If you are looking for a healthy snack on the go, then just grab a hand full of nuts. They are a great source of fiber, protein and healthy fats, but are also packed with vital antioxidants and nutrients that our bodies need to function.
Research studies has also shown that, if you are not allergic to nuts, then we should add them to our diet. That is since nuts have many health benefits, from lowering blood pressure, blood sugar and cholesterol.
However, now the question, and the focus of this article, is if raw nuts are better for you than roasted nuts. Some believe that roasting nuts influence their nutritional content. Nevertheless, roasting nuts using dry heat or using oil in a frying pan will improve their aroma, texture and taste.
What are the nutrient content difference between roasted and raw nuts?
When nuts are roasted, they lose water content due to the heat that is applied. This means their texture and color changes, but also that roasted nuts will weigh less than raw nuts. What also changes is their structure and chemical composition. What does not changes is their fat protein, and carbs composition. That means roasted nuts will have the same amount of calories than raw nuts.
Although the fat content does not change when nuts are roasted, their structure changes since the polyunsaturated fats in roasted nuts are prone to oxidation.
Will roasting damage the healthy fats found in nuts?
Nuts are high in the healthy fats of monounsaturated and polyunsaturated fats, which have health benefits of lowering blood cholesterol and could help to keep your heart healthy.
When nuts are roasted, the polyunsaturated fats could be damaged or oxidized then heat is applied to them. When this happens, the cells can be damaged and harmful free radicals can be formed. But this is normally the case when the nuts are over-roasted, and have that nasty smell. If the nuts are roasted over a low heat and not too long, the formation of free radicals are limited.
Will roasting nuts lead to a loss in some of their nutrients?
Nuts contain vitamin E, phosphorus and magnesium. Besides these nutrients, nuts are also packed with antioxidants. Several antioxidants and vitamins will gone astray during roasting, as they might be sensitive to heat. However, the decreased antioxidant activity when heat is applied to nuts will be limited to a certain point.
That does not mean all the antioxidants are damaged during roasting. The antioxidants of lutein and zeaxanthin in pistachios and hazelnuts will not be influenced by roasting. Here it should also be mentioned the loss of nutrimental value depends on the type of nuts.
Research has also shown that vitamin E (particularly the active form of vitamin E, namely alpha-tocopherol); thiamine and carotenoids are lost during roasting. Then again, the type of nut roasted and the temperature by which they are roasted will affect the amount of loss that will occur. Nuts that will loss the most vitamins are walnuts and almonds, whereas pistachios will have a minimum loss.
Although some vitamins are lost when nuts are roasted, it should be noted that nuts are not the main sources of these vitamins. It is only almonds that are a notable source of vitamin E, and should ideally not be roasted.
When roasting nuts, will harmful chemicals form?
A chemical reaction, called the Maillard reaction, occurs then nuts are roasted. Although this reaction gives nuts that beautiful color, aroma and tasty flavor, when nuts are heated above 120 °C and there is a reaction between the natural sugar and amino acid asparagine within the nuts.
A harmful chemical, called acrylamide can be formed during the Maillard reaction. Researchers has found that this substance is responsible for cancer in animals if they eat a lot of it. The research on this substance on humans are lacking. What is known, is that the formation of this chemical rest on on the roasting heat more than the period of the roasting. Almonds are the most prone of the nuts. This is since almonds contain a high level of amino acid asparagine and acrylamide is formed if the nuts are heated between 139–162°C. The amount of acrylamide that can be formed and digested is however not found to be harmful, since it is a small amount.
Will roasting not kill harmful bacteria?
Raw nuts could contain Salmonella and E. coli, which are harmful bacteria. Nuts can be contaminated if they are in contact with bacteria in the soil. Luckily, contamination cases are rare. When there are cases, it can be serious.
To minimize the risk of Salmonella, all almonds in America are required to be pasteurized. By roasting them, will lessen the bacteria, but not eliminate it.
In addition, raw nuts can contain a toxic carcinogen aflatoxin. Roasting these infected nuts will not remove the toxic, as it is heat resistant. The best way to avoid aflatoxin is with better storage procedures rather than roasting the nuts.
Last bit of utterance
Nuts, raw or roasted, are a great healthy snack. The reality is that both contain similar quantities of protein, carbs, fiber and calories, irrespective if they are raw or heat-treated. The only difference is that once nuts are heated the fat within them can be negatively affected and their nutrient content can be reduce. More so, roasted nuts can contain the harmful chemical called acrylamide.
Still, to answer which sort of nut should be eaten then either is okay. Simply since both is healthy.
What you should be careful of is that raw nuts are at a high risk of containing harmful bacteria such as Salmonella. Although the risk is low.
In the end, if you like roasted nuts, rather buy them raw from a good source. Then at home, roast them yourself. You can then make sure that not too much oil is used, and that you do not over heat them.