How to preserve and hygienically prepared foods
There are many factors that can affect the quality of the food or cause its deterioration. To avoid this and to prevent possible poisoning, follow our tips to conserve and prepare your food.
· Physical: such as exposure to sunlight, which affects the loss of vitamins or exposure to an improper temperature, favoring the reproduction of microorganisms...
· Chemical: oxidation of fats, acidification by reactions in cans...
· Biological: attacks by action of insects or invasion of microorganisms (fungi, viruses, bacteria or parasites), among others.
Why are contaminated food
The most common reasons that a food can become contaminated and transmit disease to reach are:
· Leave food at room temperature.
· Foods that are prepared in advance to their consumption, without proper conservation.
· Food that to overheating do not acquire the necessary temperature allowing to destroy possible bacterial pathogens (notably staphylococcal toxin).
· Contaminated food that not have been washed and cooked properly.
· That the manipulator is a carrier of pathogens.
· An inappropriate freezing process, or that the cold chain has been damaged at some point before consumption.
As causal agents include:
· Salmonella (usually Salmonella typhimurium), causing salmonellosis.
· Staphylococcus aureus, causing, inter alia, gastroenteritis.
· Clostridium perfringens, causing, inter alia, enteritis.
· Clostridium botulinum, which causes botulism.
· Bacillus cereus.
· Escherichia coli.
· Vibrio parahaemolyticus.
· Campylobacter.
The types of food are classified into:
Cold storage
· Cooling: there is a drop in temperature, which reduces the speed of chemical reactions and the proliferation of microorganisms.
· Freezing: temperature applied is lower than 0 ° C, causing that part of the food water becomes ice. It is important to carry out the freezing in the shortest time and at a very low temperature, so that the quality of the product is not affected. The optimum temperature is - 18 ° C or lower.
· Freezing: is to descend the temperature of the food by means of different processes such as cold air, plates or immersion in liquids to very low temperatures, etc.
The freezing and freezing are the methods of conservation resulting in fewer alterations in food.
Conservation by heat
·
Parboiled: consists of a prelude to the freezing of some vegetables to improve their conservation. Vegetables, once clean, are immersed in boiling water; They are subsequently packed in freezer, vacuum bags and indicating the date of initial freezing. The consumer, in this way, can calculate the time of conservation of food.
· Pasteurization: is the application of heat over a period of time (which will vary depending on the food) at temperatures averaging 80 ° C. Germs capable of producing disease are thus inactivated. What is not inactivated are their spores, so the milk once opened should be kept in the refrigerator, and if it is not consumed within a period of 3-4 days, have to discard it. There is no loss of nutrients in this method of conservation.
· Sterilization: this process Yes removes germs and the spores. Applies to food temperatures that hover around the 115 ° C. Food in this process are affected in their organoleptic (sterilized milk has a yellowish appearance and some roasted flavor), and the loss of nutrients such as water-soluble vitamins (vitamin C and Group B) depending on the duration of the heat submitted to food.
Chemical methods
·
Salted: is based on the addition of more or less abundant salt so salt captures the water causing dehydration of food. In this way avoids the proliferation of microorganisms.
· Smoked: is a mixture of drying and salting.
· Acidification: is a method based on the reduction of the Ph of the food that prevents the development of microorganisms. For example, vinegar.
· Escabechado: is a set of salt and vinegar, giving a characteristic flavor and a proper conservation. Vinegar brings its preservative action thanks to acetic acid, and salt dehydrates food.
· The addition of sugar when it takes place at high concentrations promotes the protection of food against the proliferation of microorganisms. This process takes place in condensed milk, jams, compotes, etc.
Other methods of food preservation
·
Dehydration: whole process that involves the loss of water.
· Freeze-drying: is based on a drying where occurs the change from solid to gas without passing through the liquid phase. It consists of removing water from a frozen food by applying vacuum systems. What happens is that the vacuum and ice at low temperatures (below - 30 ° C), solid state gas, without passing through the liquid state.It is the process where the nutritional value of the food is barely affected. It has a high cost, so it is usually applied only to coffee or decaffeinated soluble and in products such as children's milk.
· Drying: applies an extraction of moisture containing food under natural environmental conditions.
· Radiation: Modified atmospheres.
· Vacuum: this method is used to remove the air surrounding the food. They are inserted into plastic bags designed for that purpose and removed as much air as possible. Besides the food, then, can be chilled or frozen.
Food additives
They are defined according to the code Spanish food, "those substances which may be added intentionally to food and beverages in order to modify their characters, their development or conservation techniques or improve their adaptation to the use to which they are intended".
They do not aim to change the nutritional value, since they leave it unchanged, but it is used to improve aspects of the food as a time of conservation, improvement of the flavor, color, etc. For example: when Ascorbic acid is added to a fruit juice, is performed to improve its conservation, and not as a nutrient.
They are classified into four groups:
· Dyes.
· Preservatives.
· Antioxidants.
· Stabilizers.
· First, frozen foods must be stored in the freezer, and then foods that need refrigeration such as meat and fish, eggs, yogurt, and those fruits and vegetables that will not eat at the time.
· Finally, place the foods that do not require these conditions as canned legumes, pasta, etc.
Frozen foods
A frozen food has all the health guarantees if the cold chain is maintained and the preparation at home is suitable. As requirements must be met:
· If food is not to be consumed immediately or in the coming days (depends on the food) it must be kept in the freezer.
· They must buy at the last minute, and transport them home in bags.
· They must present adequate, clean and without waste characteristics.
· Containers or containers must be in perfect condition with no breaks or tears.
· Foods that are already frozen, must keep the same temperature below - 18 ° C.
· Foods prepared at home, if you want to freeze, must reach temperatures of - 25 ° C, clean and protected with plastic or aluminium foil. Please do for rations.
· When you want to defrost a food (there are many that do not require defrosting cooking), must be made in advance and leave to thaw in the refrigerator. For example, place them in the bottom of the refrigerator the night before the day of their consumption.You can also be done in the microwave.
Fish
The conservation of the fish must be in the refrigerator, perfectly clean and in a sealed container so not transmit smell to other foods. Fresh fish should be consumed on the day, and as much the next day, however frozen fish can be kept in the freezer several months.
A fresh fish features as well adhered scales, firm, rigid bodies with glitter, little intense smell, etc.
The meat
Fresh meat can be kept in the refrigerator up to a week. If it is minced meat, then you should eat in the day (except that is frozen), as well as offal products.
Frozen meat is preserved in the freezer several months.
Sausages, if they occur in whole pieces (sausage, pork, etc) can be stored outside the refrigerator, but if they are cut into slices it is advisable to keep them in the refrigerator.
Milk and its derivatives
Fresh products and yogurt should be kept in the refrigerator. Pasteurized milk of the day should be kept in the refrigerator and once opened the package, should not be consumed later than 48 hours. Sterilized milk is kept for several months, but once opened the container should keep in the refrigerator and consume it as soon as possible.
Milk powder should be kept in dry places and closed containers free of moisture, to prevent that they from matting.
Vegetables
Vitamins should be stored in the refrigerator for their conservation, as well as consume them as soon as possible to avoid to lose nutritional value, mostly.
Legumes
Its conservation is simple because it is enough to keep them isolated from the heat, contact with insects and moisture. Over time their skins tend to harden, causing a longer cooking time.
Fruits
They should observe to do the purchase of this food based on what we are able to consume in the next 3 days, to take advantage of all its benefits.
Depending on the heat and the State of maturation, it should keep in the fridge.
Eggs
It is recommended to consume the eggs until within 15 days. Its conservation is carried out in the fridge, and with the tip pointing down; in this way prevents the yolk to come in contact with the shell avoiding possible contamination.
A fresh egg presents a full shell, without roughness, with a transparent clear, and a firm yolk. There are absence of odors.
Fats
They should be stored in places that are dark and fresh or packaged to avoid light and which may alter its properties. In addition also prevents the air so that they are not enrancien.
The solid type such as butter fat, butter or margarine are preserved and the refrigerator.
Canned
In general, many canned foods don't need refrigeration, however, it should be protected from high temperatures.
It must reject those presenting a look rusty or dented, with pores or cracks, either the lack of labelling or expiration date. Those to open them present a cloudy liquid, gas-generating or there is foam, it is advisable not to eat them since it is likely that features that have are due to the presence of bacteria.
Utensils
Utensils should be preferably of stainless steel or other smooth and impermeable materials. Thoroughly clean the utensils that have been used to prepare raw food before using them with cooked foods.
Tables used to cut raw food is better than polyurethane (plastic), since those of wood being porous they are more difficult to clean and favour the accumulation of germs.
Person who prepares foods
· Wash your hands.
· No smoking.
· Avoid coughing or sneezing on food.
· Adequately cover the wounds.
The preparation
It should seek to preparing food at the time of its consumption. If it is not, they should be stored in the refrigerator. It must be especially careful with sauces, especially if they are prepared with egg.
Prepare vegetables
These foods are very rich in vitamins and minerals. If it's raw vegetables, such as salads, we ensure:
· Wash them thoroughly.
· The ingredients used must be as fresh as possible.
· Leaves dark, do not dispose of them since they are the ones with greater vitamin content.
· The acidic environment is protected to vitamins, therefore it is advisable to dress them with vinegar or lemon.
· If washing after cutting nutritional value is lost.
If it's cooked veggies:
· Cooking time must be minimized to prevent loss of nutrients.
· If they prepare baked or boiled, cook them with their skin.
· Do not put them to soak.
· Do not reheat.
· Use the boiled water sparingly, and use water left for soups or purees since this stock has a high nourishing power.
Prepare fruit
Its nutritional value, including vitamins, they are not only in the skin, also in the rest of the food. Usually eaten raw, so its contents are preserved in nutrients.
When they are crushing to make a fruit salad, be eating them freshly cut, to prevent the destruction of vitamins.
Prepare vegetables
Legumes, unless they are of very good quality and the harvest of the year, because of the cellulose-containing need soaking to soften when it comes to cooking them they properly. With twelve hours of soaking in cold water, no nutrient is not lost.
Prepare meats
This type of food accepts all types of cooking: grilled, baked, stew, fried foods, etc. It is recommended that the meat is cooked to avoid that it is raw on the inside, thus avoiding possible food poisoning.
The minced meat is more susceptible of alteration, by which it is advisable to prepare anything more be crushed.
Prepare fish
Depending on the species, forms of preparation are very varied:
· Fish coming canned contains the nutritional value that may have one fresh, the difference lies in that it provide more calories by the oil contained.
· The small species tend to eat fried (anchovies, whitebait, etc.). In addition, when consumed with spines constitute an important source of calcium.
· For large fish, cooking in the oven is suitable as well as Cook in water.
· For medium-sized species, the slices are suitable to prepare on grill.
Prepare fried
The oils more advisable for this type of cooking are the seeds and the olive that despite such high temperatures that are reached, do not lose their properties. Some tips are:
· The oil should be heated to medium heat, you do not need to come to smoke, since toxic substances are produced.
· Do not mix oils of different class.
· If they are prepared to moderate temperatures, fats are better digested.
Excess oils must filter not to heat up substances that develop bad taste or contaminate the frying again. Keep it in clean containers, protected from light and in a cool environment.
Conservation and food preparation
Many factors are involved in the loss of the original quality of a food or its deterioration. The origins can be:· Physical: such as exposure to sunlight, which affects the loss of vitamins or exposure to an improper temperature, favoring the reproduction of microorganisms...
· Chemical: oxidation of fats, acidification by reactions in cans...
· Biological: attacks by action of insects or invasion of microorganisms (fungi, viruses, bacteria or parasites), among others.
Why are contaminated food
The most common reasons that a food can become contaminated and transmit disease to reach are:
· Leave food at room temperature.
· Foods that are prepared in advance to their consumption, without proper conservation.
· Food that to overheating do not acquire the necessary temperature allowing to destroy possible bacterial pathogens (notably staphylococcal toxin).
· Contaminated food that not have been washed and cooked properly.
· That the manipulator is a carrier of pathogens.
· An inappropriate freezing process, or that the cold chain has been damaged at some point before consumption.
As causal agents include:
· Salmonella (usually Salmonella typhimurium), causing salmonellosis.
· Staphylococcus aureus, causing, inter alia, gastroenteritis.
· Clostridium perfringens, causing, inter alia, enteritis.
· Clostridium botulinum, which causes botulism.
· Bacillus cereus.
· Escherichia coli.
· Vibrio parahaemolyticus.
· Campylobacter.
Methods of food preservation
Years ago was the best way to preserve well because we had shortages, either, because it was not produced. Thanks to that search, currently there are adequate food storage systems, since a food before coming to the table has been manipulated or transformed.The types of food are classified into:
Cold storage
· Cooling: there is a drop in temperature, which reduces the speed of chemical reactions and the proliferation of microorganisms.
· Freezing: temperature applied is lower than 0 ° C, causing that part of the food water becomes ice. It is important to carry out the freezing in the shortest time and at a very low temperature, so that the quality of the product is not affected. The optimum temperature is - 18 ° C or lower.
· Freezing: is to descend the temperature of the food by means of different processes such as cold air, plates or immersion in liquids to very low temperatures, etc.
The freezing and freezing are the methods of conservation resulting in fewer alterations in food.
Conservation by heat
·
Parboiled: consists of a prelude to the freezing of some vegetables to improve their conservation. Vegetables, once clean, are immersed in boiling water; They are subsequently packed in freezer, vacuum bags and indicating the date of initial freezing. The consumer, in this way, can calculate the time of conservation of food.
· Pasteurization: is the application of heat over a period of time (which will vary depending on the food) at temperatures averaging 80 ° C. Germs capable of producing disease are thus inactivated. What is not inactivated are their spores, so the milk once opened should be kept in the refrigerator, and if it is not consumed within a period of 3-4 days, have to discard it. There is no loss of nutrients in this method of conservation.
· Sterilization: this process Yes removes germs and the spores. Applies to food temperatures that hover around the 115 ° C. Food in this process are affected in their organoleptic (sterilized milk has a yellowish appearance and some roasted flavor), and the loss of nutrients such as water-soluble vitamins (vitamin C and Group B) depending on the duration of the heat submitted to food.
Chemical methods
·
Salted: is based on the addition of more or less abundant salt so salt captures the water causing dehydration of food. In this way avoids the proliferation of microorganisms.
· Smoked: is a mixture of drying and salting.
· Acidification: is a method based on the reduction of the Ph of the food that prevents the development of microorganisms. For example, vinegar.
· Escabechado: is a set of salt and vinegar, giving a characteristic flavor and a proper conservation. Vinegar brings its preservative action thanks to acetic acid, and salt dehydrates food.
· The addition of sugar when it takes place at high concentrations promotes the protection of food against the proliferation of microorganisms. This process takes place in condensed milk, jams, compotes, etc.
Other methods of food preservation
·
Dehydration: whole process that involves the loss of water.
· Freeze-drying: is based on a drying where occurs the change from solid to gas without passing through the liquid phase. It consists of removing water from a frozen food by applying vacuum systems. What happens is that the vacuum and ice at low temperatures (below - 30 ° C), solid state gas, without passing through the liquid state.It is the process where the nutritional value of the food is barely affected. It has a high cost, so it is usually applied only to coffee or decaffeinated soluble and in products such as children's milk.
· Drying: applies an extraction of moisture containing food under natural environmental conditions.
· Radiation: Modified atmospheres.
· Vacuum: this method is used to remove the air surrounding the food. They are inserted into plastic bags designed for that purpose and removed as much air as possible. Besides the food, then, can be chilled or frozen.
Food additives
They are defined according to the code Spanish food, "those substances which may be added intentionally to food and beverages in order to modify their characters, their development or conservation techniques or improve their adaptation to the use to which they are intended".
They do not aim to change the nutritional value, since they leave it unchanged, but it is used to improve aspects of the food as a time of conservation, improvement of the flavor, color, etc. For example: when Ascorbic acid is added to a fruit juice, is performed to improve its conservation, and not as a nutrient.
They are classified into four groups:
· Dyes.
· Preservatives.
· Antioxidants.
· Stabilizers.
Conservation of food at home
Once the purchase has been at home, they should be putting food properly for its conservation.· First, frozen foods must be stored in the freezer, and then foods that need refrigeration such as meat and fish, eggs, yogurt, and those fruits and vegetables that will not eat at the time.
· Finally, place the foods that do not require these conditions as canned legumes, pasta, etc.
Frozen foods
A frozen food has all the health guarantees if the cold chain is maintained and the preparation at home is suitable. As requirements must be met:
· If food is not to be consumed immediately or in the coming days (depends on the food) it must be kept in the freezer.
· They must buy at the last minute, and transport them home in bags.
· They must present adequate, clean and without waste characteristics.
· Containers or containers must be in perfect condition with no breaks or tears.
· Foods that are already frozen, must keep the same temperature below - 18 ° C.
· Foods prepared at home, if you want to freeze, must reach temperatures of - 25 ° C, clean and protected with plastic or aluminium foil. Please do for rations.
· When you want to defrost a food (there are many that do not require defrosting cooking), must be made in advance and leave to thaw in the refrigerator. For example, place them in the bottom of the refrigerator the night before the day of their consumption.You can also be done in the microwave.
Fish
The conservation of the fish must be in the refrigerator, perfectly clean and in a sealed container so not transmit smell to other foods. Fresh fish should be consumed on the day, and as much the next day, however frozen fish can be kept in the freezer several months.
A fresh fish features as well adhered scales, firm, rigid bodies with glitter, little intense smell, etc.
The meat
Fresh meat can be kept in the refrigerator up to a week. If it is minced meat, then you should eat in the day (except that is frozen), as well as offal products.
Frozen meat is preserved in the freezer several months.
Sausages, if they occur in whole pieces (sausage, pork, etc) can be stored outside the refrigerator, but if they are cut into slices it is advisable to keep them in the refrigerator.
Milk and its derivatives
Fresh products and yogurt should be kept in the refrigerator. Pasteurized milk of the day should be kept in the refrigerator and once opened the package, should not be consumed later than 48 hours. Sterilized milk is kept for several months, but once opened the container should keep in the refrigerator and consume it as soon as possible.
Milk powder should be kept in dry places and closed containers free of moisture, to prevent that they from matting.
Vegetables
Vitamins should be stored in the refrigerator for their conservation, as well as consume them as soon as possible to avoid to lose nutritional value, mostly.
Legumes
Its conservation is simple because it is enough to keep them isolated from the heat, contact with insects and moisture. Over time their skins tend to harden, causing a longer cooking time.
Fruits
They should observe to do the purchase of this food based on what we are able to consume in the next 3 days, to take advantage of all its benefits.
Depending on the heat and the State of maturation, it should keep in the fridge.
Eggs
It is recommended to consume the eggs until within 15 days. Its conservation is carried out in the fridge, and with the tip pointing down; in this way prevents the yolk to come in contact with the shell avoiding possible contamination.
A fresh egg presents a full shell, without roughness, with a transparent clear, and a firm yolk. There are absence of odors.
Fats
They should be stored in places that are dark and fresh or packaged to avoid light and which may alter its properties. In addition also prevents the air so that they are not enrancien.
The solid type such as butter fat, butter or margarine are preserved and the refrigerator.
Canned
In general, many canned foods don't need refrigeration, however, it should be protected from high temperatures.
It must reject those presenting a look rusty or dented, with pores or cracks, either the lack of labelling or expiration date. Those to open them present a cloudy liquid, gas-generating or there is foam, it is advisable not to eat them since it is likely that features that have are due to the presence of bacteria.
Hygiene when preparing food
Appropriate hygienic measures must be taken to avoid damage to the properties of foods, as well as avoid possible food poisoning. Its nutritional value is thus takes full advantage.Utensils
Utensils should be preferably of stainless steel or other smooth and impermeable materials. Thoroughly clean the utensils that have been used to prepare raw food before using them with cooked foods.
Tables used to cut raw food is better than polyurethane (plastic), since those of wood being porous they are more difficult to clean and favour the accumulation of germs.
Person who prepares foods
· Wash your hands.
· No smoking.
· Avoid coughing or sneezing on food.
· Adequately cover the wounds.
The preparation
It should seek to preparing food at the time of its consumption. If it is not, they should be stored in the refrigerator. It must be especially careful with sauces, especially if they are prepared with egg.
Prepare vegetables
These foods are very rich in vitamins and minerals. If it's raw vegetables, such as salads, we ensure:
· Wash them thoroughly.
· The ingredients used must be as fresh as possible.
· Leaves dark, do not dispose of them since they are the ones with greater vitamin content.
· The acidic environment is protected to vitamins, therefore it is advisable to dress them with vinegar or lemon.
· If washing after cutting nutritional value is lost.
If it's cooked veggies:
· Cooking time must be minimized to prevent loss of nutrients.
· If they prepare baked or boiled, cook them with their skin.
· Do not put them to soak.
· Do not reheat.
· Use the boiled water sparingly, and use water left for soups or purees since this stock has a high nourishing power.
Prepare fruit
Its nutritional value, including vitamins, they are not only in the skin, also in the rest of the food. Usually eaten raw, so its contents are preserved in nutrients.
When they are crushing to make a fruit salad, be eating them freshly cut, to prevent the destruction of vitamins.
Prepare vegetables
Legumes, unless they are of very good quality and the harvest of the year, because of the cellulose-containing need soaking to soften when it comes to cooking them they properly. With twelve hours of soaking in cold water, no nutrient is not lost.
Prepare meats
This type of food accepts all types of cooking: grilled, baked, stew, fried foods, etc. It is recommended that the meat is cooked to avoid that it is raw on the inside, thus avoiding possible food poisoning.
The minced meat is more susceptible of alteration, by which it is advisable to prepare anything more be crushed.
Prepare fish
Depending on the species, forms of preparation are very varied:
· Fish coming canned contains the nutritional value that may have one fresh, the difference lies in that it provide more calories by the oil contained.
· The small species tend to eat fried (anchovies, whitebait, etc.). In addition, when consumed with spines constitute an important source of calcium.
· For large fish, cooking in the oven is suitable as well as Cook in water.
· For medium-sized species, the slices are suitable to prepare on grill.
Prepare fried
The oils more advisable for this type of cooking are the seeds and the olive that despite such high temperatures that are reached, do not lose their properties. Some tips are:
· The oil should be heated to medium heat, you do not need to come to smoke, since toxic substances are produced.
· Do not mix oils of different class.
· If they are prepared to moderate temperatures, fats are better digested.
Excess oils must filter not to heat up substances that develop bad taste or contaminate the frying again. Keep it in clean containers, protected from light and in a cool environment.
Article contributed for educational purposes