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Lesson 18. JAM, JELLY AND MARMALADE
Module 5. Jam, jelly, marmalade, and glazed and crystallized fruits
Lesson 18
JAM, JELLY AND MARMALADE
18.1 Introduction
In previous lesson (No.17), the role played by several functional ingredients in preparation of sugar preserved foods like Jam, Jelly and Marmalade were discussed. In this lesson the mode of preparation of these products and means to prevent any defect in such products will be taken into account.
18.2 Fruit Jam/Fruit Cheese
As per FSSA, Jam means the product prepared from sound, ripe, fresh, dehydrated, frozen or previously packed fruits including fruit juices, fruit pulp, fruit juice concentrate or dry fruit by boiling its pieces or pulp or puree with nutritive sweeteners namely sugar, dextrose, invert sugar or liquid glucose to a suitable consistency. It may also contain fruit pieces and any other ingredients suitable to the products. It may be prepared from any of the suitable fruits, singly or in combination. It shall have the flavour of the original fruit(s) and shall be free from burnt or objectionable flavours and crystallization.
The specific requirements for Jam are as follows:
Total soluble solids (m/m) - Min. 65.0 %
The product shall be manufactured from minimum 45.0% by weight, of original prepared, fruit, exclusive of any added sugar or optional ingredients of finished product, except for Strawberry or Raspberry fruit, where it shall contain minimum 25.0% fruit.
As per FSSA, Fruit cheese means the product prepared from pulp/puree of sound, ripe fruit (s), whether fresh, frozen or previously preserved or dry fruits, by cooking with salt, nutritive sweeteners to attain a thick consistency so that it sets on cooling. The fruit cheese shall be neither too soft nor too hard to chew. It may be prepared from any of the suitable fruits, singly or in combination. It shall have the flavour of the original fruit(s) and shall be free from burnt of objectionable flavours and crystallization.
The specific requirements of Fruit cheese are the same as specified for Fruit Jam.
18.2.1 Salient characteristics of jam
The amount of pectin in the gel is quite small (< 1.0% of the weight of jam); sugar content is very high (60-70%). Of the remainder, the bulk is water with a small amount of fibrous matter and seeds.
For a chunky texture, some pieces of fruit are added about 5 minutes before the cooking is finished. If a stiffer or sweeter jam is desired, more thickener or pectin, honey or sugar may be added.
18.2.2 Fruit or fruit combinations
Some fruits such as lemons and bitter oranges are rich in both acid and pectin and can be easily made into jam.
Some popular combinations include: pineapple and paw paw, orange and banana, apple and plum.
18.2.3 Sugar
55 parts of sugar is required for every 45 parts of fruit. With excess sugar, the jam becomes gummy and sticky.
The finished jam should have 30-50% invert sugar / glucose to avoid crystallization of cane sugar during storage.
18.2.4 Acid
Acidity can be supplemented by use of citric, tartaric or malic acid. The pH influences inversion of sugar and setting of the jam.
For pectin jam, pH of 3.3 gives a good set. For Apple and Plum jam, the pH range of 3.2-3.5 is desirable; optimum being 3.35.
18.2.5 Preparation of jam
The process for preparing Fruit Jam is depicted in Fig. 18.1.
Fig. 18.1 Flow chart for preparation of jam
18.2.6 Judging the end-point or point at which boiling is stopped
18.2.6.1 Determining the boiling point with thermometer
Thermometers or thermocouples are used to indicate the temperature which should be approximately the boiling point of a 65% sugar solution (103.9-105°C), when the process is complete. A 65% solids boils at 104.8°C at sea level. It should be 8-9°C higher than the boiling point of water at that place.
18.2.6.2 Hydrometers
They help in determining the specific gravity of material.
18.2.6.3 Refractometer
We can determine the percentage solids i.e. TSS read directly on scale. Use Abe or Zeiss type refractometers and for dark colored jams/jelly, use projection type refractometer.
18.2.6.4 Sheeting or ladle test
a) Cold plate test
A drop of boiling liquid from the pan is placed on a plate and allowed to cool. If the jelly is about to set, it will crinkle when pushed with a finger.
b) Sheet or Flake test
Some portion of a jelly is taken in a large spoon or wooden ladle and cooled slightly. When dropped, if it falls in the form of flake or sheet, the end point is reached. If the jelly drips like syrup, it is required to further concentrate.
18.2.6.5 Weighing
The boiling pan is weighed before and after putting the fruit extract and sugar in it. The weight of finished jelly should be 1.5 times the weight of sugar used. Industry uses specific gravity method, which gives a reliable indication of the point of readiness.
18.2.7 Storage of jam
The surface of jam is susceptible to mold growth; yeast cannot grow or thrive. There is risk of mold development and fermentation, with alteration in the taste. Permitted preservatives may be used at levels sufficient to inhibit the growth of yeast and molds.
Jam should be stored in a fairly cool place or else some moisture evaporates resulting in surface graining and shrinkage of jam. It should be stored in a place having RH of ~ 80%.
18.3 Fruit Jelly
As per FSSA, Fruit Jelly means the product prepared by boiling fruit juice or fruit(s) of sound quality, with or without water, expressing and straining the juice, adding nutritive sweeteners, and concentrating to such a consistency that gelatinization takes place on cooling. The product shall not be syrupy, sticky or gummy and shall be clear, sparkling and transparent.
The specific requirements are as shown below:
Total soluble solids (m/m) - Min. 65.0 %
The product shall be manufactured from minimum 45.0%, by weight, of original prepared fruit, exclusive of any added sugar or optional ingredients of finished product.
18.3.1 Manufacture of jelly
Fig. 18.2 Flow chart for preparation of jelly
18.3.2 Defects in jelly
18.3.2.1 Crystals in Jelly
Sugar crystallization may result from:
Crystals may sometimes be found in jelly because during the boiling, syrup spatters on the side of the pan and dries up. In subsequent pouring of the finished product, these crystals (act as seed material) are carried into the glasses of jelly.
18.3.2.2 Cloudy jelly
Usually occurs with the red juices. It is caused by imperfect straining. Restraining of juice without pressure brings a lower yield, but ensures a clear product.
18.3.2.3 Failure to gel
a) Causative factors
Improper balance of pectin, acid, sugar and mineral salts, which may come about in several ways:
18.3.2.4 Tough Jelly
The jelly becomes tough or stringy when too little sugar is used for the quantity of fruit juice used or when boiling is continued after the jellying point has been reached.
18.4 Marmalade
As per FSSA, Marmalade means a product prepared by boiling sound fruits with peel, pulp and juice, with or without water, added nutritive sweeteners and concentrating to such a consistency that gelatinization takes place on cooling of the product. It shall not be syrupy, sticky or gummy and shall be clear and transparent. The photograph of Marmalade is furnished in Figure 18.3.
Fig. 18.3 Photograph of packaged marmalade
The specific requirements are as follows:
The container shall be well filled with the product and shall occupy not less than 90% of the net weight of the container, when packed in the rigid containers.
Lesson 18
JAM, JELLY AND MARMALADE
In previous lesson (No.17), the role played by several functional ingredients in preparation of sugar preserved foods like Jam, Jelly and Marmalade were discussed. In this lesson the mode of preparation of these products and means to prevent any defect in such products will be taken into account.
18.2 Fruit Jam/Fruit Cheese
As per FSSA, Jam means the product prepared from sound, ripe, fresh, dehydrated, frozen or previously packed fruits including fruit juices, fruit pulp, fruit juice concentrate or dry fruit by boiling its pieces or pulp or puree with nutritive sweeteners namely sugar, dextrose, invert sugar or liquid glucose to a suitable consistency. It may also contain fruit pieces and any other ingredients suitable to the products. It may be prepared from any of the suitable fruits, singly or in combination. It shall have the flavour of the original fruit(s) and shall be free from burnt or objectionable flavours and crystallization.
The specific requirements for Jam are as follows:
Total soluble solids (m/m) - Min. 65.0 %
The product shall be manufactured from minimum 45.0% by weight, of original prepared, fruit, exclusive of any added sugar or optional ingredients of finished product, except for Strawberry or Raspberry fruit, where it shall contain minimum 25.0% fruit.
As per FSSA, Fruit cheese means the product prepared from pulp/puree of sound, ripe fruit (s), whether fresh, frozen or previously preserved or dry fruits, by cooking with salt, nutritive sweeteners to attain a thick consistency so that it sets on cooling. The fruit cheese shall be neither too soft nor too hard to chew. It may be prepared from any of the suitable fruits, singly or in combination. It shall have the flavour of the original fruit(s) and shall be free from burnt of objectionable flavours and crystallization.
The specific requirements of Fruit cheese are the same as specified for Fruit Jam.
18.2.1 Salient characteristics of jam
The amount of pectin in the gel is quite small (< 1.0% of the weight of jam); sugar content is very high (60-70%). Of the remainder, the bulk is water with a small amount of fibrous matter and seeds.
For a chunky texture, some pieces of fruit are added about 5 minutes before the cooking is finished. If a stiffer or sweeter jam is desired, more thickener or pectin, honey or sugar may be added.
18.2.2 Fruit or fruit combinations
Some fruits such as lemons and bitter oranges are rich in both acid and pectin and can be easily made into jam.
Some popular combinations include: pineapple and paw paw, orange and banana, apple and plum.
18.2.3 Sugar
55 parts of sugar is required for every 45 parts of fruit. With excess sugar, the jam becomes gummy and sticky.
The finished jam should have 30-50% invert sugar / glucose to avoid crystallization of cane sugar during storage.
18.2.4 Acid
Acidity can be supplemented by use of citric, tartaric or malic acid. The pH influences inversion of sugar and setting of the jam.
For pectin jam, pH of 3.3 gives a good set. For Apple and Plum jam, the pH range of 3.2-3.5 is desirable; optimum being 3.35.
18.2.5 Preparation of jam
The process for preparing Fruit Jam is depicted in Fig. 18.1.
Fig. 18.1 Flow chart for preparation of jam
18.2.6 Judging the end-point or point at which boiling is stopped
18.2.6.1 Determining the boiling point with thermometer
Thermometers or thermocouples are used to indicate the temperature which should be approximately the boiling point of a 65% sugar solution (103.9-105°C), when the process is complete. A 65% solids boils at 104.8°C at sea level. It should be 8-9°C higher than the boiling point of water at that place.
18.2.6.2 Hydrometers
They help in determining the specific gravity of material.
18.2.6.3 Refractometer
We can determine the percentage solids i.e. TSS read directly on scale. Use Abe or Zeiss type refractometers and for dark colored jams/jelly, use projection type refractometer.
18.2.6.4 Sheeting or ladle test
a) Cold plate test
A drop of boiling liquid from the pan is placed on a plate and allowed to cool. If the jelly is about to set, it will crinkle when pushed with a finger.
b) Sheet or Flake test
Some portion of a jelly is taken in a large spoon or wooden ladle and cooled slightly. When dropped, if it falls in the form of flake or sheet, the end point is reached. If the jelly drips like syrup, it is required to further concentrate.
18.2.6.5 Weighing
The boiling pan is weighed before and after putting the fruit extract and sugar in it. The weight of finished jelly should be 1.5 times the weight of sugar used. Industry uses specific gravity method, which gives a reliable indication of the point of readiness.
18.2.7 Storage of jam
The surface of jam is susceptible to mold growth; yeast cannot grow or thrive. There is risk of mold development and fermentation, with alteration in the taste. Permitted preservatives may be used at levels sufficient to inhibit the growth of yeast and molds.
Jam should be stored in a fairly cool place or else some moisture evaporates resulting in surface graining and shrinkage of jam. It should be stored in a place having RH of ~ 80%.
18.3 Fruit Jelly
As per FSSA, Fruit Jelly means the product prepared by boiling fruit juice or fruit(s) of sound quality, with or without water, expressing and straining the juice, adding nutritive sweeteners, and concentrating to such a consistency that gelatinization takes place on cooling. The product shall not be syrupy, sticky or gummy and shall be clear, sparkling and transparent.
The specific requirements are as shown below:
Total soluble solids (m/m) - Min. 65.0 %
The product shall be manufactured from minimum 45.0%, by weight, of original prepared fruit, exclusive of any added sugar or optional ingredients of finished product.
18.3.1 Manufacture of jelly
Fig. 18.2 Flow chart for preparation of jelly
18.3.2.1 Crystals in Jelly
Sugar crystallization may result from:
(a) Too much sugar
(b) Too little acid
(c) Overcooking of jelly
(d) Too long a delay in sealing the container of jelly.
(b) Too little acid
(c) Overcooking of jelly
(d) Too long a delay in sealing the container of jelly.
Crystals may sometimes be found in jelly because during the boiling, syrup spatters on the side of the pan and dries up. In subsequent pouring of the finished product, these crystals (act as seed material) are carried into the glasses of jelly.
18.3.2.2 Cloudy jelly
Usually occurs with the red juices. It is caused by imperfect straining. Restraining of juice without pressure brings a lower yield, but ensures a clear product.
18.3.2.3 Failure to gel
a) Causative factors
Improper balance of pectin, acid, sugar and mineral salts, which may come about in several ways:
- Fruit used may lack sufficient pectin or acid or both
- Overcooking may destroy so much pectin that a gummy mass is formed
- Undercooking, due to insufficient concentration
- Too much water used for extraction of juice, so that the proportion of sugar is too great for the pectin and the long time required for evaporation may destroy some of the pectin.
18.3.2.4 Tough Jelly
The jelly becomes tough or stringy when too little sugar is used for the quantity of fruit juice used or when boiling is continued after the jellying point has been reached.
18.4 Marmalade
As per FSSA, Marmalade means a product prepared by boiling sound fruits with peel, pulp and juice, with or without water, added nutritive sweeteners and concentrating to such a consistency that gelatinization takes place on cooling of the product. It shall not be syrupy, sticky or gummy and shall be clear and transparent. The photograph of Marmalade is furnished in Figure 18.3.
Fig. 18.3 Photograph of packaged marmalade
The specific requirements are as follows:
(i) Total soluble solids (m/m) - Min. 65.0 %
(ii) Fruit content except peel (m/m) - Min. 45.0 %
(iii) Peel in suspension - Min. 5.0 %
(ii) Fruit content except peel (m/m) - Min. 45.0 %
(iii) Peel in suspension - Min. 5.0 %
The container shall be well filled with the product and shall occupy not less than 90% of the net weight of the container, when packed in the rigid containers.
Last modified: Thursday, 1 November 2012, 7:19 AM