High-valued comprehensive utilization method of almond green seedcase

Abstract

The invention relates to the technical field of almond green seedcase conversion, and discloses a high-valued comprehensive utilization method of almond green seedcases. According to the invention, through synergistic fermentation of bacteria and fungi, lactic acid bacteria, bacillus and white-rot fungi are introduced into a fermentation system taking vinasse and almond green tangerine peel as substrates, so that advantages of various microorganisms are complementary, and complementary advantages of bacteria and fungi in the aspects of metabolites and enzyme systems are fully utilized; on one hand, peculiar smell and toxic and harmful substances in the vinasse and the almond green tangerine peel raw materials are eliminated, and on the other hand, the nutritional value and palatability of the vinasse and the almond green tangerine peel raw materials are improved, so that the safe and efficient ruminant feed additive is prepared, efficient detoxification value-added treatment of the vinasse and the almond green tangerine peel is realized, and the safe and high-nutrition ruminant feed is produced.

Description

Technical Field

[0001] The present invention relates to the technical field of almond green peel transformation, and in particular to a method for high-value comprehensive utilization of almond green peel. Background Art

[0002] Distillers' grains, the fermentation residue left after brewing alcoholic beverages such as baijiu and beer, are rich in nutrients such as crude fiber, some crude protein, and B vitamins. However, due to their high water content, distillers' grains are prone to spoilage and deterioration, and often contain residual amounts of ethanol and organic acids. Direct use of distillers' grains as feed presents challenges such as poor palatability, difficulty in digestion, and the presence of potentially harmful residues. In particular, volatile acidic substances such as acetic acid remaining in distillers' grains can produce a pungent odor, hindering livestock and poultry from feeding. Furthermore, improper storage of distillers' grains can foster mold growth and produce toxins such as aflatoxins, posing a safety risk to animal feeding.

[0003] Almond peel is the green outer layer of the almond fruit and a byproduct of almond nut processing. Rich in crude fiber and polyphenols, almond peel has low edible value and is often discarded or used as inefficient fertilizer. If fed directly to ruminants, it is difficult to digest due to its high lignin and tannin content. Furthermore, the peel of some varieties contains toxic components such as amygdalin, which can decompose under certain conditions to produce toxic substances such as hydrocyanic acid. Therefore, unprocessed almond peel should not be used directly as feed. Furthermore, during post-harvest storage, almond peel is susceptible to contamination by fungi such as Aspergillus flavus, resulting in the contamination of mycotoxins. These factors limit the use of almond peel in feed, resulting in resource waste and environmental burden.

[0004] Currently, microbial fermentation is commonly used to improve the feed value of brewing by-products such as distiller's grains. Traditionally, single-species fermentation is the most common method. For example, anaerobic fermentation with lactic acid bacteria to produce silage effectively preserves distiller's grains and inhibits spoilage. However, this method primarily produces organic acids for preservation, with limited effectiveness in reducing fiber and removing mycotoxins. Another approach is fungal fermentation. Using strains with lignocellulose degradation capabilities (such as white-rot fungi) to aerobically ferment distiller's grains or fiber-based by-products can partially decompose crude fiber and lignin, improving digestibility and degrading some mycotoxins. Research has shown that fermenting distiller's grains with multiple fungi significantly increases the activity of fiber-degrading enzymes (for example, cellulase and xylanase activities are 4–5 times higher than with single-strain fermentation). However, single-fungal fermentation is associated with long fermentation cycles, the tendency for protein to be lost through excessive degradation, and susceptibility to contamination by other bacteria during the initial fermentation period. Furthermore, fungal degradation alone cannot rapidly eliminate odorous substances such as acetic acid from distiller's grains, resulting in poor palatability of the fermented product.

[0005] In summary, existing technologies struggle to simultaneously address multiple challenges in the utilization of distiller's grains and almond peels as feed, including deodorization, flavor enhancement, detoxification, and nutritional preservation. Lactic acid bacteria alone cannot degrade stubborn mycotoxins, while white rot fungi alone cannot eliminate the sour and unpleasant odor of the raw materials and may result in nutrient loss. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a method for high-value comprehensive utilization of almond green peel.

[0007] The specific technical solutions of the present invention are: The present invention provides a method for high-value comprehensive utilization of almond green peel, which comprises the following steps: (1) Mixing distiller's grains with almond peel in a mass ratio of 5:1-1:1, and adjusting the water content of the mixture to 50-65 wt% to obtain a fermentation matrix; (2) inoculating a bacterial agent and a fungal agent into the fermentation matrix and mixing them evenly, wherein the bacterial agent comprises a composite strain of lactic acid bacteria and Bacillus, and the fungal agent comprises a white rot fungus; (3) The fermentation substrate after inoculation is piled and fermented at 20-40°C for 5-10 days; (4) After the fermentation is completed, the fermentation product is dried to a water content of less than 12 wt %, and then pulverized to obtain a fermented feed.

[0008] The present invention provides a fermentation method with synergistic action of bacteria and fungi. By introducing lactic acid bacteria, Bacillus and white rot fungi into a fermentation system with distiller's grains and almond peel as substrates, the advantages of various microorganisms are complemented, and the complementary advantages of bacteria and fungi in metabolites and enzyme systems are fully utilized. On the one hand, the odor and toxic and harmful substances in the raw materials of distiller's grains and almond peel are eliminated, and on the other hand, their nutritional value and palatability are improved, thereby preparing a safe and efficient ruminant feed additive, realizing efficient detoxification and value-added treatment of distiller's grains and almond peel, and producing safe and highly nutritious ruminant feed.

[0009] As a preferred embodiment of the above method, in step (2), the amount of bacterial agent added is 0.5-5% of the weight of the fermentation substrate, and the amount of fungal agent added is 1-10% of the weight of the fermentation substrate.

[0010] As a preferred embodiment of the above method, in step (3), the relative humidity of the fermentation environment is controlled to be 57% to 63%, and the fermentation is stirred once every 1-2 days during the fermentation period.

[0011] As a preferred embodiment of the above method, in step (3), the initial pH of the fermentation substrate is 5.5-7.5.

[0012] As a preferred embodiment of the above method, in step (1), the lees are lees from the distillation of white wine; the almond peel is the dried pod obtained after the nut kernel and shell of the almond fruit are peeled off, and the almond peel is a crushed product that can be sieved through a 40-60 mesh sieve.

[0013] Based on the above method, the present invention provides a fermented feed.

[0014] Preferably, the fermented feed is ruminant feed.

[0015] Preferably, the fermented feed is feed for feeding Daolang sheep.

[0016] Compared with the prior art, the present invention has the following technical effects: The present invention provides a fermentation method with synergistic action of bacteria and fungi. By introducing lactic acid bacteria, Bacillus and white rot fungi into a fermentation system with distiller's grains and almond peel as substrates, the advantages of various microorganisms are complemented, and the complementary advantages of bacteria and fungi in metabolites and enzyme systems are fully utilized. On the one hand, the odor and toxic and harmful substances in the raw materials of distiller's grains and almond peel are eliminated, and on the other hand, their nutritional value and palatability are improved, thereby preparing a safe and efficient ruminant feed additive, realizing efficient detoxification and value-added treatment of distiller's grains and almond peel, and producing safe and highly nutritious ruminant feed.

[0017] In particular, the fermented feed provided by the method of the present invention can provide a cheap and high-quality feed for Xinjiang's unique Daolang sheep made from local winemaking and nut processing waste, thereby realizing the resource utilization of agricultural by-products and improving breeding efficiency. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the following embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only a portion of the embodiments of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0019] In one embodiment, a method for high-value comprehensive utilization of almond peel is provided, which comprises the following steps: (1) Mixing distiller's grains with almond peel in a mass ratio of 5:1-1:1, and adjusting the water content of the mixture to 50-65 wt% to obtain a fermentation matrix; (2) inoculating a bacterial agent and a fungal agent into the fermentation matrix and mixing them evenly, wherein the bacterial agent comprises a composite strain of lactic acid bacteria and Bacillus, and the fungal agent comprises a white rot fungus; (3) The fermentation substrate after inoculation is piled and fermented at 20-40°C for 5-10 days; (4) After the fermentation is completed, the fermentation product is dried to a water content of less than 12 wt %, and then pulverized to obtain a fermented feed.

[0020] This embodiment provides a fermentation method with synergistic action of bacteria and fungi. By introducing lactic acid bacteria, Bacillus and white rot fungi into a fermentation system with distiller's grains and almond peel as substrates, the advantages of various microorganisms are complemented, and the complementary advantages of bacteria and fungi in metabolites and enzyme systems are fully utilized. On the one hand, the odor and toxic and harmful substances in the raw materials of distiller's grains and almond peel are eliminated, and on the other hand, their nutritional value and palatability are improved, thereby preparing a safe and efficient ruminant feed additive, realizing efficient detoxification and value-added treatment of distiller's grains and almond peel, and producing safe and nutritious ruminant feed.

[0021] In one embodiment, as a preferred embodiment of the above method, in step (2), the amount of bacterial agent added is 0.5-5% of the weight of the fermentation substrate, and the amount of fungal agent added is 1-10% of the weight of the fermentation substrate.

[0022] In one embodiment, as a preferred embodiment of the above method, in step (3), the relative humidity of the fermentation environment is controlled to be 57% to 63%, and the fermentation is stirred once every 1-2 days during the fermentation period.

[0023] In one embodiment, as a preferred embodiment of the above method, in step (3), the initial pH of the fermentation substrate is 5.5-7.5.

[0024] In one embodiment, as a preferred embodiment of the above method, in step (1), the lees are lees from the distillation of white wine; the almond peel is the dried pod obtained after the nut kernel and shell of the almond fruit are peeled off, and the almond peel is a crushed material that can be sieved through a 40-60 mesh sieve.

[0025] Based on the above method, in one embodiment, a fermented feed is provided.

[0026] In another embodiment, preferably, the fermented feed is ruminant feed.

[0027] In another embodiment, preferably, the fermented feed is feed for feeding Daolang sheep.

[0028] Example 1 Provided is a method for high-value comprehensive utilization of almond green peel, comprising the following steps: (1) Raw material preparation: Take fresh liquor lees and air-dried almond peel. Liquor lees are derived from solid-state fermentation of sorghum, with a water content of 60wt%, a pH of 4.0, a crude protein content (dry basis) of 18wt%, and a crude fiber content of 12wt%. Almond peel is the outer peel peeled from processed almond nuts, which has been naturally dried, with a water content of 10wt% and a crude fiber content of about 30wt%. Grind the almond peel into small pieces of about 3 mm. Prepare the ingredients in a ratio of 80 parts of liquor lees (wet weight) to 20 parts of almond peel (dry weight), and mix them evenly in a clean stainless steel blender. The total water content of the mixed materials is 55wt%.

[0029] (2) Preparation and inoculation of bacterial strains: Lactic acid bacteria, Bacillus and white rot fungi were selected as fermentation strains. The commercially available freeze-dried powder of Lactobacillus plantarum was used for lactic acid bacteria, which was activated and revived with sterile saline and cultured to 10 8 CFU / mL. Bacillus subtilis seed liquid was purchased from the market, and the suspended spore count was 10 8 CFU / mL. White rot fungi were detected using Lentinus edodes mycelium suspension (expanded from solid culture medium to liquid PD culture medium, mycelium concentration of about 5 g / L) and Trichoderma viride spore suspension (spore concentration of about 10 7 A 1:1 mixture of lactic acid bacteria (Lactobacillus) and Bacillus subtilis (Bacillus) (Bacillus subtilis ...

[0030] (3) Fermentation: The inoculated materials are piled into a small pile about 40 cm high in the fermentation room. A layer of breathable gauze is covered on the surface of the pile to keep it warm and moist but not sealed for anaerobic conditions. The environment is controlled at a temperature of 28-32°C and a relative humidity of 65% or more. During the fermentation process, the pile is turned upside down and inside and outside with a sterile iron shovel every 24 hours to ensure oxygen infiltration and uniform fermentation. Observe and record the fermentation changes: the material temperature begins to rise 12 hours after the start of fermentation, and the center temperature reaches 35°C after 24 hours. The lactic acid bacteria are active and produce a sour taste; after 48 hours, the pile emits a sour aroma with a slight wine aroma, and the pH is about 4.5. From the third day, white and light green mycelium can be seen growing and spreading on the surface of the material, and the material temperature is maintained at about 32°C; on the fifth day, the mycelium has penetrated deep into the material, and most of the raw materials are stuck together by the mycelium into a mass, emitting a strong aroma of koji and mushrooms, and basically no sour and rancid smell of the original lees. Fermentation is stopped on the seventh day. At this time, the pH of the pile rises to about 5.5, indicating that the Bacillus has neutralized part of the acid. Sampling and testing showed that the aflatoxin B1 content dropped from the initial 48 μg / kg to 2.5 μg / kg, with a degradation rate of 94.8%.

[0031] (4) Fermentation product processing: The fermented material on the 7th day was spread thinly to a thickness of 5 cm and placed in a forced air drying oven with hot air at 45°C for 24 hours until the moisture content dropped below 10%. The material temperature did not exceed 50°C during the drying process to protect the activity of the bacteria and enzymes. After drying, the fermented material was lightly crushed and passed through a 4 mm sieve. The final fermented feed product was collected. The product was brown in color, with a light mushroom and grain aroma, and no moldy or mutated smell.

[0032] (5) Nutritional and safety index testing: The main components and safety indexes of the raw material mixture before fermentation (control) and the fermented and dried product were tested and compared. The results are shown in Table 1 below.

[0033] Table 1 Comparison of main components and safety indicators of raw materials before and after fermentation index Raw material mixture before fermentation Fermentation products Moisture (%) 55.0 9.8 Crude protein (%) 15.2 18.0 Crude fiber (%) 20.5 15.3 Lactic acid (%) 1.2 0.5 Butyric acid (%) 0 0.8 4-Ethylguaiacol Not detected Detected (0.15 mg / kg) <![CDATA[Aflatoxin B1 (μg / kg)]]> 48 2.5 Amygdalin* exist Degrade to safe levels In Table 1, amygdalin is calculated as hydrocyanic acid equivalent. The raw material before fermentation was measured to have a hydrocyanic acid equivalent of about 50 mg / kg, and no free hydrocyanic acid was detected after fermentation.

[0034] As shown in Table 1, the synergistic fermentation treatment of the present invention significantly improved various feed indicators. Moisture content was significantly reduced to within a safe storage range; crude protein content increased from 15.2% to 18.0%, an increase of approximately 18%, attributed to the enrichment of microbial protein and the reduction of nutrient losses. Crude fiber content decreased from 20.5% to 15.3%, a decrease of approximately 25%, indicating that the fiber became more digestible through biodegradation. 0.8% butyric acid and a small amount of lactic acid were detected in the fermentation product, indicating that beneficial short-chain fatty acids accumulated during the fermentation process, which helps improve rumen fermentation in ruminants. 4-Ethylguaiacol, which was not detected in the raw material, was detected at 0.15 mg / kg after fermentation, demonstrating that the synergistic fermentation produced this aromatic compound, imparting a mellow aroma to the feed. Most importantly, aflatoxin B1 content was significantly reduced to 2.5 μg / kg, well below the national upper limit of 20 μg / kg. Toxic components such as amygdalin were also degraded to safe levels after fermentation, and no free hydrocyanic acid residues were detected. These results demonstrate that the fermentation product is nutritious and safe.

[0035] Example 2 Comparative test of different fermentation treatment methods The raw materials from Example 1 were subjected to the following three treatments: (A) direct drying without fermentation (control); (B) fermentation with bacterial inoculum alone; (C) fermentation with white-rot fungi alone; and (D) fermentation with the bacterial-fungal complex of the present invention (i.e., the conditions of Example 1). After five days of fermentation, the aflatoxin B1 content and sensory odor of each product were measured. Results: In the control (A), aflatoxin B1 content was 50 μg / kg, accompanied by a distinct sour and rancid odor. In the bacterial fermentation alone (B), the toxin content was reduced to 30 μg / kg, with essentially no sour odor but a light sour aroma. In the fungal fermentation alone (C), the toxin content was reduced to 8 μg / kg, but the product still had a slight musty and bitter odor. In the composite fermentation group (D), the toxin content was reduced to only 2 μg / kg, and the product had a pure, fragrant, and odorless aroma. This indicates that bacteria alone are unable to completely degrade toxins, and fungi alone are unlikely to fully improve palatability. Only synergistic fermentation with bacteria and fungi can achieve both deodorization and efficient detoxification.

[0036] Example 3 Evaluation of the effect of feeding fermentation products to Dawlang sheep Twenty healthy, uniformly grown young Dolan sheep were randomly divided into an experimental group and a control group of 10 each. The control group was fed a basal diet (conventional feed such as grass hay, corn, and soybean meal), while the experimental group replaced 20% of the concentrate feed with the fermented feed obtained in Example 1 of the present invention. Both groups had free access to food and water for 60 days.

[0037] Results showed that the experimental group exhibited good feed intake, showed no picky eating, and exhibited superior spirits and coat luster compared to the control group. The experimental group achieved an average daily weight gain of 175 grams, compared to 158 grams in the control group, an increase of approximately 10.8%. The feed-to-weight ratio (air-dried feed consumption / weight gain) in the experimental group was approximately 9% lower than that in the control group, indicating improved feed conversion efficiency. Throughout the trial, both groups maintained normal health, with no signs of poisoning or illness. Feces in the experimental group were well-formed, with no diarrhea, while two sheep in the control group experienced mild soft stools (suspected to be related to intestinal irritation from consuming unfermented distiller's grains). Blood samples were collected from the sheep for biochemical analysis after the trial, revealing normal liver and kidney function in the experimental group, with no signs of aflatoxin poisoning.

[0038] This demonstrates that the fermented product of the present invention is safe and effective for feeding Dolan sheep, improving growth performance and feed utilization efficiency. The fermented feed has good palatability and nutritional value, can partially replace concentrated feed, and reduce breeding costs.

[0039] Unless otherwise specified, the raw materials and equipment used in the present invention are commonly used in the art; the methods used in the present invention are conventional methods in the art unless otherwise specified.

[0040] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for high-value comprehensive utilization of almond peel, characterized by: The following steps are involved: (1) Mixing distiller's grains with almond peel in a mass ratio of 5:1-1:1, and adjusting the water content of the mixture to 50-65 wt% to obtain a fermentation matrix; (2) inoculating a bacterial agent and a fungal agent into the fermentation matrix and mixing them evenly, wherein the bacterial agent comprises a composite strain of lactic acid bacteria and Bacillus, and the fungal agent comprises a white rot fungus; (3) The fermentation substrate after inoculation is piled and fermented at 20-40°C for 5-10 days; (4) After the fermentation is completed, the fermentation product is dried to a water content of less than 12 wt %, and then pulverized to obtain a fermented feed.

2. The method for high-value comprehensive utilization of almond peel according to claim 1, characterized in that: In step (2), the amount of bacterial agent added is 0.5-5% of the weight of the fermentation substrate, and the amount of fungal agent added is 1-10% of the weight of the fermentation substrate.

3. The method for high-value comprehensive utilization of almond peel according to claim 1, characterized in that: In step (3), the relative humidity of the fermentation environment is controlled at 57% to 63%, and the fermentation is stirred once every 1-2 days during the fermentation period.

4. The method for high-value comprehensive utilization of almond peel according to claim 1, characterized in that: In step (3), the initial pH of the fermentation substrate is 5.5-7.

5.

5. The method for high-value comprehensive utilization of almond peel according to claim 1, characterized in that: In step (1), the lees are lees from the distillation of white wine; the almond peels are dried pods obtained after the almond kernels and shells are peeled off, and the almond peels are ground into powder with a 40-60 mesh sieve.

6. The fermented feed obtained by the method according to any one of claims 1 to 4.

7. The fermented feed according to claim 5, wherein: The fermented feed is ruminant feed.

8. The fermented feed according to claim 6, wherein: The fermented feed is feed for feeding Daolang sheep.