Jelly and preserve products are characterized by concentration of fruit components and sugars to produce a preserved product of high solids and low pH. Products in this category include fruit butters, jellies, preserves, jams and similar products. Some of these products have standards of identity in the regulations.

Typical manufacture of these products requires concentration of the fruit component prior to the addition of sugar, the addition of pectin and pH adjustment with citric acid. Other safe and suitable ingredients may be used depending on the product.

Standards of identity have been enacted to require specific amounts of the comparatively expensive fruit ingredient. Without these guides, pectin and sugars could substitute for fruit, given additional flavor or color. Only the products of specific fruits are defined in the regulation. For example: a product such as jalapeno pepper jelly is not defined. It does however, have certain composition limits within which it will set and will be a safe product.

Some standards

Fruit jellies have 45 parts by weight of the fruit component to each 55 parts of the sweetener solids (45:55). The finished soluble solids content of a jelly is not less than 65%.

Fruit preserves and jams are divided into two groups, generally the berries and the pomes. Those made from the berry group require 47 parts by weight of the fruit component to 55 parts of the sugar. Those made from pomes are 45:55. In both cases the finished product is not less than 65% solids.

Weights of components

The regulation provides for the calculation of the weight of the fruit component by listing numerical factors to calculate the pounds of fruit at a standard solids level. An example should suffice.

The law requires jelly to be 45 parts by weight juice to 55 parts by weight sugar. To determine the weight of the single strength juice when using a concentrate:

I. Check the Brix (% sugar) or soluble solids (using the refractometer) of the fruit juice or concentrate. For instance: apple concentrate (three-fold) at 40o Brix.

II. Multiply the percent solids by the weight of the ingredients and divide by 100. For instance 100 lbs apple concentrate at 40% solids.

(100 x 40) /100 = 4000/100 = 40

III. Subtract any added sugar solids for a sweetened or capped concentrate or juice.

IV. Multiply by the factor in Table 1

40 x 7.5 = 300

The advantage of not diluting the concentrate to single strength is that cooking time may be regulated by judicious addition of water. The above combination would be only about 61% solids and the excess water must be "cooked off" until 65% solids is reached. The sugar ingredient may be added as a syrup and its water can be taken into account in the formulation.
 
 

The Soluble Solids Content

Refractometers are made for specific ranges of solids, so the same refractometer may not suffice for single strength juice and for finished jellies or preserves. The percent sugar is read directly on the refractometer scale and is usually referred to a "degrees brix". Sixty six percent sugar is (66o Brix). The accuracy of the reading is temperature dependent, so the refractometer and the sample should be at room temperature.
 
 

Pectin

Citrus pectin is commonly used to supplement the pectin in jelly products. Pectins are graded for their ability to set a specific weight of sugar solids under standardized conditions. A 150 grade pectin should set 150 lbs of sugar in solution at the prescribed brix.

Pectins are also categorized by how quickly they set on cooling. As jellies cool, air bubbles slowly rise to the top to allow a clear product. A slow set pectin is desirable. However, should one wish to produce a cherry preserve in which the fruit tends to float, a rapid set pectin would be desirable. The pectin must be carefully chosen for each product.

The pectin set is a function of temperature, soluble solids, pectin type and concentration, and pH. Usually it is advantageous to cook the fruit and sugar components to produce a syrup in which certain sugar changes called "inversion" take place. Water is also removed at this step or often later in a vacuum pan.

When the predetermined solids level has been reached, pectin is added. The mixture can be handled until the pH is adjusted to 2.8-3.2, usually with citric acid. At this point, time is of the essence. The hot product is packed into jars and capped.

Safety and Spoilage

The Regulation

Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age or disability. North Carolina State University, North Carolina A & T State University, U.S. Department of Agriculture, and local governments cooperating.

FOOD PROCESSING DRAFT FSE 95-3(08-95)