Inline Refractometers for the Production of Jams and Jellies

Refractometers for the Production of Jams and Jellies
Refractometers are used to maintain
standards of jams and jellies.
The quality and uniformity of a food product is paramount to the sales of that product. Assuring that standards are maintained is key to quality and consistency.  Jams, jellies, marmalades, conserves and fruit butters are characterized by concentration of fruit components and sugars. Attention to solids content, pH, and sweetness is essential, and controlling these variables in a production environment requires the proper systems, instruments, and automation.

Jams, jellies, marmalades, conserves and fruit butters are made by boiling fruit and sugar together to give a high solids product, and are characterized by concentration of their fruit components and sugars.

inline refractometer for jam and jelly production
Inline refractometer for jam and jelly production.
Accordingly, standards of identity have been enacted to require specific amounts of the comparatively expensive fruit ingredient. Without these guides, producers could substitute flavored and colored pectin and sugars in place of real fruit.

  • Jam – a product containing both soluble and insoluble fruit constituents.
  • Conserve or preserve – large pieces of fruit are present.
  • Butter - a smooth, semisolid fruit mixture with no fruit pieces or peel. May be spiced
  • Marmalade – are made from citrus fruits and contain some peel.
  • Jelly – is made from filtered fruit juice, no pieces of fruit or insoluble solids present.
In the U.S. jams and jelly products are graded as follows:
  • Fancy  - 50 parts fruit to 50 parts sugar 
  • Standard  - 45 parts fruit to 55 parts sugar 
  • Imitation - 35 parts fruit to 65 parts sugar
  • Fruit butters - At least 5 parts fruit to 2 parts sugar
Standards of identity can be easily formulated with the aid of a refractometer - and instrument that the sugar/solids content by the angle that the solution refracts or bends light. Refractometers are the preferred method of determining of measuring soluble solids and sugars in many food products.

In large scale commercial food production environments, inline process refractometers provide real-time sugar and solids measurement allowing plant operators tight control of product variables so that product uniformity and quality is maintained.