acid value

Thân thiện

The chemist records the acid value of the oil sample.

Definition

1. Noun:
   • A chemical measurement: The acid value is a number that indicates the amount of free acid present in a substance like fat or oil. It is measured by finding the mass in milligrams of potassium hydroxide (KOH) needed to neutralize one gram of the sample.

Usage

• The acid value is a critical quality parameter in industries that produce or use fats, oils, and waxes.
• It is used to assess the freshness or degree of spoilage (rancidity) of fats and oils, as spoilage creates free fatty acids.
• A higher acid value typically indicates a greater level of decomposition or lower purity.

Examples

• Noun:
  • The laboratory report showed an acid value of 2.0 for the new batch of olive oil, which is within the acceptable range for extra virgin quality.
  • Monitoring the acid value over time helps predict the shelf life of the cosmetic product.
  • An increasing acid value in the stored butter confirmed that it was beginning to turn rancid.

Advanced Usage

• "To determine the acid value": This is a standard phrase used in analytical chemistry procedures.
  • The protocol requires us to determine the acid value of all incoming oil shipments.
• "Acid value determination": Refers to the analytical process or test itself.
  • Acid value determination is performed via titration with a potassium hydroxide solution.

Variants and Related Words

• Acid Number (n): A fully synonymous term for acid value, used interchangeably in chemistry and industry.
  • The specification sheet lists the maximum permissible acid number.
• Free Fatty Acid Content (n): A related concept often expressed as a percentage; it is directly correlated to the acid value.
• Saponification Value (n): Another important chemical number for fats, measuring the amount of base needed to saponify the fat, often discussed alongside acid value.

Synonyms

• Acid Number: The direct synonym.
• Neutralization Value: A less common but accurate synonym describing what is measured.

Related Phrases

• Acid value test: The specific procedure or experiment to find the acid value.
  • We run an acid value test on every production lot.
• To have a high/low acid value: Describes the state of the measured substance.
  • This batch of wax has a surprisingly low acid value, indicating high purity.

Học thuật

Noun

1. (chemistry) the amount of free acid present in fat as measured by the milligrams of potassium hydroxide needed to neutralize it
   • as the glycerides in fat slowly decompose the acid value increases