We loose almost 30% of our total produce as waste due to spoilage. Poor handling practices, poor hygiene, lack of infrastructure, lack of cold chain, lack of technical knowledge and technological advancements in food processing are some of the attributes for such losses. Freezing and cold chains are very much needed to protect our food from spoilage and saving our country from huge losses.
It is imperative to understand the importance of freezing and maintaining a cold chain in production of processed frozen foods. It is also desired to know why it is needed and how it works.
Any commodity or food product spoils in the following three ways:
Microbes are part of nature and are present in every environment – water, soil and air. Foods coming from land or water contain microorganisms specific to their environment however most of the pathogenic organisms (disease causing ones to human beings) are terrestrial in nature. Foods of terrestrial origin may bring in contaminations from the farm itself like root vegetables and tubers. Fruit and leafy vegetables may get contamination from the soils in contact, dust, bird droppings, human excreta, through insects found in that environment. Water used in irrigation is also a potent contamination source. Farm workers and food handlers during post harvest operations can contribute to contamination if it is carried out under unhygienic conditions.
Seafoods immediately after catch are considered free from pathogenic contamination. This is a generalized concept and has several exceptions.
Autolytic spoilage (enzymatic)
Animals, vegetables and fruits have their own enzymes, which are essential for digestion and other metabolic activities while they are alive. After death these enzymes start digesting their own tissues and carry out break downs of proteins, carbohydrates and fats and spoil the product. Enzymatic reactions are also like microbial ones and are directly proportional to atmospheric temperatures, thus with reduction in the temperature enzymatic spoilage slows down and almost stops (approx 90%) at –18 degree Celsius and 100% at below –60 degree Celsius.
All products either from plant or animal origin contain some percentage of oil and fats. In chemical language they are called triglycerides (three molecules of fatty acids bonded with one molecule of Glycerol) and partially are unstable in nature. Triglycerides keep breaking in higher temperatures into glycerol and fatty acids, reaching to highest levels at cooking or rather frying temperatures. As they are free from the bond they are called free fatty acids. Free fatty acids are highly reactive with oxygen which they derive from surrounding air and get converted into peroxides and other compounds which are not in good taste and aroma and sometimes unhealthy too.
Refrigeration and Freezing
All these three types of putrefactions processes are directly or indirectly related with temperature abuse and can be controlled by keeping the food in a temperature-controlled atmosphere.
We can control all three type of spoilage by freezing a commodity to a temperature of –18 degree Celsius,. Even at this temperature some reactions are going on. They are however very slow and do not have any impact on the edible qualities till at least up to 18 months, if temperature is maintained at -18 degree Celsius continuously. At any stage if product temperature is allowed to go up all above three processes will resume their activities and render the product inedible or spoiled.
In case of fresh foods also same is true. Therefore till product is taken for consumption, it should be stored under refrigeration if time required for storage is less or it should be frozen and stored to a temp of –18 degree Celsius.
Quality of Frozen Food vs Fresh
Quality of frozen foods had been always under doubts. In fact unfrozen products the so-called “FRESH” may not be always fresh. The unsold fruits, vegetables and meat products are kept for next day sales by vendors and this process continues till either it is sold or till gets spoiled. As cold chain infrastructure in India is still not available widely, fruits and vegetables are left at ambient temperatures for next day sales. Vegetables and fruits keep metabolizing. most of their stored energy and nutrients and might have consumed most of it before a customer has purchased these after few days. If same vegetable has been frozen immediately after harvesting and stored at desired temperatures, it will still be close to fresh preserving fully its chemical, organoleptic and nutritional values. In similar way meat products too keep deteriorating slowly even if they are kept under refrigeration.
PIMM™ SuD accepts data on an in-time or real-time basis using the same User Interface. The user should choose the logger that best supports their environment. For example, frozen loads can be monitored with a PIMM™ LogTag (In-Time Logger) vs. a more perishable sensitive product like produce or berries may be better suited for a PIMM™ AirTag (Real-Time Logger).
Real-Time Loggers like the PIMM™ AirTag and PIMM™ TMC provide an extra layer of quality and security by providing real-time notifications during transit. This allows the plant, carrier and distributor to have advanced warnings in order to initiate corrective actions during transit.