Aust-US research team unlocks secret of an enzyme’s role in cheese-making

A discovery which explains the regulation of an enzyme in the bacterium Lactococcus, which is used as a starter culture in cheese production, has important implications for industrial cheesemaking.

The new knowledge on the inner workings of the bacterium has been reported by researchers at the University of Queensland School of Agriculture and Food Sciences, Columbia University and University of Washington. 

UQ Associate Professor Mark Turner said the research provides new insights into the food bacterium.

“Australia produces more than a billion dollars’ worth of cheese each year, and Lactococcus is the most commonly used starter culture,” Dr Turner said.

Two UQ PhD students in Dr Turner’s food microbiology research laboratory – Thu Vu and Huong Pham – found the enzyme known as pyruvate carboxylase was essential for efficient milk acidification, an important industrial trait in Lactococcus starter cultures.

Dr Turner said the enzyme was essential for synthesising the amino acid aspartate, and bacteria defective in the enzyme were unable to produce high levels of lactic acid in milk, which is required for the first stage of cheese making.

The collaboration also found that a recently discovered small molecule in bacteria, called cyclic-di-AMP, directly binds to and inhibits the pyruvate carboxylase enzyme.

“The molecule is essential for growth in a wide range of bacteria, including many human pathogens, and we are only in the early stages of understanding how it controls important processes in bacteria.”

Dr Turner this year won the 2017 Australian Institute of Food Science and Technology Keith Farrer Award of Merit, which recognises achievements in food science and technology in research, industry and education.

The bacterium research is published in the Proceedings of the National Academy of Sciences (doi 10.1073/pnas.1704756114).

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Taste and health affect consumer choices for milk and non-dairy beverages

Education on nutritional value and correcting misconceptions should be a focus of the dairy industry, if it is to benefit from recent research findings on consumer behaviour in the US.

The researchers from North Carolina State University used surveys, conjoint analysis, and means-end-chain analysis to uncover the underlying values among dairy milk and non-dairy beverage consumers.

Their aim was to learn more about what affects consumer decisions regarding fluid milk purchases, researchers

The results of the study highlighted the most important factors for both milk and non-dairy beverages, which were the same: they must be healthy and taste good.

In recent years, retail sales of fluid milk have changed significantly and per capita consumption has decreased at a rate of 830 mL per year since 1975.

Between 2011 and 2014, sales of fluid milk have decreased 3.8% but the amount of non-dairy, plant-based beverages sold increased 30% between 2010 and 2015.

No previous work directly studied values held by consumers and how those attitudes influence milk purchases.

To assess this, a survey was completed by 999 primary shoppers between 25 and 70 years old, 78% female and 22% male, who reported purchasing dairy milk, non-dairy beverage, or both at least two to three times per month.

Most consumers (87.8%) did not follow a specific diet or claim to be lactose intolerant (88.4%). Twenty-seven percent of consumers purchased one or both beverages more than once a week, 47.0% purchased one or both beverages once a week, and 25.0% purchased one or both beverages two to three times per month.

Consumers ranked fat as the most important attribute in dairy milk, whereas sugar level was most important for non-dairy beverages. Dairy milk consumers reported a preference for 2% or 1% fat, and almost 70% of dairy milk sales in 2014 were reduced or fat-free milk.

Non-dairy consumers preferred plant beverages that were naturally sweetened or had no added sugar. Almond beverage was the most desirable plant-derived beverage, representing more than 65.0% of non-dairy beverages sold in 2014.

Protein had universal appeal for both milk and non-dairy beverages, with higher utility scores for higher levels of protein content.

“We found that consumers choose milk based on habit or because they like the flavor. Milk that is appealing in flavor could convince nondairy beverage drinkers to consumer more dairy milk; likewise, lactose-free milk or milk from grass-fed cows might also be appealing,” lead author Kara McCarthy said.

“By further focusing consumer education on trust building as well as nutrition, farm practice, and animal welfare, the appeal of dairy milk could be broadened.”

With the results of this study in mind, along with the many features attractive to consumers of both dairy milk and non-dairy beverages, the dairy industry can more effectively market and position milk as well as dispel any misconceptions

This AgScience post is based on a report posted by Science Daily (HERE).

Journal Reference:

K.S. McCarthy, M. Parker, A. Ameerally, S.L. Drake, M.A. Drake. Drivers of choice for fluid milk versus plant-based alternatives:What are consumer perceptions of fluid milk? Journal of Dairy Science, 2017.

MPI’s honey test results prompt call from Labour for further restructuring

The Labour Party is reported to be calling for the Ministry for Primary Industries to be split again because it’s “too big” and failing industries like the lucrative manuka honey business.

Damien O’Connor, Labour’s spokesman for Primary Industries, said the 2012 merger of the Ministry of Agriculture and Forestry, Ministry of Fisheries and the New Zealand Food Safety Authority was meant to be about efficiency.

But he said the ministry now was “simply too big” to have the expertise required in the highly technical areas of food safety and biosecurity.

His comments (HERE) followed MPI’s deputy director of general regulation and assurance, Bryan Wilson, acknowledging a problem with the testing of manuka honey.

The Government last month released its scientific definition to authenticate New Zealand manuka honey, which is the first step leading to a standard.

This followed claims in a British trade magazine, The Grocer, that consumers were being misled over what they are buying and at vastly inflated prices.

The honey industry earns $242 million in exports a year, about 80 per cent of this from manuka honey.

But some producers say up to 20 per cent of the purest honey – worth about $10 – 20 million – is failing MPI testing.

Radio NZ reported on this issue yesterday (HERE):

Independent industry adviser John Hill said he has had clients whose honey has failed under the proposed standards despite being some of the best in the country.

He said producers had been testing hundreds of samples of the best mānuka honey, worth up to $300 a kilogram, and about 20 percent had failed.

Mr Hill said the significant fail rate had huge implications for mānuka honey producers and he wanted MPI to sort it out as soon as possible.

He said it had already been a bad year for beekeepers, with the weather affecting produce.

Bryan Wilson was intervieweed for the Radio NZ news item.

He said there appeared to be a problem with the laboratory testing methods used, and work was being done to fix it.

“It’s the way in which the testing for DNA is undertaken. There is potentially some interference with some of the chemicals, so we’re working on how that might be fixed and we think we’ve got a solution,” he said.

Mr Wilson said the test was designed to separate mānuka honey from other sorts of honey.

“We are pretty confident in the way we have got that set up. We would expect a level of difference between what our tests show and what the industry’s tests show. That’s why we started this process in the first place.”

Submissions for fresh testing ends on 13 June. Mr Wilson was confident any issues could be fixed at the end of the consultation process.

Where’s the lab beef produced in a gadget at home? On the back-burner

Promises of lab meat were overly optimistic, Discovery magazine reports (HERE).

It has revisited an article it published in 2006, when biologist Vladimir Mironov dreamed of growing lab meat in a coffee-maker-like device that could, overnight, turn a few animal muscle stem cells into a nice chunk of meat.

The muscle cells would be harmlessly extracted from an animal and – with the right nutrients and environment – would multiply just as they would in their original host, but more rapidly.

The idea was to target three issues raised by traditional meat farming – protect animals from inhumane conditions and eventual slaughter; reduce the environmental damage of large-scale livestock operations; and give humans healthier meat and better food security.

In an update published this month, the magazine reports that Mironov’s vision hasn’t changed, but he’s put the project on the back burner. His lab at the University of South Carolina shut down in 2011 due to personnel issues and now he’s concentrating on organ printing at a 3-D bioprinting company in Russia.

“Maybe I will return to the topic,” he wrote in an email. “In vitro meat production is the inescapable future of humanity.”

Mark Post, physiology chair at Maastricht University in the Netherlands, shares Mironov’s optimism about in vitro meat’s potential. But he says the future isn’t in at-home devices.

“Quite frankly, I don’t see that as a very pragmatic solution,” says Post, who debuted his lab-produced meat (cost: $325,000 per burger) in a highly publicised taste test in London in 2013.

Instead, the focus now is on ramping up efforts to produce it in factory-like settings, Post said.

Bigger production would mean more burgers for more than just a few taste testers, while also sending costs way down.

“In essence, it’s available,” Post says, “but not at the scale that you need for [mass] consumption.”

His optimistic scenario — which depends on the production infrastructure being in place and regulatory approvals — is having a $10 cell-grown hamburger patty on the shelves in four to five years.

But production must be scaled “to a tremendous level” to meet the requirements of supermarkets.

Edible insects could supplement our diets and help reduce harmful emissions

Eating insects instead of beef could help tackle climate change by reducing emissions linked to livestock production, an Edinburgh University news item (HERE) says.

It cites research which suggests replacing half of the meat eaten worldwide with crickets and mealworms would cut farmland use by a third, substantially reducing emissions of greenhouse gases.

While consumers’ reluctance to eat insects may limit their consumption, even a small increase would bring benefits, the research team says. This could potentially be achieved by using insects as ingredients in some pre-packaged foods.

Using data collected primarily by the UN’s Food and Agriculture Organisation, the scientists have compared the environmental impacts of conventional meat production with those of alternative sources of food. It is the first study to do so.

Researchers at Edinburgh and Scotland’s Rural College considered a scenario in which half of the current mix of animal products is replaced by insects, lab-grown meat or imitation meat.

They found that insects and imitation meat – such as soybean-based foods like tofu – are the most sustainable as they require the least land and energy to produce. Beef is by far the least sustainable, the team says.

In contrast to previous studies, lab-grown meat was found to be no more sustainable than chicken or eggs, requiring an equivalent area of land but using more energy in production.

The team, which includes scientists involved in the N8 Research Partnership’s AgriFood programme, says halving global consumption of animal products by eating more insects or imitation meat would free up 1680 million hectares of land – 70 times the size of the UK.

Similar land savings could also be made by switching from the current mix of animal products to diets higher in chicken and eggs, the team says.

They found that the land required to produce these was only marginally greater than for insects and imitation meat.

As well as being a major contributor to human-induced greenhouse gas emissions, current livestock production has other environmental impacts.

Globally, pasture covers twice the area of cropland, and livestock consume around a third of all harvested crops.

The research, published in the journal Global Food Security, was supported by the UK’s Global Food Security Programme and the European Union’s Seventh Framework Programme. It was carried out in collaboration with the University of York, Karlsruhe Institute of Technology and the Centre for Australian Weather and Climate Research.

New Zealand futurist Robert Hickson, on his Idealog blog, has written about changing dietary habits and trends and challenges associated with traditional western food consumption.

In a recent post (HERE), he noted:

Insects aren’t yet big on fancy restaurant menus in the US. But they are a gaining popularity in Japan. The UK has at least one restaurant specialising in our invertebrate friends. And Ikea has been thinking about introducing insect meatballs for a couple of years. A Swiss supermarket is planning to sell burgers and meatballs made from mealworms from next month.

New Zealand is no stranger to edible invertebrates, if only occasionally. I couldn’t find reports of insect meals being a staple in New Zealand, but at least two companies offer gourmet arthropod treats – Crawlers and Anteater. Some other food stores offer products containing cricket flour.

Hickson further noted that lab-grown meat prices are dropping rapidly and producers of meat-free burgers “are on a PR offensive”.

And the world’s largest pork producer, Smithfield Foods, is hoping to become a major supplier of organs for human transplants.

In short, agricultural and social changes will influence why and what we farm. It obviously will influence the relevant science, too.

NZ researchers take step towards tackling allergy with modified milk

New Zealand agricultural scientists have learnt that the calves of a cow modified to have less allergenic milk also have less allergenic milk.

A post on Sciblogs (here) by Dr Grant Jacobs, a Dunedin-based computational biologist, drew AgScience’s attention to the research. He was commenting on an article in the New Zealand Herald, headed GE cow’s offspring show ‘super-milk’ potential.

The research raises hopes of developing a variety of cattle that will produce milk that can be drunk by people with one type of milk allergy.

Dr Jacobs explains that milk allergy is not lactose tolerance.

A number of us are allergic to milk, in a similar way that a number of us are allergic to other types of foods.

β-lactoglobulin is regarded as the main allergen in milk.* (β is the Greek letter, beta; you’ll also see it written beta-lactoglobin.) β-lactoglobulins is considered an important allergen in part because there’s no β-lactoglobulin in human milk.

Around 2-3% of children are allergic to milk. Those with milk allergy can show any of the symptoms of allergy; skin, gastric and breathing problems, including, in rare cases, acute allergic reaction (anaphylaxis).

Usually kids grow out of the allergy, but they carry a higher risk of eczema, egg allergy or allergic asthma in adulthood.

One way to tackle this allergy might be a little prevention: to breed cows that don’t make β-lactoglobulin – without this protein, the allergy problem isn’t there.

The New Zealand researchers blocked the gene that makes β-lactoglobulin.

This way you get just the thing you’re wanting, Dr Jacobs says, and you can try it out on a small scale using a small research team.

One of the great values of genetic engineering is that it enables small teams to do stuff that might otherwise need very large-scale projects.

A catch with the technique they’ve chosen to use, known as RNAi, is that you want to know if the offspring also doesn’t make the protein – is it inherited?

That’s the latest news – they’ve succeeded at that, as you can read in Jamie’s report.

There’s still a long way to go, says Dr Jacobs, “but less-allergenic milk might give an option to those who have developed milk allergy”.

He offers a thought for opponents: if those that don’t want to use milk from cows that were bred to make modified milk, they don’t have to — but there’s no need to block that option for others that do want to.

And he says he would like to learn to what extent the caseins in low β-lactoglobulin milk provokes allergic reactions.

Presumably this milk would be for those allergic to β-lactoglobulin, but not those allergic to caseins.

One line of research suggests that people are allergic to β-lactoglobulin when it lacks iron.** β-lactoglobulins can bind a number of organic molecules, including siderophores. One thing siderophores can do is strongly bind iron. Research has shown that when the β-lactoglobulin protein carries an iron, by holding onto siderophore binding iron it triggers an immune response (e.g. inflammation).

The more widely-known lactose intolerance is because as adults many of us can’t break down & absorb the lactose sugar in milk. It’s more common in non-European people. Since humans starting drinking milk, we’ve started to produce lactase, the enzyme that breaks down lactose, as adults — adaptive evolution in humans as a result of farming!   Adapting to produce lactase as an adult has happened several times independently in different parts of the world.

Dr Jacobs reminds us of his earlier discussion in an article about tracking disease and human migration through genetics.

Massey investigating the possibilities of new food technology

Massey University researchers are investigating whether establishing an Innovation Centre focused on a novel food processing technology could transform New Zealand’s food industry.

The university is hosting representatives from American-based company 915 Labs, which has commercialised the technology, at a workshop on the Manawatu campus today. They have been joined by more than 50 representatives from major food companies, researchers, scientists and Government.

The Microwave Assisted Thermal Sterilisation (MATS) and Microwave Assisted Pasturerisation (MAPS) technology was originally developed by Washington State University over a 10-year period, funded by the US government and a wide range of food companies. 915 Labs holds the exclusive, worldwide license to the technology.

MATS uses microwaves to speed up the heating process for packaged foods, essentially combining a continuous retort with a microwave. By reducing the cooking time, food quality can be significantly improved without compromising food safety or shelf life. It also provides an extended shelf-life on heat sensitive products like fish and vegetables that previously have adversely affected by thermal treatment.

MAPS is similar to MATS but operates with lower temperatures and shorter heating times required for pasturerisation. In the MAPS system, packaged foods and beverages are heated simultaneously with hot water and microwave energy to a temperature of 70-90°C for 2-10 minutes, eliminating viral and bacterial pathogens.

Dr Abby Thompson, Director of Massey’s Riddet Innovation, says the technology means products look and taste fresher and retain more sensitive nutritional components, achieving safe food with an extended shelf life.

“This technology enables the development of premium fresh-life foods and meals with enhanced consumer appeal with sufficient shelf life to supply both domestic and export markets with products targeting retail, food service and institutional applications. It is a real game changer,” Dr Thompson says.

The technology has primarily been developed for human ready meals, but there is also a lot of interest in premium pet foods. “Aroma, flavor and colour are all significantly fresher, and we believe there should be higher protein digestibility due to the reduction in heat exposure. Logic also suggests it should be possible to produce premium products with heat-sensitive bioactives that may otherwise not be feasible with traditional methods,” Dr Thompson says.

915 Labs manufactures and sells pilot-scale and commercial-scale MATS systems and will begin producing a MAPS-only system in 2017. Massey University is looking to establish an Innovation Centre for this technology, based at the FoodPilot in Palmerston North. This would be supported by a dedicated team providing food technology, process engineering and regulatory expertise, and would undertake development and validation projects on behalf of the international food industry. The Centre would also enable exciting research collaborations with overseas research groups.

Michael Locatis, chief executive of 915 Labs, was looking forward to meeting with members of the New Zealand food industry and experts from Massey University to talk about the future of packaged food and the impact of microwave processing on the quality and nutrition of ready-to-eat and shelf-stable products.

Phil McGrath, chief executive of Food Locomotive Limited said he was excited by the possible venture.

“MATS is a ground breaking technology that enables us to create true clean label products with improved nutrition, texture and flavour for our customers. This exciting new technology allows us to showcase New Zealand’s quality produce across the globe. MATS is the value-added opportunity we have been looking for.”

Craig Nash, chair of the FoodHQ Commercialisation Stream, is working with Massey University to secure the technology.