Special Ingredients

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BY DEBORAH KOMLOS

What we eat may not resemble the pills and ointments stockpiled on pharmacy shelves, but the course of moving from ingredients to food products involves many of the same principles behind formulating drugs from synthetic chemicals.

Extraction, purification and sterilization are some common “bioprocesses” required to prepare products for the food sector. Also in use, however, are methodologies more typically associated with biotechnology, such as summoning the power of microbes. Examples of such “bio” systems include the selection and optimization of yeast strains for bread and wine production, and encapsulation methodology to more effectively deliver probiotics in dairy products.

Despite some bioprocessing novelty in the food sector, the field still needs work, says Murray Moo-Young, PhD, professor emeritus in the department of Chemical Engineering at the University of Waterloo (Waterloo, ON).

“The (food) industry is reluctant to apply (novel methodologies) because it is afraid of the consumer perception,” Moo-Young says. “So nothing tried, nothing done . . . Just need to have done, like in the pharmaceutical industry where, 20 years ago, you just needed one company in California to start making drugs by fermentation rather than synthetic chemistry and it took off and the biotech industry boomed.”

Moo-Young experienced the difficulty in acceptance of a novel food type in the late ’80s when there was an attempt to sell the rights to a bioconversion methodology he invented to a Japanese company by the Vancouver firm that had initially purchased the rights from Moo-Young and his group at U of W. His method involves the production of protein-rich products by growing an edible fungus on various process “leftover” materials such as whey, pulp byproducts and straw. The deal collapsed, Moo-Young says, when a connection was incorrectly made between mycotoxins and the fungus-produced single-cell proteins made via protocols such as the one he created.

A similar process was eventually developed by Marlow Foods Ltd. (Marlow, UK), Moo-Young says, and is now being successfully applied in its line of Quorn™ products. But the British firm’s process uses a different microbe, and unlike that in his protocol, its fungus is not on the GRAS (generally recognized as safe) list, he says.

Though Moo-Young regrets that his own invention did not also make it to market, he does applaud the appearance of new products in the food industry and would like to see more innovation emerging in that sector, with increased awareness of the need for bioprocessing.

Food Matrices

Among Canadian food-engineering research efforts are those happening at INAF (Institut des nutraceutiques et des aliments fonctionnels; Nutraceuticals and Functional Foods Institute), a Laval University (Quebec City, QC) institute, where more than 60 INAF-affiliated scientists are dealing with various food-science specializations, including nutraceutical molecules, functional food procedures and technologies, and clinical nutrition.

One of INAF’s members is Muriel Subirade, PhD, a researcher at Laval University’s Dairy Research Centre STELA and holder of the Canada Research Chair in Protein, Biosystem and Functional Food Physical Chemistry. Subirade’s research aim is to improve the bioavailability of active compounds and increase their action through the use of engineered food biopolymers.

Her work involves whey and soya globular proteins, studying their use in biopolymers such as hydrogels and microspheres.

“We chose these proteins (whey and soya) and these biopolymers because they are used in traditional foods as emulsifiers, as gelling agents,” Subirade says. “So they are food proteins and edible proteins, and it’s interesting to use them in functional foods to transport and protect bioactive compounds, especially nutraceutical components.”

The premise of the compound delivery modes is not unique, she says, because they are employed like drug-delivery systems. But working with edible compounds involves using renewable materials and can have promising application value. For instance, Subirade and her group are currently developing hydrogels for use against Alzheimer’s and other neurodegenerative diseases.

As part of its research, the team has studied the conformational changes — such as the gelling process — of globular proteins at the molecular level using Fourier transform infrared (FTIR) spectroscopy and rheological methods. The team has also devised a new emulsification/cold gelation method to produce whey protein beads (see image above).

“We try to correlate this conformational change with the properties of proteins,” Subirade says. Some of the protein characteristics her team has studied include swelling, elasticity, deformability and change in relation to pH levels.

The Gut of the Matter

A specific application of Subirade’s research is through a collaboration with fellow INAF and Dairy Research Centre STELA researcher, Ismaïl Fliss, PhD, DVM, whose work in food microbiology focuses on probiotics — friendly micro-organisms that are thought to be beneficial for digestion, nutrition and immunity.

Fliss and his team are assessing the antimicrobial properties of human-fecal-isolated strains of bifidobacteria, including the production of antimicrobial peptides called bacteriocins. Bifidobacteria are important components in the intestinal microflora of humans. Because of their poor tolerance of gastric pH, bifidobacteria typically have very low survival rates in the gastrointestinal tract, Fliss says, adding that they tend to be poor competitors. The team is also working with bacteriocins produced by some strains of lactic acid bacteria.

Bacteriocins function like antibiotics, Fliss explains, to kill intestinal pathogens such as E. coli and Salmonella. Once the specific antimicrobial strains of bifidobacteria are selected, the group uses simulation software to assess the microbial activity of the active peptides in the human intestinal tract.

The collaboration with Subirade involves using her whey encapsulation technique for bifidobacteria, with an ultimate goal of incorporating these microbes into foods such as cheese and fermented milk.

“In general, milk-based products are a good delivery system for probiotics,” Fliss says. With its many proteins and fat, milk has beneficial protective effects against acidic conditions, he says. Fliss’s group is currently focusing on cheddar cheese because it is the main type of cheese in Canada, and INAF has the facility to produce different batches of the cheese and at different conditions.

“We know that we have probiotics supplements on the market — capsules of them — but not in cheese,” Fliss says, which is another reason why his group is trying to develop probiotic cheddar. “When you eat one capsule, the pH in the stomach is very, very low and a large part of these bacteria are dead in the intestines. So just a small portion reach the intestines.”

The team has also developed antibodies to bifidobacteria, and when used in combination with specific labels such as protein A-gold, the bacteria can be monitored within the cheese by microscopy.

Scaling Up

Research strategies are driven by product development goals, and some services in Canada, such as those offered through the Bioprocess Platform of the National Research Council of Canada’s Biotechnology Research Institute (BRI) (Montreal, QC), are helping to provide process optimization and process-end scale up.

Dany D’Amours, project leader and supervisor of the pilot plant with the Microbial & Enzymatic Technology Group of the Bioprocess Platform, says probably 90 per cent of the group’s work is with biopharmaceuticals. However, he adds, the same principles and technologies are used within the food sector.

The BRI platform uses its 1,500-litre, pilot-scale fermentor to provide materials for research activities.

“So we’re just before the commercial step,” D’Amours says. “The company has an idea for the project at the bench scale and we develop all the process so that after they can use it commercially.”

Commonly dealing with engineered micro-organisms such as E. coli and S. cerevisiae, the group “can in fact go from gene through to protein,” D’Amours says. “We have a team that can do transformation of the cells and make recombinant cells and we can grow them and we can purify the proteins and have proteins at the end.”

Down the Production Line

Determining the ideal set of conditions in which to grow the microbes and be able to produce good-quality products in good amounts is always an objective of the work, D’Amours says. And a large part of the challenge is figuring out how to replicate processes that were initially done in a laboratory setting.

“Sometimes, your process works really well in the bottle and you try to do it exactly in the same way with the large scale, but it doesn’t work,” D’Amours says. “So you have to fine-tune and to find different solutions to different problems.”

An example of process optimization, D’Amours explains, is determining at the larger scale how much glucose or other growth media is required to produce the right amount of yeast. Often the team uses fed-batch fermentation to cultivate the microbes, and based on the measured respiration from the fermentor, an algorithm is used to calculate how much feed should be added to achieve the desired result.

D’Amours says the group typically starts with a relatively smaller volume of 20 litres, then gradually scales higher to save on cost by identifying and handling process problems early on.

Private contract R&D organization POS Pilot Plant Corp. in Saskatoon, Sask. also serves food bioprocessing efforts but operates at a more expanded scale.

Comprising five pilot plants and 11 laboratories, POS Pilot Plant operates 24 hours per day, five days per week and offers the broadest range of services in the industry, says president and CEO Robert E. Morgan.

“Our equipment in our pilot plant is really small scale of what you will find in the industry,” Morgan says. “The other key part of that is that we can take a quantity of seed through an entire process to come up with, let’s say, if you wanted an oil, we could come out with the oil at the other end without changing the scale in any way.”

The POS in the firm’s name refers to protein, oil and starch, which were the initial focal points when POS Pilot Plant was created just over 25 years ago. In 1972, Morgan explains, the canola industry was becoming established in Canada and the federal government and food industry were looking to create a facility that could enhance the value of Canadian exports beyond raw materials.

Since its founding, Morgan says the firm has changed and now handles a wide range of materials, including fermentation items, marine life, crops and forestry products.

Morgan says POS Pilot Plant’s four main strengths are extraction, purification, fractionation and modification. The firm deals mainly with the proof-of-concept stage, he adds, and does not do packaging and may not do final formulations. For instance, he says, POS Pilot Plant may be asked to extract and supply a particular plant compound for addition to a food item such as margarine, but the client would have to find a formulator to add the extract and produce the end product.

While novelty and optimization in food processing is essential to progress, Moo-Young says another important aspect — and one that he would like to see — is the enrichment of food in terms of nutrition. This would help ensure that people would not just become accustomed to the tastes of food that may be too high in fat and other less-healthy constituents.

“When we were kids we were given all this stuff so we got this acquired taste for these salty things or sweet things and so on,” Moo-Young says. But “things are looking up,” he says.

Many advocacy groups are emerging that are promoting better nutrition, Moo-Young says. “I think people are finally paying attention and maybe the food industry will wake up and realize that look, the populace is not so ignorant after all, but that maybe we should be trying something new, some new products.”