KR20040103818A - Low-lactose milk and its production method - Google Patents

Abstract

PURPOSE: A method of making low-lactose milk by hydrolyzing milk with lactase, concentrating the obtained hydrolyzed lactose milk by a nanofiltration method to partially remove glucose and galactose and then adding with water is provided. It removes glucose and galactose by the nanofiltration method and produces the product low in sweetness and off-flavor. CONSTITUTION: Milk is hydrolyzed with lactase to give hydrolyzed lactose milk, which is concentrated by a nanofiltration method and then added with water to remove the sweetness. For an example, milk is added with 0.03% by weight of lactase(Validase), hydrolyzed at 4deg.C for 24hr and then heated at 65deg.C for 30min to give hydrolyzed lactose milk, which is concentrated with a nanofiltration membrane(DL4040F1020, Osmonics) at 40deg.C at 150psi. In the process, the inflow amount of the hydrolyzed lactose milk is about 35L/min and outflow amount of a filtrate is about 1.8L/min.

Description

Low lactose milk and its manufacturing method {Low-lactose milk and its production method}

In the present invention, lactose-decomposed milk is filtered and concentrated by nanofiltration, followed by hydrolysis to reduce the concentration of glucose and galactose to reduce sweetness, while low lactose made of calcium and riboflavin less than 15-20%. It relates to milk and a method of manufacturing the same.

Milk is a very nutritionally important food containing essential nutrients such as high quality protein, calcium and riboflavin. Milk contains 4.8-5.2% of lactose as carbohydrates. When milk is ingested, lactose is digested and digested into glucose and galactose by lactose enzymes located on the mucous membranes of the small intestine.

However, most Asians and blacks, including some Westerners, grow after weaning after weaning, resulting in a rapid decrease in lactose in the small intestine, resulting in a lack of lactose-degrading capacity (J. Am. Col. Nutr., 19, 165S ( 2000): J. Am. Col. Nutr., 20, 198S (2001): J. Pediatr.Gastroenterol.Nutr., 30, 283 (2000): Korean Journal of Dairy Science, 16, 105 (1994)). Therefore, milk of about 200ml (containing about 10g of lactose) does not cause lactose digestion symptoms in most people, but this symptom occurs in people who are lactose deficient if they consume 20-50g or more of lactose on an empty stomach. . The symptoms of lactose digestion disorders are that when milk is ingested, lactose is not digested and absorbed in the small intestine, so it enters the large intestine, inhibits the absorption of water by increasing the intestinal osmotic pressure, and increases the acidity, gas, and toxin production by the growth of E. coli. Will cause softening of the feces, release of gas and diarrhea. People who experience these symptoms are one of the major reasons for avoiding milk. Reduced milk intake in young adults and adults during growth can lead to inhibition of physical growth and osteoporosis due to lack of calcium.

For those with lactose digestion disorders, lactose-degraded milk produced by treating milk with lactose or immobilized lactose by decomposing lactose into glucose and galactose has been developed and produced (US patent 5,357,852, (1994. 10. 25). ): Kim Young-kyo, Kim Young-ju, Kim Hyun-wook, Science of Milk and Dairy Products, Advanced Culture History (1981) 194). However, lactose-decomposed milk contains glucose and galactose, which is stronger than milk, can accelerate browning reaction when heated at high temperature, decreases fresh taste, and is not suitable for digestive physiology because of high osmotic pressure. have.

Lactose-free milk (U.S. patent 20030031754 (February 13, 2003)) was developed by filtration of milk by ultrafiltration to remove some lactose, reducing it with water, and then treating it with lactose. In 2001, Valio Ltd produced lactose-free milk that physically completely eliminated lactose (Tiina Mattila-Sandholm and Maria Saarela, Functional dairy products, Woodhead Publishing Ltd (2003) 9-10). However, the ultrafiltration method may considerably remove nutrients such as calcium and riboflavin in milk as well as lactose, depending on the concentration, which may result in significant loss of nutrients.

Membrane filtration is classified into reverse osmosis, nanofiltration, ultrafiltration, and microfiltration. Nanofiltration and ultrafiltration can be used to remove sugar from milk and concentrate proteins and fats. Nanofiltration concentrates organic compounds with a molecular weight of 300 or more and polyvalent ions such as calcium, magnesium and phosphoric acid (J. Membrane Sci. 98: 249 (1995)). Ultrafiltration is a method that can concentrate substances with a molecular weight of 1,000 to 1,000,000 or more (E. Renner and M.H. ABD El-Salam, Application of ultrafiltration in the dairy industry, Elsevier Applied Science (1991) 9). Since the molecular weight of lactose in milk lactose is 354, the molecular weight of glucose and galactose is 180 and the molecular weight of riboflavin is 376, lactose and riboflavin can be concentrated using nanofiltration and the glucose and galactose can be filtered.

U.S. In the ultrafiltration method used in patent 20030031754 (February 13, 2003), a filtration membrane filters milk lactose. This method not only filters riboflavin with similar molecular weight, but can also filter significant amounts of calcium. On the other hand, in the present invention, the nanofiltration method has the advantage of filtering glucose and galactose of lactose-degraded milk and suppressing the loss of riboflavin and calcium.

Therefore, an object of the present invention is to concentrate lactose-decomposed milk 1.5 to 3 times using nanofiltration method to remove glucose and galactose, and then to reduce the sweetness by reducing the sweetness while reducing the loss of calcium and riboflavin 15% or less and 20% or less, respectively. By minimizing the production of low lactose milk.

1 is a general manufacturing process of low lactose milk

In the constitution of the present invention, lactose-degraded milk prepared by adding lactose to the milk and reacting at a constant temperature and time is concentrated by a nanofiltration method and then water is added to prepare low lactose milk. 1 shows a general low lactose milk production method. If the hygienic quality of lactose-degraded milk is inferior or the reaction temperature is high during mammary enzyme treatment, the milk is heated (eg, 65 ° C., 30 minutes) to sterilize and inactivate the enzyme in the milk (optional step). Appropriate lactose is added to milk and allowed to react for a certain temperature and time to break down lactose into glucose and galactose. Lactose digested milk is heated (eg 65 ° C., 30 minutes) to inactivate lactose enzymes (selectable step). If it has already been sterilized and there is no need to stop lactose decomposition, it does not need to be heated. Filtration and clarification are the processes in which milk is filtered or centrifuged to remove foreign substances in the milk. Homogeneous is a process of dispersing milk fat to prevent the separation of cream, can be selected according to the type of product and can be carried out before and after sterilization treatment (optional step).

When the lactose-decomposed milk is introduced into the nanofiltration filtration device, it operates at a temperature lower than that suggested by the filtration membrane manufacturer. The flow rate and pressure of milk comply with the conditions suggested by the filter membrane manufacturer, and the optimum conditions are determined and used so that the filtrate flow rate is high. Depending on the degree of lactose decomposition, lactose-decomposed milk may be concentrated to 1.5 to 3 times and then hydrolyzed to reduce to a certain volume so that the sweetness is the same as fresh milk or the sweetness may be further reduced. Contamination may occur during filtration, hydrolysis, and reduction, so that milk can be sterilized in LTLT (65 ° C, 30 minutes), HTST (73 ° C, 15 seconds), or UHT (130 ° C, 2 seconds), and then filled into clean containers and low lactose Prepare milk. In case of sterile milk, sterilize UHT and fill it into sterilized containers in aseptic condition.

EXAMPLE

Lactobacillus (Validase, Valley Research, Inc.) was added 0.03% to the milk and reacted at 4 ° C for 24 hours, followed by heating at 65 ° C for 30 minutes to inactivate and sterilize lactose-degraded milk. Lactose digested milk was concentrated using a nanofiltration filtration membrane (DL4040F1020, Osmonics) at a pressure of 150 psi at 40 ° C. At this time, the flow rate of lactose-decomposed milk was about 35 L / min and the discharge flow rate of the filtrate was about 1.8 L / min. Lactose digested milk and filtrate samples were collected when lactose digested milk was concentrated 2 and 2.5 times.

Low lactose milk was prepared by adding water to the concentrated lactose-degraded milk to the original volume of the lactose-decomposed milk. The sensory test was performed to compare the sweetness of milk with low lactose milk adjusted to 15 ℃. Moisture (atmospheric drying), milk fat (Gerber method), crude protein (Kjeldahl method), crude ash (dry calcification method), lactose, glucose and galactose (HPLC method), calcium and sodium (Atomic absorption) and riboflavin (HPLC method) were quantitatively analyzed.

Five of the six participants who participated in the sensory test responded that low-lactose milk, which had been reduced after doubling, was sweeter than milk, and one responded that milk was more sweet. All six responded that the milk was sweeter than the low-lactose milk, which had been reduced and reduced by 2.5 times. Therefore, low-lactose milk with a sweetness similar to milk could be said to be reduced milk after concentration of 2 to 2.5 times.

As shown in Table 1, the lactose concentration of lactose-degraded milk was 0.8% and about 84% of the lactose in the milk was decomposed. The lactose concentration was 1.0% or less, which is a legal standard (processing standard and ingredient standard of livestock products, National Veterinary Research and Quarantine Service (2001) 18-19). The water content of low lactose milk was 1.5-2.1% higher than that of lactose-degraded milk and the changes of milk fat, crude protein and lactose were small. The low-lactose milk hydrolyzed after 2 times concentration was 68%, 71% and 68% of the concentrations of glucose, galactose and sodium, respectively, compared to lactose-degraded milk. Calcium and riboflavin, on the other hand, were 93% and 90%. The low-lactose milk, which had been hydrolyzed after 2.5-fold concentration, had a concentration of 55%, 59% and 61% of glucose, galactose and sodium, respectively, as compared to lactose-degraded milk. On the other hand, calcium and riboflavin were 90% and 86%. From these results, it can be seen that calcium and riboflavin were selectively concentrated in comparison with glucose, galactose and sodium by the nanofiltration method. Therefore, low lactose milk with similar sweetness to milk could maintain at least 90% calcium and at least 85% riboflavin compared to lactose-degraded milk.

In the present invention, low lactose milk made by removing glucose and galactose, which are sweet components of lactose-decomposed milk, can be prevented from diseases caused by lactose digestion disorder as well as low sweetness and less off-flavor, resulting in high overall milk consumption. It is expected to increase. When using the nanofiltration method used in the present invention, loss of calcium and riboflavin, which are important nutrients in milk, can be kept at least 15% and 20%, respectively, to minimize the loss.

Claims (3)

A method for producing low-lactose milk, characterized in that the lactose-degraded milk prepared by treating milk with lactose is concentrated by a nanofiltration method, followed by hydrolysis to reduce sweetness. Low lactose milk prepared by the method of claim 1. Food made by further processing the low lactose milk of claim 2.