Palm-based Non-dairy Ice Cream
Palm-based Non-dairy Ice Cream
Palm-based Non-dairy Ice Cream ICE CREAM is produced by freezing a mix of several ingredients, which usually consist of milk products, sugar, corn syrup and flavours. Additionally, egg-based ingredients, food stabilisers, emulsifiers and colouring may be added. Apart from these, water and air, incorporated during the processing, are major constituents. The composition of ice cream, to a large extent, is governed by local food 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 and emulsifiers. A number of ice cream-related products are also available. These include sherbets containing fruit juices and sugars, ice milk containing less milk and milk solids than ice cream, and water ices, which are similar to sherbets but without dairy-based products.
43
Palm Oil/Palm Kernel Oil Applications
Palm-based Non-dairy Ice Cream
Advantages of Using Palmbased Non-dairy Ice Cream
Non-dairy ice cream is also a common feature in many countries and in the USA such products are termed as ‘mellorine’. These are frozen products, which differ from ice cream in such a way that the milk fat is replaced with suitable vegetable fats. Palm-based non-dairy ice cream is formulated using palm-based fats to replace milk fat. These palm-based fats are functionally and nutritionally desired and have become a common ingredient in non-dairy ice cream products in many parts of the world.
A fat base with sharp melting properties at body temperature is highly desirable to ensure good organoleptic characteristics. Palm-based fats can be formulated with less than 5% solids at body temperature. For persons who are lactose intolerant, palm-based non-dairy ice cream formulated with reduced milk fats and milk solids can be a desirable product. Milk fat is an expensive ingredient in many developing countries and palmbased fats provide an inexpensive, yet high quality, alternative.
Manufacturing Process Ingredients The ingredients are first selected based on a desired recipe and actual amounts required are calculated and weighed. This is called the ice cream mix. A typical palm-based non-dairy ice cream mix is provided in Table 1. Typically, the milk fat component is replaced with a palm fat formulation whose characteristics are described in Table 2.
44
Palm-based Non-dairy Ice Cream
Processing Steps 1. Blending The weighed ingredients are blended together to produce the ice cream mix. High-speed blenders are desirable to ensure a homogenous mix.
2. Pasteurisation This is designed to destroy any pathogenic bacteria that may be inherent in the mix. It also reduces the spoilage organisms and hydrates proteins and stabilisers in the mix. Either a batch or continuous pasteurisation method may be used. During pasteurisation, the mix is heated in a vat to about 72oC and held for 30 minutes.
3. Homogenisation Following pasteurisation the mix is rapidly homogenised under high pressure at the pasteurisation temperature and passed through a plate of heat exchanger to cool the mix rapidly to 4oC. This results in a fat emulsion. A two-stage homogenisation is preferred to reduce clumping of the fat. This operation reduces the fat globule size, increases surface area and resistance to melting of the mix. As a result, a thinner and more rapidly whipped mix is obtained which in turn improves smoothness of the final product, palatability and meltdown properties.
45
Palm Oil/Palm Kernel Oil Applications
4. Ageing The homogenised mix is aged for a minimum of four hours or preferably overnight. This causes the fat globules to slowly crystallise and coalesce and for the proteins and polysaccharides to fully hydrate. A refrigerated tank maintained at or below 5oC is used for ageing. At this stage, it is important to ensure that the mix is not frozen.
5. Freezing and Hardening This aged mix is next drawn into a barrel freezer, which is a scraped-surface tubular heat exchanger. The mix is pumped through the freezer and rapidly drawn at the other end resulting in about 50% of its water content freezing. Rotating blades inside the barrel scrape the ice thus formed while simultaneously whip the mixture to incorporate air, which gives the product its characteristic lightness. At this stage, fruits, nuts and other desired ingredients may also be added.
6. Packaging The ice cream is then filled into desired containers and placed in a blast freezer (-30oC to -40oC) where the remainder of the water is frozen. When stored at below -25oC, the ice cream thus produced is indefinitely stable. The shelf life will however be dependent upon the storage temperature, which affects the rate of crystal growth in ice cream.
46
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 ice cream Apparent viscosity (cp) Overrun (%)
30.42 100
Melting properties Minute 10 20 30 35 40 45
19.0 26.0 29.0 32.7
Firmness penetration depth Minute 0 5 10 20
121 130 133 195
Palm-based ice cream 31.82 100
ml 20.6 27.0 35 38 mm 103 141 159 190
Fatty Acid Content And 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
-
-
-
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
RBD = Refined, Bleached, Deodorised PO = Palm Oil PKO = Palm Kernel Oil
0.3
HPKOo = Hydrogenated Palm Kernel Olein SMP = Slip melting point
47
Palm Oil/Palm Kernel Oil Applications
Process Flow Chart FAT Milk Solid Non Fat
Sweetener BLENDING Emulsifier/Stabiliser PASTEURISATION HOMOGENISATION COOLING Flavour/Colour AGEING
Air
FREEZING FILLING HARDENING STORAGE
Solid Fat Content of Palm Products
48
Palm-based Non-dairy Ice Cream ICE CREAM is produced by freezing a mix of several ingredients, which usually consist of milk products, sugar, corn syrup and flavours. Additionally, egg-based ingredients, food stabilisers, emulsifiers and colouring may be added. Apart from these, water and air, incorporated during the processing, are major constituents. The composition of ice cream, to a large extent, is governed by local food 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 and emulsifiers. A number of ice cream-related products are also available. These include sherbets containing fruit juices and sugars, ice milk containing less milk and milk solids than ice cream, and water ices, which are similar to sherbets but without dairy-based products.
43
Palm Oil/Palm Kernel Oil Applications
Palm-based Non-dairy Ice Cream
Advantages of Using Palmbased Non-dairy Ice Cream
Non-dairy ice cream is also a common feature in many countries and in the USA such products are termed as ‘mellorine’. These are frozen products, which differ from ice cream in such a way that the milk fat is replaced with suitable vegetable fats. Palm-based non-dairy ice cream is formulated using palm-based fats to replace milk fat. These palm-based fats are functionally and nutritionally desired and have become a common ingredient in non-dairy ice cream products in many parts of the world.
A fat base with sharp melting properties at body temperature is highly desirable to ensure good organoleptic characteristics. Palm-based fats can be formulated with less than 5% solids at body temperature. For persons who are lactose intolerant, palm-based non-dairy ice cream formulated with reduced milk fats and milk solids can be a desirable product. Milk fat is an expensive ingredient in many developing countries and palmbased fats provide an inexpensive, yet high quality, alternative.
Manufacturing Process Ingredients The ingredients are first selected based on a desired recipe and actual amounts required are calculated and weighed. This is called the ice cream mix. A typical palm-based non-dairy ice cream mix is provided in Table 1. Typically, the milk fat component is replaced with a palm fat formulation whose characteristics are described in Table 2.
44
Palm-based Non-dairy Ice Cream
Processing Steps 1. Blending The weighed ingredients are blended together to produce the ice cream mix. High-speed blenders are desirable to ensure a homogenous mix.
2. Pasteurisation This is designed to destroy any pathogenic bacteria that may be inherent in the mix. It also reduces the spoilage organisms and hydrates proteins and stabilisers in the mix. Either a batch or continuous pasteurisation method may be used. During pasteurisation, the mix is heated in a vat to about 72oC and held for 30 minutes.
3. Homogenisation Following pasteurisation the mix is rapidly homogenised under high pressure at the pasteurisation temperature and passed through a plate of heat exchanger to cool the mix rapidly to 4oC. This results in a fat emulsion. A two-stage homogenisation is preferred to reduce clumping of the fat. This operation reduces the fat globule size, increases surface area and resistance to melting of the mix. As a result, a thinner and more rapidly whipped mix is obtained which in turn improves smoothness of the final product, palatability and meltdown properties.
45
Palm Oil/Palm Kernel Oil Applications
4. Ageing The homogenised mix is aged for a minimum of four hours or preferably overnight. This causes the fat globules to slowly crystallise and coalesce and for the proteins and polysaccharides to fully hydrate. A refrigerated tank maintained at or below 5oC is used for ageing. At this stage, it is important to ensure that the mix is not frozen.
5. Freezing and Hardening This aged mix is next drawn into a barrel freezer, which is a scraped-surface tubular heat exchanger. The mix is pumped through the freezer and rapidly drawn at the other end resulting in about 50% of its water content freezing. Rotating blades inside the barrel scrape the ice thus formed while simultaneously whip the mixture to incorporate air, which gives the product its characteristic lightness. At this stage, fruits, nuts and other desired ingredients may also be added.
6. Packaging The ice cream is then filled into desired containers and placed in a blast freezer (-30oC to -40oC) where the remainder of the water is frozen. When stored at below -25oC, the ice cream thus produced is indefinitely stable. The shelf life will however be dependent upon the storage temperature, which affects the rate of crystal growth in ice cream.
46
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 ice cream Apparent viscosity (cp) Overrun (%)
30.42 100
Melting properties Minute 10 20 30 35 40 45
19.0 26.0 29.0 32.7
Firmness penetration depth Minute 0 5 10 20
121 130 133 195
Palm-based ice cream 31.82 100
ml 20.6 27.0 35 38 mm 103 141 159 190
Fatty Acid Content And 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
-
-
-
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
RBD = Refined, Bleached, Deodorised PO = Palm Oil PKO = Palm Kernel Oil
0.3
HPKOo = Hydrogenated Palm Kernel Olein SMP = Slip melting point
47
Palm Oil/Palm Kernel Oil Applications
Process Flow Chart FAT Milk Solid Non Fat
Sweetener BLENDING Emulsifier/Stabiliser PASTEURISATION HOMOGENISATION COOLING Flavour/Colour AGEING
Air
FREEZING FILLING HARDENING STORAGE
Solid Fat Content of Palm Products
48
