Functional Cakes

As the incidence of obesity and diabetes at all ages increases globally, weight-conscious consumers are seeking products with fewer calories, reduced sugar, less fat and a lower glycaemic response.

A study conducted by Danisco has resulted in a sponge cake that has at least 30% reduction in sugars using bulking agents and polyols. It has the same characteristics as a typical cake but with a longer shelf life. Before revealing the details of the study, let’s understand the ingredients used in developing the product.

The nutritional profile of a sponge cake can be improved when manufacturers use polydextrose and lactitol to partially replace sucrose.

Bulking agents

Generally, bulking agents provide body and texture to the product and they are usually low in sugar and calories. Polydextrose, a commonly used bulking agent, is a polysaccharide that has randomly crosslinked glucose molecules with all types of glycosidic bonds (where 1,6 bonds predominate) that contain small amounts of bound sorbitol and acid. Since its commercialization in the early 1980s, polydextrose has demonstrated its versatility both as a sugar and a partial fat replacer in food. It has an energy value of 1 kcal/g compared with fat at 9 kcal/g and sugar at 4 kcal/g.

Polydextrose is partially fermented by intestinal micro-organisms, thereby producing volatile fatty acids that are absorbed and utilized. It is also digested as dietary fibers. The dietary fiber and prebiotic qualities of polydextrose are considered beneficial in many countries such as the US and Japan, where it has been used as a source of dietary fiber for years.

Sugar alcohols

Sugar alcohols, or polyols, are produced by the catalytic hydrogenation of their corresponding saccharides – lactitol for example is produced from lactose, and xylitol from xylose. They are naturally found in plants and fruit, although extraction from these sources is still not economically viable, as hydrogenation greatly modifies the physical-chemical properties of the sugar alcohol compared to that of precursor sugar. The hydrogenated sugar alcohols would also be less prone to microbiological fermentation and therefore more difficult for mammals to digest and absorb. It is for this reason that sugar alcohols have a reduced caloric value and they can be used in low glycaemic products and are therefore suitable for diabetics.

• Lactitol

With a relative glycaemic response of three, lactitol is available in both anhydrous and monohydrate form. It has a sweetness level of about 40% when compared to sucrose and it can be used in various sweetening applications. Lactitol can be used to substitute the sugar, weight for weight, in bakery applications. Lactitol-sweetened products generally have similar characteristics to products that are commonly sweetened by sucrose, although the level of sweetness may need some adjustment using intense sweetener combinations.

Lactitol enables manufacturers to create a less-than-sweet version of a product. In cakes, crystalline lactitol formulates and processes in the same way as sucrose. Due to a similar viscosity at low to moderate concentrations, similar batters can be developed, enabling manufacturers to produce cakes with desired textural and visual qualities and nutritional claims.

Chart 1: Formulation used in a study that Danisco conducted on cakes.

Cake test Three cakes were used in the study that Danisco conducted. They are:

1. A control cake (Control) that was made with sucrose at 22.35%; 2. Sponge Cake II that was made with sucrose at 11.17%, lactitol at 5.59% and polydextrose at 5.59%; and 3. Sponge Cake III that was made with sucrose at 11.17% and polydextrose at 11.18%.

• Recipe

1. Mix the dry ingredients for 20 minutes at Speed 1 using a Hobart type mixer, fitted with a paddle.

2. Add the cake gel, eggs and high fructose corn syrup (HFCS) and mix at Speed 1 for one minute.

3. Mix the batter for three minutes at Speed 2.

4. Scrape the side wall and the base of the mixing bowl.

5. Mix the batter at Speed 1 for three minutes while adding water and oil into the mixture slowly.

6. Measure specific gravity.

7. Pour batter into a rectangular cake tray and spread the batter evenly on the tray.

8. Bake in MIWE oven at 190°C for 20 minutes.

The cakes were baked and packed in suitable packaging of 1000μm thick. The samples were kept at ambient conditions (25-30°C, 40- 50% relative humidity) and were analyzed for softness and moisture over 92 days of storage.

Results

The cake batters of the Control and Sponge Cake II had similar specific gravity results, whereas the cake batter of Sponge Cake III had a higher specific gravity (see Figure 1). As Sponge Cake III had 50% of its sugar replaced by polydextrose, which is a non-crystalline material, there was unsatisfactory aeration when compared to the crystalline sugar and polyol used in the Control and Sponge Cake II. A significantly higher specific gravity for the cake batter was observed after all the batters were whipped to 27 minutes. The specific gravity of Sponge Cake III batter would be lower if the batter were to be mixed for a longer time, as the aeration would improve with more whipping.

Figure 1. Specific gravity of the cake batters.

Similar crumb texture and color were observed in all the sponge cakes, which indicated that the use of polydextrose and lactitol did not affect the appearance of the cakes (see Figure 2).

Figure 2. Crème cakes on the first day of the study.

Texture analysis was conducted over 92 days. Analysis results (see Figure 3) showed that Sponge Cake II had the softest crumb after 92 days. This indicated a partial replacement of sugar by polydextrose and lactitol, which gave a significantly softer texture when compared to the Control.

Figure 3. Firmness of the crème cakes over 92 days.

Polydextrose, when used at an optimal dosage was also seen to function well as a humectant. It was able to maintain the softness of the cakes over the trial period. Results of Sponge Cake III showed that when higher amounts of polydextrose were added to the cake, it became slightly gummy and had a firmer texture than expected. Optimal dosage of polydextrose would therefore depend on the final formulation used.

The moisture content variation observed in Sponge Cakes II and III over the three-month storage period was seen to be lower than the Control (see Figure 4). The water activity (Aw) range of all the cakes was found to be between 0.77 and 0.85 over the trial period.

Figure 4. Moisture content and water activity (Aw) of the crème cakes over a period of 92 days.

Conclusion

The study has shown that the polydextrose and polyol lactitol used improved the nutritional profile of a sponge cake, as the ingredients were used to replace 50% of the original amount of sucrose needed. When used in Sponge Cake II, the ingredients provided the added benefi t of fi ber enrichment and improved shelf life, due to the fiber content and humectancy capabilities of polydextrose.

The study also showed that there is a need for sufficient crystalline material in the formulation in order to provide the desired aeration of the cake batter, as much non-crystallizing material would provide a denser product, thereby affecting the soft texture of cakes.

From the study, the nutritional profile of a sponge cake can be improved when manufacturers use polydextrose and lactitol to partially replace sucrose. Further studies have also showed that the nutritional profile of certain cakes can be improved by reducing fat without affecting mouth-feel.

www.danisco.com/sweeteners

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Drug-Free Honey

It is necessary to test honey for antibiotic contamination in order to prevent the export of tainted products.

BY SENA RAYOS, RESEARCH ASSOCIATE, DR MINGANG CHEN, DIRECTOR, R&D, BIOO SCIENTIFIC

Honey is commonly used by consumers as a sweetener in beverages and in bakery products. Manufacturers worldwide are also producing products such as mead, an alcoholic drink, and cough drops made from honey. According to the Food and Agriculture Organization (FAO), China is the biggest honey producer followed by the US, Argentina, Turkey and Ukraine.

Honey has a desiccation ability to draw water out of the microorganisms and kill them with osmotic pressure. The low moisture content and hyperosmotic nature of honey prevent bacterial and yeast growth. Its hygroscopic property absorbs moisture and removes it from the air that has a relative humidity of over 60%. Its high acidity level (pH values between 3.2 and 4.5) also prevents bacterial growth. When producing honey, bees add an enzyme called glucose oxidase in the substance to accelerate the oxidation of glucose to produce hydrogen peroxide and gluconic acid, which possess anti-bacterial benefi ts.

To meet rising demand, the mass production of honey can sometimes lead to poor product quality and beekeepers supplementing the bees with antibiotics in order to control diseases.

Antibiotic use in honey production

To meet rising demand, the mass production of honey can sometimes lead to poor product quality and beekeepers supplementing the bees with antibiotics in order to control diseases. To prevent bees from being infected by parasitic mites and diseases such as the foulbrood disease, some beekeepers use antibiotics such as tetracycline, streptomycin, amphenicol, sulfonamide and chloramphenicol on them, resulting in the presence of trace levels of residual antibiotics in honey. This alarms consumers and the media as antibiotics like chloramphenicol have rare but severe side effects such as idiosyncratic aplastic anemia, which is a condition that can be debilitating and potentially fatal. Other side effects of antibiotics include allergies, deafness, renal failure and a loss of appetite.

The regular consumption of honey that is laced with antibiotics can potentially increase one’s chances of becoming resistant to antibiotics, making antibacterial treatment more difficult. Although the amount of antibiotics found in affected honey is extremely low when compared to doses of anti-bacterial drugs dispensed by doctors to patients, it is still a health concern as potential hazards remain unknown.

Natural bacterial flora helps the digestive system to break food down, protect one against pathogens and stimulate immune response. The trace levels of antibiotics found in honey could reduce the amount of indigenous microbiota found in the human digestive tract, thereby requiring the regulation of antibiotic-free honey. America and Europe currently ban imported honey containing trace amounts of antibiotics.

Chloramphenicol incident in China

In 1997, a bacterial epidemic swept through thousands of beehives in China, resulting in a decrease in the country’s honey production by over 60%. While the affected beehives are usually burned to prevent the spread of the disease, some Chinese honey producers sprayed chloramphenicol on the disease-ridden bees.

A potent antibiotic, chloramphenicol is an inexpensive, broad-spectrum antibiotic that is usually used on humans as a last resort to fight bacterial infection. The China’s Ministry of Agriculture in 2005 outlawed the use of chloramphenicol in food production, making it illegal to use the drug in apiculture. Chloramphenicol was however detected in honey and caught worldwide attention in 2007.

Honey from China remains on top of the US Food and Drug Administration watch list since 2002. Honey from countries such as Argentina has also tested positive for the presence of antibiotics such as nitrofurans. Meanwhile, the European Union lifted its 2002 ban on Chinese honey in 2004 as it found “significant improvement” in veterinary standards.

Ensuring safe honey

It is necessary to test honey for antibiotic contamination in order to prevent the export of tainted products. Detection methods include standard microbial inhibition, high performance liquid chromatography and liquid chromatography-mass spectrometry (HPLC and LC/MS; see in Table 1).

Table 1. Tests used to detect antibiotics in honey.

HPLC allows users to separate, analyze and identify compounds in their samples. The samples are usually prepared by organic solvent extraction and are injected in the sample port of the HPLC instrument for analysis. Samples of honey spiked with antibiotics and certified drug-free honey are used as standards and controls respectively.

LC/MS combines HPLC capabilities with mass spectrometry, which allows the analysis of compounds found in the samples. The mass spectrometer can measure the mass of the compounds when their molecules are converted to gas-phase ions. The ions are directed into an electromagnetic field, which are analyzed for mass-to-charge ratio. The data system converts the current to a digital input that displays it as a mass spectrum. The antibiotics present will show certain peaks in the mass spectrum display and multiple antibiotics can be analyzed at one time.

Honey has a desiccation ability to draw water out of the microorganisms and kill them with osmotic pressure.

To test honey using the microbial inhibition method, samples are applied to a 96-well plate containing Bacillus spores, which are sensitive to antibiotics. The spores will not grow if the samples are contaminated with antibiotics. Microbial inhibition methods can detect 10-1000 parts per billion (ppb) of certain antibiotics. In order to determine the type of antibiotics present, an enzyme linked immunosorbent assay (ELISA), HPLC and/or LC/MS are performed on honey samples. By adding these testing in existing processes, manufacturers, regulators and consumers will be ensured of continued food safety, even in this common food.

www.biooscientific.com

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Protecting Consumers

Manufacturers should voluntarily label products in the interest of their consumers.

BY DANIEL TSI, REGIONAL DIRECTOR, WAI MUN POON, REGIONAL REGULATORY AFFAIRS MANAGER, EAS STRATEGIC ADVICE, SINGAPORE

Nutrition labeling is important to stakeholders – regulators consider nutrition labels as a medium to convey accurate information about food for public health and education; consumers use the labels to help them make informed food choices; and companies leverage on the labels in their marketing efforts.

While most Southeast Asian countries do not require compulsory nutrition labeling of “general food” products, it can be mandatory for “specific foods” that are enriched and fortified with vitamins and minerals for dietary uses, and/or when adding a nutritional claim to the product.

Indonesia, the Philippines, Singapore and Thailand for example require the labeling of such foods. Most of these countries require manufacturers to label four core nutrients – energy, fat, carbohydrates and protein – on the product packaging. Companies that fail to comply with the rules could face fines and in some cases, a jail term.

Allergy alert

Besides nutrition labeling, more manufacturers in Asia are also providing information on food allergens on pre-packaged food labels due to a greater public awareness of food allergies. While there are laws and guidelines in Europe and the US on the labeling of common food allergens, there are no similar regulations in most Southeast Asian countries. This could possibly be due to a lack of comprehensive information on food allergies in the region.

Based on existing literature, milk, seafood and eggs are commonly listed as allergens in products. However, according to a research in Current Opinion in Allergy and Clinical Immunology in 2006, there could be more ingredients with potentially allergenic affects in food such as bird’s nest, buckwheat, royal jelly and sesame.

While more studies on food allergies are needed to develop viable food allergen labeling guidelines in Southeast Asia, authorities in some countries are considering revising existing regulations on pre-packaged food labeling. In the meantime, manufacturers should indicate the presence of any known food allergen in their products voluntarily in the interest of their consumers.

www.eas-asia.com