Storage of Fruits and Vegetables

It is due to a defense mechanism in the fruit, which is activated when the fruit is cut from the tree.

There are three main factors involved in the ripening and browning process, they are: enzymes, oxygen and phenols. Enzymes are protein-like substances that speed up or initiate chemical reactions. Phenols are defensive mechanisms the plant uses to fend off insects and microbes. The specific enzyme is called polyphenoloxidase. When the banana is attacked, the phenols are activated in the presence of oxygen by this enzyme. In this process the brown color is produced as a side effect. The first time the banana is attacked is when it is cut from the tree. Exposure to cold air, certain gases, and physical damage of the fruit will hasten the process.

A banana will ripen and eventually rot faster at room temperature.

The skin of a banana turns brown or black faster in a refrigerator, but the banana meat itself does not ripen that much more. In fact, it is recommended that ripened bananas be frozen to preserve them even longer. The cold temperature of a refrigerator encourages an enzyme (polyphenyl oxidase), which is naturally found in the banana, to polymerise phenols in the banana skin into polyphenols. Polyphenols are similar to melanin, the pigment responsible for the color in our skin. This is what blackens the skin of the bananas. Despite the color, the cold temperature will keep bananas firmer than a banana that has been left at room temperature for the same amount of time. The enzymes that break the starch into sugar, which makes the banana soft and ripe, work better at room temperature.

Most fruit ripening is regulated by the gas Ethylene, this is produced by the fruit as it ripens and acts as a catalyst speeding up the ripening process.

If the Ethylene is not removed quickly the fruit becomes overripe and then starts to rot. Bear in mind that this is the normal process in nature, fruit are supposed to rot and release the seed (if the fruit is not eaten by something first).

Ethylene can be used to assist the ripening of certain fruits, for example if you have a bunch of green banana's, put them in a bag with an already ripe banana, this will initiate and speed the ripening process.

When fruit are shipped long distances (for example when they are exported), they are often shipped unripened or "green", the air is normally removed form the shipping container and replaced with Carbon dioxide which is inert, this prevents Ethylene production in the container from ruining the fruit before they arrive. On arrival they simply add Ethylene to get the ripening process started.

Fruit bowls that do not have holes in the base can cause fruit to rot quickly, the Ethylene is released by the fruit and is "trapped" at the bottom of the bowl, this causes the fruit at the bottom to become over ripe and rot.

Plastic wraps made from polyethylene or polyvinylidene chloride (PVC) are effective at preventing oxidation because they are impermeable to air. These wraps create a barrier that helps preserve the freshness of food items and prevent them from spoiling due to exposure to oxygen. It's important to ensure a tight seal when wrapping food to maximize the protective benefits of the plastic wrap.

Blanching is the scalding of vegetables in boiling water or steam. Blanching slows or stops the action of enzymes. Up until harvest time, enzymes cause vegetables to grow and mature. If vegetables are not blanched, or blanching is not long enough, the enzymes continue to be active during frozen storage causing off-colours, off-flavours and toughening. Blanching time is crucial and varies with the vegetable and size of the pieces to be frozen. Under-blanching speeds up the activity of enzymes and is worse than no blanching. Over-blanching causes loss of flavour, colour, vitamins and minerals.

Freezing slows down the metabolic processes in peas, reducing spoilage. By freezing peas, ice crystals form within the vegetable, preventing the growth of bacteria and enzymes that cause food to spoil. This helps to maintain the freshness, color, and flavor of peas for an extended period of time.

Fruits with higher water content like berries, peaches, and melons tend to mold faster than fruits with lower water content like apples and oranges. Factors like ripeness, storage conditions, and cleanliness can also affect the rate of molding.

Sugar preserves food by lowering the water activity (aw). If the aw is 85 or less, spoilage and pathogenic microorganisms can't grow. Microorganisms all need proper food, water, temperature and acidity to grow and adding sugar to appropriate levels can prevent bacterial growth.

I know one way that slaves used to store food was in items called sub-floor pits, which are basically holes in the ground. This would keep food cooler and slaves would also put it in there so it wouldn't get stolen. If multiple families of slaves lived in one area they would have several sub-floor pits. Slaves usually who where everyones sub-floor pit was and if they saw someone going into someone elses they knew they were stealing from them. Slaves often kept other valuable goods there and ritual items.

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Slaves? Who said anything about slaves?

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A more sophisticated version of the pit was the Ice House, which was a typically cylindrical building sunk into the ground. The floor was extended downwards in conical form, with a drain to a soakaway at the bottom. The sub-surface part was filled with ice from local ponds during the Winter, and perishable foods stacked on that, with a covering of straw for extra insulation. Provided sufficient ice was used, it would keep food cold right through the Summer.

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Foods could also be preserved in salt, vinegar or (if fruit & veg.) by conversion to pickles etc.

The cold refrigerator environment delays the natural ripening process by preventing the starch in the fruit to change to sugar.

Placing fruit in a brown paper bag can further speed up the ripening process. As fruit ripens it gives off a chemical called ethylene, which accelerates ripening. The fastest way to ripen fruit is to place it in a brown paper bag with a ripe banana. in conclution fruits ripen faster in a paper baq!!! shut up

For my calculations I say 4 hours because after cooking it you should steam it for about 2n'1/2 hours :) ........ That's all thank you....add me on face book jamesdaryl_rivera@yahoo.com

If the once cut pineapples are not refrigerated and are kept in open air, there is every possibility of bacteria forming over the cut portion, resulting in health hazard. In every municipal areas, there is noticeboard displaying against sale and use of cut fruits,simply for the health safety of the citizens.

There are a number of reasons why salsa would spoil. If you are at an altitude of more than 1,000 feet above sea level and do not adjust your processing time, if you do not remove the air bubbles prior to putting the lid on the jars, if the rim of the jar has any food residue on it, or if you did not follow the USDA's guidelines for home canning your food may spoil. Follow a tested recipe when making anything for home canning. Refer to the National Center for Home Food Preservation (NCHFP) website, it is an excellent source for current research-based recommendations for most methods of home food preservation. They also have tested recipes for many different home canning projects.

Yes, you can. The problem with this is as it freezes, the liquid inside the cells will rupture the cell membranes and when you thaw it out again, you wind up with an onion flavored mush. The best thing to do is stew them till they are "broke down" and freeze the onions, stew and all.

Vegetables that are similar in cellular structure like peppers, celery and leafy greens such as collards, spinach, turnip greens and kale will not hold up to being frozen as the same thing will happen.

Fruits can be kept in a freezer. The issue is over what period can the quality can be maintained which is also dependent on the freshness when stored. Fruit will obviously lose its firmness but can be stored for 3-4 months with little loss in quality and be very suitable for cooking. maximum about a week's storage can be considered good enough for raw consumption taking into account the freshness and taste. beyond that it is all compromise. when you get fresh fruit round the year no point in keeping for longer time in the freezer . what say ?

Potatoes were unknown to the Anglo Saxons.

Potatoes are native to the Americas and were unknown in Europe until after the Spanish began exploring and conquering the Americas, after 1500 AD.

Applying lemon juice to sliced apples helps prevent oxidation.

it will last about 2 or 3 weeks ..It's normal for it to separate during this process

Note - just shake it and taste it before using it to assure it's fresh if

Yes. Drain them, store them is zip lock bag with as little air in it as possible, and freeze them. There will be a slight change in their texture when thawed, but not too much.

It most certainly does not! Glad Cling Wrap contains low density polyethylene. Saran Premium is also based on this. The original Saran wrap does contain PVC. PVC is oh so very harmful to the environment. If we take care of the earth, the earth will take care of us. Just remember (don't forget), "green is the new black"!

What ever the date on the can say's,

or if no date about 1 year

You should keep foods out of the danger zone to prevent bacteria from forming on foods. Bacteria can form on foods in the danger zone after just an hour. The danger zone is under 145 degrees and over 45 degrees.

Bitterness can be caused by too little water, but often the bitterness can be inherited from the parent plant. Never save the seeds of a bitter lettuce. Also, some varieties are more prone to producing the occasional bitter-tasting lettuces.

That depends on the make/model of fridge. The manufacturer will have supplied that information for each type of fridge they sell - however, the time given assumes you are NOT opening the door.

Different fridge makes/models come with different standards of insulation.