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Palm-based Non-dairy Ice Cream

Palm-basedNon-dairy Ice Cream

ICE CREAM is produced by freezing a mix of several ingredients, whichusually consist of milk products, sugar, corn syrup and flavours.Additionally, egg-based ingredients, food stabilisers, emulsifiers andcolouring may be added. Apart from these, water and air, incorporatedduring the processing, are major constituents.

The composition of ice cream, to a large extent, is governed by localfood legislations. In the United States of America (USA), for example,the average composition (weight %) is 38% total solids of which 11%are milk solids, 12% milk fat, 15% sugar and 0.3% stabilisers andemulsifiers. A number of ice cream-related products are also available.These include sherbets containing fruit juices and sugars, ice milkcontaining less milk and milk solids than ice cream, and water ices,which are similar to sherbets but without dairy-based products.

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Palm Oil/Palm Kernel Oil Applications

Manufacturing ProcessIngredientsThe ingredients are first selected based on a desired recipe and actual amounts requiredare calculated and weighed. This is called the ice cream mix. A typical palm-basednon-dairy ice cream mix is provided in Table 1. Typically, the milk fat component isreplaced with a palm fat formulation whose characteristics are described in Table 2.

Palm-based Non-dairy IceCreamNon-dairy ice cream is also a commonfeature in many countries and in the USAsuch products are termed as ‘mellorine’.These are frozen products, which differfrom ice cream in such a way that themilk fat is replaced with suitablevegetable fats. Palm-based non-dairy icecream is formulated using palm-basedfats to replace milk fat. These palm-basedfats are functionally and nutritionallydesired and have become a commoningredient in non-dairy ice creamproducts in many parts of the world.

Advantages of Using Palm-based Non-dairy Ice CreamA fat base with sharp melting propertiesat body temperature is highly desirableto ensure good organolepticcharacteristics. Palm-based fats can beformulated with less than 5% solids atbody temperature.

For persons who are lactose intolerant,palm-based non-dairy ice creamformulated with reduced milk fats andmilk solids can be a desirable product.

Milk fat is an expensive ingredient inmany developing countries and palm-based fats provide an inexpensive, yethigh quality, alternative.

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Palm-based Non-dairy Ice Cream

Processing Steps

1. BlendingThe weighed ingredients are blended togetherto produce the ice cream mix. High-speedblenders are desirable to ensure a homogenousmix.

2. PasteurisationThis is designed to destroy any pathogenicbacteria that may be inherent in the mix. Italso reduces the spoilage organisms andhydrates proteins and stabilisers in the mix.Either a batch or continuous pasteurisationmethod may be used. During pasteurisation,the mix is heated in a vat to about 72oC andheld for 30 minutes.

3. HomogenisationFollowing pasteurisation the mix is rapidlyhomogenised under high pressure at thepasteurisation temperature and passedthrough a plate of heat exchanger to cool themix rapidly to 4oC. This results in a fatemulsion. A two-stage homogenisation ispreferred to reduce clumping of the fat. Thisoperation reduces the fat globule size, increasessurface area and resistance to melting of themix. As a result, a thinner and more rapidlywhipped mix is obtained which in turnimproves smoothness of the final product,palatability and meltdown properties.

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Palm Oil/Palm Kernel Oil Applications

4. AgeingThe homogenised mix is aged for a minimumof four hours or preferably overnight. Thiscauses the fat globules to slowly crystallise andcoalesce and for the proteins andpolysaccharides to fully hydrate. A refrigeratedtank maintained at or below 5oC is used forageing. At this stage, it is important to ensurethat the mix is not frozen.

6. PackagingThe ice cream is then filled into desiredcontainers and placed in a blast freezer (-30oCto -40oC) where the remainder of the water isfrozen. When stored at below -25oC, the icecream thus produced is indefinitely stable. Theshelf life will however be dependent upon thestorage temperature, which affects the rate ofcrystal growth in ice cream.

5. Freezing and HardeningThis aged mix is next drawn into a barrel freezer,which is a scraped-surface tubular heatexchanger. The mix is pumped through thefreezer and rapidly drawn at the other endresulting in about 50% of its water contentfreezing. Rotating blades inside the barrel scrapethe ice thus formed while simultaneously whipthe mixture to incorporate air, which gives theproduct its characteristic lightness. At this stage,fruits, nuts and other desired ingredients mayalso be added.

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Palm-based Non-dairy Ice Cream

Table 1. Palm-based Non-dairy Ice Cream Formulation

Ingredient %

Fat (palm oil or its products) 11-12

Skim milk powder 11-12.5

Sugar 12-16

Glucose syrup 5

Emulsifier & stabiliser 0.02-0.5

Flavour 0.1

Water 60-64

Table 2. Comparison of Palm-based Ice Cream with Dairy Ice Cream

Dairy Palm-basedice cream ice cream

Apparent viscosity (cp) 30.42 31.82Overrun (%) 100 100

Melting propertiesMinute ml10 - -20 - -30 19.0 20.635 26.0 27.040 29.0 3545 32.7 38

Firmness penetration depthMinute mm0 121 1035 130 14110 133 15920 195 190

Fatty Acid Content And Slip Melting Point

RBD = Refined, Bleached, DeodorisedPO = Palm OilPKO = Palm Kernel Oil

HPKOo = Hydrogenated Palm Kernel OleinSMP = Slip melting point

FATTY ACIDS 6:0 8:0 10:0 12:0 14:0 16:0 18:0 18:1 18:2 18:3 20:0 SMP

Palm Oil Products

RBD PO - - - 0.3 1.1 43.7 4.5 39.2 10.1 0.4 0.4 34.2

RBD PKO 0.3 4.4 3.7 48.3 15.6 7.8 2.0 15.1 2.7 - 0.2 27.3

HPKOo 0.3 4.1 3.4 43.8 14.1 8.6 25.6 - - - - 40.6

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Palm Oil/Palm Kernel Oil Applications

Process Flow Chart

Solid Fat Content of Palm Products

FAT

BLENDING

PASTEURISATION

HOMOGENISATION

COOLING

AGEING

FREEZING

FILLING

HARDENING

STORAGE

Milk SolidNon Fat

Sweetener

Emulsifier/Stabiliser

Air

Flavour/Colour