February 1, 2009
As dairy producers develop new expertise in protein processing, ingredients are changing for the better. Milk and whey concentrates, not traditionally favoured for bar applications, are now stepping up with both improved functionality as well as flavour advantages. Rachel Marshall explains
Consumers are becoming increasingly aware of the important role that protein plays as part of their daily food intake. They seek protein for a number of reasons, including weight management, satiety, building lean muscle, sports performance and recovery. Depending on the protein source, the nutritional quality varies, with dairy protein, especially whey, topping the list in terms of bioavailability, protein digestibility corrected amino-acid score (PDCAAS), and protein efficiency ratio (PER), all common measures of protein quality.
Bar manufacturers are responding with an increasing number of protein-fortified products, including some that traditionally contain relatively low levels of protein, such as granola bars. In addition, high-protein products such as nutrition and sports bars are being launched with even higher levels of protein or in new, more indulgent formats to appeal to a wider audience.
Despite their benefits, proteins have some limitations that cannot be ignored and must be carefully managed. Key issues include unpleasant flavours and changes during shelf life, especially bar hardening. Currently, many protein-enhanced products are purchased by niche customers, such as performance athletes, who are willing to sacrifice enjoyment to receive the nutritional benefits. However, to meet the needs of mainstream consumers, it is critical for products to be both permissible and palatable.
With many protein-fortification ingredient choices, it can be a challenge to decide which to use. Each ingredient differs in composition, resulting in different functionality. Table 1 (see page 32) summarises the key nutritional and functional characteristics of a range of standard dairy-protein ingredients regularly used by bar formulators.
Typically, formulators use protein blends to manage the pros and cons of individual ingredients. They make trade-offs to achieve the best compromise in terms of processability, shelf life, texture, flavour, colour and formulation cost. These trade-offs become increasingly difficult at increasingly high protein levels. Often dairy proteins are blended with vegetable proteins, such as soy, which typically offer some cost advantages but are limited in other dimensions such as flavour. Blend components seen regularly in bars include calcium caseinate, whey protein hydrolysate and soy protein isolate.
As dairy producers develop new expertise in protein processing, ingredients are changing for the better. Products such as milk-protein concentrates (MPC) and whey-protein concentrates (WPC), not traditionally favoured for use in bar applications, can now be functionalised to perform well in bar formulations, and at the same time bring important flavour advantages.
For example, Fonterra has recently launched three new functionalised ingredients designed especially for bars. Studies at the Fonterra Research Center have shown PowerProtein 4857 (MPC 4857) and PowerProtein 515 (WPC 515) to have similar functional performance to calcium caseinate and whey-protein hydrolysate, respectively. The PowerProteins have been demonstrated to have a cleaner flavour and reduced rates of bar hardening compared to their traditionally used counterparts. Texture analysis results demonstrate that the rate of hardening of 30 per cent protein (per gram) bars is lower for these functionalised ingredients.
It is important to note that all milk-protein concentrates and whey-protein concentrates are not equal in terms of functional performance. They can be functionalised in different ways to produce different results in the end application.
For example, whey ingredients can be difficult to process and difficult to consume due to high levels of cohesiveness and stickiness. Typically they cause shelf-life issues due to high rates of bar hardening. Fonterra's new WPC allows higher levels of whey incorporation because it results in a dough that is less cohesive and sticky than a dough made with a typical whey-protein concentrate. This new ingredient behaves much like whey-protein hydrolysate (WPH) in terms of its bar-softening and shelf-life improvement advantages. Unlike WPH, however, where the use level tends to be limited due to flavour, it has a very clean flavour. It is also more cost effective.
Each ingredient contributes differently to the texture of the final protein blend. At the Fonterra Research Center, a mixture study was carried out to demonstrate the effect of each functional PowerProtein on bar texture. PowerProtein 4857 gives a softer texture, with a shorter bite, while PowerProtein 515 also has a soft texture, but is relatively more cohesive (though not excessively so like standard whey ingredients).
PowerProtein 4861 (MPC 4861), a third ingredient, helps to build texture in bar formulations where this is needed, such as in high-carbohydrate energy bars.
When blended together, a range of textures can be achieved in conjunction with improved taste and shelf life, giving formulators more scope than ever before to make protein-containing bars with broad consumer appeal. New functionalised ingredients are increasingly replacing traditional ingredients offering the same benefits without the limitations. Perhaps health-conscious consumers who are not prepared to compromise on indulgence will soon be able to 'have their cake and eat it, too.'
Rachel Marshall is technical manager for bars and snacking, Fonterra (USA). The Fonterra (USA) Technical Center develops dairy applications for customers.
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