Nuts contain a lot of oil and are easily oxidized. Nutritionist: Reducing oil oxidation and preserving freshness are the key

In the "My Plate" promoted by the National Health Administration, nuts are an important category. According to the national nutrition survey, the intake of nuts by Chinese people is very insufficient. This is related to our habit of eating nuts. Either we don't eat them, or we often eat too much at once. In addition to eating enough, because nuts contain a lot of oil and are easily oxidized, nutritionists recommend eating them "fresh" to be healthy!

Well-known origins of common nuts such as cashews, almonds, and walnuts

Taiwan produces very few types of nuts. Strictly speaking, there are only two types: peanuts and sesame. Therefore, most nuts need to be imported from abroad. Therefore, based on the concept of "eating local", you can choose nuts that have a "place of origin" and are produced in the production area, as the quality will be better.

The following are some of the most well-known producing areas for common nuts:

– Almonds (American almonds) Origin: The United States, Australia, etc., with the United States accounting for more than 70% of the world's production.

– Cashew nut origin: Vietnam, Cambodia, India, Brazil, etc., among which Vietnam and Cambodia are the most famous.

– Walnut production areas: China, the United States, etc., with China’s production accounting for more than 40% of the world’s total.

– Hazelnut production areas: Türkiye, Italy, Greece, etc., with Türkiye accounting for 70% of the world’s production.

– Macadamia nut origin: Australia, Hawaii, etc., with Australia as the origin.

It is claimed that the fresh products are harvested in season, shortening the storage time to keep fresh

Since most nuts are imported, long periods of storage and transportation can easily lead to oil oxidation in the nuts and produce an oily smell, which greatly reduces their freshness and taste, and also affects their nutritional value. Some nut brands harvest and process nuts in season, which can reduce the storage time after harvesting and shorten the time from harvesting to processing, making the nuts closer to the freshness of the day they are harvested.

Key preservation technology to keep nuts fresh

Consumers are increasingly demanding on the quality of nuts, and freshness is their primary requirement for food. So what are the key preservation technologies for nuts?

Raw materials cold chain transportation and low temperature storage and packaging to maintain the freshness of nuts

We all focus on whether the storage and transportation after processing can maintain freshness, and also pay attention to the shelf life, but ignore the preservation measures on the raw material side. After agricultural products are harvested, their quality can easily deteriorate due to temperature, so the cold chain including field cooling, low-temperature transportation and temperature-controlled packaging is the key to keeping the "raw materials" fresh.

Nuts have a high oil content, so their quality is easily deteriorated by high temperatures. Therefore, if key cold chain preservation measures can be taken at the raw material end, it can provide an additional guarantee.

Use low temperature baking to preserve nut nutrients and reduce oil oxidation

Roasting is an important process for nuts to produce fragrance and crispness. High-temperature roasting will make nuts more fragrant due to the Mena reaction, but it will also destroy some heat-sensitive nutrients and promote the oxidation of oils, making nuts "not fresh" and "not durable". Therefore, nutritionists recommend the "low-temperature baking" method to strike a balance between deliciousness, freshness, taste and health, so that we can eat the healthiest nuts. How to choose? How can we choose the freshest and healthiest nuts?

In addition to the above-mentioned techniques, how can we choose to identify the freshest and most suitable nut products? Nutritionists list several principles for your reference:

1. The source of the nuts is indicated to make the source more transparent

Regardless of whether they are imported in their original form or repackaged, many nut brands will indicate the import sources of various nuts on their official websites or packaging. The transparent labeling method allows consumers to know where the nuts they buy come from. Consumers can compare the fruit producing areas written above or check the period to see where the nuts in their hands come from.

However, there are still many brands that do not indicate the "origin", which actually goes against the current trend of "production and sales transparency". Therefore, consumers are advised to buy brands that have their origins indicated.

2. Is there temperature control and low-temperature baking during the nut processing?

Nut processing is the key to the freshness of nuts. Currently, there are processing methods that control "temperature" and "humidity" throughout the entire process. In addition to low-temperature baking, cold chain transportation, storage, etc. are all key points. These measures can also help consumers protect the quality of nuts.

3. Small packaging, no need to consume too much to keep fresh

Many people are accustomed to buying a can of nuts and keeping them at home, but they may keep them for three months before eating them all. Over time, the nuts may be oxidized or even moldy. In addition, canned nuts can make it difficult for us to control our intake and we may keep eating them, leading to excessive calorie intake. Therefore, nutritionists recommend buying nuts in small packages to keep them fresh while also controlling our intake.

A bag of nuts is about 30 grams, which is about twice the recommended amount. If you buy them for consumption, you should eat a lighter diet on a daily basis to avoid the problem of excessive fat intake. Nutritionists recommend adding dried fruits and unseasoned nuts. A bag of grab-and-go or small package of nuts is about equal to the recommended daily serving, so there will be no problem of overdose, and you can also supplement other nutrients to a certain extent.

Nuts can provide high-quality fatty acids, vitamin E and minerals, and the content of these nutrients will also be affected by the quality of the nuts. Poor quality nuts may also bring health burdens. Therefore, in addition to understanding the nutrition of nuts, we must also understand the preservation technology of nuts, not only to eat healthily, but also to eat fresh.

This article is from "Good Food Class" by nutritionist Lin Shihang