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Preserving nutrients in baked goods

Steve Osborn and Naomi Diaz-Osborn of The Aurora Ceres Partnership and Richard Horton of Carritech Research describe a new, low temperature baking technology able to preserve temperature sensitive nutritional ingredients

The food and beverage industry trend-watchers have declared for many years that consumers desire more natural products. A core part of this is a demand for products that are considered to be minimally processed, since the input of heat into a product can have negative implications for taste, structure and, importantly, nutritive properties. Vitamins and amino acids in particular are degraded by exposure to elevated temperatures for relatively short periods of time. However, there is no doubting that the application of heat is an essential part of food production and processing, not the least due to the broad food safety benefits of adequate heat treatment.

In recent years the food industry has shied away from shouting about the science and technology that is inherent in food processing. This has also led to a reticence to invest in novel technologies that can add value, for fear of not achieving the return on investment that sticking to traditional processes would yield. If the ‘holy grail’ of less processed foods is that they deliver taste, texture, stability and safety, a fundamental change in philosophy is required by the industry to adopt new and emerging technologies, but also on the part of the consumer to recognise the value that the input of science in food can deliver.

New food technologies are being developed all the time that aim to solve many problems with today’s food and drink; typical examples include High Pressure Processing and ColdBake, a low temperature vacuum application.

High Pressure Processing

High Pressure Processing (HPP) has started to establish itself in the beverage sector in recent years, despite the process itself having been around for many decades. It provides a cold pasteurisation process for products that if left unprocessed would exhibit microbiological and quality instability. Whilst heat treatment or pasteurisation is an obvious solution to such issues, it can have a detrimental effect on the nutrition, taste and colour of the product. The comparative low temperature of HPP therefore becomes extremely desirable in the preservation of vitamins, such as C and B-Carotene, as well as colour parameters, whilst achieving equivalent pasteurisation[1]. The current limitation of HPP is its requirement for flexible packaging but it shows huge potential in achieving less harsh, low temperature processing capability.

ColdBake

Another prime example of minimal processing is seen with ColdBake, a low temperature baking process that can deliver enhanced nutrition in a light crispy textured product. ColdBake could be described as a progressive, patented technology that bares the hallmarks of the paradigm shift in thinking that the food and drink industry needs to embrace in order to deliver the healthier, more nutritious products that consumers want.

The patent for this technology, ‘Chemical compositions for delivery of pharmaceutical agents’[2], describes how light crispy textured products can be created by using a combination of low temperature, less than 75°C, and vacuum technology. This technology holds the potential to challenge and disrupt the notion that baked products cannot deliver enhanced nutrition.

ColdBake technology enables crunchy or chewy ‘carrier’ products to be produced typically at close to human body temperature, thereby preserving the functional properties of temperature sensitive ‘payloads’ – nutrients or medicines - contained within them. By applying ColdBake technology it is possible to produce honeycomb-textured nutrient- or medicine-enriched products that appear and taste as though they have been baked, but without using normal baking temperatures.

A recognised challenge in the functional foods sector is the retention of activity of heat sensitive nutritional ingredients during the process of manufacturing palatable edible formats. Conventional processes, such as baking and extrusion cooking, subject these ingredients to temperatures which are liable to render them inactive. ColdBake technology, however, enables crunchy foods and ‘intermediate ingredients’ to be produced at low temperatures, thereby preserving the functional properties of temperature sensitive ingredients.

How it works

The process is largely based on vacuum oven technology: vacuum expansion and drying. Mixing, forming and conditioning process steps are also critical and essential features.

Typically, the sequence of process steps is:

• weighing and blending of powdered ingredients;

• adding and mixing in of liquid ingredients and water;

• shaping the resulting moist powders or dough into granules, pellets or larger pieces;

• allowing them to ‘condition’;

• then expanding and drying them in a vacuum oven.

Additional process steps may be introduced to achieve some particular end product formats, (e.g. moulding to produce bars or particular shapes, or size-reduction processes to achieve some types of granular products).

At their most basic, the end products can be thought of as having two components: a ‘carrier’ food material, which has a honeycombtype structure, (e.g. biscuit, expanded snack, granules, bars or fingers), and a ‘payload’, which can be one or more nutrients or medicines. Usually, the payload is uniformly distributed throughout the carrier.

ColdBake technology enables crunchy or chewy ‘carrier’ products to be produced typically at close to human body temperature, thereby preserving the functional properties of temperature sensitive ‘payloads’."

The formulations normally consist of five categories of ingredients:

1. Structural - essentially the ingredients that form and hold together the walls of the honeycomb-textured carrier.

2. Structure-modifying - ingredients that alter the texture of the carrier, making it harder, softer, crisper, chewier, etc.

3. Flavouring - the products can have a wide range of sweet or savoury flavours, which sometimes can be selected to mask the taste of unpleasant nutrients or medicines.

4. Nutritional or medicinal payload - often present in small or trace amounts, but can sometimes be a bulk structural ingredient, (e.g. whey protein).

5. Expansion agent - normally water which vaporises as vacuum is applied, but alternative expansion agents would sometimes be more suitable, depending on the nutritional or medicinal payload. The novel carrier formulations contain widely available ingredients, such as readily available flours, modified flours, dietary fibres, sugars and milk or other protein-containing powders, that are commonly used in conventional baked and extruded snack products, so generally speaking there is no ingredient cost penalty in using the ColdBake technology. No chemical raising agents are used and there is no requirement for the use of artificial or unnatural ingredients. The payloads can be a wide range of nutrients (e.g. vitamins, minerals, polyunsaturated fatty acids, bioactives) and medicines in powder or liquid form. Additionally, no acrylamide is formed as a result of the low processing temperatures.

Technical validation

Projects undertaken in conjunction with the University of Ulster and with Leatherhead Food Research have both demonstrated that nutrients (fish oil omega-3 and vitamin B1) contained within a typical ColdBake biscuit or snack are not only undamaged, but also are as bioaccessible as if they were consumed in conventional capsules.

Vitamin B1 study

In order to validate the process from a nutrition perspective, it was important to evaluate the comparative bioavailability, when compared to commercially available alternatives. Vitamin B1, was selected as a typical heat sensitive vitamin and was compared to commercially available vitamin B1 supplements in gel capsule form. The bioavailability was tested using simulated digestion methodology, in vitro. Coldbake products containing 23mg of vitamin B1 per biscuit and commercial gel capsules containing an equivalent amount of vitamin B1 powder underwent gastric digestion at pH 2.5 in the presence of lecithin and the gastric enzymes pepsin and lipase for 2 hours at 37˚C. This was then followed by duodenal digestion at pH 6.5 for 2 hours at 37˚C with trypsin, chymotrypsin, pancreatic lipase, pancreatic amylase and bile salts. The resulting digesta was analysed by HPLC to determine the levels of vitamin B1 remaining after digestion.

Vitamin B1 was recovered from the digestion of the gel capsules at 106.8 ± 2.8% and at 77.2 ± 5.4 % for the biscuits. This equated to a relative bioavailability of vitamin B1 of 72.6 ± 7.0% from the biscuits.

The findings of the study demonstrated that vitamin B1 is bioavailable in the test product, in vitro, at relatively high levels (>70%) demonstrating that ColdBake technology is suitable for delivering particularly heat sensitive compounds, such as vitamin B1, to the consumer and may be applied to similarly unstable nutrients of health benefit. A high temperature process would have rendered the nutrient inactive.

Fish oil – omega-3 study

The preservation of nutrients was further validated by a twoweek intervention comparing omega-3 oil-enriched ColdBake products and gelatine capsules. Concentrations of total serum n-3 polyunsaturated fatty acids (PUFA), serum eicosapentaenoic acid (EPA) and serum docosahexaenoic acid (DHA) increased in the trial group receiving both of the enriched products. The placebo group, by comparison, showed no significant change. These results showed that the bioavailability of nutrient from the ColdBake product is similar to that of the same amount of nutrient provided in a capsule form. This finding indicates that the bioavailability of these nutrients from the two sources is equivalent and provides strong evidence for the suitability of the snack as a nutrient carrier within the functional foods market.

Whilst there was not a specific sensory element to this study, it was observed that the level of compliance with the supplementation regime was extremely high, which gave a rudimentary indication of product acceptability.

From these trials it is considered that the ColdBake technology not only satisfies the desire amongst consumers for minimally processed foods, but also has the potential to provide a new platform for sensorially desirable, snack products with enhanced nutrition.

References
1. Michelle K Bull, Katherine Zerdin, Effie Howe, Dimitria Goicoechea, Priscilla Paramanandhan, Regine Stockman, Jay Sellahewa, Elizabeth A Szabo, Robert L Johnson, Cynthia M Stewart. The effect of high pressure processing on the microbial, physical and chemical properties of Valencia and Navel orange juice. (2004). Innovative Food Science & Emerging Technologies, Volume 5, Issue 2, June 2004, Pages 135–149.
2. Horton R., Patent Chemical compositions for delivery of pharmaceutical agents, 2014. Patent US, 14/0167307A1

Steve Osborn BSc (Hons), M.Phil., CSci, FIFST Principal Consultant - Food and Beverage and
Naomi Diaz-Osborn BSc (Hons), M.Sc. Principal Consultant – Strategy and Innovation,
The Aurora Ceres Partnership Ltd, Dr Richard Horton, Carritech Research Ltd
Web: www.auroraceres.co.uk Tel: 07956 144188



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