Canning

Canning | Food Prosessing | Canning - how to canning, for canning, canning jars, canning food - is a method of preserving food by first sealing it in air-tight jars, cans or pouches, and then heating it to a temperature that destroys contaminating microorganisms that can either be of health or spoilage concern because of the danger posed by several spore-forming thermo-resistant microorganisms, such as Clostridium botulinum.Spores of C.Botulinum(in a concentration of 104/ml)can resist boiling at 100°C(212°F)for more than 300 minutes; however, as temperature increases the times decrease exponentially, so at 121°C(250°F)for the same concentration just 2.8minutes are required.

The Trapezoidal Integration Method for Calculating Fo Values in Fishery Products Canning

A mathematical method in which the time-temperature data are used to measure changes I in lethality during heating and cooling. By using standard time intervals the lethal value: is computed in stages and the cumulative L value for the process is found without the need for graphical representation of the heating and cooling curves.

Calculating Fo Values in Fishery Products Canning: The improved general method

A plot of temperature versus time is made on specially constructed lethal rate paper which has on its left-hand vertical axis product temperature (on a log scale) while on the other vertical axis is drawn lethal rate (on a linear scale). Thus for each temperature can be shown the corresponding lethal rate. Time is plotted along the horizontal axis, using a convenient scale.

The Principles of Canning for Fishery Products: Calculating Fo Values

Thermocouple probe

To be sure of commercial sterility the Fo value at the SHP, the thermal centre of the container, must be sufficient to kill all Clostridium botulinum and reduce survival probabilities for other more heat resistant bacteria to an acceptable level. It is assumed that bacterial spores will randomly contaminate the fish and that therefore they may be located at the SHP. Although a pessimistic approach, this caters for the ``worst case`` scenario on which product safety must be based.

The Principles of Canning for Fishery Products: Lethality of Heat During Heating and Cooling

Clostridium botulinum

Although by convention the sterilising effect of a process is expressed in standard units of minutes at 121.1 ºC (the symbol used is Fo), the product inside a can does not instantaneously reach processing temperature and in some cases of conduction heating, the temperature at the thermal centre of the can never reaches that of the heating medium (which need not be at 121.1 ºC).

The Principles of Canning for Fishery Products: Bacterial Spores Heat Resistance

It is desirable that the test organism in comparative thermal death time determinations be one which grows readily on the ordinary culture medium, with the production of an abundant yield of spores in a minimum time.

It should, furthermore, be an organism which has a characteristic type of growth, or should possess some readily determinable which will serve to differentiate it from contaminants likely to be encountered.

The Principles of Canning for Fishery Products: Selection of Thermal Processing Conditions

The purpose of sterilizing cans of fishery products is to rid the container and the contents of all pathogenic micro-organisms and to prevent. spoilage by non-pathogenic contaminants under normal storage conditions. Selection of processing conditions necessary to fulfill these criteria is based upon experimental studies in which the rate of heat penetration to the slowest heating point (SHP) of the container is measured during simulated retorting cycles.

The Principles of Canning for Fishery Products Preservation

What is Canning?

Canned fish

Canning is a method of preserving food in which the food is processed and sealed in an airtight container, providing a typical shelf life ranging from 1 year to 5 years and under specific circumstances a freeze dried canned product can last as long as 30 years and can still be safely consumed. The process was first developed as a French military discovery by Nicolas Appert in 1810. The packaging prevents microorganisms from entering and proliferating inside.

A Guide for Canning Vegetables

A Canned vegetables

As all we known that all agricultural products is perishable. This perishable characteristic is all because of a high water content level consisting in them. This condition happened to vegetables as one of agricultural products that need time to reach to the consumers. 

Therefore, it's need a technique to preserve vegetables to not defect when it's ready to be consump by the consumers. One of the preservation techniques that reliable for vegetables is canning.