RU2296454C2 - Sweet pepper storage method - Google Patents

Abstract

FIELD: agriculture and food-processing industry, may be used in vegetable stores and public catering enterprises.

SUBSTANCE: method involves creating regulated medium and periodically smoking it with vapors of formaldehyde produced by mixing of 50 ml of formalin and 50 g of KMnO₄ per 1 m² of store surface; providing treatment combined with active ventilation at air flow rate of 100 m³/t of sweet pepper. Treatment with formaldehyde vapors may be performed at periodicity of once per week.

EFFECT: provision for creating of resource saving, ecologically clean, safe storage process, prolonged shelf life and retention of commercial appearance of pepper.

2 cl, 1 tbl

Description

The invention relates to the agricultural industry, in particular to the storage of sweet pepper, can also be used in catering.

A known method of storing vegetables (RZH "Chemistry and Food Technology" No. 8, 1999, p. 10) using a film consisting of simple polyester and polyamide, with controlled transmission of CO ₂ and O ₂ depending on the type of vegetables. The properties of five types of films from low to ultra high transmittance for water vapor are described.

The disadvantage of using such polymers in storage is its cost and the complexity of the process, and this method does not slow down the ripening of vegetables.

A known method of creating a controlled gas environment during storage of fresh vegetables using a membrane installation (RZ "Chemistry and technology of food production" No. 3, 1999, p. 11). The method consists in the selective removal of oxygen from the storage chamber, a gas medium of a given composition is created depending on the type and type of product (94% N ₂ , 5-1% O ₂ , 1-5% CO ₂ ). The time required for this is about 1.5 days. The installation consists of a block of gas separation modules based on an asymmetric membrane, an oil-free compressor and a sealed storage chamber.

The disadvantage of this method is the aggregate capacity, a long time to achieve the specified environmental parameters, the issue of the maturation of raw materials is not resolved.

It is known to use ozone for the disinfection of fresh fruits and vegetables during washing and storage (RZH "Food and Processing Industry" No. 2, 2002, p. 47). The possibilities of using ozonated water for washing and disinfection of fruits and vegetables, and in the storage of gaseous ozone to prevent the development of bacteria, molds and yeast on the surface of products are considered.

This method of processing products is promising compared to processing with chemical reagents, but this method is expensive and does not affect the ripening speed of sweet pepper varieties.

Since sweet pepper is a seasonal raw material with a short shelf life, it is necessary to search for effective means that have a beneficial effect on increasing the keeping quality of sweet pepper and creating a favorable environment for its storage.

One of such methods and the closest to the achieved effect is the method of storage of agricultural products (RF patent No. 2084115), including the tab in the store and periodic processing of the insecticide. Propionic acid is used as the insecticide, and the products are processed by saturated vapors during its active ventilation.

The disadvantage of this method is the need to process the surface of the pepper, which negatively affects the taste of pepper, in addition, this treatment does not affect the ripening speed of the pepper, and propionic acid is an expensive raw material.

The technical task is to develop a resource-saving, environmentally friendly technology for storing sweet pepper, extending the shelf life, preserving the presentation by slowing down the maturation.

The main defects during storage of vegetable pepper are overriding and various physiological and bacterial diseases. In this regard, we decided to use chemical compounds for the treatment of pepper that have properties that inhibit overriding.

The problem is solved by periodically treating sweet pepper with formaldehyde vapor in combination with active ventilation. Processing was carried out once a week. Formalin + KMnO ₄ was used as a source of formaldehyde for dry fumigation of pepper.

Processing the controlled environment in which sweet pepper is stored allows you to significantly slow down the rate of pepper ripening due to the effect on the dynamics of changes in polyphenols (chlorogenic acid).

The storage method is as follows. Before laying for storage, sweet peppers were sorted, mechanical impurities were removed, washed, dried. Peppers were taken at the technical stage of maturity in order to analyze the ripening process. Then sweet pepper was divided into three lots, placed in boxes and placed in different airtight storage. The first batch was stored with active air ventilation once every 2 days in an amount of 100 m ³ / t of pepper. The second batch was ventilated and fumigated with vapors of formaldehyde, which was released by mixing formalin and potassium permanganate in a ratio of 50 ml of formalin and 50 g of KMnO ₄ per 1 m ² of storage area.

In an aqueous solution (40% paraformaldehyde), formalin polymerizes into a solid polymer. When heated, this substance regenerates formaldehyde. Therefore, it is a convenient source of gaseous formaldehyde. The chemistry of this process is presented below:

In the presence of KMnO _4, formaldehyde is partially oxidized to formic acid, which decomposes to form carbon dioxide.

Alcohol is used for heating. Thus, a double effect is achieved. Formaldehyde and carbon dioxide are formed, which contribute to a better preservation of quality and extend the shelf life of sweet pepper.

Mixing was carried out in a laboratory flask and then the mixture was transferred to special containers with a wide bottom. Peppers were smoked once every seven days.

The third batch of pepper served as a prototype, i.e. pepper was treated with propionic acid and stored in a separate storage. Sweet pepper was stored for 42 days.

At the end of storage, the chemical composition of the pepper was analyzed, the dynamics of weight loss, pepper spoilage, as well as the dynamics of polyphenols (chlorogenic acid), as an indicator of pepper ripening, were studied.

Mass loss was determined by the method of fixed samples. It consists in the fact that the marked (fixed) samples are weighed before and after storage every month. Mass loss in% to the initial weight is calculated by the formula

X = (a-b) · 100 / a;

where a is the weight of the raw material when laying for storage;

b - weight at the end of storage.

The solids were determined by drying the samples in the bottles in an oven to a constant weight. The total drying time is 3 hours. The removed boxes from the oven were cooled and weighed on an analytical balance. Drying and weighing were repeated several times until the repeated weighings differed by more than 2 mg.

Solids were determined by the formula

where A is the weight of the box;

B - weight of the bottle with a crude hitch;

B - weight of the bottle with a dry hitch.

Pepper spoilage - determined by weighing spoiled fruits and found a percentage of the initial weight of the pepper.

The content of chlorogenic acid was determined by its ability to interact with phosphate or phosphate-butyrate buffer, followed by its measurement on an SF 4-1 spectrophotometer. The results of the data obtained were tabulated.

Experience setting Wound results Natural decline, % Damage,% Chlorogenic acid, mg% Ventilation and Fumigation 3.99 7.83 12,4 Ventilation 5.56 22.92 18.2 Prototype 18.97 26.61 19.5

As can be seen from the table, when storing pepper with active ventilation and periodic fumigation with formaldehyde released when formalin was mixed with potassium permanganate, we observed a clear antiseptic effect. In pepper, losses from decay decreased during this treatment by 3 times in comparison with ventilation without fumigation and by almost 4 times in comparison with ordinary container storage (control). The character of spoilage also changed somewhat - there was no mold during fumigation.

The content of chlorogenic acid at the end of storage was the smallest in pepper, which was fumigated with formaldehyde vapor, and amounted to 12.4%, respectively.

Therefore, gaseous formaldehyde released at the time of mixing 50 ml of formalin and 50 g of potassium permanganate, improves the quality of the pepper, slow down the maturation and extend its shelf life.

Claims (3)

1. A method of storing sweet pepper by creating a controlled environment, characterized in that the controlled environment is created by periodically fumigating with formaldehyde vapor obtained by mixing 50 ml of formalin and 50 g of KMnO ₄ per 1 m ² of storage surface. 2. The method according to claim 1, characterized in that the treatment is carried out with active ventilation with an air flow of 100 m ³ / t sweet pepper. 3. The method according to claim 1, characterized in that the treatment with vapors of formaldehyde is carried out with a frequency of 1 time per week.