sensory taste evaluation results of the product:

	color and luster	Flavor (I) and flavor (II)	Degree of greasiness	Juicy meat	Chewiness of the product
						New Orleans leg 1#	6.15	6.69	7.12	6.53	6.83
New Orleans leg Row 2#	6.59	6.81	7.15	6.72	7.02
						New Orleans leg 3#	7.33	7.17	7.33	7.14	7.43

Compared with the new Orleans leg steaks No. 1,2 and 3, the product yield is improved and the taste is improved after the citrus fiber is added. The new Oerlang leg-row No. 3 product rate is improved, and the sensory quality is improved more obviously. The citrus fiber is added into the product formula after fully absorbing water, and has higher yield and sensory quality than the addition of dry powder.

Example 6

(1) Weighing fruits, juicing, dividing into 100g (calculated on dry matter) of solid components, adding water according to the weight ratio of the dry matter to the water of 1:40, adjusting the pH value to 2.0, and keeping the temperature at 75 ℃ for 90min to obtain residue I;

(2) adding water into the residue I according to the weight ratio of the dry matter to the water of 1:25, adding alkali to adjust the pH value to 7, stirring for 15min, naturally reducing the pH value to 4, and separating to obtain residue II;

(3) mixing the residue II separated in the step (2) with 70% ethanol water solution according to the volume ratio of 1:2, stirring uniformly, and adjusting the pH value to 2 to obtain a cellulosic ethanol solution

(4) Mixing the cellulosic ethanol solution obtained in the step (3) with ethanol with the mass fraction of 80% according to the volume ratio of 1:2, adjusting the pH value to 5, and separating and extruding to obtain a solid phase with the water content of 70%;

(5) drying the solid phase components separated in the step (4) at 80 ℃ to obtain a citrus fiber semi-finished product with the water content of 8%;

(6) and crushing the semi-finished product of the citrus fiber to obtain a citrus fiber sample No. 1.

(7) Mixing the cellulosic ethanol solution obtained in the step (3) with ethanol with the mass fraction of 80% according to the volume ratio of 1:2, adjusting the pH to 6, separating and extruding to obtain a solid phase with the water content of 70%, and then obtaining the index of the No. 2 citrus fiber of the citrus fiber sample according to the processing modes of (5) to (6):

fiber sample	Firmness (g)	Hardness (g S)	Viscous force (g/g)
				Citrus fiber sample No. 1	25.60	389.38	-20.15
Citrus fiber sample No. 2	33.95	451.08	-24.82

(2) stirring and pulping the citrus fibers 1#, 2# and water according to the weight ratio of 1: 10;

(3) adding the citrus fiber pulp obtained in the step (2) into the plastic bag obtained in the step (1), and rolling and kneading for 10 min;

(4) continuously weighing the plastic bags in the step (3), adding carrageenan, modified starch, soybean protein isolate and external water retention substances, and rolling and kneading for 10 min;

(5) preserving the plastic bag in the step (4) after refrigerating at 4 ℃ and standing for 5 h;

(6) removing the plastic bag package in the step (5), and flatly paving the leg rows in a tray for freezing for 2 h;

(7) frying the frozen leg steak in the step (6) at 170 ℃ for 5min to obtain a new Orleans leg steak No. 4, No. 5.

Yield evaluation results:

sensory taste evaluation results of the product:

	color and luster	Flavor (I) and flavor (II)	Degree of greasiness	Juicy meat	Chewing feeling
						New orleans leg 4#	7.167	6	7.125	6.111	7.5
New Orleans leg 5#	7.6	6.625	6.875	6.778	7.833

Compared with the new Orleans leg rows No. 4 and No. 5, the orange fiber No. 2 is higher in beating firmness, hardness and viscosity, higher in yield when applied to products and more obvious in taste improvement.

Example 7

(2) adding water into the residue I according to the weight ratio of the dry matter to the water of 1:25, adding alkali to adjust the pH value to 9, stirring for 15min, naturally reducing the pH value to 6, and separating to obtain residue II;

(6) and crushing the semi-finished product of the citrus fiber to obtain a citrus fiber sample No. 3.

(7) Juicing the fruits weighed in the step (1), separating to obtain 100g of solid components (calculated by dry matters), adding water according to the weight ratio of the dry matters to the water of 1:40, keeping the temperature at 75 ℃ for 90min without adjusting the pH, separating to obtain a residue I, and then processing according to the processing modes of (2) to (6) to obtain a citrus fiber sample No. 4.

The performance index tests were performed on citrus fiber sample # 1 and citrus fiber sample # 2, as specified in the following table:

through the comparison of the insoluble fiber content of the fiber sample with the water holding capacity, the firmness, the hardness and the viscous force indexes, the 3# citrus fiber is subjected to acidolysis on compact fibers to a certain degree through low pH treatment in the preparation process, and pectin and soluble fibers are removed, so that the insoluble fiber content is improved, and the improvement of the key performance indexes of the citrus fibers is facilitated.

Example 8

(1) Weighing fruits, juicing, separating to obtain 100g (calculated on dry matter) of solid components, adding water according to the weight ratio of the dry matter to the water of 1:40, adjusting the pH value to 1.8, and preserving the temperature at 75 ℃ for 120min to obtain residue I;

(2) adding water into the residue I according to the weight ratio of the dry matter to the water of 1:25, adding alkali to adjust the pH value to 8, stirring for 15min, naturally reducing the pH value to 5, and separating to obtain residue II;

(3) mixing the residue II separated in the step (2) with 70% ethanol water solution according to the volume ratio of 1:1.5, stirring uniformly, and adjusting the pH value to 3 to obtain a cellulosic ethanol solution

(4) Mixing the cellulosic ethanol solution obtained in the step (3) with ethanol with the mass fraction of 80% according to the mass ratio of 1:2, uniformly stirring, adjusting the pH value to 5, and separating and extruding to obtain a solid phase with the water content of 70%;

(6) and crushing the semi-finished product of the citrus fiber to obtain a citrus fiber sample No. 5.

(7) Adding water into the residue I obtained in the step (1) according to the weight ratio of dry matters to water of 1:25, adding alkali to adjust the pH value to 8, continuously adding alkali to ensure that the pH value is maintained at 8, and separating to obtain residue II; and then, obtaining a citrus fiber sample No. 6 according to the treatment modes of (3) to (6).

Performance tests were performed on citrus fiber sample # 5 and citrus fiber sample # 6 as follows:

the comparison of the performance indexes of the fiber samples No. 5 and No. 6 shows that the preparation process of the No. 6 citrus fiber adopts a conventional pH adjusting mode, the pH is constantly controlled in a fixed range, the alkali treatment strength is high, and the indexes of the firmness, hardness and viscosity of the final product are low.

Example 9

(2) adding water into the residue I according to the weight ratio of the dry matter to the water of 1:25, adding alkali to adjust the pH to 9, stirring for 15min, naturally reducing the pH to 6, and separating to obtain residue II;

(3) mixing the residue II separated in the step (2) with 70% ethanol water solution according to the volume ratio of 1:1.5, stirring uniformly, and adjusting the pH value to 2.5 to obtain a cellulosic ethanol solution

(4) Mixing the cellulosic ethanol solution obtained in the step (3) with ethanol with the mass fraction of 80% according to the mass ratio of 1:2, uniformly stirring, adjusting the pH value to 6, and separating and extruding to obtain a solid phase with the water content of 70%;

(6) and crushing the semi-finished product of the citrus fiber to obtain a citrus fiber sample No. 7.

(7) Mixing the cellulosic ethanol solution obtained in the step (3) with ethanol with the mass fraction of 80% according to the mass ratio of 1:2, stirring uniformly, separating and extruding without adjusting the pH value to obtain a solid phase with the water content of 70%; and then, obtaining a citrus fiber sample No. 8 according to the treatment modes of (5) to (6).

Performance tests were performed on citrus fiber sample 7# and citrus fiber sample 8# as follows:

the comparison of the performance indexes of the fiber samples No. 7 and No. 8 shows that the pH value of the product before the 8# citrus fiber is dried is low, and the product is aggregated to a certain extent in the drying process, so that the indexes of the firmness, hardness and viscosity of the final product are low.

Claims

1. Citrus fibre for use in solid food products, characterized in that the citrus fibre has an insoluble fibre content of more than 60% and a soluble fibre content of 5-20%, and in that a 5-10% aqueous solution of the fibre is solid, having a firmness of more than 20g, a hardness of more than 300g S and a viscosity of less than-10 g/g.

2. The citrus fiber of claim 1 wherein the insoluble fiber and soluble fiber are present in amounts corresponding to the amount of water present in the citrus fiber when removed.

3. A method of making citrus fiber according to claim 1, comprising the steps of:

step 1, juicing citrus fruits and separating to obtain solid components;

4. The method according to claim 3, wherein the citrus fruit of step 1 comprises one or more of orange, lemon, grapefruit, and mandarin orange.

5. The production method according to claim 3, wherein the mass ratio of the solid component to the added water in step 2 is 1:20 to 1: 60.

6. The method according to claim 3, wherein the pH of the system is adjusted to 1.5 to 2.5 in step 2.

7. The method according to claim 3, wherein the mass ratio of the first residue to the added water in the step 3 is 1:15 to 1: 25.

8. The method according to claim 3, wherein the pH of the system is adjusted to 7 to 10 in step 3.

9. The method according to claim 3, wherein the volume ratio of the residue two to the ethanol solution in the step 4 is 1:1 to 1: 3.

10. The method according to claim 3, wherein the ethanol content in the aqueous ethanol solution in the step 4 is 0 to 70%.

11. The method according to claim 3, wherein the ethanol content of the ethanol system in the dehydration in the step 5 is 70 to 90%.

12. The method according to claim 3, wherein the ethanol system is added in the step 5 to dehydrate the solution to a pH of 4 to 7.

13. Use of citrus fibre according to claim 1 or 2 in solid food products.

14. The use of claim 13, wherein the citrus fiber is pre-treated prior to use, and in particular, the citrus fiber product is mixed with water in a weight ratio of 1:5 to 1:20, and then the mixture is blended at high speed using a blender, a shearer, or a chopper mixer and added to the solid food product.