How do raisins become oily after washing

The appearance of oily substances on the surface of raisins after washing is a normal phenomenon, mainly caused by the analysis of natural sugars on the surface or residual food grade oils and fats from processing. The greasiness of raisins may come from the wax layer secreted by the fruit itself, vegetable oils added during processing, or a mixture of dust and oil adsorbed during drying. During the drying and storage process of raisins, the sugar inside the fruit gradually penetrates to the surface to form crystals. When these sugars dissolve in water, they produce a sticky texture. Some manufacturers spray a small amount of vegetable oil before packaging to maintain the color and prevent adhesion of dried fruits. This type of edible oil is safe and edible, but it can easily form an oil film when it comes into contact with water. Traditional dried raisins may absorb dust from the environment and the skin's own oil, which can mix and form a cloudy oily floating substance when washed.

Some imported raisins may undergo paraffin coating treatment to extend their shelf life due to long-distance transportation needs. Although these substances meet the standards for food additives, it is recommended to thoroughly clean them before consumption. Individual low-priced products may have a processing environment that does not meet standards, leading to oxidation and deterioration of the oil. If accompanied by odor or abnormal color, consumption should be stopped.

It is recommended to rinse raisins quickly with warm water to avoid nutrient loss caused by prolonged soaking. Organic raisins can be adsorbed with flour water or starch water to remove surface impurities, washed and drained before consumption. Daily storage should be sealed and away from light, and in humid areas, refrigeration can be used to prevent oil spoilage. If there are doubts about the processing technology, priority can be given to choosing organic certified raisins without added drying products or regular channels.