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First biosensor for detecting lactose in waste streams

30 Jul, 2013

A biosensor developed by Lincoln University researchers to detect lactose in waste streams is set to upgrade milk processing in New Zealand to the next level.

Lactose, a sugar present in milk made up of glucose and galactose, is a valuable commodity used in a wide range of product categories, such as functional foods, pharmaceuticals, ethanol production, infant formulae, stout beer and bakery goods. Global demand for the product currently exceeds supply, and according to Lincoln University, the market is estimated to be growing at 20% annually with prices increasing rapidly.

Demand motivating production maximisation

This demand is motivating dairy plant processors to maximise production of lactose. The average plant in New Zealand processes 14 million litres of milk a day. The milk itself is made up of 87% water and 13% solids. Of the solids, around 5% is likely to be lactose.

At present, some lactose is being lost in the waste streams from dairy processing. Monitoring this loss currently relies on retrospectively testing a composite sample from a processing waste stream collected over a 24-hour period. Because this testing is done after the milk has been processed, it does not allow for adjustments to be made while the plant is operating to limit losses in real time, leading to large quantities of valuable milk components being lost if adjustments to the processing are required.

Enzyme-based biodetector

In a recent press release from Lincoln University, Dr Neil Pasco from Lincoln Agritech (a subsidiary of Lincoln University) announced the development of the world’s first at-line enzyme-based biosensor for detecting and measuring lactose in milk processing plant waste streams.

Dr Pasco says the product Lactosenz provides results in almost real time, a significant improvement on the lactose-loss monitoring methods currently used. The improved monitoring of the waste stream means operators should be able to improve the efficiency of the plant to reduce losses of milk solids and also reduce their compliance costs.

Lactosenz incorporates a lactose-detecting enzyme on to a screen-printed electrode. The lactose concentration is detected by the enzyme and generates an electrical signal that is displayed to the operator.

Efficient detection

The Lactosenz sensor detects lactose in a processing stream in about 3 minutes and can detect lactose at very low concentrations, around 0.001 w/v%.

Dr Pasco says the biosensor works much like the glucose test strips used by diabetes patients. “Diabetics are able to quickly test their blood sugar levels with a convenient swab test. Our research allows the lactose levels in milk processing streams to be tested just as quickly.”

As well as dairy processing plants here and overseas, Lincoln Agritech sees future market opportunities for Lactosenz in analytical dairy laboratories, food manufacture companies and food testing industries.


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