All foods have an expiration date and a shelf life. So in natural vegetable oils there is a certain period after which the oil is probably not worth using. The shelf life of natural vegetable oils depends on storage conditions, as well as on their composition. If these terms are not met, then after a month even freshly squeezed vegetable oils will go rancid and become unusable.
Vegetable oil is fat obtained from seeds, fruits and other parts of plants, which is very necessary for our body. This product is indispensable for the preparation of salad dressings, in baking and for frying, it is used in cosmetology and medicine.
What is vegetable oil made from?
Raw materials for vegetable oils can be:
- Oilseeds (sunflower, soy, rape, cotton, flax, sesame, milk thistle, black cumin, mustard, poppy, hemp),
- Fruits of oil plants (palm trees, olives),
- Oily waste from the processing of plant materials (wheat, corn, rice, fruit seeds of cherry, grape, apricot, watermelon seeds, seeds of melon, tomato, pumpkin, fir, sea buckthorn),
- Nuts (macadamia, pecans, cedar, Brazilian, walnut, pistachio, coconut, hazelnuts, almonds)
The best packaging for vegetable oil is a bottle made of transparent or translucent plastic, and preferably glass. On the label of the bottle with vegetable oil must be indicated all the information that the buyer needs to know:
- name of vegetable oil in accordance with the name of the raw material from which the oil is made,
- the name and address of the manufacturer, or the address of the organization of the representative of the country of manufacture of the vegetable oil,
- net weight and product volume per pack,
- the composition of the oil in order to reduce the content of ingredients, with the obligatory indication of food additives, dietary supplements, vitamins, micronutrients, flavors, the presence of GMOs,
- nutritional value and energy value of vegetable oil,
- expiration date and storage conditions.
Shelf life of vegetable oils
Vegetable oils with a high content of saturated fatty acids are stored longer than those that have a high content of unsaturated fatty acids. The content of vitamin E also increases the shelf life of transport oil (carrier oils, base oils, base oils, carrier oils - these are vegetable oils that are used in aromatherapy to dissolve essential oils, as well as for independent use).
Shelf life and shelf life are not the same thing. Shelf life is the shelf life in unopened containers and is indicated on the product label. The expiration date from the date of the oil spill is considered, which in turn must be applied to the label of the bottle.
The shelf life of most vegetable oils, like all natural products, is relatively small.
When storing vegetable oils under ordinary conditions, in unopened packaging, the shelf life is up to 1 year. The shelf life of the oil without preservatives is 4 months.
For a longer time, the oil is stored only with the addition of artificial antioxidants. So, if it says “No preservatives” on the label, then the oil cannot be stored for more than 4 months.
Sometimes manufacturers claim expiration dates of several years. These deadlines are not real. But this does not apply to some individual highly stable species, such as jojoba oil and krambe oil. The shelf life of the latter is at least 3 years, but this is an exception.
Vegetable oil, especially refined, devoid of natural antioxidants, with a shelf life of more than 4 months, necessarily contains synthetic antioxidants that prevent its decomposition.
In open form, the shelf life for refined oil is 4 months, for unrefined - 2 months. Oil has two enemies - it is light and heat. Therefore, open vegetable oil should be stored in a dark place at a temperature of no higher than 20 ° C. Best in the fridge.
The value of vegetable oils
Vegetable oil is called because it is obtained from plant components - fruits, seeds, roots and other parts of plants. These fruits, seeds, roots consist of complex glycerins, wax, phosphatides, free fatty acids, vitamins and other substances that give the oil its color, taste and smell.
Vegetable oil is valuable because it is an important source of components and trace elements, it contains substances that are not synthesized in the human body. One such substance is linolenic acid. These are unsaturated fatty acids, with the help of which the construction of cell membranes occurs, as well as phospholipids, which are the main component of these membranes. Therefore, we can understand how important and useful this product is for the human body.
Since ancient times, vegetable oils have been a medicine, a product, and a means to maintain beauty. A lot of recipes for healing, rejuvenation with the help of various types of vegetable oils have survived to our times.
Temperature and humidity
The product can be stored both in liquid and in solid state. The consistency of the oil in no way affects its beneficial qualities and depends on the ambient temperature. Already at 25-27 degrees above zero, it "melts".
The main requirement for storing the product is a temperature of no higher than 20 degrees and a humidity of at least 60%. Thus, it would be wise to put coconut oil in some cool place. It could be a refrigerator.
It is important that the access of oxygen to the container in which the finished product is stored is limited. If the cover is not closed tightly, rancidity and oxidation of the liquid are not ruled out. Therefore, the optimal container for its storage is a bottle with a tight stopper, and not with a twisting cap.
The fact is that the twisting lids are often not tightly attached to the neck of the container, and the air gets inside anyway. If you are going to store the product in a glass jar, then it is better to pick up a glass, not a polypropylene lid.
The place where you will keep a healthy product should not be exposed to direct sunlight. For coconut oil, this is fatal. It is better to pour the liquid into a container of darkened glass and securely hide it behind the door of a cabinet or refrigerator.
If you purchased cold pressed coconut oil for bottling or by weight, then pack it in accordance with the above recommendations. A product purchased in factory containers can not be overfilled, but only on condition that it is not made of plastic. After opening the original packaging, the container should be carefully closed.
If the liquid is in ampoules that are packed in a box, then do not rush to throw it out - it will effectively protect the ampoules with the useful product from sunlight until the moment of use.
Caution: Do not store coconut oil in the freezer. Better put it on the top shelf of the refrigerator.
An interesting feature of coconut oil is that at temperatures below 25 degrees it becomes white and thick. Therefore, do not be alarmed if after storage in the refrigerator it has changed the consistency and color - this is completely normal and does not affect its beneficial qualities.
Before using the product from the refrigerator, heat it in a water bath, then the oil will again become liquid and transparent.
How to understand that the product is unsuitable for use? In this case, it acquires a poisonous yellow color. At the same time, a light golden hue is quite acceptable and does not indicate spoilage of the product.
How to store a liquid product
Before you put the product in the refrigerator or cabinet, carefully study the packaging. If it indicates that the finished product should not be stored for longer than one year, and preservatives are present in it, it makes no sense to transfer it to another container for storage. In this case, no measures taken by you are able to extend its shelf life.
You can pour pure cold-pressed oil into a jar or a bottle of dark glass, but make sure that the lid is always tightly closed. The ideal option is a clean bottle of dark glass with a cork, for example, a bottle of wine. Before pouring liquid into the container, rinse it thoroughly and dry it.
How to store the drug in capsules and ampoules
If you purchased coconut oil in portioned capsules made of clear glass or plastic, it is recommended that you store them in a cool and dark place. As already mentioned above, the packaging in which the ampoules are lying should not be thrown away, since it reliably protects the product from sunlight. In this case, the packaging should always be tightly closed.
In a refrigerator, place capsules and ampoules with coconut liquid only when their expiration dates are near the end.
To make sure that the coconut oil you bought is suitable for use, open one capsule and squeeze a drop of liquid from it. If there is no bright yellow tint, put the product packaging in place, where there is no access to heat and moisture.
How to store coconut oil made by yourself
Many people prefer to cook coconut oil themselves, especially since no special knowledge or skills are required for this. For cooking, it is enough to pour coconut flakes into cold water in a 1: 1 ratio and bring the mixture to a boil over low heat, stirring constantly. After boiling, it is kept on fire for another 4-5 minutes, after which it is allowed to cool to room temperature and filtered.
Unfortunately, the shelf life of such a product does not differ in duration. They store it in the same way as natural, i.e. in a dark bottle, under a tight stopper and in the refrigerator, but not longer than two weeks.
How to store edible coconut oil
For food purposes, a hot-pressed product is used. In this case, it should be stored in a refrigerator or dark cabinet for no longer than six months.
Even considering the fact that cold pressed coconut oil has a sufficiently long shelf life, do not rush to immediately stock it in large quantities. After all, the rule: the fresher, the better - no one has canceled. Better get the right amount of oil as needed. And then the beneficial effect that it will produce on your body will be several times higher than the effect of the product, the shelf life of which is already drawing to a close.
During storage, the quality of the butter may deteriorate under the influence of microorganisms, oxygen, light, and other factors.
A characteristic microflora of butter are lactic acid bacteria. However, extraneous microflora can develop in it: putrefactive, butyric, propionic and other bacteria, as well as mold and yeast. During storage, all food substances contained in cow oil may change. However, the most noticeable effect on the quality of the product is a change in its main part - fat.
During storage in the butter, certain changes occur in the cow.
Under the action of enzymes during storage, hydrolysis of fat occurs - its decomposition into glycerin and fatty acids. Free fatty acids are easily oxidized. The primary oxidation products are peroxides and hydroperoxides, which easily undergo further oxidation with the formation of aldehydes, ketones, and other compounds. Fatty acid breakdown products give the oil a rancid taste. Some of these substances are not harmless to health. II destroy vitamins in mixed foods.
Already in the first stage of rancid fat, the quality of the oil is markedly reduced. With the further development of the vice, oil becomes unsuitable for sale.
The process of rancidity is in the presence of oxygen. The larger the contact surface of fat with air, the faster the oxidation process. Oil storage in hermetically sealed containers, as well as in an inert gas atmosphere delays the process of oil spoilage.
Butter stored in an atmosphere of nitrogen or carbon dioxide retains its freshness much longer than stored at the same temperature under normal conditions.
With decreasing ambient temperature, the rate of fat oxidation decreases. It is believed that when the air temperature in the storage is increased by 10 ° C, the rate of fat oxidation increases by about 2 times. However, even at a temperature of -30 ° C and lower, oxidative processes, although they slow down, do not stop. Under these conditions, microorganisms do not develop, but the enzymes secreted by them retain their ability to decompose fat.
An active accelerator of oxidative processes of fat is light, especially the ultraviolet part of the spectrum. Keeping it in the light accelerates oxidative processes by more than 4 times.
The oxidation of fat is also accelerated in the presence of salts of iron, copper and some other metals, which can enter the oil through containers and equipment used in its processing. Along with this, there are a number of substances that delay oxidation. Fats have natural antioxidants - carotene, phosphatides, tocopherol and some others.
With rancidity of fats, there is an induction period when no visible changes in fat are observed due to the action of antioxidants. The less antioxidants in fat, the shorter this period, with a decrease in ambient temperature, it lengthens.
It starts from the surface of the monolith, and then penetrates deep into. Accompanied by a change in taste and smell, the grade of oil is reduced. It is established that the greening of the oil is due to a change in the carotene contained in it. With decreasing ambient temperature, the risk of greening the oil increases. At a temperature of -18 ° C, greening can begin after 3-4 months, at -10 ° C - after 4-5 months. At temperatures above -8 ° C, greening is less common.
During prolonged storage at positive temperatures, this defect does not appear. Changing the color of ghee is not immediately accompanied by a deterioration in its taste. At the first stage of color change, the taste may not deteriorate, but then defects appear in the oil, indicating fat oxidation. Therefore, oil whose color begins to change should be quickly sold.
During storage of butter, its surface layer with a thickness of 1-2 mm becomes yellow, which differs sharply from the color of the deeper layers, as well as a peculiar unpleasant smell and taste. The staff is formed as a result of a decrease in the moisture content and the development of oxidative processes in the surface layer of the product. Factors slowing down the formation of staff are the packaging of oil in air and vapor impermeable materials - foil lined with parchment or plastic film “seen”, cooling immediately after manufacture and storage at the lowest possible temperature.
Mold can get into the oil both during manufacturing and during storage. Raw materials, equipment, containers, air and surrounding objects can be a source of mold infection of butter. Ghee is not subject to mold due to its low moisture content.
Mildew usually develops on the surface in the form of colored or colorless spots. If there are voids and cracks in the monolith, mold can penetrate deeper, especially often when the oil is loosely packed in containers.
Before leaving the customers, bulk oil with mold on the surface is cleaned, and mold-affected inside is not allowed for sale. The packaged butter with mold is defective and cannot be sold.
The rate of development of mold depends on the degree of contamination of products, temperature, relative humidity and other factors. With decreasing air temperature, the rate of development of molds is delayed and almost completely stops at temperatures below -11 ° C, and at -18 ° C, molds do not develop. Compliance with sanitary rules when receiving, transporting and storing protects the oil from mold.
It was established that even with prolonged storage of oil, the moisture content decreases only in its surface layer, not exceeding 5 mm. In deeper layers of monoliths, the moisture content does not change. The sizes of oil shrinkage increase with increasing moisture content and go most intensively in the first months of storage, but usually even during long-term storage these losses do not exceed 20-40 g per monolith, depending on its type.
The packaging of oil monoliths in foil lined on parchment or polymer films allowed for contact with fats reduces these losses by at least 3 times.
With a sharp fluctuation in the room temperature in the warm season, moisture condensation occurs on the surface. When the containers become wet and moisture condenses on the surface of the oil, the risk of mold growth increases.
Certain types of cow's butter have varying shelf life. Сливочное масло, содержащее сахар, белки и много влаги, является лучшей средой для развития микроорганизмов, чем топленое, в котором почти нет белков и сахара и мало влаги. Поэтому при плюсовой температуре, благоприятной среде для развития микроорганизмов топленое масло более стойко при хранении, чем сливочное.Under these conditions, sour cream is better stored than sweet cream, and salty is better than unsalted, as lactic acid and salt have some preservative effect.
At low sub-zero temperatures, when the development of microorganisms stops, the opposite pattern is observed. Sweet cream butter is more stable during storage than sour cream, and unsalted butter is more stable than salted butter. Under these conditions, lactic acid and sodium chloride, in which a certain amount of iron is usually present, contribute to the oxidation of fat.
At a positive temperature, when oil spoilage may be due to the development of microorganisms, the oil produced by the conversion of high-fat cream is stored slightly better than that produced by the whipping method, due to the difference in the degree of dispersion of the moisture contained in them.
At low temperatures, when the development of microorganisms stops, the stability of butter in different production methods is approximately the same.
The storage stability of various types of oil decreases as the moisture content of milk and non-fat substances in milk increase. Oil produced in the pasture period is more stable during storage than oil produced in the stall period.
However, in practice there is uneven stability during storage of the same type of oil produced during the same period.
The poor storage stability of the oil is mainly due to the violation of sanitary requirements during production, improper handling and packaging, and insufficient cooling of the product immediately after production.
Violation of sanitary requirements in the production of oil leads to increased contamination of its microorganisms. In the course of their life, substances accumulate causing oil spoilage. Staying oil, even for a short time, immediately after production or in the first days of storage in an uncooled room reduces its stability during subsequent storage in refrigerators even at low temperatures. This is due to the rapid development of microflora in the oil at positive temperatures, producing enzymes that decompose the components of the product.
In refrigerators, the development of microflora in oil slows down, and at a temperature of -18 ° C it stops completely, but the enzymes accumulated during storage of oil at a positive temperature retain their stability even at low temperatures.
The main way to maintain the quality of the oil is to use low temperatures. Immediately after manufacture, the oil should be cooled at sub-zero temperatures. In creameries, warehouses and shops, it should be stored in refrigerated rooms. From creameries, the oil is released chilled to a temperature of no higher than 10 ° C. During transportation, care must be taken to ensure that the oil temperature does not rise. Therefore, it is necessary to transport it over long distances in ice-wagons, trains with mechanical cooling or on refrigerated steamers. At the destination, the oil is immediately unloaded from the wagons into the refrigerated rooms.
Oil should be delivered to the distribution network by refrigerated trucks or vehicles with isothermal bodies. In the case of transportation in summer by open cars, the oil is covered with insulating blankets. Transported in the coolest time of the day. Taking the oil from suppliers, as well as before the holidays to customers, be sure to check its quality. The lower the ambient temperature, the more butter can be stored.
For long-term storage, the oil is placed in refrigerators, where the temperature is maintained not higher than -12 ° C or better -18 .... -25 ° C. Oil reserves for the current supply of the population are stored in warehouses of retail trading organizations at a temperature not exceeding -4 ° C and in stores at a temperature not exceeding 8 ° C.
Oil easily perceives odors, therefore, separate chambers are allocated for refrigerators and warehouses for its storage. Only for short-term storage, the joint placement of oil with other products that require the same storage mode and do not emit odors (frozen meat, etc.) is allowed. In stores, butter is usually stored together with other dairy products.
Before loading into refrigerator storage chambers, oil having a temperature above -6 ° C is first placed in freezers, where it is cooled to the temperature of the storage chamber. In storage chambers, boxes and barrels of oil are stacked, boxes are placed in a tight stack without laying rails, and barrels are installed in a vertical position, laying between the rows of racks to avoid breakage of chimes. Stacks are stacked on slats or grilles. The distance of stacks from walls and cooling batteries is at least 30 cm.
It is very convenient to store oil in cargo packages on pallets, which with oil boxes are stacked in stacks in 3 rows in height.
Shelf life of oil in monoliths on distribution refrigerators are given in table 1.
Table 1 - Shelf life of butter in monoliths in refrigerators
The aforementioned storage periods of unsalted sweet cream of the highest grade, which has a 41 point mark in taste and smell, are reduced by 2-3 months. Unsalted and amateur butter developed during the stall period (from November to April inclusive) is recommended to be stored only at a temperature of -18 ° C and below for: premium - no more than 3 months, 1st grade - no more than 5 months . Sandwich oil in monoliths may be stored in refrigerators at a temperature of -15 ... -18 ° C for 3 months, at -5 ... -7 ° C for 2 months.
Since the storage stability of the oil is determined by many factors, the shelf life can be extended or shortened at the conclusion of the specialists of refrigerators, who must systematically monitor the change in its quality during storage.
The oil that was packaged up at the enterprises of industry was immediately placed in a refrigerator with the lowest possible temperature, but no higher than -12 ° C. After filling in the refrigerators, the oil is kept for the end of the technological process in refrigerators at a temperature not higher than -18 ° C, and then stored until release to a retail network at a temperature not higher than -12 ° C for no more than 5 days. (in parchment) and 15 days. (in laminated foil). The temperature of the packaged oil when leaving the refrigerator should not exceed -6 ° C.
Shelf life is calculated as follows: for packaged oil at industrial enterprises - from the moment of packaging, and for packaged in refrigerators - from the moment of completion of refrigeration processing.
Ghee in barrels and aluminum jars is recommended to be stored at a temperature of -3 ... -6 ° C for up to 12 months. When storing oil at temperatures below -6 ° C, the processes that cause fat oxidation slow down, but under these conditions there is a danger of greening the oil. Therefore, the storage of this oil is allowed at temperatures from -6 ... -10 ° C to 4 months, and from -10 ° C and below - no more than 3 months.
Ghee, packaged in glass jars, is stored in refrigerators at a temperature of 0 ... 3 ° C for no more than 3 months.
In the warehouses of retail trading organizations, bulk oil can be stored at a temperature of no higher than -4 ° C for no more than 10 days. Packaged oil should not be delivered to these warehouses. Storage should be organized in such a way as to prevent a decrease in the quality of the goods.
During storage, the room regulates the temperature and relative humidity, maintain cleanliness, systematically inspect containers and packaging material, monitor the quality of the goods. If signs of spoilage or mold are found on the container or packaging material, the oil is immediately sold.
In stores, oil is stored in refrigerators at a temperature not exceeding 8 ° C in the same container in which it was received. The following shelf life of oil in stores (per day):
creamy in monoliths - 10,
melted - 15.
Deadlines for the sale of packaged butter, including transportation, storage at industrial enterprises, bases, refrigerators and in the retail network: packed in parchment - 10 days., Packed in lined foil - 20 days. from the moment of packaging. Packaged butter should be stored in a cool place tightly packed in boxes, which slows the formation of staff on the surface.
In the trading room, weighted butter is taken out cleaned and freed from containers and parchment. The air temperature here is higher than in the utility room, therefore, the surface layer of oil, which is not protected from the action of atmospheric oxygen and daylight, quickly oxidizes. The oil, stored for a long time on the counter, needs to be cleaned again, which increases the size of the waste .. Faster is covered with stuff and packaged butter. Therefore, at the seller’s workplace, butter should be stored in refrigerated cabinets or refrigerated counters.