The new generation of whole soya products have numerous benefits for producers and consumers alike, but what are their production challenges and how do you solve them?
A history of whole soya
Whole soya products are not exactly new. Soya beverages have been consumed for over a thousand years in East and Southeast Asia, and were often prepared at home. But such home-based techniques frequently didn’t remove the insoluble okara fibres, which led to certain issues with the end product – typically a chalky or sandy taste, and a beverage that was too viscous.
Even in modern times, many producers have tried and failed to produce a full-fibre, whole soya beverage from the whole bean – the resulting products have often had a taste marked by bitterness, or a gritty or itchy mouthfeel, the hallmarks of poorly produced plant-based products. So, when considering whole soya bean products, it’s crucial to understand how some of these quality characteristics are defined, and how they interact.
Whole soya gives an improved taste & mouthfeel
“When making whole bean soya beverages, no fibre or other ingredients in the raw materials are removed – the okara is simply ground with the rest of the bean,” says Tony Zhang, a beverage category leader at Tetra Pak. “But if these hard fibres or particles are not ground finely enough, it will lead to a chalky or ‘sandy’ taste.” Similarly, the high fibre content – due to the okara – leads to an increase in viscosity with whole bean soya beverages. But soften or expand these fibres too much, and you’ll be left with an overly viscous mouthfeel.
The solution, says Zhang, is to “pass the hard fibres and particles through several grinders in line to reduce the particle size – advances in grinding and milling technology mean that better particle size reduction is now possible, leading to an acceptable mouthfeel.” As for viscosity, with whole bean soya beverages, this is mainly decided by the overall heat load across the entire process – setting up a suitable heat load will give a smooth or creamy, but not sticky, consistency. “Processing this fibre in a specific, controlled way gives whole bean soya beverages their rich, creamy, smooth texture.”
When it comes to taste, people typically associate soya beverages with “beaniness” or a “green” flavour. “This is due to the oxidization of fat in soya beans,” says Zhang. “Lipoxidase in soya beans can accelerate the oxidization process and make the ‘beaniness’ or ‘green’ flavour very obvious. But if the grinding temperature is high enough, the lipoxidase will be deactivated. And if we want to make the unpleasant flavour even less, hot grinding can be combined with other technology to prevent oxygen being mixed in – this will reduce the level of ‘beaniness’ or ‘green’ flavour to an unperceivable level.”
An upgrade with an ROI of less than a year
But what about the challenge in terms of new equipment or upgrading existing soya lines, or increases in costs from a production perspective? According to Andreas Rueppell, an expert in whole soya production at Tetra Pak, several aspects impact the Total Cost of Ownership. “From an energy usage perspective, it’s probably about the same, but the major cost implication relates to the raw material – from the same amount of raw soya beans, you produce much, much more product because the yield with whole soya is 100%.”
“So, you transform what used to be waste – the okara – and the cost of that waste into a full, 100% yield. In effect, you are reducing your ingredient cost while the actual processing costs remain more or less the same – so line production becomes significantly lower.” In fact, after upgrading your line for whole soya, Rueppell estimates that producers will see a ROI in less than a year.
Zero okara waste & other benefits
From a sustainability perspective, using the whole bean – incorporating the okara – leaves you with zero okara waste, saving you the hassle and cost of dealing with it. Furthermore, the 100% yield means that an equivalent amount of raw material gives you far more end product (typically, commercially manufactured traditional extracted soya products have a yield of around 60%), which has numerous other benefits..
“If you take the whole supply chain, from the amount of farmland required to grow the soya beans to transport costs, storage, etc., it can all be slimmed down because you need less raw material for the same level of nutrition on our plates or in our glasses,” says Rueppell. “This is a big, positive impact.”
Upgrading existing soya lines to produce whole soya products is relatively simple – they can easily be converted with limited investments in new equipment. Such a line can then produce both regular and whole soya beverages. As stated, the ROI will be well within twelve months, but Rueppell notes that it’s important to consider bringing in an end-to-end solution and supplier, someone with extensive experience with integrated solutions in whole soya production.
Why an end-to-end, integrated approach is best
“Whole soya production is like a chain – everything is linked. So, one small parameter change in the process can lead to other, unforeseen changes elsewhere, perhaps impacting the flavour or viscosity.” Formulation is another area where supplier expertise is crucial – if a producer has a particular end product goal in mind, they should be able to help you realise that goal.
“You need a supplier who knows how to adjust all the parameters and set up the process correctly to achieve the desired end product – that’s where the skill is,” says Rueppell. “That way, the customer can be reassured that their investment will deliver the right product according to their needs, particularly if they are new to, or inexperienced with, whole soya.”
