The culture of yogurt

For an ancient dairy format, there is plenty that is new with yogurt and fermented creams, the Society of Dairy Technology found at its spring conference, which had the theme, “Yogurt & Fermented Creams: What’s New?” It looked at technology and quality control, from the ingredients to the shipping out to the retailer, for that standard that is yogurt.

Ben Kinsey, technical account manager at Novonesis (formerly Chr Hansen), was first up, looking at “Maximising productivity in yogurt manufacture with natural biosolutions.” He noted that there are new combined cultures for yogurt production, in satisfying what consumers are looking for in yogurt. The combination of Chr Hansen’s 150 years of microbial expertise and Novozymes’ 80 years in enzymes, means more opportunity for the processor on the microbes front.

“Consumer surveys show what people are looking for in yogurt. Flavour and price are the most important in Scandinavia, while natural is a crucial theme for the UK buyers. Overall, preservatives are disappearing from the yogurt market,” Kinsey says.

Typical dairy cost pressures include the milk and powder prices, climate regulation, raw materials costs and availability, energy costs, retail margin pressure, labour costs and availability, he observes. “A key aspect for us in texturising cultures, is making the raw materials go further. We offer YoFlex Premium texturising cultures and FreshQ bioprotective cultures – both enable longer shelf life and lower contamination, with less scrappage.”

Overall yogurt texture depends on three factors: starter culture, milk composition and the manufacturing process. YoFlex Premium 11 is the most recent culture in the company’s range, with the highest texture development and robust post-acidification control. “It offers improved texture, increased mouth thickness and gel firmness, a mild flavour profile, and this flavour helps reduce the need to add sweetness. It also has reduced post acidification, which increases filling temperatures,” Kinsey notes.

It is also quite advanced, as many producers are still using texturising cultures that are lower than the company’s earlier versions, he says. “Premium 11 offers less processing time, fewer complications and reduced recipe costs.”

The new format also addresses the changes in pH from the point of packing to the end of life. “Traditional yogurt cultures often have an acid development. The post-acidification profile of Premium 11 is more stable over its shelf life versus Premium 1.0, and this is more important with the requirements for longer shelf life in yogurts,” Kinsey states.

Another new item is FreshQ Premium, which combines one-pouch cultures with biofermentation. “A product based on Premium 11, with added FreshQ12, reduces the need for expensive skim milk powder in the yogurt recipe. A yogurt with a protein content of four per cent with Premium 1.0, delivers same texture with less powder in FreshQ Premium 11. When we drop protein content down to 3.8 per cent, we still get the same results and same mouthfeel,” he adds.

He observes that bioprotective cultures inhibit yeast and mould, through the control of manganese, which is essential for both starter cultures and yeast and mould. “Certain lactic acid and bacteria strains can absorb manganese through a transporter. FreshQ mops up the spare manganese to reduce the availability of the nutrient to yeasts and moulds, and it still available when consumed,” Kinsey points out.

“We have done a lot of work on protective cultures, with a lot of challenge testing, to demonstrate the performance of FreshQ on the products. We are quite proud of our yeast and mould collection,” he chuckles.

“A look at the typical yogurt shelf across global markets underscores the fact that there is no normal shelf life. In UK, there is a fairly short shelf life of 25 days. In other markets, for example, the US, it is up to 55-75 days – some countries have longer transport links. For Turkey it is 21 to 52 days, while in Brazil, it is 50-55 days. A significant extension of shelf life is possible. It’s about stability of the yogurt, and a longer life can expose other things in yogurt. This shows you what is possible and how producers can be maximising shelf life,” Kinsey says.

When looking at yogurt, and its packaging in one to two-kilogram buckets, the contaminants can show themselves very quickly, he observes. “It’s all about reducing the risk of contamination, so consumers are not throwing away the yogurt and continue to use it,” Kinsey concludes.

Impact for fermented creams

Kirsten Lauridsen, principal designer for IFF in Braband, Denmark, discussed “Opportunities within starter cultures for fermented creams impacting flavour formation, fermentation time, texture creation and extending shelf life.”

She stated the role of the starter culture is to control acidification, provide texture creation, flavour production, gas formation (optional) and taste stability. “Milk is a very good base for fermentation, and by converting lactose into lactic acid, it turn liquids into something we will be eating with a spoon,” Lauridsen notes.

There are fairly big temperature variation around fermented creams, from 20-34ºC, she said, depending on what type it is – kefir, buttermilk, etc. All have different optimal temperatures. Acidification conditions are also critical for flavour. Flavour and gas production in the product depends on minor differences in temperatures.

Depending on the product, what is the optimal temperature? For a firm/thick texture – increase fermentation temperature, and for a glossy appearance and velvety texture, decrease fermentation texture. For fermented creams, the taste stability can also be short compared to yogurt. The taste profile changes over two to three weeks’ time, she observes.

Hybrid alternatives

Emer Mackle of Salutivia and Maor Dahan of ChickP, were speaking on plant powered hybrid yogurt and fermented cream trends and innovation. Mackle observes that while the dairy alternative market is expected to reach $4.08 billion in 2029, consumers aren’t necessarily willing to eliminate dairy from their diets, and plant-based products’ taste and texture don’t meet their expectations. Thus, dairy hybrids, with plant proteins blended into dairy products, may be the answer. Hybrids combine familiar textures and health benefits, plus taste, and may be an emerging market opportunity, Mackle stated.

Dahan explains what ChickP was, a 90 per cent chickpea protein isolate, suitable for dairy and dairy alternative products such as yogurt, barista milk, cheese and cream cheese. Unlike other plant proteins such as soy and pea, the chickpea product is very mild, with an easy to mask taste. Its base colour is white, and it needs less water and fertiliser than other crops. The company is testing 50/50 products currently with as little preservative as possible.

Equipment

Carin Cronström, line solutions manager for chilled and fermented dairy applications at Tetra Pak, discussed, “Future proofing yogurt production – reducing your costs and environmental footprint.”

She notes that while she spends most of her days thinking about the amazing world of yogurt, most consumers know very little about the effort it takes to make these products. “There are so many process steps from intake to fermenting to add flavours to send off to the supermarket,” she states. “There is an innovative spirit for new products on the market, but not much innovation on the processing side. However, there is a window of opportunity to do something differently. Consumers and governments are asking us to put a more sustainable food system in place. For the average family, the top priority is economic, but the want good products, good quality and a wide variety.”

Tetra Pak offers a way to run a plant in the most optimal way, PlantMaster.

“If we want to make a big difference, we also must make some big changes. For example, OneStep technology is a new way of preparing yogurt milk,” she says.

“It’s quite different from how you’re doing yogurt today.” She notes it comes with a

40 per cent lower investment cost, 30 per cent lower running costs, 50 per cent lower water consumption, and 25 per cent lower emissions.

Conventionally, milk comes into the dairy, is heat treated and put into silos. It is then sent to the mixing station, where ingredients are added. Tetra Pak looked at every step and asked, is it really necessary to do every step for high quality yogurt?

It thus integrated a separator, mixer and standing unit into the yogurt milk pasteuriser. Dry ingredients are prepared in batches and continuously added to skim milk at the high shear mixer. The raw milk goes to pasteuriser, and then is aerated, homogenised and heat treated in yogurt fermentation tank.

“When taking away the mixing station and tanks, and having continuous mixing, the system needs to be on target every time, integrated into one unit,” she states. It is more complicated and needs to have a very clever control system. The Tetra Pak Pasteuriser D flows, levels, controls, concept from raw milk to yogurt milk in one step. It can be applied to all kinds of yogurt products and is patent pending.

Harry Flannery and David Cole, of Watson-Marlow Fluid Handling Technology Solutions

detailed how two out of five consumers are interested in yogurts to replace traditional desserts. With yogurt manufacturers, viscosity is the biggest aspect to maintain through the process, and better process equipment can reduce costs, and the need for additions to make up for process losses. By using a Certa pump, there is a 20 per cent loss of viscosity versus a 30 per cent loss with traditional pumps. The pump itself is very gentle, prevents aeration and foaming and can handle up to 255,000 litres per hour, eight million cP and 15 bar, with up to 50 per cent less power consumption versus other pumps.

John Kirwin, sales and marketing director at Penmann, detailed the benefits of rapid cooling on yogurt and fermented creams. In 1995, the company was approached by Muller to design an inline palletised cooling system. Now, it has installed Arla cream cooling tunnels, along with static coolers for smaller dairies. Its Clauger rapid cooling cell has seen 150 installations, with 3,500 units globally.

Simon Gregory of Food Works SW took a few minutes to explain the venue. It opened in April 2020 to support businesses. North Somerset Council built it as a food and drink forum, and a not-for-profit arena for technical food support, such as product development, easy access to information events, workshops, seminars on packaging, meet the buyer, food safety, shelf life, etc. It offers 12 purpose-built premises, which are all occupied at the moment, including a gelato, vegan cheese, and ready meals maker. The setup is opening a trial and pilot dairy as well, with more homogenisers coming in, to handle everything from pilot launches to scaling up of production.

Vincent Corden, general manager at CEM UK, examined the “Rapid component analysis of yogurt and fermented cream.” He states the firm provides tech for testing, and instrumentation for protein fat analysis. “It’s about making standard lab processes safer and easier,” he says.

Discussing the company’s offerings, its Sprint machine is for protein. It manages this is in under four minutes, and tags only the amino acids found in proteins, and ignores all sources of non-protein nitrogen. It provides the advantage of speed and accuracy of just looking at protein. The other instrument, the Oracle, is a rapid fat analysis instrument. It is radio frequency pulsed for total fat results and the entire sample is measured.

the company has a dairy specific report for Oracle’s accuracy and is operating in over 10,00 sites globally.

Quality is for everyone    

Chris Edwards, OBE, head of quality at Müller Yogurt & Desserts and former president of the SDT), was up last and looked at “Operationalising quality in yogurt for tomorrow.”

He observes, “People are often concentrating on where value is added but it’s on the line where it is actually added. It is interesting as when you visit a plant, there is the same laboratory you saw 20 years ago. In healthcare labs, it’s a different world, and the level of digitisation and automation there is phenomenal,” he points out.

In quality, it’s about the difference in speed. Everyone in a plant is in in the area of quality control and getting the right stuff out the door. Without the right information, you won’t get to the actual solution for a quality issue in a plant,” Edwards says. He stated that there is a lack of skilled people, for laboratory analysis work. “The food industry is bigger than the football leagues, but we don’t attract people to it.”

On the traditional testing front, there is a 48-hour gap from production line to release to the distribution network. “It is quite staggering how much it costs us if we don’t get the supply on the shelf,” he notes. This includes shelf-life testing, micro and pH taste panels, and other incubation. With spoilage issues, if it is caught but there is a supply chain disruption, it means frustration and additional work.

There has been a change, with accelerated shelf-life testing, which means 27 hours versus 48 hours, and release after 27 hours. In the end, it is about getting the pots out the door, and how well and safely it gets done. “We need the confidence in our lines, with people at the top of the list. Yes, we need standards and standard operating procedures (SOPs), but still need people to think about the product,” he points out.

There are several questions for operators to ask themselves: “How is that operationalised? Are we capability focused? Are all our efforts focused on that line?” It is about embracing technological advancements, and implementing robust SOPs, staff training and skill development. “We need tech to support us in advancing improvements. It’s about staff training for the future, not just looking at data and writing it down. Do they know what the problem means, and what the numbers are saying? It’s about regular audits and inspections by people on the line, to make sure they know their lines. We need to look at supplier collaboration and ingredient control as part of a continuous improvement culture.

“Digitisation is about converting data into digital formats, while digitalisation is about converting the manufacturing processes into a more digital format. Digital transformation is converting all the aspects of the business and connecting these aspects together to improve the productivity of the firm continuously,” he notes.

“It depends on where that data comes from. I want it to come from the line, not the lab. Data is really important, so make sure you have a lab that supports the operations. It’s about embracing tech advancements, because if we don’t do this, we will forever be behind, and the cost of quality will always be seen as a cost.”

Nick Edwards, the president of the Society, ended by stating, “We need operators who understand their process and make changes as production goes along.”

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