A fresh fruit peel residue squeezing dewatering process

Abstract

The present application relates to the technical field of agricultural product waste processing, in particular to a fresh fruit peel residue squeezing dehydration process. The process adopts a dehydration accelerator for short-time reaction with fresh fruit peel residue, and then realizes effective dehydration through physical squeezing again. The water content of the fruit peel residue can be reduced from 78.03% to 66.67%. The process optimizes the dehydration effect, nutrient retention, ash control and other indicators, which can not only significantly improve the squeezing dehydration efficiency, but also has less nutrient loss and greatly improves the commercial utilization value of the fruit peel residue.

Description

Technical Field

[0001] This invention relates to the field of agricultural waste processing technology, specifically to a pressing and dehydration process for fresh fruit peels and pomace. Background Technology

[0002] my country is a major producer and processor of fruit, especially citrus fruits.

[0003] To overcome the drawbacks of fresh fruit peel and pomace, such as high moisture content, susceptibility to mold, poor palatability, low protein content, and the presence of anti-nutritional factors, appropriate processing is necessary. However, due to the large amounts of pectin and lignocellulose in fresh fruit peel and pomace, it is difficult to remove most of the moisture through pressing. Current processing techniques mainly include drying and fermentation. Drying methods include natural sun drying, hot air drying, fluidized bed drying, and microwave vacuum drying. Natural drying is low-cost but inefficient and produces inconsistent quality, while mechanical drying is highly efficient but extremely energy-intensive. The high cost of drying is a major factor limiting the widespread application of fruit peel and pomace, especially as an unconventional feed resource, making it difficult to use as a bulk feed ingredient.

[0004] It is evident that reducing the drying cost of fruit peel pomace is a crucial way to effectively utilize large quantities of waste. Physical pressing followed by drying can effectively improve drying efficiency and reduce energy consumption. However, for fresh fruit peel pomace with high moisture content and high viscosity (such as citrus peel pomace), direct pressing not only results in extremely low dehydration efficiency due to its status as a waste product, but also leads to gelatinization and sticking after further pressing and drying. The resulting dried pomace has a poor color, which is detrimental to subsequent processing. Furthermore, balancing dehydration efficiency with the retention of nutrients in the fruit peel pomace is a significant challenge facing the industry.

[0005] Therefore, there is an urgent need for an effective dehydration process for fresh fruit peels and pulp. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a fresh fruit peel and pomace pressing and dehydration process. The process involves mixing a dehydration accelerator with fresh fruit peel and pomace and reacting for 10-20 minutes, followed by physical pressing for dehydration. This process not only significantly improves pressing and dehydration efficiency but also minimizes nutrient loss and significantly enhances the appearance quality of the dried fruit peel and pomace. The dehydration accelerator used in this invention is widely available and inexpensive, resulting in a low overall cost, short processing time, and minimal requirements for processing equipment, making it suitable for industrial application.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a fresh fruit peel and pomace pressing and dehydration accelerator, the accelerator comprising lime powder and plant-based raw material powder, wherein the mass ratio of lime powder to plant-based raw material powder is 0.5~0.9:0.1~2.5.

[0009] Furthermore, the lime is slaked lime.

[0010] Furthermore, the plant-based raw material powder includes, but is not limited to, one or more of rice husk powder, wheat husk powder, sorghum husk powder, millet bran husk powder, buckwheat husk powder, corn cob powder, and peanut shell powder. The plant-based raw material powder is obtained by directly pulverizing plant-based raw materials (rice husk, wheat husk, sorghum husk, millet bran husk, buckwheat husk, corn cob, and peanut shell).

[0011] In a second aspect, the present invention provides a process for pressing and dehydrating fresh fruit peel and pomace, the process comprising the following steps:

[0012] After cutting the fresh fruit peel and pomace, add the accelerator mentioned in the first aspect above, mix evenly, let stand and react for 10-20 minutes, pour the reacted material into a press for pressing and dehydration, and collect the dehydrated peel and pomace and the extract.

[0013] In a third aspect, the present invention provides a process for drying fresh fruit peel residue, the process comprising: pressing and dehydrating the fresh fruit peel residue using the process described in the second aspect above, and drying the pressed and dehydrated fruit peel residue.

[0014] In a fourth aspect, the present invention provides depeeled fruit pulp prepared by the process described in the second aspect above.

[0015] In a fifth aspect, the present invention provides dried fruit peel residue prepared by the process described in the third aspect above.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The dehydrating agent used in this invention has simple components, and the plant-based raw materials are agricultural processing by-products with wide availability, resulting in a low overall price for the dehydrating agent. After a short-term reaction between the dehydration accelerator described in this invention and fresh fruit peel and pomace, effective dehydration can be achieved again through physical pressing, reducing the moisture content of the fruit peel and pomace from 78.03% to 66.67%.

[0018] The process described in this invention comprehensively optimizes multiple indicators, including dehydration effect, nutrient retention, ash content, and pH control. After pressing, the dry matter content in the extract is only 13%–16%, indicating that the pressing process mainly removes water, with minimal loss of solids and pulp, effectively preserving the nutrients in the fruit peel residue. The ash content of the processed fruit peel residue is controlled below 8%, and the pH is maintained in the neutral to slightly alkaline range. This characteristic allows the dehydrated or dried fruit peel residue to be directly used as feed raw material, exhibiting good safety and application value. The pH of the extract generated during the pressing process is also controlled within the slightly alkaline range, reducing the difficulty and cost of wastewater treatment. The process described in this invention has low energy consumption and is environmentally friendly, causing no impact on the environment.

[0019] The fruit peel residue treated by the pressing, dehydration and drying process of this invention has less loss of nutrients and a significantly improved appearance: the peel residue is loose and uniform, with a natural and bright color, no sticking or clumping, and high particle regularity; the appearance quality is significantly improved, which greatly enhances the commercial utilization value of the fruit peel residue. Attached Figure Description

[0020] Figure 1 Results of drying different fresh citrus peel residues at 75°C: A was dried using the process described in Example 14; B was dried directly at 75°C.

[0021] Figure 2 Results of drying different fresh citrus peel residues at 105℃: C Fresh citrus peel residues were directly dried at 105℃; D The drying process described in Example 15 was used for drying. Detailed Implementation

[0022] The following detailed description is merely illustrative and intended to further illustrate the technical solutions of the present invention, rather than limiting the scope of protection of the present invention. Unless otherwise specified, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] The terminology used herein is for describing specific embodiments only and is not intended to limit the scope of protection of the invention. Unless the context clearly specifies otherwise, singular expressions should be understood to include plural forms.

[0024] The terms “comprising,” “including,” “having,” “containing,” and their grammatical synonyms used in this article are all open-ended expressions and should generally be understood as not excluding other elements, components, or steps not explicitly stated, unless otherwise specifically limited or understood from the context.

[0025] As used herein, the phrase “one or more of…” should be understood to include each of the items listed below, as well as any combination of two or more items. For the phrase “and / or”, it should be understood to mean any one, any two or more of the listed items, unless the context clearly implies otherwise.

[0026] In this document, "A and / or B" refers to the following three scenarios: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. "At least one" means one or more, and "multiple" means two or more. "At least one of the following" means any combination of the listed items, including a single item or a combination of any number of items.

[0027] It should be understood that the order of the steps or the order in which certain actions are performed is not important as long as the invention remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0028] The use of any and all instances or exemplary language such as “e.g.” or “including” in this document is merely intended to better illustrate the invention and is not intended to limit the scope of the invention unless the claims are made. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of the invention.

[0029] Furthermore, the numerical ranges and parameters used to define the present invention are approximate values, and the relevant values ​​in the specific embodiments have been presented as precisely as possible. However, any value inevitably contains standard deviations due to individual test methods. Therefore, unless explicitly stated otherwise, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately". Here, "approximately" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific value or range.

[0030] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0031] The embodiments or test examples of this invention describe some cases, in which the embodiments illustrate certain implementations of the invention. However, this does not mean that the effects of the invention can only be achieved in these cases.

[0032] To address the problems described in the background section, the first aspect of this invention provides a fresh fruit peel and pomace pressing and dehydration accelerator, the accelerator comprising lime powder and plant-based raw material powder, wherein the mass ratio of lime powder to plant-based raw material powder is 0.5-0.9:0.1-2.5.

[0033] Further, the mass ratio of lime powder to plant-based raw material powder is 0.65–0.7:1.5–2. In some specific embodiments of the present invention, the mass ratio of lime powder to plant-based raw material powder is any one of 0.65:1.5, 0.65:2, 0.7:1.5, 0.7:1.6, 0.7:1.7, 0.7:1.8, 0.7:1.9, 0.7:2, or any combination thereof.

[0034] Furthermore, the lime is slaked lime.

[0035] Furthermore, the plant-based raw material powder includes, but is not limited to, one or more of rice husk powder, wheat husk powder, sorghum husk powder, millet bran husk powder, buckwheat husk powder, corn cob powder, and peanut shell powder. The plant-based raw material powder is obtained by directly pulverizing plant-based raw materials (rice husk, wheat husk, sorghum husk, millet bran husk, buckwheat husk, corn cob, and peanut shell).

[0036] In a second aspect, the present invention provides a process for pressing and dehydrating fresh fruit peel and pomace, the process comprising the following steps:

[0037] After cutting the fresh fruit peel and pomace, add the accelerator mentioned in the first aspect above, mix evenly, let stand and react for 10-20 minutes, pour the reacted material into a press for pressing and dehydration, and collect the dehydrated peel and pomace and the extract.

[0038] Further, the amount of lime powder in the accelerator accounts for 0.5% to 0.9% of the weight of fresh fruit peel and pomace, and the amount of plant-based raw material powder accounts for 0.1% to 2.5% of the weight of fresh fruit peel and pomace. In some specific embodiments of the present invention, the amount of lime powder accounts for any one of 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, and 0.9% of the weight of fresh fruit peel and pomace, or any combination thereof; the amount of plant-based raw material powder accounts for any one of 0.1%, 1.0%, 1.5%, 2.0%, and 2.5% of the weight of fresh fruit peel and pomace, or any combination thereof.

[0039] This invention reveals that as the amount of lime powder used gradually increases, the dehydration efficiency of fresh fruit peel pomace gradually increases. However, when the amount of lime powder exceeds 0.9%, although the dehydration efficiency increases, the pH of the dehydrated peel pomace and the extract becomes too high, which undoubtedly increases the difficulty and cost of wastewater treatment. Simultaneously, the high ash content in the peel pomace fails to meet the corresponding standards for feed ingredients. Furthermore, when the amount of plant-based raw material powder used is too high, although the juice yield further increases, the dry matter content of the extract rises significantly, indicating that the pressing intensity is too high, causing a large amount of fruit pulp particles to flow out with the water, resulting in significant nutrient loss. Within the dosage range described in this invention, not only can the dehydration efficiency be significantly improved, but the nutrients in the fruit peel pomace can also be preserved, while avoiding excessively high ash content in the peel pomace and excessively high pH in the peel pomace and the extract.

[0040] Furthermore, after the lime powder and plant-based raw material powder in the accelerator are mixed evenly, they are added to the chopped fresh fruit peel residue. This invention has found that when processing fresh fruit peel residue on a laboratory scale, the addition method of lime powder and plant-based raw material powder does not affect the dehydration effect because the amount of fresh fruit peel residue used is small. However, when processing fresh fruit peel residue by weight in tons, if lime powder is added first, it quickly clumps together with the surrounding fruit peel residue during mixing, making it almost impossible to mix the lime powder evenly with the fresh fruit peel residue. However, if the lime powder and plant-based powder are mixed evenly before being added to the fresh fruit peel residue, the materials are easily mixed evenly.

[0041] Furthermore, a screw press is used for pressing, and the pressing is repeated at least three times; or a roller press is used for pressing once.

[0042] In a third aspect, the present invention provides a process for drying fresh fruit peel and pomace, the process comprising:

[0043] Fresh fruit peels and pomace are pressed and dehydrated using the process described above, and the pressed and dehydrated fruit peels and pomace are then dried.

[0044] In a fourth aspect, the present invention provides depeeled fruit pulp prepared by the process described in the second aspect above.

[0045] In a fifth aspect, the present invention provides dried fruit peel residue prepared by the process described in the third aspect above.

[0046] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0047] Example 1

[0048] A process for pressing and dehydrating fresh fruit peel and pomace includes the following steps:

[0049] S1. Cut the fresh fruit peel and residue into strips;

[0050] S2. First, mix the components of the dehydration accelerator evenly, then add it to the fresh fruit peel residue and mix evenly. Let it stand for 11 min 20 s to react.

[0051] The dehydration accelerator is composed of slaked lime powder and rice husk powder, with the amount of slaked lime being 0.7% of the weight of fresh fruit peel residue and the amount of rice husk powder being 2.0% of the weight of fresh fruit peel residue.

[0052] S3. Pour the reacted material into a screw press for one pressing, and collect the dehydrated residue and the extract after pressing.

[0053] Example 2

[0054] The difference from Example 1 is that the amount of quicklime used is 0.5% of the weight of fresh fruit peel residue, and the amount of rice husk powder used is 0.1% of the weight of fresh fruit peel residue. All other aspects are the same as in Example 1.

[0055] Example 3

[0056] The difference from Example 1 is that the amount of quicklime used is 0.9% of the weight of fresh fruit peel residue, and the amount of rice husk powder used is 2.5% of the weight of fresh fruit peel residue. All other aspects are the same as in Example 1.

[0057] Example 4

[0058] The difference from Example 1 is that the amount of quicklime used is 0.65% of the weight of fresh fruit peel residue, and the amount of rice husk powder used is 1.5% of the weight of fresh fruit peel residue. All other aspects are the same as in Example 1.

[0059] Example 5

[0060] The difference from Example 1 is that after adding the dehydration accelerator, the reaction was allowed to stand for 10 minutes; otherwise, it was the same as Example 1.

[0061] Example 6

[0062] The difference from Example 1 is that after adding the dehydration accelerator, the reaction was allowed to stand for 20 minutes; otherwise, it was the same as Example 1.

[0063] Example 7

[0064] The difference from Example 1 is that quicklime powder is used in the dehydration accelerator, while everything else is the same as in Example 1.

[0065] Example 8

[0066] A process for pressing and dehydrating fresh fruit peel and pomace includes the following steps:

[0067] S1. Cut the fresh fruit peel and residue into strips;

[0068] S2. First, mix the components of the dehydration accelerator evenly, then add it to the fresh fruit peel residue and mix evenly. Let it stand for 11 min 20 s to react.

[0069] The dehydration accelerator is composed of slaked lime powder and rice husk powder, with the amount of slaked lime being 0.7% of the weight of fresh fruit peel residue and the amount of rice husk powder being 2.0% of the weight of fresh fruit peel residue.

[0070] S3. After the reaction, the material is poured into a screw press for one pressing. The peel residue and the extract are collected. The collected peel residue is then pressed five more times, and the dehydrated peel residue and extract are collected separately.

[0071] Example 9

[0072] A process for pressing and dehydrating fresh fruit peel and pomace includes the following steps:

[0073] S1. Cut the fresh fruit peel and residue into strips;

[0074] S2. First, mix the components of the dehydration accelerator evenly, then add it to the fresh fruit peel residue and mix evenly. Let it stand for 11 min 20 s to react.

[0075] The dehydration accelerator is composed of slaked lime powder and rice husk powder, with the amount of slaked lime being 0.7% of the weight of fresh fruit peel residue and the amount of rice husk powder being 2.0% of the weight of fresh fruit peel residue.

[0076] S3. Pour the reacted material into a double-roll press (containing five sets of rollers) for one pressing; collect the dehydrated residue and the extract separately.

[0077] Example 10

[0078] The difference from Example 7 is that the dehydration accelerator is composed of quicklime powder and wheat husk powder, while everything else is the same as in Example 7.

[0079] Example 11

[0080] The difference from Example 7 is that the dehydration accelerator is composed of quicklime powder and sorghum husk powder, while everything else is the same as in Example 7.

[0081] Example 12

[0082] The difference from Example 7 is that the dehydration accelerator is composed of quicklime powder and millet husk powder, while everything else is the same as in Example 7.

[0083] Example 13

[0084] The difference from Example 7 is that the dehydration accelerator is composed of quicklime powder and corn cob powder, while everything else is the same as in Example 7.

[0085] Example 14

[0086] The difference from Example 7 is that the dehydration accelerator is composed of quicklime powder and peanut shell powder, while everything else is the same as in Example 7.

[0087] Example 15

[0088] A process for drying fresh fruit peels and pomace includes the following steps:

[0089] (1) Fresh fruit peel and pomace were pressed and dehydrated using the method described in Example 1;

[0090] (2) Dry the dehydrated fruit peel residue at 75°C.

[0091] Example 16

[0092] A process for drying fresh fruit peels and pomace includes the following steps:

[0093] (1) Fresh fruit peel and pomace were pressed and dehydrated using the method described in Example 1;

[0094] (2) Dry the dehydrated fruit peel residue at 105℃.

[0095] Experimental Example 1

[0096] A pressing and dehydration test was conducted using fresh citrus peel residue as a sample. The initial moisture content of the fresh citrus peel residue was 78.03%. The fresh citrus peel residue was weighed and divided into 18 groups for pressing and dehydration tests. The peel residue and extract from each group were collected.

[0097] The pressing conditions for each group are as follows:

[0098] Groups 1-14 were subjected to pressing and dehydration using the pressing and dehydration processes described in Examples 1-14, respectively.

[0099] Group 15 was the control group 1: The difference from Example 1 was that no dehydration accelerator was added, and the fresh citrus peel residue was directly pressed and dehydrated, while all other conditions were the same as in Example 1.

[0100] Group 16 is control group 2: The difference from Example 1 is that only 0.1% of the weight of fresh citrus peel residue as quicklime is added, and all other conditions are the same as the process described in Example 1.

[0101] Group 17 is control group 3: The difference from Example 1 is that only 1.5% of the weight of fresh citrus peel residue as quicklime is added, and all other conditions are the same as the process described in Example 1.

[0102] Group 18 is the control group 4: The difference from Example 1 is that only 4% of the weight of fresh citrus peel residue in rice husk powder is added, and all other conditions are the same as the process described in Example 1.

[0103] For Examples 1-7 and Control Groups 1-4, the following indicators were measured on the collected pomace and extract from each group:

[0104] (1) Juice yield

[0105] Juice yield (%) = (mass of extracted liquid / initial fresh residue mass) × 100%

[0106] (2) Dry matter content

[0107] The constant weight method at 105℃ was used to determine the weight. 70g of the extract was accurately weighed into a weighing dish that had been pre-weighed and dried at 105℃ to constant weight.

[0108] Dry matter content (%) = (Mass of residue after drying / Mass of extract sample) × 100%

[0109] (3) Moisture content

[0110] Moisture content of dehydrated residue (%) = ((sample mass - mass of dried residue) / sample mass) × 100%

[0111] (4) Juice Extraction Efficiency (JEE)

[0112] Juice extraction efficiency (%) = (Mass of water content in the extract (g) / (Total mass of initial water content in fresh citrus peel and pulp (g)) × 100

[0113] (5) pH value

[0114] pH was measured by pouring the extract directly into a beaker, inserting the electrode, and letting it stand for 30 seconds before taking the reading. For the dehydrated residue sample, deionized water was added at a solid-liquid ratio of 10:25 (g:mL), and the mixture was stirred and allowed to stand until the liquid became clear before measurement.

[0115] (6) Ash content

[0116] The ash content of dehydrated citrus peel residue was tested according to the muffle furnace ignition method in GB 5009.4-2016 "National Food Safety Standard - Determination of Ash Content in Food" to ensure that the ash content of the final product is <8%. The table shows the air-dried basis.

[0117] The results are shown in Table 1 below.

[0118] Table 1. Effects of different pressing processes on the dehydration of fresh citrus peel pomace

[0119]

[0120] Note: The dry matter mentioned refers to the mass of dry matter in the extract.

[0121] As shown in Table 1, control group 1, directly pressing and dehydrating fresh citrus pomace not only results in a low dehydration rate but also causes significant nutrient loss. Using the pressing and dehydration process described in Examples 1-7 of this invention effectively improves the pressing and dehydration efficiency. The dry matter content in the extract is only 13%–16%, indicating that the pressing process mainly removes water, with less loss of solids and pulp, and better nutrient retention. The ash content is controlled below 8%, preventing excessive ash content during the reuse of the peel and pomace. The pH of the peel, pomace, and extract is controlled within a neutral or slightly alkaline range. As shown in control group 2, adding a small amount of quicklime alone resulted in the worst dehydration effect, with a juice yield of only 6.07% and a JEE of only 6.34%. As shown in control group 3, adding a higher amount of quicklime alone resulted in a higher juice yield and JEE, but the ash content was as high as 14.67%, and the pH was significantly higher, posing a risk of excessive alkalinity and quality deterioration. As shown in control group 4, adding rice husk powder alone resulted in a lower juice yield and a higher dry matter content in the extract, indicating a higher loss of nutrients from the fruit pomace. This suggests that relying solely on physical adsorption or loose structure is insufficient to achieve the desired dehydration effect.

[0122] The moisture content of the dehydrated sludge obtained in Examples 8-14 was determined, and the results are shown in Table 2 below.

[0123] Table 2 Moisture content of dehydrated sludge in each group

[0124]

[0125] As shown in Table 2, the moisture content of the citrus pomace in Example 8 can be as low as 66.65%, indicating that the screw-type multiple-cycle pressing can fully release the dehydration potential of fresh citrus peel and pomace. Although the dehydration effect of the process described in Example 9 is slightly lower than that of Example 8, the use of a roller press for single pressing makes it more suitable for continuous engineering production.

[0126] The nutritional components of the dehydrated citrus peel residue prepared by the process described in Example 8 and the fresh citrus peel residue that has not undergone pressing and dehydration are shown in Table 3 below.

[0127] Table 3. Nutrient content of different groups

[0128]

[0129] As shown in Table 3, the process described in this invention can not only achieve effective dehydration, but also does not show significant loss of nutrients in the residue after dehydration.

[0130] Experimental Example 2

[0131] A pressing and dehydration test was conducted using fresh citrus peel residue as a sample. The initial moisture content of the fresh citrus peel residue was 78.03%.

[0132] The fresh citrus peel residue was weighed and divided into 4 equal groups, with 3 parallel drying operations in each group. The drying methods for each group are shown below:

[0133] Group A: Drying was carried out using the drying process described in Example 14;

[0134] Group B: Fresh citrus peel residue was directly dried at 75℃;

[0135] Group C: Fresh citrus peel residue was directly dried at 105℃;

[0136] Group D: Drying was carried out using the drying process described in Example 15;

[0137] All the above groups used the same drying equipment and other drying conditions.

[0138] The results are as follows Figure 1 , Figure 2 As shown.

[0139] Depend on Figure 1 , Figure 2 The results showed that the drying effects of dehydrated pressed pomace and fresh pomace at 75℃ and 105℃ were significantly different in terms of physical properties. Dehydrated pressed citrus pomace (groups A and D) retained their intact fiber structure after drying, appearing as loose filaments or granules, with a light yellowish-brown color and no obvious browning or clumping. The sample dried at 75℃ retained its fiber morphology more completely, while the sample dried at 105℃ appeared as uniformly dry granules with good flowability. In contrast, the untreated fresh pomace (groups B and C) showed severe browning and clumping after drying, deepening in color to dark brown and becoming hard. At 75℃, it already exhibited obvious clump-like adhesion, and at 105℃, further charring occurred, completely destroying the fiber structure. This indicates that pressing and dehydration is a crucial step in the pretreatment of citrus pomace before drying. Fresh residue contains a large amount of free water and soluble sugars. During drying, the evaporation of water causes a rapid increase in local temperature, and the sugars and organic acids undergo violent Maillard reactions and caramelization reactions, which are the main reasons for browning, clumping and nutrient loss in the samples. In contrast, dehydrated and pressed residue removes most of the free water, the fiber structure is combed out, and the water is evenly diffused during the drying process, avoiding local high temperature and caramelization reactions, thus preserving the physical properties and nutritional quality of the raw material.

[0140] In the drying process of dehydrated pressing residue, the effect of temperature on sample properties showed a regular difference. Samples dried at a low temperature of 75℃ had intact fiber structure and uniform color, and could retain the heat-sensitive nutrients (such as vitamins and flavonoids) in the raw material to the greatest extent, making them more suitable for use as functional feed ingredients; samples dried at a high temperature of 105℃ showed significantly improved drying efficiency, and the samples were dried into uniform granules with better flowability and storage stability, making them more suitable for large-scale production and subsequent processing.

[0141] In summary, directly drying fresh pomace without pressing and dehydration is not only energy-intensive and inefficient, but also leads to severe degradation of sample quality, making it unsuitable for large-scale application. In contrast, citrus pomace that has been pressed and dehydrated can be dried to a stable quality within the range of 75℃ to 105℃, and the drying temperature can be flexibly selected according to subsequent uses, providing a feasible process for the feed utilization of citrus pomace.

[0142] The process described in this invention not only has a good dehydration efficiency for citrus peel residue with high pectin content, but also has a good dehydration effect on other types of fruit peel residue.

[0143] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A fresh fruit peel and pomace pressing and dehydration accelerator, characterized in that, It includes lime powder and plant-based raw material powder, wherein the mass ratio of lime powder to plant-based raw material powder is 0.5-0.9:0.1-2.

5.

2. The fresh fruit peel and pomace pressing and dehydration accelerator according to claim 1, characterized in that, The mass ratio of lime powder to plant-based raw material powder is 0.65-0.7:1.5-2.

3. The fresh fruit peel and pomace pressing and dehydration accelerator according to claim 1 or 2, characterized in that, The lime is slaked lime; Preferably, the plant-based raw material powder includes one or more of the following: rice husk powder, wheat husk powder, sorghum husk powder, millet bran husk powder, buckwheat husk powder, corn cob powder, and peanut shell powder.

4. A process for pressing and dehydrating fresh fruit peel and pomace, characterized in that, Includes the following steps: After cutting the fresh fruit peel and pomace, add the accelerator described in any one of claims 1 to 4, mix evenly, let stand and react for 10 to 20 minutes, pour the reacted material into a press for pressing and dehydration, and collect the dehydrated peel and pomace and the extruded liquid. Preferably, the amount of lime powder in the accelerator is 0.5% to 0.9% of the weight of fresh fruit peel and pomace.

5. The fresh fruit peel and pomace pressing and dehydration process according to claim 4, characterized in that, After the lime powder and plant-based raw material powder in the accelerator are mixed evenly, they are added to the chopped fresh fruit peel residue.

6. The fresh fruit peel and pomace pressing and dehydration process according to claim 4, characterized in that, The pressing is carried out using a screw press, and the pressing process is repeated at least three times.

7. The fresh fruit peel and pomace pressing and dehydration process according to claim 4, characterized in that, A double-roll press is used for single pressing.

8. A process for drying fresh fruit peels and pomace, characterized in that, The process includes: pressing and dehydrating the fresh fruit peel residue using the process described in any one of claims 4 to 7, and drying the pressed and dehydrated fruit peel residue.

9. The depeeled fruit pulp prepared by the process according to any one of claims 4 to 7.

10. The dried fruit peel residue prepared by the process described in claim 8.

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