Apricot Kernels - Shelf-life & Storage

How long will apricot kernels keep and why is this information important?

 

An apricot kernel's state of health plays a major role in its nutrient content. The length of time out of the shell and exposed to open oxygen will dictate how long they'll last once in your possession. Oxidation is not only the number one enemy to vitamins, it also causes nut and seed oils to go rancid at room temperature.

There are several factors that influence an apricot kernel's shelf-life. After apricot stones (whole seed, shell and all) have been removed from the fruit and allowed to dry naturally, they will keep for, at least, 3 years at ambient temperature (room temperature) if stored dry. The shell preserves the seed and protects it from environmental contaminants and oxidation. Once cracked and exposed to oxygen, the shelf-life begins, as does the process of rancidity. How the kernels are stored from this stage will dictate the shelf-life.

At refrigeration temperatures and stored sealed, either in an oxygen barrier bag or some other air-tight containment, the shelf-life will be approximately 2 years. However, how long ago the kernel was cracked must be taken into consideration. For this reason, a good rule of thumb is to halve the shelf-life, as it can seldom be known when the kernel was actually cracked from the shell. This is particularly true of imported nuts and seeds. Imported seeds are often well on their way to rancid, if not rancid already. A study conducted a few years ago (which I'm presently trying to find to reference directly) found that most imported nuts and seeds sold were, on average, at least, two years old before they made their way into the consumer's home.

When stored sealed and refrigerated, the process of rancidity is greatly slowed. At room temperature, an average shelf-life will be about 6 months to be safe. That said, nuts and seeds should always be stored refrigerated to prolong their life, their nutrient spectrum, and prevent them from going rancid. This will also prevent pest infestation, such as the dreaded pantry or meal moth.

Apricot kernels can be stored in the freezer, contrary to conflicting information elsewhere. Freezer storage has no impact on amygdalin levels; however, sub-zero temperatures will effectively kill living seeds, as the embryo can't survive prolonged periods of freezing. Once frozen, it's best to keep them frozen, as they are now dead and will enter a state of decomposition at warmer temperatures. They can be used straight from the freezer without concern of defrosting. Dried apricot kernels have very low moisture content, so they will never freeze solid and they will last indefinitely in this state. That said, my belief is that raw, living seeds are always best. Living seeds retain their full spectrum of nutrients, including those yet discovered.

Apricot Kernels - All About

Definition of Apricot Kernel

An apricot kernel is the nut-like object found within the hard, outer shell of the apricot seed or stone.

Definition of Apricot Seed

The term apricot seed refers to the whole pit found at the core of the fruit. The seed comprises a dense, hard outer shell that serves to protect a softer, fleshy kernel within from which the plant ultimately grows. The term apricot seeds is often used in reference to apricot kernels, though apricot seeds are technically whole apricot stones. The word apricot seed can be both singular and plural. The term apricot seed may refer to a collective or one, as in:  

We will process 400 tonnes of apricot seed this year.

or  

If you plant this apricot seed, its kernel will sprout and a tree will grow.

More about apricot kernels

Apricot kernels are closely related to the almond, which is also part of the rose family. They have a nutritional profile similar to that of almonds. Apricot kernels are often bitter in flavor due to varying concentrations of a cyanogenic glycoside called, 'Amygdalin'. There are hundreds of different cultivars of apricot kernels grown all over the world, each possessing different quantities of amygdalin. Those that contain very little amygdalin taste similar to almonds. Those that contain large concentrations are generally thought of as unpalatable due to their extreme bitterness. This bitterness, or lack of, is indicative of amygdalin content. Apricot kernels of these varieties are believed, by many, to have therapeutic value against various cancers due to their high concentrations of amygdalin. This concept is widely considered very controversial. The apricot itself is believed to have originated in China, where it's been used in both culinary and therapeutic capacities for centuries. Scientific studies from as recently as 2005 have demonstrated potential efficacy. Scientists in Korea found that treating human prostate cancer cells with amygdalin induced programmed cell death in vitro. They concluded, "amygdalin may offer a valuable option for the treatment of prostate cancers".

Although bitter apricot kernels are most famously known for their use in alternative cancer therapies or natural cancer treatments, many people are unaware of their other common uses. The common Italian liqueur, Amaretto, is made from bitter apricot kernels. In fact, the Italian word amaretto can mean, 'a little bitter' or 'macaroon'. Many people would be familiar with a famous Italian treat known as amaretti biscuits. These are, indeed, little macaroons also made from bitter apricot kernels.

The most famous flavor incorporating apricot kernels today is marzipan. Though marzipan was once traditionally made with bitter almonds, they have become very difficult to procure. They are often now replaced by bitter apricot kernels. When made with bitter apricot kernels, the technical term for this paste is, 'persipan', though it is often referred to as, "marzipan". Both bitter almonds and bitter apricot kernels contain amygdalin. Amygdalin can be processed down into its constituent parts to form hydrocyanic acid, benzaldehyde and glucose. The benzaldehyde component of the amygdalin molecule is sold commercially as "almond extract". This extract is often used in place of either bitter almonds or bitter apricot kernels to provide a traditional marzipan flavoring to various recipes that require it.

Apricot kernel oil is another popular use for apricot kernels.