• Food Science of Animal Resources
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• v.31 no.6
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• pp.893-898
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• 2011

Milk contains a number of nutrients required for human growth and development, such as disaccharide lactose which is significantly contained in milk and dairy products. About two thirds of world populations are reportedly suffering from lactose intolerance after drinking milk. Lactose intolerance is defined as a maldigestion of lactose in the human intestine with typical symptoms of abdominal pains, bloating, and diarrhea. In this study, incidence of lactose intolerance has been investigated for the elementary school children for 1 year from July, 2010 to June, 2011. It is found that about 70% of the total elementary students have joined the school milk program. Out of 636 total students that participated in this study, 449 were from the metropolis, 85 from middle-sized city, and 102 from the small town including rural areas (small town/rural areas). For distributions of lactose intolerance, 154 students (24.2%) were found to be positive among the total 636 subjects. Based on the size of the city, the symptoms were the most prevalent for the students in the small town/rural areas at 31.4% (32/102), followed by 30.6% (26/85) in middle-sized city, and 21.4% (96/449) in the metropolis. On the other hand, gender had no significant effect on the incidence of lactose intolerance, shown those for boys and girls were 24.8% (77/310), 23.6% (77/326), respectively. Further research is needed to confirm the correct incidence of lactose intolerance symptoms as the frequency is significantly affected by subject's digestive functions including irritable bowel syndrome.

• Journal of Dairy Science and Biotechnology
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• v.38 no.1
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• pp.1-18
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• 2020

Lactose intolerance is a pathophysiological phenomenon caused by a deficiency of the enzyme lactase present in human intestines. Changes in intestinal digestion and colon fermentation after the intake of lactose-containing products cause diarrhea and other clinical discomforts. Therefore, lactose intolerance can be easily ameliorated by consuming lactose hydrolyzed milk and dairy products. In the recent years, lactose-free dairy products have provided lactose intolerant consumers with several options, due to an improvement in the quality and an increase in the variety of products. Currently, the manufacturing of lactose-free products also represents the fastest growing sector in the dairy industry. This review, thus, aims to provide an overview of the current availability and prospects of lactose-free dairy products, and also discuss the potential benefits of the development of a variety of lactose-free dairy foods.

• Journal of Dairy Science and Biotechnology
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• v.27 no.2
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• pp.55-62
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• 2009

Milk is called an almost complete food in terms of nutrition, especially for the younger generations because it contains a number of nutrients required for growth and development. Lactose intolerance is defined as a malabsorption of lactose in the intestine with some typical symptoms of abdominal pains and bloating, and occurred at 75% of global populations, which hampers milk consumption worldwide. Lacks of milk consumption in the underdeveloped countries frequently lead to many nutrients deficiencies, so that diseases including osteoporosis, hypertension, and colon cancer are more prevalent in the recent days. Lactose in foods needs to be hydrolyzed prior to intestinal absorption. The hydrolytic enzyme responsible for splitting lactose into its monomeric forms, glucose and galactose, is called as lactase or $\beta$-galactosidase. The former is primarily used as blood sugar and energy source and the latter used in glycolipid synthesis of brain tissues in infants. Lactose is clinically diagnosed with the breath hydrogen production test as well as intestinal biopsy. Reportedly, symptoms of lactose intolerance are widely prevalent at 25% of Europeans, 50 to 80% of Hispanics, South Indians, Africans, and Jews, almost 100% of Asians and native Americans. For the adults, phenotype of lactase persistence, which is able to hydrolyse lactose, is more common in the northern Europeans, but in the other area lactase non-persistence or adult-type hypolactasia is dominant. Genetic analysis on human lactase gene continued that lactase persistence was closely related to the err site of 1390 single nucleotide polymorphism from the 5'-end. To alleviate severity of lactose intolerance symptoms, some eating patterns including drinking milk a single cup or less, consumption along with other foods, whole milk rather than skimmed milk, and drink with live yogurt cultures, are highly recommended for the lactose maldigesters. Also, delay of gastric emptying is effective to avoid the symptoms from lactose intolerance. Frequency of lactose intolerance with conventional diagnosis is thought overestimated mainly because the subjects are exposed to too much lactose of 50 g rather than a single serving amount. Thus simple and accurate diagnostic method for lactose intolerance need to be established. It is thought that fermented milk products and low- or free lactose milks help improve currently stagnant milk consumption due to lactose intolerance which contributes to major barrier in milk marketing especially in Asian countries.

• Korean Journal of Community Nutrition
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• v.23 no.6
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• pp.488-495
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• 2018

Objectives: This study examined the milk intake patterns with lactose and milk fat in Korean male adults using the following variables: milk intake level, awareness of lactose, and milk fat, health problems, and necessity of milk intake. In addition, the factors affecting milk intake were analyzed by multiple regression analysis. Methods: The subjects were 532 males aged 20 years or older among the nationwide milk purchasing group. The subjects were 223 (41.9%) in the 20-29 year age group, 188 (35.3%) in the 30-49 year age group and 121(22.7%) in the over 50 year age group. The survey was conducted using ANOVA and multiple comparative analysis to examine the differences in age and multiple regression analysis was performed to investigate the factors affecting the intake of milk. Results: The intake of milk in the subjects was $538.14{\pm}494.23ml$ per week. There were statistically significant differences in the subjects' age according to processed milk, low fat, nonfat milk, cheese, and ice cream. The perception of milk and lactose and milk fat was recognized as a good food for skeletal health when milk was consumed. Among the milk nutrients, lactose was highly recognized at the age of 20-29, and milk fat was recognized in those over 50 years. In addition to lactose and milk fat, calcium was the most highly recognized among the milk nutrients. Health problems associated with milk were skeletal health, obesity, and lactose intolerance. The perception of lactose intolerance was related to lactose intolerance and fatness, and the dietary behavior was unaffected. Conclusions: This study examined the milk intake patterns of adult Korean males. Many variables were found to be related to the intake of milk. In this study, the milk intake was high when there was no problem with the perception and dietary behaviors of milk nutrition (lactose and milk fat). This study focused on lactose and milk fat, which are major nutrients in milk, and it is a new perspective study among milk-related research.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.21 no.3
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• pp.170-175
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• 2018

Purpose: Lactose intolerance (LI) is perceived to be frequent in Asia and has been reported to have considerable impact on dietary intake, nutritional status and the quality of life. We aimed to gather information from healthcare professionals on the perceived incidence, diagnosis and management of LI in 1 to 5 year old children in Southeast Asia. Methods: An anonymous electronic survey was sent randomly among healthcare professionals registered in the database of the pediatric societies in Thailand, Indonesia, and Singapore between June and October 2016. Results: In total, 259 health care professionals responded of which 45.5% (n=118) were from Thailand, 37.4% (n=97) from Indonesia and 16.9% (n=44) from Singapore. Of the participants who responded (n=248), primary LI prevalence among children 1 to 3 years of age was estimated to be less than 5% by 56.8%. However, about 18.9% (n=47) answered they did not know/unsure. Regarding secondary LI, 61.6% of respondents (n=153) estimated the prevalence to be less than 15%. But again, 10.8% (n=27) answered they did not know or unsure. Rotavirus gastroenteritis was ranked as the top cause for secondary LI. There was considerable heterogeneity in the diagnostic methods used. The majority of respondents (75%) recommended lactose-free milk to manage primary and secondary LI. Conclusion: More education/training of pediatricians on this topic and further epidemiological studies using a more systematic approach are required.

• Journal of Dairy Science and Biotechnology
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• v.39 no.1
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• pp.20-26
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• 2021

Lactase (β-galactosidase) is abundant in the small intestine during early childhood and gradually decreases with age. Lactic acid bacteria (LAB) present in yogurt could survive in the stomach, and lactase produced by these LAB can aid in lactose breakdown in the small intestine, thereby reducing lactose intolerance. This study aims to provide preliminary data for development of lactose-free yogurts for the elderly, and investigate the effect of lactose-hydrolyzed milk on the growth of starter cultures. The pH during yogurt fermentation using lactose-free milk was slightly higher at 2 and 4 h of incubation, but reached 4.5 at the end of incubation, similar to that of the yogurt prepared from regular milk. The number of viable cells of Streptococcus thermophilus reached 108 CFU/mL after 2 h of incubation and increased to 109 CFU/mL after 4 h of incubation. During yogurt fermentation, the viable cells of Lactobacillus species and Bifidobacterium longum did not affect lactose hydrolysis. Although lactose-hydrolyzed milk did not promote the growth of starter cultures, manufacturing yogurt with lactose-free milk could be beneficial for the intestinal health of lactose-sensitive elderly.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.3
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• pp.263-275
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• 2022

Purpose: The present international survey among healthcare providers aimed to collect data on theoretical knowledge and clinical practices in the diagnosis and management of cow's milk protein allergy (CMPA) and lactose intolerance (LI) in infants. Methods: A global survey was conducted in several countries with diverse health care settings. The survey consisted of multiple-choice questions in 3 main domains: (1) understanding and clinical practices around CMPA and LI; (2) case scenarios; and (3) disease-specific knowledge and potential educational needs. Results: Responses were available from 1,663 participants. About 62% of respondents were general practitioners or general pediatricians, and the remainder were pediatric allergists/gastroenterologists (18%) or other health practitioners (20%). The survey identified knowledge gaps regarding the types of CMPA (IgE-mediated vs. non-IgE-mediated) and the clinical overlap with LI. The survey suggested diverse clinical practices regarding the use of hypoallergenic formulas, as well as misconceptions about the prebiotic benefits of lactose in extensively hydrolyzed formulas in non-breastfed infants with CMPA. Responses to the two case scenarios highlighted varying levels of awareness of the relevant clinical practice guidelines. While respondents generally felt confident in managing infants with CMPA and LI, about 80% expressed an interest for further training in this area. Conclusion: The current survey identified some knowledge gaps and regional differences in the management of infants with CMPA or LI. Local educational activities among general and pediatric healthcare providers may increase the awareness of clinical practice guidelines for the diagnosis and treatment of both conditions and help improve clinical outcomes.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.195-200
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• 2013

The ripening of cheese allows for the development of characteristic taste and flavour, nutritional substances, bio-active components and texture, helping to improve quality. Many different microbiological, biochemical and nutritional changes occur during the process depending on the quality of raw milk, added cultures and enzymes, as well as specific processing and ripening conditions. During the ripening lactose is hydrolyzed to lactic, propionic and acetic acid, helping to reduce potential effects of the problem of lactose intolerance. Fat is hydrolyzed to butyric, propionic and conjugated linoleic acid, which function as bio-active substances. Protein is hydrolyzed to different peptides and amino acids which all show various bio-activities. However, errors of cheese ripening can happen and affect the quality of the product. To guarantee good quality cheese the process needs to be managed carefully with the right microbes used and ensuring cleanliness of processing facilities, staff, ventilation and hazard analysis and critical control points (HACCP). Research into and controlling of ripening technology is crucial for producing high quality cheeses.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.25 no.1
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• pp.13-20
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• 2022

Purpose: Hydrogen-methane breath tests are used to diagnose carbohydrate malabsorption and small intestinal bacterial overgrowth. The COVID-19 pandemic has driven the modification of procedures as breath tests are potentially aerosol-generating procedures. We assessed the effect of delayed analysis of breath samples, facilitating the at-home performance of breath testing. Methods: Children provided two breath samples at every step of the lactose breath test. The samples were brought back to the clinic, and one set of samples was analyzed immediately. The second set was stored at room temperature and analyzed 1-4 days later. Results: Out of the 73 "double" lactose breath tests performed at home, 33 (45.8%) were positive. The second samples were analyzed 20 to 117 hours after the first samples (41.7±24.3 hours). There was no significant difference in the hydrogen concentration between the first and second sets (Z=0.49, p=0.62). This was not the case for methane, which had a significantly higher concentration in the second breath samples (Z=7.6). Conclusion: Expired hydrogen levels remain stable in plastic syringes if preserved at room temperature for several days. On the other hand, the delayed analysis of methane appeared to be less reliable. Further research is needed to examine the impact of delayed analysis on methane and hydrogen concentrations.

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.39-45
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• 2017

The market for lactose-hydrolyzed milk is growing due to an increased awareness of lactose intolerance, and increased market interest for modified milk with health claims. The aim of this study was to compare the quality characteristics of 2% lactose-hydrolyzed milk with its lactose hydrolysis rate, with the goal of applying the method to dairy product monitoring in the future. We observed that the freezing point of milk significantly decreased with increasing lactose hydrolysis rate. A linear relationship was found between lactose concentration and freezing point, following the equation (y=-50.416x + 767.91). However, no significant changes were observed in other physicochemical properties of the milk (pH, titratable acidity, total solids and color) (p<0.05). In conclusion, we could predict the residual lactose content quickly and easily in 2% low fat milk by measuring its freezing point. This could represent an easy means for assessing the lactose hydrolysis rate of dairy products.