Heat processing vs Cold processing
In the extraction process (such as obtaining olive oil from olives) the yield is dramatically increased and extraction time decreased if high temperatures and pressures are used. This means more product can be made quickly; reducing costs to the producer and allowing a cheap and affordable product to be made for the consumer. However, These conditions create a very unstable environment, and increase the rate of at which nutrients react with oxygen in the air. A number of very important nutrients such as omega-3 fats, vitamins and polyphenols are susceptible to oxidation damage, and once they have been oxidized have no nutritional value to the consumer and in some cases are toxic.
Cold pressing oils takes a longer, and produces a lower yield, but produces a healthy product with very little oxidation to fats or other nutrients. This processing can be taken a step further by extracting the oils in light and oxygen free environment, which will produce an even cleaner product, but will result in added expenses to production and make the end product more expensive.
Products which will benefit from cold processing
Oils (coconut oil, seed oils, fish oils and olive oil) – All fatty acids are very vulnerable to oxidation and will readily react with oxygen. Omega-3 fatty acids which are high in fish oils are particularly susceptible to oxidative damage which renders them nutritional useless and sometimes toxic. This also applies to cooking at high temperatures such as frying, which will also cause the oxygen in the air to react with the fats.
Milk – Milk contains a number of important fats, probiotics and protein, all of which will be damaged by the pasteurization process, which uses extreme heat to kill pathogens.
Whey protein – High temperatures are used in the drying process to make whey protein, and cause proteins in the why to denature. This means that the consumer will not get some of the additional benefits various proteins exert on the consumer such as immune support. Heat processing can also reduce the digestion and absorption of the protein.
Chocolate – Raw chocolate is high in nutrients called polyphenols which have a number of health benefits, including promoting probiotics in the guy, helping your immune system and protecting the body from oxidative stress. Conventional chocolate processing uses high temperatures which oxidize the polypheols, making them useless. Raw chocolate is actually very healthy as long as there is no sugar added to it.
Heat processing is generally used to reduce cost to the producer, which makes a cheap product that is appealing to consumers who are not aware of processing methods. This low cost product is damaged and will infer very little or no benefit to the consumer. Cold processing maintains important nutrients in the product, making it a much healthier option, but does cost more to produce.