SOP: Determination of Bulk Density of Dehydrated Fruits and Vegetables

GIFSQ — Global Institute for Food Safety & Quality

Principle

Bulk density is the weight of product held in a unit volume; it is measured because it matters in the packaging of the product. The weight of sample filling a cylinder of exactly 625 ml water capacity is weighed, and the bulk density in lb/cu ft is obtained by dividing the weight in grams by 10.

Apparatus required

• Glass cylinder (of exactly 625 ml water capacity)
• Hopper
• Balance

Procedure

Loose bulk density

Weigh the empty glass cylinder of exactly 625 ml water capacity to obtain its tare weight

↓

Fill the cylinder with the sample from a hopper suspended 3 cm away

↓

Strike off the excess sample level with the rim of the cylinder and weigh again

Compacted bulk density

Tap the filled cylinder repeatedly and refill it with sample; then weigh. The compacted bulk density is calculated in the same way.

Calculation

Bulk density, lb/cu ft = (Wt of sample in grams) / 10

Where,

• Wt of sample in grams = (weight of the filled cylinder) − (tare weight of the empty cylinder) (g)

Precautions

• Use a cylinder whose water capacity is exactly 625 ml.
• Keep the hopper 3 cm from the cylinder while filling.
• Strike the sample level with the rim before weighing.
• For the compacted value, tap and refill the cylinder before the final weighing.
• Note: the book carries a reference marker at this method’s heading that is illegible in the available copy, so no second citation could be verified — check the printed book for the intended reference.

References

Ranganna, S., Handbook of Analysis and Quality Control for Fruit and Vegetable Products, 2nd edition.