Studies On The Process Of Removal Of Bitterness From Bitter Apricot Seed

The bitterness of bitter apricot seed is mainly from its amygdalin which content is about2%to5%by weight. Amygdalin could be hydrolyzed in the conditions of acid, enzyme under heat, the production of this reaction are D-glucose, benzaldehyde and hydrocyanic acid. Removing bitterness is prerequisite for deep processing. The traditional process of the removal of bitterness were soaked in hot or cold water and acid treatment, which would cost a long time and large amounts of energy. These process all removed bitterness by soaking bitter apricot seed in water for a long time to hydrolyze amygdalin. After soaking bitter apricot seed, the water would be directly ruled out after simple treatment. The purpose of removal of bitterness was to satisfy the taste and reduce hydrocyanic acid which was one of highly toxic substances.Because of keeping solid form of bitter apricot seed, traditional process wasted large amounts of time and energy, with the result of reduction of nutrition and product quality. Removing bitterness after crushing, a new process was established by vacuum concentration to promote the hydrolysis of amygdalin and reduce energy and time. For the bitter apricot seed crushed, this process was suitable for deep processing. The typical traditional process of the removal of bitterness were soaked in hot water for about4hours, so the bitter apricot seed could be oxidized, the color of treated bitter apricot seed was dark yellow which decreased the value. Through the addition of some addictives, the color turned into light white with little cost, the significance of this treatment was great.1. New process of removal of bitter apricot seed was established by vacuum concentration and optimized from response surface methodology. The results showed that the optimum process conditions were vacuum concentration15min, citric acid concentration of0.24g/L, concentration temperature82℃, and ratio of liquid to material10mL*g-1. Under the optimum conditions, with little energy and time, there were no bitterness, the content of hydrocyanic acid was lower than the national standard. Hydrocyanic acid was easy to volatilize, it must be absorbed.2. The distilled liquid of vacuum concentration was reused. Natural benzaldehyde was collected by extraction, the yield of natural benzaldehyde was0.73%by the weight of bitter apricot seed. This could bring36.5%additional value of production.3. One new process of color-protection was established, the result showed that the addition of2.0g/L sodium hyposulfite and2.0g/L citric acid when the bitter apricot seed soaking in water could make the color light white. On this condition, the sulphur residues was lower than the national standard.