Fruit sugar meter to detect fruit and vegetable juice experiment
The commonly used instrument in the fruit sugar meter is a hand-held refractometer, also known as a sugar mirror and a hand-held sugar meter. By measuring the soluble solid content (sugar content) of fruits and vegetables, the quality of fruits and vegetables can be understood, and the maturity of fruits can be roughly estimated.
1. Purpose and principle: Use a hand-held refractometer to measure the total soluble solids content in fruits and vegetables, which can roughly indicate the sugar content of fruits and vegetables. The phenomenon of refraction occurs when light enters another medium from one medium, and the ratio of the sine of the incident angle is constant, and this ratio is called the refractive index. The content of soluble solids in fruit and vegetable juices is proportional to the refractive index under certain conditions (same temperature and pressure), so the concentration (sugar content) of fruit and vegetable juices can be obtained by measuring the refractive index of fruit and vegetable juices.
2. Drugs and equipment needed for the experiment:
1. Fruit samples
2. Distilled water
3. Beaker, dropper, paper roll, hand-held fruit sugar meter
3. Operation steps:
1. Open the cover of the hand-held fruit sugar meter, and carefully dry the glass surface of the prism with a clean gauze or roll paper. Put 2 drops of distilled water on the prism glass surface and cover with a cover slip.
2. In a horizontal state, observe from the eye contact, and check whether the boundary line between light and dark in the field of vision is on the zero line of the scale. If it does not coincide with the zero line, turn the scale adjustment screw so that the dividing line just falls on the zero line.
3. Open the cover, dry the water with gauze or roll paper, then drop 2 drops of fruit and vegetable juice on the prism glass surface as above, observe, and read the scale on the boundary line between light and dark in the field of vision, which is the solubleness in fruit and vegetable juice. Solid content (%) (approximate content of sugar). repeat three times.
