In general, various types of techniques are being researched and applied to reduce the sugar content in dairy products. Meanwhile, replacement, modification, and direct reduction of sugar are the most popular ones.
- Sugar substitutes
One of the most important ways to slash sugar is to replace it with sweeteners to reduce calories and maintain the sweet taste. Currently, many types of sweeteners are available to replace sugar, but as mentioned earlier, there are many challenges with sugar replacement. In addition, sugar replacement is very product-specific and the method cannot be defined by any single model. However, sugar replacement has been successfully used in many products such as frozen yogurt, ice cream, yogurt, and chocolate milk. The researchers found that:
- Stevia can be used simultaneously with some sucrose in flavored low-fat yogurt.
- Probiotic yogurt can be produced using sweeteners without affecting the viability of probiotics.
- The sweet taste of chocolate milk can be preserved to some extent with monk fruit and stevia.
- Low-calorie ice cream sweetened with sorbitol (natural) and sucralose (artificial) has 25% less sugar compared to other ice creams.
- Substitution of inulin and isomalt (natural substitutes) leads to the production of frozen yogurt with optimal sweetness and less fat.
Types of sugar substitutes
- Natural sweeteners
- Stevia, extracted from the leaves of the stevia plant, is widely used in dairy products, including Danone’s Two Good yogurt, which has only 2 grams of sugar. Newer stevia compounds include steviol glycosides, which are at least 150 times sweeter than sugar. Both ViaTech Stevia Leaf Extracts and EverSweet Stevia Sweetener give producers access to the sweetest stevia leaf components (Reb M and Reb D). For commercial-scale production with reduced carbon footprint and water consumption, scientists have turned to fermentation. Also, ClearFlo, a plant extract, can be combined with other stevia ingredients to provide better solubility and stability in concentrates such as fruit yogurt (with faster dissolution and improved flavor characteristics).
- According to FDA rules, fruit pieces, dried fruit, pulps, and purees are not considered “added sugars”. Chobani Greek yogurt with 45% less sugar is produced using natural fruit. Additionally, monk fruit is a new addition to the dairy mix found in Chobani Zero Sugar Yogurt and contains high levels of antioxidants.
- Tagatose is a rare sugar that is 90% as sweet as sucrose but has fewer calories.
- Honey is 1.5 times sweeter than sugar, so dairy producers can reduce the total added sugars in a product simply by substituting honey for sugar. Honey is unique in its popularity among consumers because it is one of the only things that can be advertised on packaging. Honey works well in combination with other sweeteners.
- Sugar alcohols
Erythritol is a sugar alcohol that is commonly used in place of sucrose in combination with other sweeteners (such as stevia). Although erythritol can be an effective sugar substitute, other bulking agents such as inulin may be needed. Erythritol and lactitol are used to produce low-calorie ice cream.
- Sugar modification (lactose hydrolysis)
Lactose hydrolysis has been investigated as a method of sugar reduction because the hydrolysis of 70% of the lactose in milk increases the sweetness of milk or yogurt to the same extent as the addition of 2% sugar, so lactose-free milk is sweeter than regular milk. Lactose hydrolysis in yogurt also results in sweeter yogurt without added sugar. It has been reported that consumers cannot tell the difference between sugar-sweetened yogurt and lactose-hydrolyzed yogurt. This technology is also used in GoodSport sports drinks. Lactose hydrolysis has also been used to reduce the sugar content of ice cream. Studies have shown that the hydrolysis of 75% of lactose in non-fat powdered milk prevents the formation of a sandy texture and reduces the sugar content by 12.5 to 25% in ice cream. Also, it improved the overall acceptability of ice cream by lowering the freezing point and increasing the apparent viscosity and sweetness of the ice cream.
Although the FDA has not yet defined the terms “lactose-free” or “lactose-reduced” in dairy products, manufacturers are required to label their products correctly. Lactose hydrolysis can be done in different ways Single-use hydrolysis is performed 2 ways:
- Adding β-galactosidase to pasteurized milk and holding it at 35-45°C, then inactivating the lactase enzyme by additional heat treatment.
- Adding sterile lactase to UHT milk before packaging. This method hydrolyzes lactose in the first few days of packaging.
Both single-use enzyme methods are costly. More cost-effective lactose hydrolysis methods include membrane recovery of soluble enzymes or immobilized systems. In the membrane recovery system, the enzyme is added to milk permeate after ultrafiltration, and the enzyme can then be recovered by filtration and reused. The hydrolyzed lactose permeate is then reintroduced into the milk.
- Direct reduction
Direct sugar reduction is a method of gradually reducing sugar consumption. In this method, the amount of sugar in dairy products is slowly and gradually reduced so that consumers gradually get used to the lower concentrations of sugar. The amount of this reduction can be obtained by determining the threshold of sugar concentration change and the perception of sweetness by 50% of consumers. This threshold is also called JND (Just Noticeable Difference).
By calculating JND, sugar can be gradually reduced by 30% without the consumer knowing. Currently, this gradual reduction has been implemented in England regarding the reduction of salt. Also, the non-acceptance threshold is important to determine when the consumer is no longer willing to purchase a product. The JND threshold is currently used to reduce the sugar content of dairy emulsions and chocolate milk. It has been found that the higher the fat concentration, the more sensitive the consumer is to reducing sugar (i.e., the lower the JND value). Therefore, even if consumers notice a difference in sweetness, a 5-20% reduction in sugar is possible in a direct way.
Studies have shown that added sugar in chocolate milk can be directly reduced by 30% and still be acceptable. Chocolate ice creams usually have a higher sugar content to mask the bitter taste of cocoa. Therefore, researchers have suggested low-sugar chocolate ice cream for dark chocolate lovers.
- Ultrafiltration
Ultrafiltration is a pressure-driven process that separates compounds in milk based on molecular weight. This method is widely used in the dairy industry to remove lactose (sugar reduction). During ultrafiltration, higher molecular weight compounds (protein, fat) are retained by UF, while lower molecular weight compounds (lactose, water, minerals, and vitamins) pass through the membrane. Water can then be added back to the suspended solids to produce lactose-free milk, which is not as sweet as milk produced by lactose hydrolysis. The final sweetness of lactose-free milk produced by UF can be improved through milk chromatography or the addition of non-nutritive sweeteners. This method of lactose removal has been investigated as a means to reduce the sugar in yogurt and cheese.
- Other techniques
Modifying the structure of sweeteners to achieve the desired nutritional properties and taste is one of the potential techniques for sugar reduction. These solutions may also act on taste receptors to mask and/or enhance taste. For example, sugarcane distillate powder prevents the perception of bitterness by blocking the bitter receptors in the taste buds. Sugarcane molasses distillation powder also increases the perception of sweetness.
In general, the most successful techniques for reducing sugar in dairy foods involve replacing sugar with non-nutritive sweeteners, both natural and artificial. Direct reducing sugar and lactose hydrolysis methods are also promising.
New IFF enzyme for dairy products
Nurica, marketed under Danisco’s range of food solutions, reduces the lactose content in milk to naturally produce high yields of prebiotic galacto-oligosaccharide (GOS) fibers. It reduces the level of sugar and lactose while bringing the balanced sweetness of natural milk. This ingredient may be added directly to milk and ensures a stable product because the GOS fibers created remain stable throughout the shelf life of the product.
Collette Lentz, regional industry leader, Dairy Enzymes, North America, IFF, said: “GOS fibers increase the population of intestinal bacterial species. Therefore, Norica Enzyme has the potential for unique innovations related to prebiotics and improving gastrointestinal health. For years, GOS has been considered “Financials have been added to certain products such as baby-related products. Now, we’re excited to bring these benefits to the mainstream product offering.”
Reference:
McCain, H.R., Kaliappan, S. and Drake, M.A., 2018. Invited review: Sugar reduction in dairy products. Journal of Dairy Science, 101(10), pp.8619-8640. DOI: 10.3168/jds.2017-14347
