Optimizing Shelf Life of Pink Oyster Mushrooms with Potassium Metabisulphite and Modified Atmosphere Packaging

Abstract

The invention relates to a method and system for preserving pink oyster mushrooms (Pleurotus eous) to extend their shelf life and maintain their quality. The method involves treating the mushrooms with a potassium metabisulphite (KMS) solution to inhibit microbial growth and oxidative degradation. The treated mushrooms are then packaged in Modified Atmosphere Packaging (MAP) using High-Density Polyethylene (HDPE) or Low-Density Polyethylene (LDPE) films, with a controlled atmosphere consisting of specific oxygen, carbon dioxide, and nitrogen concentrations to slow down respiration and spoilage. This packaging system effectively maintains the freshness, texture, and nutritional content of the mushrooms, reducing post-harvest losses and extending their marketability. The invention provides a scalable, cost-effective solution to preserve the quality and safety of fresh mushrooms in the agricultural and food industries.

Specification

Description:

Field of the Invention:
[001] The present invention pertains to the field of post-harvest preservation of edible mushrooms, with a specific focus on pink oyster mushrooms (Pleurotus eous). It addresses the challenges associated with maintaining the quality and extending the shelf life of these perishable fungi. By employing advanced preservation techniques such as Modified Atmosphere Packaging (MAP) and the application of food-grade preservatives like potassium metabisulphite (KMS), the invention ensures optimal storage stability while minimizing microbial growth, weight loss, and oxidative spoilage. This innovation is particularly relevant to the agricultural and food processing industries, enabling the efficient preservation of fresh produce, reducing post-harvest losses, and enhancing food safety.
Background of the invention and related prior art:
[002] Pink oyster mushrooms (Pleurotus eous) are highly perishable due to their high moisture content, delicate texture, and susceptibility to microbial contamination and oxidative spoilage. These characteristics result in significant post-harvest losses, posing challenges for their storage, transportation, and commercialization. Traditional preservation methods such as refrigeration alone are often inadequate to maintain the mushrooms' quality and extend their shelf life. The need for innovative and effective preservation techniques has grown in response to the increasing demand for fresh, high-quality mushrooms in both domestic and international markets. This invention addresses these challenges by combining Modified Atmosphere Packaging (MAP) with potassium metabisulphite (KMS) treatment, providing a practical and efficient solution to enhance the storage stability and marketability of pink oyster mushrooms.
[003] A patent document US12016486B2 discloses methods and apparatus for automatically preparing food for consumption in which preparation comprises dispensing, manipulation, heating, and other operations using a wide variety of ingredients. The methods and apparatus described use ingredients efficiently and maintain their quality, while avoiding contact between ingredients and apparatus to minimize the risk of system contamination.
[004] Another patent document US9869062B1 discloses methods and apparatus for manufacturing vacuum forming a produce container using a fiber-based slurry. The slurry includes a moisture barrier comprising alkylketene dimer in the range of about 4% by weight, and a cationic liquid starch component in the range of 1%-7% by weight.
[005] A document US11248348B2 discloses methods and apparatus for manufacturing a microwavable food container include: forming a wire mesh over a mold comprising a mirror image of the microwavable food container; immersing the wire mesh in a fiber-based slurry bath; drawing a vacuum across the wire mesh to cause fiber particles to accumulate at the wire mesh surface; and removing the wire mesh including the accumulated fiber particles from the slurry bath; wherein the slurry comprises a moisture barrier, an oil barrier, and a vapor barrier.
[006] Another document US4224901A discloses a combination animal collar including an outer collar portion, formed of a suitable material such as leather or nylon, for example, presenting a generally conventional outward appearance when positioned on a dog or cat, for example, and an inner collar portion, formed of a suitable insecticide impregnated material, press fitted into a longitudinally extending recess formed in the inner side of the main central length of the outer collar portion. The undersides of opposed buckle and holed end portions of the belt, outwardly of the recess, have insecticide impregnated adhesive tape portions secured thereto, extending from the respective ends of the insecticide impregnated inner collar portion to the respective extended ends of the buckle and holed ends to provide for a full 360 degree encirclement of an animal's neck by insecticide impregnated material.
[007] None of these above patents, however alone or in combination, disclose the present invention. The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.
Summary of the invention:
[008] The invention presents an innovative method for preserving pink oyster mushrooms (Pleurotus eous) to extend their shelf life while maintaining quality. It integrates Modified Atmosphere Packaging (MAP) with potassium metabisulphite (KMS) treatment to reduce spoilage and microbial contamination. By creating controlled gas environments-ranging from high to low oxygen levels using packaging materials like High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE)-the method slows oxidative and microbial processes, preserving the mushrooms' freshness, texture, and appearance. This approach addresses common post-harvest challenges such as weight loss and quality degradation, providing a cost-effective and scalable solution for the agricultural and food industries.
Detailed description of the invention with accompanying drawings:
[009] For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawing a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its preparation, and many of its advantages should be readily understood and appreciated.
[010] The principal object of the invention is to optimize shelf life of pink oyster mushrooms with potassium metabisulphite and modified atmosphere packaging.
Materials:
1. Potassium Metabisulphite (KMS): Potassium metabisulphite is used as a preservative to inhibit microbial growth and oxidative degradation in the mushrooms. A 0.2% concentration of KMS is prepared by dissolving KMS in distilled water. This solution is used to treat the mushrooms, extending their shelf life by preventing enzymatic browning and microbial contamination.
2. Packaging Films:
High-Density Polyethylene (HDPE): HDPE is selected for its durability and ability to maintain a controlled environment within the packaging. It is used in conjunction with modified atmosphere packaging to regulate oxygen, carbon dioxide, and nitrogen levels effectively.
Low-Density Polyethylene (LDPE): LDPE is used for its flexibility and permeability properties, which allow it to facilitate a modified atmosphere within the packaging. It is also chosen for its suitability in preserving the freshness of the mushrooms.
3. Modified Atmosphere Packaging (MAP) Conditions: MAP is used to control the gaseous composition around the mushrooms, with specific oxygen (O₂), carbon dioxide (CO₂), and nitrogen (N₂) concentrations designed to slow down the respiration and degradation processes.
High Oxygen Packaging (HOP): 70% O₂, 20% CO₂, 10% N₂.
Medium Oxygen Packaging (MOP): 40% O₂, 40% CO₂, 20% N₂.
Low Oxygen Packaging (LOP): 20% O₂, 60% CO₂, 20% N₂.
4. Pink Oyster Mushrooms (Pleurotus eous): Freshly harvested mushrooms are selected for experimentation. They must be processed immediately after harvest to ensure freshness and to apply the preservation methods before any spoilage begins.
Experimental Design:
1. Preparation:
KMS Treatment: A solution of KMS at 0.2% concentration is prepared by dissolving potassium metabisulphite in distilled water. Freshly harvested pink oyster mushrooms are soaked in the KMS solution for 5 minutes to allow the preservative to fully absorb. After soaking, the mushrooms are drained and left to air dry before packaging.
2. Packaging Preparation:
HDPE and LDPE packaging films are cut into suitable sizes based on the packaging requirements of the mushrooms. These films will be used to create the modified atmosphere inside the packaging.
3. Packaging:
Control Group: Mushrooms are packaged in standard atmospheric conditions without any KMS treatment or modified atmosphere packaging.
Treatment Groups:
KMS + HDPE + HOP: Mushrooms are treated with KMS and packaged in HDPE film under high oxygen conditions.
KMS + HDPE + MOP: Mushrooms are treated with KMS and packaged in HDPE film under medium oxygen conditions.
KMS + HDPE + LOP: Mushrooms are treated with KMS and packaged in HDPE film under low oxygen conditions.
KMS + LDPE + HOP: Mushrooms are treated with KMS and packaged in LDPE film under high oxygen conditions.
KMS + LDPE + MOP: Mushrooms are treated with KMS and packaged in LDPE film under medium oxygen conditions.
KMS + LDPE + LOP: Mushrooms are treated with KMS and packaged in LDPE film under low oxygen conditions.
4. Storage:
The packaged mushrooms are stored in a refrigerator at 4°C to simulate a typical post-harvest storage condition. Regular sampling is carried out at intervals of 2, 4, 8, 12, and 16 days to assess the preservation effects over time.
Analysis:
1. Physical Analysis:
Weight Loss: The physiological weight loss of mushrooms is measured regularly to assess the preservation of moisture.
Appearance and Texture: Changes in the appearance, color, and texture of the mushrooms are recorded and analyzed.
2. Biochemical Analysis:
Moisture Content: The moisture content of the mushrooms is measured at different time intervals to determine any dehydration or moisture retention over the storage period.
Chemical Changes: Various biochemical parameters, such as pH levels, sugar content, and enzyme activity, are analyzed to detect any signs of spoilage or deterioration.
3. Microbiological Analysis:
Bacterial Count: The microbial load of the mushrooms is monitored using standard plating techniques to assess bacterial growth and contamination.
Microbial Stability: The effectiveness of KMS and MAP in preventing microbial growth is evaluated by comparing bacterial counts over time.
4. Sensory Evaluation:
Color, Texture, and Odor: Sensory evaluation is conducted by trained panels to assess the color, texture, and odor of the mushrooms. This provides an overall evaluation of the mushrooms' sensory acceptability and consumer appeal.
Shelf Life Evaluation and Data Analysis:
Samples are evaluated at regular intervals, and physical, biochemical, and microbiological parameters are recorded. Statistical analysis is performed to compare the shelf life, physical attributes, biochemical properties, microbial load, and sensory acceptability across different treatment groups.
The data helps determine the most effective combination of KMS treatment and modified atmosphere packaging conditions for extending the shelf life and preserving the quality of pink oyster mushrooms.
[011] This comprehensive approach provides an innovative and practical solution to post-harvest mushroom preservation, addressing key challenges such as spoilage, microbial contamination, and quality degradation. The method has broad applications in the agricultural and food processing industries, providing a means to enhance the marketability and shelf life of fresh pink oyster mushrooms.
[012] Without further elaboration, the foregoing will so fully illustrate my invention, that others may, by applying current of future knowledge, readily adapt the same for use under various conditions of service. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention.




Advantages over the prior art
[013] Optimizing shelf life of pink oyster mushrooms with potassium metabisulphite and modified atmosphere packaging proposed by the present invention has the following advantages over the prior art:
1. Extended Shelf Life: The combined use of potassium metabisulphite (KMS) and Modified Atmosphere Packaging (MAP) significantly extends the shelf life of pink oyster mushrooms. By controlling the oxygen and carbon dioxide levels, the method slows down respiration and microbial growth, preserving the mushrooms' freshness for a longer period.
2. Reduced Microbial Contamination: The use of KMS inhibits the growth of bacteria, molds, and other microorganisms that commonly spoil mushrooms. This leads to improved microbiological safety, reducing the risk of foodborne illnesses and spoilage during storage and transportation.
3. Preservation of Quality: The packaging method helps retain the mushrooms' color, texture, and nutritional content by minimizing moisture loss and oxidative processes. This ensures that the mushrooms remain visually appealing and high-quality throughout their shelf life.
4. Minimized Weight Loss: By controlling the atmosphere within the packaging and preventing excessive moisture evaporation, the method reduces weight loss in the mushrooms, helping to maintain their fresh appearance and size over time.
5. Scalable and Cost-Effective: The use of readily available materials like HDPE and LDPE for packaging, combined with the simple application of KMS, makes the method scalable for large-scale commercial use in the mushroom industry. The process is cost-effective, requiring minimal equipment and low concentrations of preservatives.
6. Environmental Adaptability: The modified atmosphere conditions (HOP, MOP, LOP) can be tailored to different storage and transportation environments, making the system adaptable to various conditions and helping to optimize the preservation process across different markets and climates.
7. Improved Marketability: By extending shelf life and improving product quality, this invention enhances the marketability of pink oyster mushrooms. Producers can transport and sell fresh mushrooms over a longer period, reducing waste and increasing profitability.
8. Reduced Post-Harvest Losses: This method significantly reduces the post-harvest losses commonly seen with fresh mushrooms, contributing to more efficient use of resources and reducing food waste, which is a key concern in the agricultural and food industries.
9. Nutritional Retention: The controlled packaging environment helps to preserve the nutritional content of the mushrooms, including vitamins and minerals, for a longer time, ensuring that the product remains nutritionally valuable for consumers.
10. Easy Implementation: The method is simple to implement in both small-scale and large-scale mushroom production operations, making it accessible to a wide range of producers, from local farms to larger commercial operations.
[014] In the preceding specification, the invention has been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
, Claims:We claim:
1. Optimizing Shelf Life of Pink Oyster Mushrooms with Potassium Metabisulphite and Modified Atmosphere Packaging comprising the steps of:
- treating the mushrooms with a potassium metabisulphite solution at a concentration of 0.2%;
- packaging the treated mushrooms in a modified atmosphere packaging (MAP) environment, wherein the packaging is made from High-Density Polyethylene (HDPE) or Low-Density Polyethylene (LDPE);
- maintaining the modified atmosphere by regulating the oxygen, carbon dioxide, and nitrogen levels within the packaging.
2. The method of claim 1, wherein the modified atmosphere packaging comprises one of the following oxygen, carbon dioxide, and nitrogen concentrations:
- high oxygen packaging (70% O₂, 20% CO₂, 10% N₂);
- medium oxygen packaging (40% O₂, 40% CO₂, 20% N₂);
- low oxygen packaging (20% O₂, 60% CO₂, 20% N₂).
3. The method of claim 1, wherein the potassium metabisulphite solution is prepared by dissolving potassium metabisulphite in distilled water at a concentration of 0.2% and the mushrooms are soaked in the solution for 5 minutes prior to packaging.
4. The method of claim 1, wherein the packaged mushrooms are stored at a temperature of 4°C or lower to maintain freshness and quality.
5. The method of claim 1, wherein the packaging materials are selected based on their permeability to oxygen and carbon dioxide and are used to create a controlled atmosphere that inhibits microbial growth and oxidative spoilage.
6. The method of claim 1, further comprising the step of monitoring the microbial load of the mushrooms at regular intervals to ensure microbial stability.
7. A modified atmosphere packaging (MAP) system for preserving pink oyster mushrooms, comprising:
- a packaging material selected from HDPE or LDPE films;
- an atmosphere within the packaging having oxygen, carbon dioxide, and nitrogen concentrations that are optimized for mushroom preservation.
8. The system of claim 7, wherein the packaging is designed to maintain oxygen levels between 20% and 70%, carbon dioxide levels between 20% and 60%, and nitrogen levels between 10% and 40%.
9. The system of claim 7, wherein the packaging system includes potassium metabisulphite as a preservative incorporated into the atmosphere or applied directly to the mushrooms before packaging to inhibit microbial growth and oxidation.
10. A method for extending the shelf life of fresh pink oyster mushrooms, comprising the steps of:
- treating the mushrooms with a preservative solution comprising potassium metabisulphite at a concentration of 0.2%;
- packaging the mushrooms in modified atmosphere packaging (MAP) with controlled levels of oxygen, carbon dioxide, and nitrogen to reduce respiration and delay spoilage.

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