«HARD PANNING Hard pan coated confections are interesting products since they are, like all panned goods, identified by a process and not by the candy ...»
Hard pan coated confections are interesting products since they are, like all panned
goods, identified by a process and not by the candy type, such as hard candy, cremes,
fondants and caramel. Hard panned confections are divided into two types:
1. Hard sugar coated items like jaw breakers, coated chewing
gum, Jordan Almonds and chocolate lintels.
2. Hot panned items like Boston Baked Beans and French Burnt peanuts.
The variety of products produced using these methods is as large as the imagination and new products are constantly being added. Panning is also used to deliver isolated flavor sensations, such as high-acid sour chewing gum balls.
The first recorded panning operation comes from manuscripts around the 17th century. A French confectioner produced the first hard shell coated almonds by adding several coatings of a sugar syrup to almonds with each layer being allowed to dry before the addition of the next layer. A Jordan Almond type of product was produced. This was accomplished by putting the almonds in a shallow flat bottom pan with the sugar syrups added to the pan while the pan was shaken in a manner to keep the almonds from sticking together and to become evenly coated. The pan was shaken ove r a flame or in direct sunlight to evaporate the water from the sugar syrup. That left the almonds with a thin layer of sugar crystals. The continual movement of the pan rounded off the edges of the sugar crystals.
In the mid eighteen hundreds, another French confectioner got tired of shaking the pan so he attached a spindle to the bottom of the pan. The spindle was rotated between the hands allowing the coating to be distributed more quickly around the almonds with a more even buildup. It was not long before someone figured out that the spindle could be turned by a treadle similar to the early sewing machines to rotate the pan. This allowed the pan to increase in size and eventually the pan was tilted on its side and was given the typical shapes that are still being used today. There have been many different sizes and shapes and baffles in pans, but typically they are round or pear shaped and set at a definite angle. The basic concept has not changed since the seventeenth century.
Panning provided a decorative means of coating centers as well as sealing and prolonging the life of the centers. These aspects made the process of particular interest to the apothecary in the early beginnings of the modern pharmaceutical industry. Lozenges could be color coated for easy identification and the hard sugar shell provided protection 2 to the center.
Originally pans were constructed of copper. Copper was extremely malleable and could easily be formed into the various shapes required. Stainless steel has replaced copper in newer pan construction. Stainless steel is more durable and is non-reactive with materials which have problems with copper, such as lauric fat compound coatings. However, copper pans are still in common use.
The number of products which are pan coated has continued to grow. Sugar panning is now virtually the sole property of the confectioner, because the pharmaceutical industry has gone over to film coating, which provides more functionality and vastly superior shelf life.
Briefly stated, the pan-coating of candies is achieved by the tumbling of centers in a revolving pan, and the application of coating material in liquid form. The tumbling, and rubbing of the individual pieces distributes the coating material, which is made to form a firm coat by either drying or cooling. The process is variously known as Panning, Pan Coating, Drageeing, Volvoing or Comfit-making. It is a method of making candy which, in most companies, calls for a high degree of skill, experience and judgment. In recent years equipment has been designed which can be programmed to closely control the process, and eliminate the need for skilled operators.
Experience in panning demonstrates that all five of the human senses are used: the appearance of the product visually, the sound of the product tumbling, the smell of the centers and coating during the process, the feel of the product as it dries, and the taste, or tactile smoothness, of the coating on the tongue. Each of these has its place in evaluating the progress of the panning operation.
SUGAR PANNINGA. The Function of Ingredients
Corn Syrup. Corn Syrup is used to modify the characteristics of the sugar syrup to provide flexibility and strength during the early stages of coating (engrossing). Since corn syrup retards crystallization, it is not desirable in the smoothing and finishing steps in hard sugar panning.
Film Formers. Film formers are used to coat the center and provide a barrier to the transmission of oils from the center to the coat, and moisture from the coating operation to the center. Additionally, film formers provide a surface to which the sugar coat can adhere. This is absolutely essential, otherwise good panning cannot take place if the shell
is easily parted from the center. Traditional film formers are:
gum arabic - once the exclusive film former in panning, gum arabic, while still very important, is being replaced by other materials. This is due both to the cost of gum arabic and the quality. Historically, gum arabic was a relatively inexpensive material. Clean syrups of high molecular weight gum arabic could be obtained by processing clear amber sorts. The Arab-Israeli wars of the mid-60s and the shutting down of the Suez Canal isolated the users from the source of gum arabic, and the world price of gum arabic soared from 18 cents a pound for clear sorts to well over $2 lb. Powdered gum arabic of questionable quality, often containing substitute materials, found its way into the market place. These materials were of inferior quality and simply did not perform in the same manner as the pure high molecular weight material. Today most gum arabic comes in the form of spray dried. The film forming strength of this material is not up to the original standards. Solutions made from sorts retain most of the original properties. One of those properties is a gel set that is strengthened by calcium. Spray dried gum arabic is not calcium active. The problem is that even this material is often much better than the next alternative.
dextrins - modified dextrins, such as tapioca dextrin, have been successfully used in many applications, providing an adequate barrier for oils and moisture at a lower cost than gum arabic. Direct substitution of dextrins for gum arabic does not always perform satisfactorily in all applications, so some experimentation is necessary.
gelatin - gelatin can be used as a film former, however it is not as strong as a moisture barrier, by itself, as gum arabic. Gelatin is often used in conjunction with gum arabic to form a very strong seal, since gum arabic and gelatin react, crosslinking with each other to form a very tough film.
Polishing Agents - polishing agents are for the most part waxes.
Carnauba and candelilla wax: These natural waxes can be applied as fine powders. Prepared suspensions and solutions are also used.
Shellac: shellac is the principle wax in confectioners glaze. Shellac is a natural wax extracted from shellac beetles and is dissolved in alcohol to prepare confectioners glaze. Because it is an animal extract, it has a shelf life and is best stored at or below 70° F. for not more than six months.
Bee's wax: because of cost, bee's wax is used in fewer applications today. It is often used to line polishing pans B. Properties of Syrups Coating ability. Any syrup used as a coating must have the ability to uniformly coat the centers. Failure to coat uniformly will result in rough, uneven coating. Therefore, the viscosity of the syrup is critical and is a function of the syrup composition and the syrup temperature.
Syrup composition. In hard sugar panning three general types of syrup are used:
Sealing or gumming, engrossing, and smoothing. Each is different in composition to achieve the desired end result.
Sealing or gumming syrups: Depending on the nature of the center to be coated, a seal or gumming coat is applied to the center. In the case of oil-containing centers such as nuts or coffee beans, a seal coat is needed to provide a base for the adherence of subsequent sugar coats. The same is true of chocolate centers. Sealing or gumming syrups contain a film former such as gum arabic or dextrin which form the seal. Dry sugar or cocoa powder may be initially added to oily centers, followed by the seal coats.
In order to obtain the proper coating of a seal coat, concentration is usually limited to 10 - 30% film former.
Engrossing syrups: The purpose of the engrossing syrup is to add weight to the product. Engrossing syrups are higher solids than smoothing syrups and may contain some corn syrup (1-5%) to provide strength to the coating. This is particularly important when using centers with sharp edges. Sharp edges coat slowly and tend to chip. Chipping leads to debris in the pan and uneven coating.
The higher solids crystallize faster, resulting in only a moderately smooth coat.
Smoothing syrups: Smoothing syrups are lower in solids and are generally stable at room temperature (less than 67% solids). The proper solids result in good coating, with the formation of very fine crystals. Towards the end of the coating process, the concentration is often lowered further (55% -60% solids) to produce a super smooth finish.
Syrup temperature. The temperature of the syrups is often very critical. Sealing or gumming syrups must be added at or near room temperature. This is most critical in the case of chocolate or fat centers. A warm seal coat may melt the center making it impossible to coat.
Engrossing syrups can be added a little warmer because of their higher solids content, but they should never exceed the bed temperature, since they can dissolve previous coats.
Smoothing Syrups, which are stable at room temperature, should be added at room temperature. Elevated syrup temperatures will dissolve previous coats, resulting in a rough uneven coat, defeating the purpose of the smooth coat.
Adhesive properties of syrups. When a syrup is applied to the pan, it first distributes over the surface area of the product bed. The syrup also coats the pan, particularly if there is an excess of syrup. As the syrup is distributed over the large surface area of the product bed, it begins to dry and becomes sticky or adhesive.
Charging: When the charge is applied, maximum wetness is achieved and thorough distribution of the syrup must take place, often aided by manual mixing of the product bed.
Maximum adhesiveness: As the charge dries, the surface increases in adhesiveness until it reaches maximum, and then falls off dramatically as final drying begins. It is during the approach to maximum adhesiveness that dusting powders are added, since that is the time when they will best stick to the product. If added too soon, the powder will imbed in the syrup and the syrup will flow around the powder, rewetting the surface, a process called "sweat-back". Addition of more powder results in a soft coat. In the case of soft coating, such as with jelly beans, this is exactly how the coat is achieved.
The point of maximum adhesiveness is often the point when the inexperienced pan coater panics. If too much syrup has been added and reaching the maximum point is slowed, the product often sticks to the pan. One reaction is to scrape the product off the pan. This results in picking up coating off the pan and an uneven coat. The best remedy is the addition of a small amount of fine crystalline sugar, (baker's special), and allowing the product to release from the pan on its own. After the product has thoroughly dried, the charge size is then adjusted downward.
Syrup Crystallization and drying: Included in the appended reprints is an article by Dr Richard Hartel titled "Crystallization and Drying During Hard Panning" Feburary, 1995, Manufacturing Confectioner. The article is included and used with Dr. Hartel's permission.
"....the two mechanisms occurring during panning (i.e., crystallization and drying) result in different trends for concentration. That is, crystallation causes the concentration of the syrup phase to decrease while drying causes the concentration to increase. The rates at which these processes compete determines the overall quality of the panned piece."
There are a number of ways to address the science of hard sugar panning. The emphasis on how to approach this subject usually reflects the individual author’s discipline. The Artisan tends to emphasize the importance of drying time and the manipulation of the product. The Chemist tends to focus on the dynamics of crystallization. The Engineer is mainly concerned with process design. All are correct approaches and each is important to the objective of successful panning.
As you have heard from previous presentations there are two major areas of concern; Air flow and Crystallization. Both of these work together to accomplish the desired goal of Drying.
A. Air Flow: Air flow has already been covered but let us review the key points in relationship to the process of panning: the volume of air, how the air is directed into the product, the temperature of the air, and the relative humidity of the air.
Volume of air: The important criteria for air volume is that it be sufficient to:
1. Maintain the product bed temperature.
2. Be sufficient to remove the moisture from the pan.
3. Maintain the desired humidity gradient between the product and the air in the pan.
Direction of the air: In order to be effective, the air must contact the product bed. In pans where there is only surface contact with the product, the process is slower and less efficient than in pans where the air flow is through the product bed.
Air flow through the product (Figure 1), provides uniform surface conditions throughout the product bed.