GELATO AND COMPOSITION

 Introduction

Examples of Gelato

 Manufacture are fully as important as the composition in determining the best ice cream for a locality. The future will continue to bring many changes in the composition and form of frozen dairy desserts as manufacturers try to gain market share and increase profitability. As an example, frozen desserts can be used to carry health-promoting constituents—vitamins and minerals or fiber or nutraceuticals (minor constituents of foods that have been shown to have health-promoting effect). The favorable effects of conjugated linoleic acid (CLA), omega-3 fatty acids, dietary fiber, and antioxidants on human health may prompt the increase of their concentrations in frozen desserts. Also, genetically engineered plants that produce flavorings are already being grown; more will be developed. They will enable more profitable production of better flavorings.Gelato is the Italian version of ice cream and it differs from American ice cream in a few ways.Its differsfrom ice cream  in another respect, which has to do with how much sugar it contains with gelato having perhaps ten percent higher sugar content. Gelato is more creamy and dense than ice cream and is often lower in calories, fat and sugar.Depending on the on the type and portion size you choose,gelato may not always be a healthier option than ice cream.

Vanilla Ice Cream
            

    

     Ice cream is comprised of a mixture of air, water, milk fat or nondairy fats, milk solids-not-fat (MSNF), sweeteners, stabilizers, emulsifiers,and flavors. The functions and limitations of each of these components are described in 1.1 An ice cream mix is the unfrozen blend of the ingredients used to supply these constituents,except the air and flavoring materials.Mix formulations are defined as percentages of the constituents, e.g., percentage of fat, MSNF, sugars, stabilizers, and emulsifiers (the sum of which equals the total solids).These components can be combined in varying proportions within acceptable ranges.Furthermore, a wide variety of ingredients can be chosen to supply these constituents, and both the percentage and the source of a constituent can affect quality of a mix. For example, milk fat and MSNF can be derived from multiple combinations of cream, butter, and fresh, concentrated or dry whole milk or skim milk. Ingredients to supply the mix components.The composition of ice cream varies in different countries and in different localities and markets within each country.The best ice cream composition for a manufacturer to produce is often difficult to establish. Consideration must be given to legal requirements, quality of product desired, raw materials available, plant equipment and processes, trade demands, competition, and cost. These considerations will affect the choice of a minimum, average, or high component concentration and the selection of ingredients.Some firms may choose to manufacture products from only one mix formulation while others may cater to economy, regular, and premium markets with several formulations.The milk fat content of ice cream may vary from less than 1 to 20%, depending upon such factors as regulations, expected characteristics, price, and competition.Within the ice cream category, usually at >8–10% fat, as the fat content of ice cream is increased, the MSNF must be decreased so as to avoid high viscosity and the potential for “sandiness” (i.e., the crystallization of milk sugar or lactose in the finished ice cream). Local preferences, qualities of ingredients, and the technique of Composition and Formulations 1 Composition and Formulations 1.1 Functions and limitations of selected ice cream constituents

   

  Constituent Functions Limitations 1.1

     

   Milk fat 

• Increases richness of flavor
• Lubricates and insulates the mouth
• Relatively high cost and smoothness of texture
• Hinders whipping
• May limit consumption due to high calories and satiating effect

   Nondairy fats 

•  Provides good structure and texture at lower cost than milk fat, if    appropriate solid fat content
•  Contributes little to flavor and may impart of off- flavor
•  May contribute to greasy texture

  Milk solids-not-fat;milk/whey protein

• Concentrates
• Improves body and texture (protein) through emulsification and water holding capacity
• High amount may cause cooked or salty flavor
• Potential for sandiness (lactose crystallization) at high
• Promotes development of concentration over run     

  Whey solids 

• Less expensive than conventional sources of MSNF
• High amount of lactose causes freezing point depression
• Potential for sandiness greater than for conventional sources of MSNF
• Sugar Lowers freezing point 
• Excess sweetness possible
• Imparts sweetness to the ice cream
• Lower hardening temperature needed
• Ice cream is softer,affecting scooping and the potential for greater recrystallization
• Improves flavor/texture                                                                                                                                                                                   

 

Corn syrup solids  

• Lower cost than sugar Impart off flavor and chewy texture
• Improve body and texture when overused
• Increase stability of the ice cream
• Stabilizers Enhance smooth texture Excess chewiness may occur
• Provide body Increase melt resistance
• Enhance shelf life

Egg yolk solids 

• Improve whipping ability Foamy melted product
• Impart custard flavor Egg flavor may be undesirable

Emulsifiers 

• Promote fat destabilization,leading to dryness,smoothness, and good melting properties
• Increase potential for churning of fat
• Total solids Smoother texture Heavy, soggy, or sticky body
• (TS) Firmer body Reduce coldness
• Higher nutrient content
• Lessen excess coldness

Flavoring 

• Increases acceptability intensities and harshness may be unacceptable
• Coloring Improves attractiveness artificial shades
• Aids flavor identification allergic reactions of some people to yellow 
• Some consumers dislike added colors

Process of Gelato

The Base

Gelato is made with a milk base also called “white base.” which provides body and texture. White base is made from milk, cream, vegetable fats, several sugars and emulsifier-stabilizers.  The solids of the base are mixed with milk or water and pasteurized.  The solids are about 35% of the mix.  The rest is water.

Powdered or Fresh Milk Base 

Powdered Milk base, which contains New Zealand powdered whole milk.  Just add boiling water and cream. We also have a  fresh milk base (Fresh Milk Base) that contains no milk, cream or sugar.It is possible that in your country fresh milk is cheap.The advantage of the powdered milk is that it is easy for workers to use–you just mix it with boiling water.  No pasteurizer is needed.  Also, the powdered milk base does not require refrigeration as does fresh milk and the consistency of the product is always the same, which the customers like.

The fresh milk base is preferred if fresh milk is cheap in your area.  You also save on freight, duty and can sweeten as you wish.  You will need a double boiler, pasteurizer or a combo machine that heats on top and makes ice cream underneath.

Pasteurization

When pasteurization was invented in the 19th century its primary intent was to destroy harmful bacteria in various liquids. Pasteur was actually motivated to develop this process to stop the deterioration of wine caused by bacteria.

Today  smaller manufacturers usually buy pasteurized, homogenized milk.  Therefore the legal requirement to pasteurize a second time falls into a gray area not covered by law.  For the small operator, particularly those who use commercial packaged bases and sell their ice cream quickly there is relatively little risk of bacterial contamination.The reason is that commercial manufacturers use ingredients such as powdered milk, sugars and whey, which are virtually sterile when produced and then they are mechanically bagged.Commercial base-makers mix these materials mechanically and nothing is actually touched by people.

Today the pasteurizer plays a role in gelato manufacture quite different from its original intent.Today the main job of the pasteurizer (when making ice cream mix) is to combine it thoroughly, entrap maximum air and age the mix so that long chains of ingredients can be formed. This makes the mix more creamy.  And of course it also pasteurizes!Although Louis Pasteur discovered the benefits of pasteurization in the 19th century, many otherwise knowledgeable people often misstate the temperature requirements to achieve pasteurization, which are different for various liquids.The most commonly used ice cream pasteurization process heats ice cream mix to at least 80¼C/175¼F for 15­25 seconds or from 90¼C/194¼F for 3 seconds.This is called Hi-Temperature, Short Time Pasteurization (HTST).Another pasteurization approach, called “Batch Pasteurization” heats to 69C for 30 minutes.  This is often used for cream and custard mixes to better preserve the aroma.Pasteurization greatly reduces the bacteria and mold count in the mix.  But pasteurization does not sterilize. Some bacteria and mold spores survive, which is why pasteurized milk eventually spoils even if it is not opened.

Aging

Most modern batch pasteurizers also age. This means that after they heat to 83¼C, they chill to +4¼C, allowing the components of the mix to bond.  This makes the ice cream creamier.  A high-speed beater drives air into the mix during chilling and this improves lightness and texture.

Powdered milk base is instantly pasteurized when poured into boiling water.  If fresh milk is used it is heated in a pasteurizer or double boiler.  The resulting thick liquid is called–what a surprise–the mix. After mixing, the mix is chilled, then poured into a batch freezer which turns the mix into gelato in 8-18 minutes.

Batch Freezing

The batch freezer is a simple machine consisting of a compressor, which drives heat out of the refrigerant gas, turning it into a liquid.  The gas is then delivered to the space between the double walled freezing chamber (drum), where it expands and gets very cold.Inside the drum is a beater assembly called the “dasher.”  The blades of the dasher are turned by a huge motor. The motor has to be huge because more and more force is required to turn the dasher as the ice cream gets hard.The dasher scrapes the ice cream off the chamber walls and tumbles it, forcing air into the mix.  As the mix hardens it expands.  The expansion is partially caused by the freezing process and partially by the introduction of air.  If one liter of mix becomes two liters of ice cream it contains 50% air but in the trade we say “100% overrun.” You can expect 60% overrun from our products but most gelato has 35% overrun.Overrun is important for two reasons. Without it the mix would freeze as hard as ice and be inedible.  Also, the air increases the bulk, so a scoop can be made much larger without increasing the weight.  In other words, you get to sell air for the price of ice cream.  I LOVE this business!Ice cream is made by removing heat from the mix.  The heat has to go somewhere.  In air cooled machines the hot refrigerant gas passes thru a radiator cooled with blowers, just like the radiator of a car. But air cooled machines have to operate in a 24¼C environment so air conditioning is usually required.In a water cooled machine chilled water circulates around the hot gas tubes a process called “heat exchange.” Water cooling is about 45% more efficient than air cooling so a batch is made much faster. But water cooling usually requires chilled cooling water.  So, a chiller is often required if the city water is not cold.

Flavors

Ice cream base is kind of bland and uninteresting.  It is the flavorings that make ice cream exciting.Flavor: Some flavors such as chocolate are included in the base, but most are added to the mix after it is running in the batch freezer.  Those flavors are called “pastes” and are almost as thick as jelly.  They can be made from fruit, sugars, natural flavors and aromas.  They can also be made from nuts ground into paste.  Some are extracts such as vanilla, almond or coffee.  Flavor can be added to the mix in the batch freezer or swirled in as the base comes out of the machine.  Some flavors can be used in all frozen desserts and some are specialized.

Blast Freezing

Blast Freezing: Gelato is extruded from a batch freezer at about -6°C. At this temperature considerable water remains unfrozen, but it is bonded to the other ingredients by the emulsifier.Without rapid freezing the ingredients would separate.To preven.It must be frozen as quickly as possible.  This is the reason the finished product is chilled in a blast freezer at temperatures for -28 to -60°C. Sometimes, because of power failures, gelato melts.It should never be re-frozen but it can be reprocessed by running it thru the batch freezing process.

Types of Ice Cream

The first step in choosing an ice cream machine is deciding which type of ice cream to serve. The following chart describes the most common frozen desserts.

       Ice cream type                                            Description                                          

•  Ice cream      A sweet, creamy, semisolid frozen treat made   sweetened and flavored cream (also known as butterfat)                                                              

• Frozen custard  Ice cream with egg yolks added                                                                                                                                                                                                   
• Soft serve   Lower-fat ice cream with a high air content                                                                                                                                                    
• Ice milk (iced milk) Lower-fat frozen dessert made of milk instead of cream; sometimes marketed as "low-fat ice cream"                                                                                                                                 
  
• Frozen yogurt    Lower-fat frozen dessert made of yogurt instead of ice cream                                                                                                                                                                                                                                                    
• Gelato   Ultra-creamy, rich, lower-fat ice milk containing very   little air                                                                                                                                                                                                                           
• Sherbet (sherbert)  Lower-fat frozen dessert with fruit flavors                                                                                                 

• Sorbet  Frozen dessert made of water and fruit, with no dairy product added and less fat content                                                                                                                                                                                     
•  Italian ice (water ice)  A creamy, fruit-flavored, and typically dairy-free  frozen treat,like sorbet.                                                                                                                                                                                                  
• Milkshake (frappé)A whipped or blended beverage made of milk and ice cream    

H.D. Goff and R.W. Hartel, Ice Cream, DOI 10.1007/978-1-4614-6096-1_2, 19
© Springer Science+Business Media New York 2013