Microcontroller Based Raisins Manufacturing Process
Background Raisins are made primarily by sun drying several different types of grapes. They are small and sweetly flavored with a wrinkled texture. The technique for making raisins has been known since ancient times and evidence of their production has been found in the writings of ancient Egyptians. Currently, over 500 million lb (227 million kg) of raisins are sold each year in the World, and that number is expected to increase because raisins are recognized as a healthy snack. History The technique of drying fruit was likely discovered by accident. It is conceivable that our ancestors came upon fallen fruit, which had dried in the sun, and discovered its sweetness after tasting it. Evidence has shown that raisins were produced by the Egyptians as early as 2000 B.C. Raisins specifically have been mentioned in ancient writings and it suggests that they were used for eating, treating illnesses, and even paying taxes. Throughout the ages, wine making has been the most important use for grapes, however, a small amount of these grapes have always been made into raisins. During the late 1800s, Spanish missionaries from Mexico introduced grapes into the United States. Many of the vineyards established by these missionaries in California are still producing today. These early vineyards were primarily used to make wines, however in 1873 when the vineyards discovered they could make quicker profits by making raisins, the raisin industry was born. The Manufacturing Process There are four primary methods for producing raisins including the natural, dehydration, continuous tray, and dried-on-the-vine methods. The most popular of these is the natural method which will be explained in some detail. The basic steps in natural raisin manufacturing include harvesting, processing, and packaging. While a small portion of raisins are made by mechanically dehydrating grapes, the majority of them are produced by sun