A physical process causing the effect of preserving fish or meat food throughout long periods of time, tens of months, thereby preserving the properties of a fresh product, such as its color, smell, texture and taste, while preserving the proteic and vitaminic contents of the original product, is revealed. In the case of fish, the process consists of the following steps: a) Capturing, eviscerating, cleaning, and washing the fish, all in an hygienic environment; b) Keeping said fish under moderate cold, using ice scales or adequate cold facilities; c) Cutting the fish in agreement with the commercial requirements to be satisfied; d) Subjecting the fish to an initial quick freezing process reaching -5.degree. C.; e) Packaging the product in special packages, which possess high impermeability to gases and water vapor, being flexible and adaptable while being physically resistant; f) Subjecting the packed product to a "high vacuum" process, wherein "high vacuum" is defined as a 99% vacuum; g) Continuing the quick freezing of the process to reach -18.degree. C.; h) Keeping the packed product in plastified cardboard boxes on pile-up systems, at low and uniform temperatures around -18.degree. C.; i) Using the treated product; j) Consuming the treated product by cooking it using normal methods.