Raisin

Golden raisins are generally dried in dehydrators with controlled temperature and humidity, which allows them to retain a lighter color and more moisture.

Black Corinth or Zante currants are small, sometimes seedless, raisins that are much darker and have a tart, tangy flavor.

[5] In addition to this, the physical and chemical mechanisms located on the outer layers of the grape are adapted to prevent water loss.

[5] Pre-treatment is a necessary step in raisin production to ensure the increased rate of water removal during the drying process.

[5] The historical method of completing this process was developed in the Mediterranean and Asia Minor areas by using a dry emulsion cold dip made of potassium carbonate and ethyl esters of fatty acids.

These methods can encourage water transfer to the outer surface of grapes which helps to increase the efficiency of the drying process.

[5] Sun drying is an inexpensive process; however, environmental contamination, insect infections, and microbial deterioration can occur and the resulting raisins are often of low quality.

Sometimes sulfur dioxide is applied to raisins after the pre-treatment step and before drying to decrease the rate of browning caused by the reaction between polyphenol oxidase and phenolic compounds.

[6] Estimated global production of raisins in 2023–24 was 1.1 million tonnes, led by Turkey, China, Iran, and the United States as the largest producers.