Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Accurate milk enzyme measurement may cut cheese processing cost

30.05.2003


A new method to accurately measure quantities of a cheese-ripening enzyme in milk could reduce the time and cost of producing cheese, according to a report by Purdue University researchers.


Kirby Hayes hopes research at Purdue will help cheese producers lower production costs by shortening the time it takes cheese, like this Swiss variety, to ripen. Hayes is an assistant professor of food science. (Agricultural Communication photo/Tom Campbell)



Infrared spectroscopy was used in combination with statistical analysis to determine the concentration of plasminogen, a form of the enzyme integral to cheese manufacturing. The study, by co-authors Lisa Mauer and Kirby Hayes, both assistant professors in the Department of Food Science, is published in the May issue of the International Dairy Journal.

"This method allows us to see how much plasminogen there is in the conditions that we’re manipulating," said Hayes, a food chemist. "When we combine this information with currently available assays, or tests, for enzyme activity, we can look at both location and activity.


"Ultimately, this research is to gain a better understanding of the quality of both fluid milk products and fermented milk products, such as cheese and yogurt, because this enzyme affects quality both negatively and positively."

To reduce ripening time on a commercial scale, researchers will have to learn how to manipulate the enzyme system by changing specific factors such as the pH of milk during fermentation, Hayes said.

"The Holy Grail is trying to reduce cheese ripening time by understanding these enzymes," he said.

The research team focused on plasminogen concentrations in solutions that also contained milk proteins, which can change the enzyme’s activity and interfere with current testing methods. In a second part of the study, they added to the same type of solution both plasminogen and plasmin, an active form of the enzyme. They wanted to determine if Fourier-transform Infrared spectroscopy (FT-IR) could differentiate between plasmin and plasminogen and whether the method could measure how much of each was in the solution.

FT-IR uses wavelengths of light to identify types of chemical bonds. Each type of molecule absorbs light differently, producing a spectrum. Scientists use this spectral information to identify the compound much in the way a fingerprint can identify a person.

The milk enzymes the Purdue researchers are studying occur naturally in the body and are blood-borne catalysts that break down other proteins in milk. This decomposition causes milk to spoil or to ripen into cheese and other fermented dairy products. Plasmin also exists in humans as part of the blood-clotting system.

"FT-IR is a food analysis tool that has been used to measure organic compounds, such as carbohydrates, lipids, proteins and enzymes, for biomedical and pharmaceutical research," Mauer said. "However it’s more difficult to apply to foods because of the hundreds of compounds in them.

"FT-IR is basically a physical chemistry method. It gives a unique fingerprint of whatever you’re trying to measure."

By creating solutions with known concentrations of the enzymes, the researchers determined that FT-IR could accurately measure the amount of plasminogen and plasmin. With this information, they were able to create a model of the plasmin system function that can be used in future studies into the enzyme’s impact on milk products.

"This research really can have a major economic impact," Mauer said. "It’s desirable for the enzyme to cause cheese ripening, but not for it to gel shelf-stable milks. So, in one case we’re trying to speed up plasminogen activation and plasmin breaking down of milk proteins; in the other case we’re trying to stop the reactions."

In the United States, 8 billion pounds of cheese is produced annually at a cost of about 1.3 cents per pound per month of ripening, according to U.S. Department of Agriculture estimates. The ripening process takes three to 12 months depending on the type of cheese.

Plasmin is the substance that gives cheeses that have been aged longer a sharper flavor.

"Think about Colby or a new cheddar verses an aged cheddar cheese; these are two very distinct flavors," Mauer said. "That’s what the enzyme system does – it breaks down proteins and releases some of these bitter compounds."

The scientists will investigate different processing treatments and their effects on the plasmin system in an effort to make these methods commercially viable, Mauer said.

The other scientist participating in this study was Banu Ozen, who was a postdoctoral student in the Department of Food Science at the time of the research.

The Indiana 21st Century Research and Technology Fund, the U.S. Department of Agriculture and Purdue University provided funding for this research.

Susan A. Steeves | Purdue News
Further information:
http://news.uns.purdue.edu/html4ever/030529.Mauer.plasmin.html

More articles from Process Engineering:

nachricht TUM Agenda 2030: Combining forces for additive manufacturing
09.10.2019 | Technische Universität München

nachricht Copper oxide photocathodes: laser experiment reveals location of efficiency loss
10.05.2019 | Helmholtz-Zentrum Berlin für Materialien und Energie

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Virus multiplication in 3D

Vaccinia viruses serve as a vaccine against human smallpox and as the basis of new cancer therapies. Two studies now provide fascinating insights into their unusual propagation strategy at the atomic level.

For viruses to multiply, they usually need the support of the cells they infect. In many cases, only in their host’s nucleus can they find the machines,...

Im Focus: Cheers! Maxwell's electromagnetism extended to smaller scales

More than one hundred and fifty years have passed since the publication of James Clerk Maxwell's "A Dynamical Theory of the Electromagnetic Field" (1865). What would our lives be without this publication?

It is difficult to imagine, as this treatise revolutionized our fundamental understanding of electric fields, magnetic fields, and light. The twenty original...

Im Focus: Highly charged ion paves the way towards new physics

In a joint experimental and theoretical work performed at the Heidelberg Max Planck Institute for Nuclear Physics, an international team of physicists detected for the first time an orbital crossing in the highly charged ion Pr⁹⁺. Optical spectra were recorded employing an electron beam ion trap and analysed with the aid of atomic structure calculations. A proposed nHz-wide transition has been identified and its energy was determined with high precision. Theory predicts a very high sensitivity to new physics and extremely low susceptibility to external perturbations for this “clock line” making it a unique candidate for proposed precision studies.

Laser spectroscopy of neutral atoms and singly charged ions has reached astonishing precision by merit of a chain of technological advances during the past...

Im Focus: Ultrafast stimulated emission microscopy of single nanocrystals in Science

The ability to investigate the dynamics of single particle at the nano-scale and femtosecond level remained an unfathomed dream for years. It was not until the dawn of the 21st century that nanotechnology and femtoscience gradually merged together and the first ultrafast microscopy of individual quantum dots (QDs) and molecules was accomplished.

Ultrafast microscopy studies entirely rely on detecting nanoparticles or single molecules with luminescence techniques, which require efficient emitters to...

Im Focus: How to induce magnetism in graphene

Graphene, a two-dimensional structure made of carbon, is a material with excellent mechanical, electronic and optical properties. However, it did not seem suitable for magnetic applications. Together with international partners, Empa researchers have now succeeded in synthesizing a unique nanographene predicted in the 1970s, which conclusively demonstrates that carbon in very specific forms has magnetic properties that could permit future spintronic applications. The results have just been published in the renowned journal Nature Nanotechnology.

Depending on the shape and orientation of their edges, graphene nanostructures (also known as nanographenes) can have very different properties – for example,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Supporting structures of wind turbines contribute to wind farm blockage effect

13.12.2019 | Physics and Astronomy

Chinese team makes nanoscopy breakthrough

13.12.2019 | Physics and Astronomy

Tiny quantum sensors watch materials transform under pressure

13.12.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>