Page 115 - FoodFocusThailand No.219 June 2024

STAND OUT TECHNOLOGY

There are two types of lactose-free incubation time. However, tests for enzyme activity and degree of hydrolysis can
products in the market. The first is only be done at the end of the production, which may be risky for companies. Moreover,
plant-based dairy-free products, such sterile equipment is more costly than conventional equipment.
as soybean, coconut, oat, etc, which
are naturally lactose-free. The second Advanced Technologies in Dairy-based Lactose-free Ice Cream
is dairy products with lactose removed. Development
Many studies agreed that individuals 1. Filtration Technologies
would miss out on key nutrients for Lactose hydrolysis doubles the sweetness of milk, which may not suit consumers
bone mass maintenance, such as who prefer fewer sweet profiles. Filtration is an alternative to remove lactose without
calcium, vitamin D, and protein, and the added sweetness. It is widely applied in the dairy industry, and the membrane
bone formation, such as vitamin A, used depends on the particle size of the component. The particle size of lactose is
potassium, zinc, and magnesium when about 1.18 nm; hence, it is suitable for ultrafiltration and nanofiltration. However,
dairy is eliminated from one’s diet. Due most studies have not achieved 100% removal of lactose. Previous studies showed
to the nutrient benefits, more that 90% of lactose was removed from sheep whey when using a polysulfone
companies are looking into developing ultrafiltration membrane, while 87% of lactose was removed from milk while retaining
dairy-based lactose-free ice cream. 100% of the protein in both studies. Moreover, some studies utilized ultrafiltration
and nanofiltration to remove lactose in a milk product. It is then concentrated by
Traditional Method of Lactose reverse osmosis, along with the return of minerals to the UF retentate when it is
Removal in Dairy-based removed during ultrafiltration. The residual lactose is hydrolyzed with a lactase
Ice Cream enzyme to obtain a lactose-free product. Manufacturers find hydrolyzed milk’s
Lactase enzymes (β-galactosidase) sweetness advantageous to ice cream development as it can reduce the amount of
are added to the product to hydrolyze sweetener added. However, the ice cream’s softer texture as a result of increased
lactose. Being a cold-adapted enzyme, monosaccharide content, decreased total solids, and lower freezing temperature
β-galactosidase has higher substrate may be an advantage or disadvantage, depending on the company. Another issue
solubility, reaction rate, and a lower is the fouling of membranes, which is mainly caused by protein. The frequent cleaning
probability of microbial contamination. of the membranes will incur large maintenance costs.
Therefore, making it suitable for 2. Chromatographic Separation
lactose hydrolysis. Lactose hydrolysis Chromatographic separation using different separation mediums is a new and
can occur through batch or aseptic recent technology in the dairy industry. Chromatography separates components
The Next Development in Dairy-Based processes, as depicted in Figure 1. based on different affinities and residence times in the column. Strong cation exchange
1. Batch (Pre-hydrolysis)
columns can be used to separate lactose as the formation of lactose-cation complexes
In a batch process, a high dosage
slows the flow of lactose, separating it from the other milk components. However,
Lactose-Free Ice Cream of β-galactosidase is added to the ice large space requirements and high operational costs limit its practicality. Previous
cream mixture and incubated in cold
studies achieved successful lactose adsorption using Molecularly Imprinted Polymers
conditions of 4-8 C for a short duration.
o
(MIPs), showing potential for scalability. In the industry, Valio Ltd. (Finland) developed
Production Technology Pasteurization is carried out after a patent-protected process for the chromatographic separation of lactose from milk
hydrolysis to ensure that the enzyme
after successful research on the chromatographic separation of lactose from whey.
is inactivated in the final product. This
Despite accomplishing bulk removal of lactose from milk chromatographically, lactose-
is an advantage of the batch process,
as the absence of enzyme activity free milk combines chromatography, membrane separation, and enzymatic hydrolysis
to retain a slight sweetness in the milk.
would help with regulation and labeling
laws in some countries. However, as
lactose is broken down into galactose
and glucose, Maillard browning of the
ice cream mix will occur during
pasteurization, giving an undesirable
taste to the ice cream. Moreover, the
space constraints and discontinuity of
the production must be considered by
manufacturers.
2. Aseptic (Post-hydrolysis)
In an aseptic process, sterile
β-galactosidase is added post-
pasteurization, with lactose hydrolysis
occurring during a 24-hour aging stage
at < 4 C, before whipping and freezing
o
at -5 C. A lower dosage of lactase
o
enzyme can be used due to the longer
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