Are frozen vegetables less nutritious than fresh?
Frozen vegetables seem to be NO nutritionally inferior in relation to the fresh ones (of two or more days after their harvest), with the understanding that all the procedures of harvesting, processing, freezing and maintenance in freezing are set correctly.
The only best alternative option is to have your own garden and consume directly freshly harvested vegetables.
Do they contain preservatives?
The production of frozen vegetables has to do with a whole process of processing, which is strictly controlled in order to maintain the quality and nutritional value of the finished product and within which blanching and freezing of vegetables are included.
Vegetables immediately after their harvest and their fast transportation to the processing unit are steeped in boiling water (90-95°C) or exposed to steam (2-4 min), in order to disable the endogenous enzymes, which are responsible for the loss of the nutritional value and their organoleptic properties (color, texture, taste).
Then the vegetables, with the above enzymes disabled, are being deep frozen at temperatures below -18° C, where they are maintained before they finally arrive at the consumer’s plate.
Thanks, to these methods, the use of preservatives or other chemical additives is not required.
How do they retain their color, taste and ingredients?
Both the nutritional value of frozen vegetables and their color can and are kept in excellent condition thanks to the specific procedures used (blanching, freezing), of which we discussed earlier.
As for their taste, deep freeze is a natural and gentle maintenance method that does not spoil it, as long as the vegetables are maintained properly, so as not to interrupt the freezing chain in all phases of the management and distribution of frozen products (to maintain a constant temperature).
I left a product in the maintenance. Has it gone bad?
If the temperature of the maintenance is around 3-4° C, then the product can be maintained up to 24 hours. Later, however, there may be decay, which is likely to affect the quality characteristics of the product (e.g., vitamins, texture) and food safety (e.g., development of microbial flora).
That is why we must follow the instructions on the package and the product should be consumed within 24 hours from the time you removed it from the freezer.
Can I freeze vegetables in my home?
The home freezer does not have the same effect with a professional one, which can freeze automatically and in minimum time the whole seed, “sealing” its nutritional and organoleptic characteristics. The freezing process in a home freezer is much slower and does not have the same effect as the systems of industrial high-speed freezing.
Can they get spoiled?
Frozen vegetables are particularly safe -even in comparison with the fresh ones- due to a special heat treatment and the quick-freezing process, which reduce the microbial load of fresh vegetables and disable their enzymes that cause decay.
So, they can be maintained for a long time (at least up to 18 months) without any significant loss of nutritional value as long as they are maintained at temperatures below -18 °C.
What do researches say?
There have been experimental researches concerning the comparison of the nutritional quality of three fresh vegetables (peas, green beans, gumbos) with the corresponding frozen ones through the assessment of 3 nutritional quality indicators: vitamins A and C and dietary fiber.
Vitamin C is the primary quality index, the most sensitive to changes, while dietary fiber and vitamin A are secondary quality factors, as are minerals or other vitamins.
According to the results of the research, it appears that frozen vegetables outdo in their majority in their vitamin C content compared with samples of fresh vegetables, if the latter were harvested two or more days before being distributed in the market. This is because the degradation of vitamin C starts immediately after cutting the vegetables.