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Low lactose and lactose-free milk and dairy products - Prospects, technologies and applications

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Abstract

Reducing the lactose content or removing it completely from milk and other dairy products can expand availability of valuable dairy nutrients world-wide. The traditional approach to conversion of lactose by its hydrolysis to the constituent monosaccharides has been practiced industrially for almost 20 years. In Finland, the HYLA line of dairy products containing hydrolysed lactose comprises almost 100 different products. The patented Chromatographic process for removal of lactose from milk offers new opportunities for marketing of lactose-free milk and dairy products with sensory properties indistinguishable from those of the comparable traditional products. The process is described and the marketing success of the new Valio lactose-free products is documented.

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... Lactose hydrolysis has been investigated as a sugar reduction alternative because hydrolysis of 70% of the lactose in milk increases the sweetness of milk or yogurt to the same degree as adding 2% sugar would (Zadow, 1986;Mahoney, 1998;Adhikari et al., 2010). Lactose-free milk is sweeter than regular milk (Jelen and Tossavainen, 2003;Adhikari et al., 2010;Skryplonek et al., 2017). Li et al. (2015b) investigated the effect of using lactose hydrolysis to sweeten chocolate milk naturally. ...
... As stated earlier, it is impossible to hydrolyze all of the lactose in the product; therefore, in lactose-free milk such as Lactaid (McNeil Nutritionals LLC, Ft. Washington, PA) and Fairlife (Fairlife LLC, Chicago, IL, and The Coca Cola Company, Atlanta, GA), additional lactase is added into the packaged product to break down the remainder of the lactose present in the milk before consumption (Jelen and Tossavainen, 2003). These products declare "lactase enzyme" as an ingredient because some lactase is never deactivated by heat and this type of lactose-free milk must declare lactase on the label. ...
... Ultrafiltration is a well-established method for decreasing lactose in milk (Jelen and Tossavainen, 2003); it is a pressure-driven process that separates compounds in milk by molecular weight. Ultrafiltration is widely used in the dairy industry for lactose removal and, in turn, can be used for sugar reduction. ...
Article
Sugar overconsumption continues to increase worldwide and contributes to multiple health-related issues. Dairy foods represent a large market, grossing more than $125 billion per year worldwide. Consumer demands for healthier products are leading to a large push for sugar reduction in dairy foods. Sugar plays an important role in dairy foods, not only in flavor but also in texture, color, and viscosity. Replacing sugar can have negative effects, making substitution inherently difficult. Natural and artificial nonnutritive sweeteners exist for sugar reduction. Natural nonnutritive sweeteners are popular, particularly for label appeal, but many consumers still prefer the taste of artificial nonnutritive sweeteners. Sweet taste perception can also be affected by texture of the food matrix and the presence of fat. Other sugar reduction techniques include hydrolysis of lactose, ultrafiltration, and direct reduction. This review will address the role of sugar, alternative sweeteners, and sugar reduction in ice cream, yogurt, and flavored milk.
... Therefore, the membrane recovery system such as ultra-and nanofiltration are extremely helpful for the recovery and reuse of the enzymes. Ultrafiltration is a pressure-driven process that removes lactose from milk, and thus can be used as a sugar reduction technique [140]. The high molecular weight compounds such as fat and protein are retained by the ultrafilter membrane, while the low molecular weight compounds (lactose, minerals, vitamins and water) are able to pass through the membrane. ...
... Then, water is added to the suspended solids to obtain lactosefree milk. It is not as sweet as lactose-hydrolysed milk, therefore a NNS can be added to gain the desired sweetness [114,140]. This method has been applied for sugar reduction in cheese and yoghurt, where lactose was removed from the milk before processing into cheese and yoghurt [124][125][126][127]. ...
Article
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Owing to the public health concern associated with the consumption of added sugar, the World Health Organization recommends cutting down sugar in processed foods. Furthermore, due to the growing concern of increased calorie intake from added sugar in sweetened dairy foods, the present review provides an overview of different types and functions of sugar, various sugar reduction strategies, and current trends in the use of sweeteners for sugar reduction in dairy food, taking flavoured milk as a central theme where possible to explore the aforementioned aspects. The strength and uniqueness of this review are that it brings together all the information on the available types of sugar and sugar reduction strategies and explores the current trends that could be applied for reducing sugar in dairy foods without much impact on consumer acceptance. Among different strategies for sugar reduction, the use of natural non-nutritive sweeteners (NNSs), has received much attention due to consumer demand for natural ingredients. Sweetness imparted by sugar can be replaced by natural NNSs, however, sugar provides more than just sweetness to flavoured milk. Sugar reduction involves multiple technical challenges to maintain the sensory properties of the product, as well as to maintain consumer acceptance. Because no single sugar has a sensory profile that matches sucrose, the use of two or more natural NNSs could be an option for food industries to reduce sugar using a holistic approach rather than a single sugar reduction strategy. Therefore, achieving even a small sugar reduction can significantly improve the diet and health of an individual.
... Although most humans tolerate moderate amounts of milk, considerable effort has been taken by the dairy industry to develop lowlactose milk products for lactose intolerant consumers (Deng et al., 2015). Methods for reducing lactose content of milk products are welldocumented in several reviews (Harju, Kallioinen, & Tossavainen, 2012;Jelen & Tossavainen, 2003;Mahoney, 1997;Panesar, Panesar, Singh, Kennedy, & Kumar, 2006;Shukla & Wierzbicki, 1975) and only a summary of this field is given here. The low-lactose and hydrolyzedlactose milk products, which have been on the market for decades, even before the term FODMAP was coined, are the first examples of food products, where these compounds have been removed by bioprocessing. ...
... This fraction is then nanofiltered to remove the lactose, and the permeate with the minerals is concentrated by reverse osmosis. When the concentrate is combined with the protein-rich ultrafiltration retentate and the residual lactose is hydrolyzed by lactase treatment, a lactose-free milk product without extra sweetness is obtained (Harju et al., 2012;Jelen & Tossavainen, 2003). Ultrafiltration has also been applied individually for decreasing the lactose content to a suitable level and applying lactase for hydrolyzing the remaining lactose to achieve sweetness matching that of normal milk (Lange, 2005). ...
Article
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Background Fermentable oligo- di- and mono-saccharides and polyols, abbreviated as FODMAP, are components of several plant-based foods as well as milk. The FODMAPs include fructans and galacto-oligosaccharides, lactose, fructose, and sugar alcohols. Ingestion of FODMAPs may trigger gastrointestinal symptoms in people with functional bowel disorders, such as the irritable bowel syndrome (IBS). Scope and approach Studies have shown that a low-FODMAP diet improves symptoms of IBS. However, restricting the intake of FODMAP-rich foods is problematic, since many of them are rich in components important for health, such as dietary fibre, vitamins and minerals. This review describes the possibility of targeted FODMAP removal from foods by bioprocessing. Since the source of majority of FODMAPs are plant-based foods, such as fruits, grains, pulses and vegetables, FODMAP reduction by bioprocessing is also of interest in terms of the transition to more plant-based diets. Key findings and conclusions Levels of galacto-oligosaccharides, fructans and lactose can be significantly reduced by enzymatic treatment, fermentation and germination. Enzyme-aided FODMAP reduction is typically specific, whereas during fermentation and germination several enzymes are active, which may influence food characteristics via polymer degradation and metabolite formation. Enzymatic processing and fermentation can usually be implemented in hours, whereas germination is relatively slow process, taking days. Implications of targeted FODMAP reduction in foods by bioprocessing should be considered in particular from nutritional, sensory and tolerance perspectives.
... Here the need for low-lactose or lactose-free products has been exceptionally high due to the high consumption of milk. Lactose-free milk has strongly gained more popularity and has become one of the basic milks in Finland and other countries (Jelen and Tossavainen 2003). ...
... The food industry is responding to consumer demands by offering lactosehydrolysed milk and lactose-free milk products in which some lactose has been removed physically and the rest is hydrolysed to obtain the same sweetness as ordinary milk (Harju 2003;Jelen and Tossavainen 2003;Zadow 1993). Several microbial sources of beta-galactosidase and reactor types have been used for the purpose of economic production of low-lactose milk. ...
Book
This book presents the complete guide for readers to understand the applications, and pros and cons of nanotechnology applications in environmental remediation, although there are few critical reviews and textbooks available on environmental biotechnology. Water pollution has become one of the biggest concerns of the world. After the industrialisation and urbanisation, environmental pollution has become an enormous concern. Water pollution results in biomagnifications by entering the food chain. As a result water pollution and its risks need to be considered seriously and solutions need to be researched. This volume looks into such topics as bioremediation, nanobiotechnology, biosensors, and enzyme degradation to find solutions to these problems.
... Here the need for low-lactose or lactose-free products has been exceptionally high due to the high consumption of milk. Lactose-free milk has strongly gained more popularity and has become one of the basic milks in Finland and other countries (Jelen and Tossavainen 2003). ...
... The food industry is responding to consumer demands by offering lactosehydrolysed milk and lactose-free milk products in which some lactose has been removed physically and the rest is hydrolysed to obtain the same sweetness as ordinary milk (Harju 2003;Jelen and Tossavainen 2003;Zadow 1993). Several microbial sources of beta-galactosidase and reactor types have been used for the purpose of economic production of low-lactose milk. ...
Chapter
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It is estimated that over 70% of the world’s adult population have problems in digesting lactose resulting from absent or reduced β-galactosidase activity in the small intestine. Estimates of the number of Americans affected by lactose intolerance (LI) range between 30 and 50 million, whereas approximately 75 million Americans are lactose maldigesters. Maldigestion is also a common occurrence in adults who have low-intestinal lactase activity. Lactose that is not digested transits to the lower small intestine and large intestine, thus creating the potential for symptoms. β-Galactosidase is one of the relatively few enzymes that have been used in large-scale processes to perform lactose hydrolysis and galacto-oligosaccharide production. Immobilization is the limitation of movement of biocatalysts according to chemical or physical treatment. Immobilized molecules technique using biomaterials and nano-biotechnology is a very interesting topic that is touching almost all aspects of our life. This review outlines information regarding lactose intolerance, overview of β-galactosidase and recent advances of nanoimmobilization on β-galactosidase to study lactose hydrolysis potential. The plausible advantages with their use include their (1) biocatalyst efficiency, (2) specific surface area, (3) mass transfer resistance and (4) effective enzyme loading. Enzyme immobilization is a usual requirement as a solution to obtain reusable biocatalysts and thus decrease the price of the expensive biocatalysts. Various immobilization methods have been developed, and in particular, specific attachment of enzymes on metal oxides such as ZnO has been an important focus of attention. The method of immobilization has an effect on the preservation of the enzyme structure and retention of the native biological function of the enzyme. Enzymes immobilized onto nanoparticles showed a broader working pH and temperature range and higher thermal stability than the native enzymes.
... This enzyme is found most abundantly in the villus enterocytes of the jejunum (Lule et al., 2016). In mammals the lactase production progressively stops after weaning and the adults lose their ability to digest lactose, while humans can keep lactase production also in adults (Jelen and Tossavainen, 2003). Hypolactasia, lactose maldigestion or, less properly, malabsorption, are synonyms indicating a deficiency in the lactase enzyme (Kies, 2014). ...
... Casellas et al. (2010) demonstrated that conventional anamnesis reported by patients after the ingestion of lactose-containing foods are a highly unreliable tool to establish symptomatic lactose malabsorption since abdominal symptoms can have causes beyond lactose malabsorption. Low-lactose and lac- tose-free products are obtained in the dairy industry by the hydrolysis of lactose in milk using the enzyme beta-galactosidase (lactase), by chromatographic separations or by use of membrane separation, that could be also combined with lactose hydrolysis techniques (Jelen and Tossavainen, 2003). The hydrolysis of lactose, obtained by means of free or immobilized lactase (Horner et al., 2011), can influence both the technological and the sensorial properties of products. ...
... This enzyme is found most abundantly in the villus enterocytes of the jejunum (Lule et al., 2016). In mammals the lactase production progressively stops after weaning and the adults lose their ability to digest lactose, while humans can keep lactase production also in adults (Jelen and Tossavainen, 2003). Hypolactasia, lactose maldigestion or, less properly, malabsorption, are synonyms indicating a deficiency in the lactase enzyme (Kies, 2014). ...
... Casellas et al. (2010demonstrated that conventional anamnesis reported by patients after the ingestion of lactose-containing foods are a highly unreliable tool to establish symptomatic lactose malabsorption since abdominal symptoms can have causes beyond lactose malabsorption. Low-lactose and lactose-free products are obtained in the dairy industry by the hydrolysis of lactose in milk using the enzyme beta-galactosidase (lactase), by chromatographic separations or by use of membrane separation, that could be also combined with lactose hydrolysis techniques (Jelen and Tossavainen, 2003). The hydrolysis of lactose, obtained by means of free or immobilized lactase (Horner et al., 2011), can influence both the technological and the sensorial properties of products. ...
Article
Full-text available
The present work was aimed to define and validate farmstead production of lactose-free Pecorino di Osilo cheese, fresh ricotta cheese, salted and smoked ricotta cheese ( Ricotta mustia ). The enzymatic activity of the commercial preparation containing lactase (1.1 g/mL), preliminarily tested using a spectrophotometric titration, showed activity equal to 4950±40 Neutral Lactase Units/g. The amount of lactase required to obtain the lactose-free milk was then established in triplicate laboratory trials, by adding the enzyme at concentrations of 0.7, 0.9 and 1.1 g/L in flasks containing 160 mL of raw sheep’s milk. Samples were incubated under conditions expected during milk storage and cheese-making. The residual lactose content in milk was determined by enzymatic method. The addition of lactase at concentration of 1.1 g/L of milk reduced the lactose concentration below the limit of detection (LOD) of 0.06 g/L. The procedure was validated at a dairy farm, using three different batches of bulk raw sheep's lactose-free milk that were transformed into Pecorino di Osilo cheese. The resulting whey was used to produce fresh ricotta and Ricotta mustia cheese. Raw milk and whey samples were always below lactose detection limit. The residual lactose was measured in Pecorino di Osilo cheese, after 24 hours and 30 days from production; in fresh ricotta cheese, after 48 hours; in 2 Ricotta mustia cheese after 7 days. The determination of lactose content in cheese samples was conducted by a GC-FID method, which showed a LOD and limit of quantification (LOQ) respectively of 1.8 and 5.6 mg/kg for cheese, and 1.35 and 4.2 mg/kg for both ricotta cheeses. The lactose concentration was always below the relevant LOD values in all samples. The mean concentration of galactose and glucose were respectively 13,000±2000 mg/kg and 11,000±2000 mg/kg in fresh Pecorino di Osilo , 1100±300 mg/kg and 1200±300 mg/kg in fresh ricotta and 950±400 mg/kg and 750±250 mg/kg in Ricotta mustia . The results of the present study showed that the production of farmstead lactose-free Pecorino di Osilo cheese and ricotta cheeses from raw sheep’s milk is easily achievable. The main issue for farmstead production of artisanal lactose-free products is the implementation of permanent procedures based on HACCP principles aimed to guarantee the effectiveness of the process and to acquire analytical evidences to demonstrate the fulfilment of law requirements for labelling.
... However, the single-use of enzymes is an expensive strategy. Ultra-and nanofiltration are membrane filtration methodologies that, in addition to allowing enzymes to be recovered and reused, also allow the removal of lactose ( Jelen & Tossavainen, 2003). Then, used in conjunction with lactose hydrolysis, filtration methodologies represent a relatively quick and cost-effective process to reduce sugar in milk and milk-based products. ...
Chapter
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Over the last years, foods are being tailored in their compositional profiles and structural properties to promote or enhance human health and well-being over and above simple nutrition. In this context, there is a need for a detailed understanding of the physical, biochemical and sensorial properties of the food categories involved since any modification targeting improved healthiness needs to guarantee their maintenance within acceptable levels to maintain consumer satisfaction. The reduction of sugar content in food to reduce both energy density of food and glycemic response is currently a key focus of the food manufacturing industry that poses several challenges. In this chapter, an overall perspective of sugar and its technological/functional role as well as the negative health implications associated to its excessive consumption is presented upholding the need for reformulation strategies to reduce free sugar intake. In this framework, the different solutions developed over the last years will be discussed including sugar structure modification and encapsulation to enhance sweet perception, food grade alternatives to sugar or in-situ enzymatic sugar conversion into non-digestible saccharides with enhanced (prebiotic) functionality. Examples of commercial products and market challenges will also be detailed.
... Recently, there has been a national push for sugar reduction in many foods including dairy foods. Studies have shown direct sugar reduction at 30%, sugar substitution with non-nutritive sweeteners, lactose hydrolysis, and ultrafiltration to be successful methods for chocolate milk sugar reduction for adults and children (Jelen and Tossavainen, 2003;USDA-FNS, 2012;Li et al., 2015a,b;Oliveira et al., 2015;McCain et al., 2018). The current study used a school lunch formulation with minimal added sugar (3.7%) for a total of only 8.8 g of added sugar per 1 cup (237 mL) serving and still received relatively high overall liking scores from children (5.2-5.8 on 7-point hedonic scale). ...
Article
Schools participating in federal meal programs are limited to serving skim or low-fat (≤1%) flavored and unflavored milk. Few studies have directly addressed child perceptions and preferences for milk containing different amounts of milkfat. The objective of this study was to determine whether children can differentiate between flavored and unflavored fluid milk containing varying levels of milkfat and whether preferences for certain levels of milkfat exist. Flavored and unflavored milks containing 4 different percentages of milkfat (≤0.5, 1, 2, and 3.25%) were high-temperature, short-time processed, filled into half-gallon light-shielded milk jugs, and stored at 4°C in the dark. Milks were evaluated by children (ages 8–13 yr) following 7 d at 4°C. Acceptance testing and tetrad difference testing were conducted on flavored and unflavored milks with and without visual cues to determine if differences were driven by visual or flavor or mouthfeel cues. Child acceptance testing (n = 138 unflavored; n = 123 flavored) was conducted to evaluate liking and perception of selected attributes. Tetrad testing (n = 127 unflavored; n = 129 flavored) was conducted to determine if children could differentiate between different fat levels even in the absence of a difference in acceptance. The experiment was replicated twice. When visual cues were present, children had higher overall liking for 1% and 2% milks than skim for unflavored milk and higher liking for chocolate milks containing at least 1% milk fat than for skim. Differences in liking were driven by appearance, viscosity, and flavor. In the absence of visual cues, no differences were observed in liking or flavor or mouthfeel attributes for unflavored milk but higher liking for at least 1% milk fat in chocolate milk compared with skim was consistent with the presence of visual cues. From tetrad testing, children could visually tell a difference between all unflavored pairs except 2% versus whole milk and could not detect consistent differences between milkfat pairs in the absence of visual cues. For chocolate milk, children could tell a difference between all milk fat pairs with visual cues and could tell a difference between skim versus 2% and skim versus whole milk without visual cues. These results demonstrate that in the absence of package-related flavors, school-age children like unflavored skim milk as well as milk with higher fat content in the absence of visual cues. In contrast, appearance as well as flavor and mouthfeel attributes play a role in children's liking as well as their ability to discriminate between chocolate milks containing different amounts of fat, with chocolate milk containing at least 1% fat preferred. The sensory quality of school lunch milk is vital to child preference, and processing efforts are needed to maximize school milk sensory quality.
... These defects in the finished product are considered major challenges for operators in the lactose-free dairy industry, [42]. An alternative to avoid the appearance of sweet taste in milk is to use different filtration methods such as microfiltration, nanofiltration, ultrafiltration and reverse osmosis, through filtration membranes a part of lactose is separated, after which the classical process continues ( Figure 5), or chromatography techniques (combined with the hydrolysis of the remaining lactose) are used [43,44]. ...
Article
Full-text available
The paper is a review of the importance of expanding the lactose-free dairy segment to give consumers the opportunity to consume milk and dairy products if they suffer from lactose intolerance. When there is a lactase deficiency in the body, in the small intestine lactose is not hydrolyzed, the volume increases and the fluidity of the intestinal contents increases, allowing lactose to reach the colon where it is fermented by colonic bacteria. Lactose intolerance is a condition that depending on the form developed will show different symptoms and consumers suffering from this disease may ingest amounts between 12-24 g of lactose consumed during a day, taking into account certain recommendations, compared to allergy to milk proteins, where the consumption of dairy products is prohibited. Due to the rich intake of important macro and micronutrients in human nutrition, dairy products cannot be missing from the daily diet. In this context, methods are proposed, in particular ultrafiltration, for obtain free lactose milk that does not affect its composition and properties. Consumers suffering from lactose intolerance should be properly informed about the lactose content in manufactured lactose-free dairy products. This can be done after using highperformance instrumental methods of analysis that can detect the lowest values of lactose content in dairy products.
... Lactose-free ultrapasteurized milk is characterized by a more intense boiling aroma and a sweeter taste compared to lactose-free ultrapasteurized milk [19] [20]. This could be an obstacle to the consumption of lactose-free dairy products by the lactose intolerant population. ...
... In general, if we compare conventional and lactose-free products, the first one contained minor levels of free glucose and galactose, because these concentrations increase after the delactosation process, as the lactose breaks down into its constituent molecules. Since lactose hydrolysis increases the sweetness of milk, processes were developed to remove part of the lactose using chromatography and/or ultra and nano filtration operations combined with the remaining lactose hydrolysis to reach a comparable sweetness to the conventional milk [30]. ...
Article
Full-text available
Milk and its derivatives are the basis of human nutrition since childhood. Given their importance within a balanced diet, the determination of carbohydrates in milk and its derivatives is fundamental for two reasons: one of alimentary origin related to intolerances and the other one of technological origin, especially for PDO (Protected Designation of Origin) products. The dietetic approach, including lactose-free products, has a crucial role in the management of lactose intolerance, but labelling and compositional rules indicating the absence or reduced presence of lactose in food are currently not harmonised at Union level. Considering the above-mentioned issues and the absence of official methods for the determination of low sugar concentrations, we propose a new and simple IC-HRMS method to detect carbohydrates in milk and different lactose-free derivatives, which can allow the definition of concentration limits useful to characterise products suitable for specific dietary regimes.
... As these consumers with selfreported lactose intolerance generally limit their intake of dairy products, lactosefree dairy products are more popular than would be estimated based on real rates of lactose intolerance. This has led dairy companies to develop lactose-free dairy products, even in countries with low levels of lactose intolerance, like Finland (Jelen & Tossavainen, 2003), even though their consumption is not related to a reduction in perceived lactose intolerance-related symptoms (Suarez, Savaiano, & Levitt, 1995), as discussed in more detail in Chapter 3, Lactose intolerance and other related food sensitivities. ...
Chapter
Lactose, the main carbohydrate in milk, is a unique sugar produced in the mammary gland of mammals. Lactose is synthesized in the mammary gland of cows from its precursor glucose. Lactose, being a main determinant of the osmotic pressure of milk, drives the milk yield of cows. The lactose produced in the mammary gland is the main carbohydrate in the newborns’ diet and an important source of energy. Compared to other sugars, lactose has many specific physical and chemical properties, such as its relative low solubility and specific crystallization behavior. In other aspects, it is similar to other reducing sugars, for example, as reactant in the Maillard reaction. These physical and chemical properties of lactose play a major role in the properties and quality of many dairy products and dairy-based ingredients. It is the energy source for the lactic acid bacteria used during fermentation, and its breakdown leads to the formation of specific flavor components in such fermented products. In concentrated and dried dairy products, the concentration of lactose becomes so high that many of the properties of the product are determined by lactose. In addition to playing a role in dairy consumer products, lactose can also be present in, or form the basis of several, dairy-based ingredients. Many dairy-based ingredients are based on whey and therefore rich in lactose. From such streams, it can be isolated for direct use in, for example, animal feed or pharmaceutical applications, and it can also be chemically converted into many lactose-derived components, which have very different functionalities. Lactose, in both dairy products and other food products containing dairy-based ingredients, is important from consumer perspective as well. Finally, at the end of this chapter, a perspective is given on future research needs with regard to lactose in the dairy chain, from primary production to the consumer level.
... Manufacturing of LLM and LFM is based on the hydrolysis of lactose into glucose and galactose by addition of soluble lactase (Jelen & Tossavainen, 2003). Since the two monosaccharides increase the perceived sweetness of the milk, filtration is sometimes introduced to reduce the concentration of lactose prior to the enzymatic conversion (Harju, Kallioinen, & Tossavainen, 2012). ...
Article
Manufacturing shelf-stable Ultra-high temperature hydrolyzed-lactose milk (UHLM) is a challenge for dairy producers, as the product undergoes chemical changes during storage due to both reducing sugars reactivity and proteolysis arising from the impurity of the lactase preparations. In the present study, the “in batch” production system, which includes the addition of the lactase before the thermal treatment, was demonstrated a valuable alternative to the more popular “in pack” system, where lactase is added directly into each milk package after thermal sterilization. The features of the technology were investigated by monitoring the changes in free amino acids, volatile organic compounds, color and sensory properties of UHLMs produced with three different lactase preparations (LPs), up to 120 days at 20°C. Upon UHT processing, the proteolytic side activity of lactases was minimized, so minimum breakdown of milk protein was achieved. The release of free amino acids was dependent on the lactase purity only in the early production phases, whereas it did not change over time. The Strecker aldehydes benzaldehyde and 2-methylbutanal resulted as effective markers to correlate with the initial lactase purity during storage. Color and sensory slightly changed during storage but were poorly correlated with the different lactases resembling to phenomena typical of milk aging. This latter result suggested that production costs might be lowered by opting for less-purified lactases when considering the “in batch” technology supporting the application of this production system for the design of UHLM with high-quality standards and low risk of alterations during shelf-life.
... To reduce the typical doubling of sweetness after lactose hydrolysis, and restored a conventional palatability, ultra and nano-filtration, or chromatography techniques (combined with the hydrolysis of the remaining lactose) are used [18,45,46]. The result is excellent quality milk that tastes almost identical to regular milk. ...
Article
Full-text available
Abstract Worldwide, 70% of the adult population has limited expression of lactase enzyme with a wide variation among different regions and countries. Lactase deficiency may lead to lactose intolerance (LI). Depending both on the amount of lactose ingested and on the lactase activity, people who suffer from lactose malabsorption might experience numerous gastrointestinal and extra-intestinal symptoms and manifestations. Treatment of LI mainly consists of reducing or eliminating lactose from the diet until the symptoms disappear as well as supplementing lactase, and inducing colon microbiome adaptation by probiotics. Cow’s milk is one of the major source of calcium and several other vitamins and minerals. Thus, a complete exclusion of dairy products may favor the development of bone diseases such as osteopenia and osteoporosis. Therefore, the dietetic approach has a crucial role in the management of LI patients. Additionally, the use of lactose and milk-derived products in non-dairy products (e.g., baked goods, breakfast cereals, drinks, and processed meat) has become widespread in the modern industry (the so-called “hidden lactose”). In this regard, a strict adherence to the lactose-free diet becomes challenging for LI patients, forced to continuous check of all products and food labels. In fact, lactose-free product labeling is still controversial. Considering that nowadays a specific cut-off value establishing “lactose-free” labeling policy is lacking and that there is no universal law regulating the production and commercialization of “delactosed” products, identification of specific safe and suitable products with a well-recognized lactose-free logo might help consumers. This narrative review aims to identify the dietary management for lactose intolerant people, avoiding symptoms and nutrients deficiencies, helped by the use of specific labelling to guide them to choose the safer product on the market.
... Addition of free soluble lactase in the milk is the most popular process applied in industry for the production of hydrolysed lactose milk (HLM) (Jelen & Tossavainen, 2003). Alternative processes include acid hydrolysis, membrane reactors, immobilised systems for enzymatic hydrolysis, and cellular extract from lactobacilli (Harju, Kallioinen, & Tossavainen, 2012). ...
Article
UHT hydrolysed-lactose milk (HLM) is prone to chemical changes, giving rise to off-flavours in the product. To investigate this better, headspace solid-phase micro-extraction gas chromatography (HS-SPME/GC-MS) was applied to monitor the volatiles profile of HLM during production and shelf-life. Optimum extraction conditions for volatiles were explored, focussing on compounds affecting milk aroma. This study is the first investigating industrial scale manufacturing under controlled conditions, allowing direct associations between specific reactions and changes in milk volatiles. The effect of UHT treatment on milk flavour was shown, while the lactase, potentially containing undesirable proteases and odours, did not alter the milk “volatilome” after addition. Commercial samples exhibited different trends in the volatiles along the shelf-life due to differences in production systems, lactase purity and packaging. Merging all results, HS-SPME/GC-MS successfully mapped the phenomena causing modifications in the volatiles profile of UHT HLM at each step of the product life-cycle.
... Lactase is commonly used to hydrolyze lactose into galactose and glucose to produce lactose-free milk (Jelen and Tossavainen, 2003;Harju et al., 2012). This method is expensive and cannot eliminate the galactose from milk. ...
Article
Yogurt making traditionally relies on the simultaneous utilization of 2 starters: Streptococcus thermophilus and Lactobacillus bulgaricus, but these 2 strains normally metabolize the glucose portion of lactose and release galactose into extracellular medium, resulting in high levels of residual galactose and unfermented lactose in yogurt, which leads to several industrial and health concerns. In this study, we found that Lactobacillus plantarum could effectively metabolize both lactose and galactose. Comparative genomic analysis demonstrated the constant presence of a chromosome-encoded Leloir pathway for galactose metabolism in Lb. plantarum species, and the gal operon was driven by a strong constitutive promoter in Lb. plantarum WCFS1, displaying great potential in low-sugar yogurt making. To test this hypothesis, Lb. plantarum WCFS1 was co-cultured with S. thermophilus or Lb. bulgaricus in lactose-based medium. Results showed that lactose was consumed completely and galactose was metabolized efficiently. For yogurt making, co-cultivation of Lb. plantarum WCFS1 with yogurt starter cultures produced a higher reduction of total sugar content compared with the traditional fermentation processes. In addition, the sensory analysis indicated that the yogurt fermented with yogurt starter cultures and Lb. plantarum WCFS1 was acceptable to consumers in appearance, texture, and flavor. Therefore, this study emphasized the potential to manufacture low-sugar yogurt by the co-cultivation of Lb. plantarum with yogurt starter cultures.
... However, Medeiros de Melo, Bolini, and Efraim (2009) studied the effect of using WPC (whey protein concentrate) to replace fat in chocolate. An interesting opportunity for reducing sugar is the use of lactose-free milk powders in which lactose has been hydrolysed to glucose and galactose, which are significantly sweeter than lactose and increase the sweetness of milk-based ingredients (Jelen & Tossavainen, 2003). Lactose-free milk powders may increase sweetness and bring protein as a bulking agent for reduced sugar chocolate. ...
Article
The opportunity to replace sugar with a milk-based protein and the effect of ash-protein ratio on the properties of chocolate was evaluated. The textural properties of chocolates with reduced sugar content were at the same level as those of the control chocolate. Consumers rated the chocolate samples according to their overall liking, liking of taste and texture and the attributes sweetness, saltiness and sandiness. The correlations between chocolate composition and the sensory results were evaluated. The ash-protein ratio had the strongest positive correlation with the overall liking as well as how much the respondents liked the texture and taste. The ash-protein ratio had the strongest negative correlation with sandiness. In the mouth, chocolate samples with higher ash-protein ratios are sensed as smoother. Replacing sugar with a milk-based protein in chocolate made it possible to produce an acceptable chocolate when the ash-protein ratio was close to the control chocolate's ash-protein ratio.
... Glucose and galactose resulting from hydrolysis of lactose are sweeter than lactose, and thereby can increase the sweetness of the lactose-free milks. (Jelen & Tossavainen, 2003). ...
Research
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Buffalo milk which was used to prepare lassi had moisture, total solids, fat, solid non fat, protein, lactose, glucose and galactose content of 83.6%, 16.4% ,6.92%, 9.42% and 3.79%, 4.87%, 0.01% and 0.18% respectively. The average acidity and pH of buffalo milk were 0.13% and 6.64 respectively.By various methods like Lane and Eynon, Fourier Transform Infrared Spectroscopy (FTIR) and spectrophotometer it was not possible to differentiate between lactose, glucose and galactose. So by High Performance Liquid Chromatography Evaporative Light Scattering Detector HPLC-ELSD different concentrations of lactase enzyme that is 5%, 2%, 1% of buffalo milk sample and lassi sample having 1% lactase enzyme were analyzed for lactose percent. The lactose was 0% for all above concentrations.Glucose and galactose resulting from hydrolysis of lactose are sweeter than lactose, and thereby increase the sweetness of the lactose-free lassi. So lassi sample A, sample B, sample C, sample D were prepared by varing sugar concentrations. Control sample had hedonic score 8.5. Lassi sample A, sample B, sample C had average of 7.0, 7.0, 7.7 and sample D had 8.0 hedonic score So, Sample D was selected on the basis of sensory analysis and overall acceptability.The lassi sample D of 12% sugar added and 1% lactase enzyme added was further analyzed which had average of moisture, total solid, fat and lactose content of 81.22%, 18.78%, 3.1% and 0% respectively. The acidity and pH of lassi were 0.54% and 4.44 respectively. By shelf life analysis of lassi sample D it was found to be 10 days acceptable in food grade polystyrene cups. By microbial analysis of lassi sample D the coliform count on prepared day and on 12 th day was not detected. Similarly the yeast mold count was not detected on prepared day but it was 70cfu/ml on the 12 th day.
... Different lactose-hydrolysis techniques are now available for making lactose hydrolyzed milk and lactose-free milk for further utilization of lactose modified dairy products. The available techniques in this case are using bioprocessing treats (such as, specific enzymes and lactose fermenting cultures) and the application of UF-technology (Nguyen et al., 2007;Awad et al. 2015, Troise et al., 2016, Moreira et al., 2017, Jelen & Tossavainen, 2003and Harju et al., 2012. Thus, the objectives of this study is to make lowlactose recombined white soft cheese using different bioprocessing treats, compared to UF-technique and to evaluate their effects on the properties of the resultant white soft cheese during storage. ...
... More than 70% of the world population suffers from lactose intolerance (Schmidt et al., 2017), but its occurrence largely depends on the population group: only approx. 10% of Northern Europeans but more than 90% of South-East Asians suffer from lactose intolerance (Jelen, Tossavainen, 2003). For this reason, majority of the world population encounters problems due to their consumption of foods containing high amount of lactose. ...
... Since lactose hydrolysis leads to a doubling of the sweetness of milk, processes were developed to remove part of the lactose using chromatography or (ultra and nano) filtration techniques combined with the hydrolysis of the remaining lactose so an exact sweetness is regenerated [13,14]. The resulting lactose-free milk produced with this process is of excellent quality, and the taste is almost identical to regular milk. ...
Article
Full-text available
Lactose-free dairy is able to provide the essential nutrients present in regular dairy products, like calcium and vitamins, to those that are not able to digest lactose. This product category currently has a wide and growing health appeal to consumers. In recent years, the quality and product variety in the lactose-free dairy segment has been increasing significantly, giving consumers more tempting products to decide from. As a result, lactose-free dairy is now the fastest growing market in the dairy industry. This review discusses the market developments and production possibilities and issues related to the wide variation of lactose-free dairy products that are currently available. Additionally, the health benefits that lactose-free dairy may offer compared to dairy avoidance are illustrated.
... There are four possible options to tackle above mentioned problem; (a) avoidance of dairy products from routine diet; (b) removal of lactose from milk and milk products; (c) lactose hydrolysis and/or (Suchy et al., 2010); and (d) conversion to value added functional ingredients like galacto-oligosaccharides (GalOS). From the past four decades, several efforts have been conducted to produce low-lactose or lactose free dairy products and some of them are available in European markets (Jelen & Tossavainen, 2003) at small scale. These products have been produced thorough lactose hydrolysis, however, the newly produced monosaccharides might increase the complications for certain group of people, for example, diabetic patients. ...
... It has been observed that lactose-free diet therapy often has low content of certain nutrients i.e. it contains less than 0.01% lactose (the maximum permitted lactose content for lactose-free products by the authorities) and the glucose and galactose content is approximately 1.4% each. Due to the lower carbohydrate content [87] the product also contains less energy as compared to the corresponding traditional product, with approximately 83% of energy content which suggests that the RDA for individual nutritional needs is not being met. ...
Article
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Lactose intolerance is a pathophysiological situation that occurs due to insufficiency of the “lactase” enzyme present in the jejunum. Ingestion of lactose containing products leads to alteration in intestinal digestion and colonic fermentation, leading to diarrhoea and other clinical discomforts. The articles reviewed were selected based on the following key descriptors such as lactose, lactose intolerance, lactose-free diet, non-dairy products, cost, nutritional composition and sensory attributes. Some lactose-free products made from the lactose hydrolysed milk or from the alternate milk sources possessing low nutritional and sensory quality are available in the market. These alternatives are high-priced comparative to the foods containing lactose. So, there is a strong urge to develop lactose-free products that are nutritionally adequate, economical and well accepted by the consumers with main focus on special considerations viz., finding an alternate non-lactose source, ensuring sensory and nutritional attributes, compliance with the concerned regulatory guidelines and economics. This unique comprehensive review will help the manufacturers in developing lactose-free products.
... Each Kilogram of produced hard cheese generates, in average, 9 liters of whey (Jelen & Tossavainen 2003, Onwulata & Huth 2008. World production of milk whey is estimated at 180 to 190× 10 6 tones/ year, with an yearly increase rate of 1-2%, but only around 50 % is processed (Baldasso et al., 2011, Román et al., 2012. ...
... It is the most contaminating waste generated in the production of cheese (Rajeshwari et al., 2000). It accounts for about 85e95% of the milk's volume, and retains 55% of milk nutrients, i.e., on average 10 L of milk generates approximately 1 kg of cheese and 9 L of cheese whey (Jelen and Tossavainen, 2003). For these reasons, making use of cheese whey has been the subject of much research. ...
Article
This study presents the effect of certain porous materials on the production of biogas from the anaerobic co-digestion of a mix of sheep manure (20 wt.%) and cheese whey (80 wt.%). These porous materials are custom-made from recycling agricultural and forestry wastes - almond shells, walnut shells, kenaf fibre, and charcoal. The manufacturing cost is therefore low. They are crushed and sieved, and then fed into the bioreactor to form a fixed bed in order to make a greater surface available for bacterial adhesion, and thus increase the microbial population in the reaction medium. The ultimate objective is to increase biogas production, i.e., to maximize the energy yielded by the codigestion of this mixture. The conclusion drawn from the results of the study was that the greatest long-term (for reaction times over 168 days) biogas production is obtained when using charcoal as the porous material. There was a 27.82% increase in methane (CH4) production compared with the biomethanization of the mixture without any porous material in the reactor (control experiment), and a 50% reduction in chemical oxygen demand (COD). The study of the economic viability of an industrial plant, based on previous results, showed that the period of return on investment (PRI), net present value (NPV), and internal rate of return (IRR) economic parameters are highly favourable. In particular, with the use of charcoal, a PRI of 8 years and an IRR of 10% are achieved.
... Given the fact that lactose-free dairy products have been gaining more space in the market, analytical methods are needed that allow effective control of lactose presence or absence with fast analysis and accuracy (Jelen and Tossavainen 2003;Bunaciu et al. 2016). This work proposes an analytical method to discriminate between ultra high temperature (UHT) regular and lactose-free milks using ultra-compact and benchtop NIRS instruments and multivariate classification techniques. ...
Article
Full-text available
Lactose hydrolyzed milk was developed in the 1970s to serve individuals with lactose intolerance. This demand for lactose-free products by lactose-intolerant consumers has created a market segment for this food whose quality control has to be guaranteed. In order to assess milk samples for lactose content, this work proposes an analytical methodology to classify regular and lactose-free ultra high temperature (UHT) milks using multivariate classification methods and NIR spectra obtained in FT-NIR and ultra-compact NIR spectrometers, aiming at field analysis. For this, 71 samples were purchased; 41 were lactose-free UHT milk and 30 regular UHT milk. Diffuse transflectance spectra were obtained by FT-NIR (833 to 2500 nm, 4 cm−1 of resolution and mean of 16 scans), and by ultra-compact NIR (908 to 1676 nm, with 12.5 nm of resolution and mean of 50 scans). The classification models were obtained by PLS-DA and LDA techniques with robust variables selection by SPA and GA, evaluating different spectral pre-processing (MSC, SNV, and derivatives). The three models developed (PLS-DA, GA-LDA, and SPA-LDA) with benchtop equipment spectra correctly classified all samples with sensitivity and specificity of 100%. For the portable equipment spectra, PLS-DA and GA-LDA models obtained sensitivity and specificity of 100%. The SPA-LDA model, however, presented sensitivity and specificity of 80 and 100%, respectively. These results indicate that methodologies using NIR equipment, especially the ultra-compact NIR, with multivariate classification techniques are feasible in discrimination between regular and lactose-free milk in the field, thus enabling a quick and precise analysis.
... Both, αla and βlg are excellent source of essential amino acids (Alcântara et al., 2011) and, in general, whey proteins possess high biological value, because they are almost totally absorbed by the digestive system (Kreczmann et al., 2015). However, whey contains also certain amounts of fat (Fagan, Castillo, O'Callaghan, Payne, & O'Donnell, 2009) that hinder recovery of proteins (Torkamani et al., 2016), and high concentration of lactose (Kalaivani & Regupathi, 2015), which has been identified as the main problem for the use of this by-product (De Souza et al., 2010), because many people around the world suffer from lactose intolerance (Jelen & Tossavainen, 2003). ...
Article
Full-text available
Whey is a by-product of cheese manufacture and contains proteins that can be recovered, but lactose presence limits its use. Proteins can be separated with aqueous two-phase extraction (ATPE), thus the objective was to evaluate this strategy to recuperate proteins from whey attending lactose elimination. An ATPE system with (NH4)2SO4 and polyethylene glycol 4000 (PEG4000) was studied at 25°C. As PEG4000 diminished the volume ratio between phases diminished and a biphasic system was maintained in absence of the polymer. Minimum protein recovering and lactose elimination were 54.5% and 62.1% with mixtures having 25% PEG4000 and 12.1% (NH4)2SO4, but values were 93.0% and 72.3%, respectively, with 0.1% PEG4000 and 34.7% (NH4)2SO4. Therefore, whey incorporated with (NH4)2SO4 in concentration higher than 34% and without polyethylene glycol can be used in ATPE systems to maximize lactose elimination and protein recovering and to concentrate proteins up to 2.45 times through a non-energy strategy.
... There are four possible options to tackle above mentioned problem; (a) avoidance of dairy products from routine diet; (b) removal of lactose from milk and milk products; (c) lactose hydrolysis and/or (Suchy et al., 2010); and (d) conversion to value added functional ingredients like galacto-oligosaccharides (GalOS). From the past four decades, several efforts have been conducted to produce low-lactose or lactose free dairy products and some of them are available in European markets (Jelen & Tossavainen, 2003) at small scale. These products have been produced thorough lactose hydrolysis, however, the newly produced monosaccharides might increase the complications for certain group of people, for example, diabetic patients. ...
... The growing focus on developing new hydrolysed-lactose (LH) milk products has its basis in the increased awareness of the unfulfilled market potential of lactose-free dairy products as 70% of the world's population is lactose intolerant (Jelen & Tossavainen, 2003;Leonardi, Gerbault, Thomas, & Burger, 2012). Consumers in the globalised dairy market are now also requesting products with decreased sugar content, and from general health perspective may prefer LH dairy products over conventional products despite the fact that they are not lactose intolerant. ...
Article
Storage-induced changes in lactose-hydrolyzed (LH) ultra-high-temperature (UHT)-treated milk were studied using proteomics. Five commercial lactase preparations were used to hydrolyze lactose in semi-skimmed milk after UHT treatment. The proteolytic side-effects of lactase preparations on UHT milk during storage for up to 60 days were compared with their effects on conventional UHT milk. The level of free amino groups increased more during storage in all LH UHT milk samples than in conventional UHT milk. The increase was partly ascribed to release of C-terminal amino acid residues from intact β- and αs1-casein, indicating carboxypeptidase activity. During storage, three of the enzyme preparations increased release of peptides derived from the hydrophobic regions of β- and αs1-casein, which could potentially contribute to development of bitterness in the milk samples. The authors propose that residual protease side-activity in the lactase preparations accelerate product deterioration and decrease shelf-life of LH UHT milk.
Chapter
The main objective of this introductory chapter is to provide an overview of the main topics of interest concerning lactose, a carbohydrate uniquely associated with milk of almost all mammals. Some historical milestones of the discovery and research progress in elucidation of the nature and some chemical properties of this disaccharide are briefly mentioned. Topics to follow include lactose biosynthesis and functions in milk; properties and reactions characterizing the behaviour of lactose in various systems and processing conditions; industrial production and uses of isolated lactose and lactose derivatives; and finally biological, technological and nutritional significance of lactose in human foods, including dairy products such as yogurt. Some industrial approaches used to counteract complications that lactose may pose in certain situations such as crystal development in ice cream are touched upon. All these subjects are explored in more depth in the chapters to follow.
Chapter
Enzymes are biocatalysts that catalyse a desired chemical reaction. Enzymes are specific in their action and yield into products. The enzymes that are utilized in the dairy industry for processing milk and milk products, like yoghurt, cheese, and fermented milks, are commonly known as dairy enzymes. These enzymes mostly aid in coagulation, cheese production, and enhancing shelf life of various dairy products. The most used dairy enzymes include lactase, amylase, lipases, transglutaminase, protease, catalase, and rennet. The functions of enzymes vary with the kind of the product to be processed. Both endogeneous and exogeneous enzymes are important for dairy application to provide functionality and safety to the product along with shelf life extension.KeywordsEnzymesDairy productsCheeseFermented products
Article
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El lactosuero es un subproducto de la fabricación de queso que contiene proteínas que pueden recuperarse, pero están muy diluidas y en mezcla con lactosa, lo que limita su aprovechamiento. La técnica de extracción acuosa en dos fases (ATPE, por sus siglas en inglés) es un procedimiento con potencial para separar proteínas. El objetivo fue evaluar el comportamiento de un sistema de extracción acuosa proteína-(NH4)2SO4 aplicado para la recuperación de proteínas de lactosuero, atendiendo la reducción de lactosa. Se construyó un diagrama binodal de fases mediante una técnica de inspección de alto rendimiento. Se prepararon soluciones de (NH4)2SO4 en concentraciones entre 22 y 40 % usando lactosuero como disolvente. El volumen de la fase superior de los sistemas fue menor que el de la inferior, pero el incremento de (NH4)2SO4 causó aumento gradual de la fase superior. La proteína de lactosuero se concentró en mayor cantidad en la fase superior alrededor del 80 %, en tanto que más del 79 % de la lactosa se separó en la fase inferior. La técnica de ATPE tiene potencial para separar proteínas del lactosuero y la mejor alternativa se basa en sistemas con 34 % de (NH4)2SO4.
Article
The lactose-free dairy sector has been growing considerably, requiring rapid and accurate methodologies for lactose determination. The present work aimed to explore spectroscopy and statistic strategies to estimate the lactose content in cow milk using mid infrared spectroscopy (MIRS) and chemometric tools. Firstly, regular and lactose-free milk discrimination was successfully performed using the spectral range of 935−1200 cm⁻¹ along with Partial Least Squares Discriminant Analysis (PLS-DA). Secondly, to estimate the percentage of lactose in lactose-free milk, calibration models were developed by Partial Least Squares (PLS), Multiple Linear Regression (MLR), and Least Squares Regression (MQ) with and without spectral transformation. The three methods proved to be efficient, with the best performance obtained by the PLS model using Multiplicative Scatter Correction from 935 to 1200 cm⁻¹, with low RMSE values and R² > 0.99 for calibration, cross and external validation. Furthermore, high-performance liquid chromatography (HPLC) was used to attest the good predictive ability of lactose content in lactose-free milk by MIRS-PLS. Finally, the models were used to monitor the lactose content during the enzymatic hydrolysis, showing the applicability and efficiency of the proposed method. Therefore, MIRS associated with chemometric tools constitutes a method with a high capacity to discriminate between regular and lactose-free milk, as well as to predict lactose content in both milk samples.
Article
The features of technologies for low- and lactose-free dairy products, which provide for special operations to hydrolyze lactose or remove it using ultra- or nanofiltration followed by hydrolysis of the residual amount, are considered. Dairy products manufactured using these technologies in different countries as well as enterprises leading in this field of production are presented. The analysis of the methods used to determine the quantitative content of residual lactose in low- and lactose-free dairy products is carried out: enzymatic, HPLC, HPAEC-PAD, amperometric biosensors, Raman spectroscopy. Due to the dairy industry’s need for analytical methods for the determination of lactose in milk and dairy products with low- or lactose-free content, the AOAC Stakeholder Group on Strategic Food Analysis Methods approved Standard Performance Requirements for Biosensor Methods (SMPR®) 2018.009. These requirements were introduced for the quantitative determination of lactose in milk as well as in dairy and milk-containing products with a low or no lactose content. The biosensor method is recommended for use as the official first step of AOAC method. Additionally, it is advisable to use high performance liquid chromatography (HPLC) with mass spectrometric detection, as well as high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) as an international standard method of analysis for the determination of lactose in milk with low- or lactose-free content.
Article
Lactose, a major carbohydrate of mammalian milk is being digested by the intestinal enzyme lactase. Lactase activity decreases in later childhood and throughout life in the majority of the world's population leading towards lactose intolerance. To overcome this challenge, lactose-free milk and milk products have emerged as a boon to lactose-intolerant people all over the world. The wide availability of lactose-free products is encouraging consumers to select them as a preferred choice for dairy foods, driven by the increasingly wide product range. Lactose content should be less than 100 mg/L in order to comply with the legal standards of lactose-free milk products. During the preparation of lactose-free products, lactose hydrolysis increases the level of glucose and galactose in milk along with galactooligosaccharides (GOS) due to transgalactosylation activity of the lactase enzyme. These carbohydrate moieties interfere in the accurate estimation of lactose in lactose-free milk. This review summarizes various techniques such as chromatographic, enzymatic, or sensor-based developed to estimate residual lactose in low lactose milk system along with their advantages and limitations. Among all the detection methods, high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) showed the highest accuracy and specificity without any interference from other disaccharides. However, it is quite expensive and therefore not used widely. Thus, there is a need to develop a rapid and cost-effective method for the detection of residual lactose in a low-lactose milk system.
Chapter
Lactose intolerance is suffered in varying degree by ∼75% of the world population. It is characterized by the inability to hydrolyze lactose in the small intestine, after childhood. This leads to diarrhea and flatulence when lactose-containing products are consumed. β-Galactosidases (lactases) can be used to prevent this. Both neutral and acid lactases are available in the market, for application in dairy products and as nutritional supplements, respectively. These enzymes are very different in sequence, structure, and biochemical properties and belong to different families of glycosyl hydrolases. Besides the use of neutral lactase in milk for lactose-intolerant people, many other advantages of the use of this enzyme have been recognized and will be discussed. Production of galacto-oligosaccharides is another application of β-galactosidases. This article focuses on the biochemical properties of lactases and their use in the dairy industry.
Article
Background Lactose hydrolysed milk and milk products have emerged as a boon to lactose intolerant people worldwide, however, many challenging technical issues are faced during their processing. These low lactose products suffer from many drawbacks which tend to reduce consumer acceptability e.g. Maillard browning due to increased monosaccharides content. Scope and Approach The literature on Maillard reaction in milk and food products is quiet extensive, however, it lacked emphasis on browning in lactose hydrolysed milk and milk products. Understanding the factors which accelerate the rate of Maillard browning will result in effective mitigation. Key Findings and Conclusions Preparation of lactose hydrolysed milk products and problems associated with enhanced Maillard reaction have been dealt in detail. Further, various feasible strategies to mitigate Maillard browning have also been discussed in this review.
Article
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Lactose‐free dairy products undergo several chemical modifications during shelf life due to the reactivity of glucose and galactose produced by the lactose enzymatic hydrolysis. In this study, proton transfer reaction‐mass spectrometry (PTR‐MS), coupled with a time‐of‐flight (TOF) mass analyzer, was applied to get an insight on the phenomena occurring during the shelf‐life of ultra‐high‐temperature (UHT) lactose‐free milk (LFM). UHT LFMs produced by three different commercial lactase preparations were evaluated during storage at 20°C over a 150 days period, sampling the milk every 30 days. Production was repeated three times, on three consecutive weeks, in order to take milk variability into consideration. Principal Component Analysis applied to the whole “volatilome” data demonstrated the capability of PTR‐TOF‐MS in detecting the milk batch‐to‐batch variability: freshly produced milk samples were distinguished based on the week of production at the beginning of shelf‐life. Additionally, a clear evolution of the volatiles organic compounds (VOCs) profiling during storage was highlighted. Further statistical analysis confirmed VOCs temporal evolution, mostly due to changes in methyl ketones concentration. Differences caused by the commercial lactases did not emerged, except for benzaldehyde. All together data demonstrated PTR‐TOF‐MS analysis as a valuable and rapid method for the detection of changes in the VOCs profiling of ultra‐high‐temperature lactose‐free milk.
Article
The concept of lactose intolerance and solution approaches of this problem using modern dairy processing technologies are considered in this study. The protein and lipid constituents were calculated to select the basis of a low-lactose milk beverage. The β-galactosidase preparation was chosen and enzymatic hydrolysis conditions were optimized to obtain a dairy drink that meets the requirements for low-lactose products. To determine the residual amount of lactose in fermented milk, the method for determining whole blood glucose by enzymatic colorimetric method using Shimadzu UV-1800 spectrophotometry was adopted. The influence of technological factors on the dairy low-lactose drink properties was studied. The formulation has been developed and the manufacture process for obtaining a range of low-lactose beverages was adopted, the protein and lipid constituents in the finished product were calculated. The results of this study are considered to be socially significant since the low-lactose products are intended for people suffering from lactase deficiency.
Article
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Individuals with Lactose Intolerance (LI) tend to exclude milk from their diet since this behavior seems to relieve the symptoms caused by the disease. However, milk is a food of high nutritional value, and complete exclusion of dairy products may favor the development of bone diseases such as osteopenia and osteoporosis. The objective of this review was to evaluate the scientific evidence on the adequate management of patients with LI. This study was carried out from the review of the scientific literature in PubMed and SciELO databases. Complete exclusion of conventional dairy products is not necessary since most individuals with LI can tolerate up to 12 grams of lactose daily in a single dose. Yogurts and cheeses matured for having low amounts of lactose are part of the strategy that allows consumption of dairy products by patients with LI. Currently, there is a diversity of products considered as “milk substitutes” and supplements aimed at individuals with LI. However, these strategies still require better-designed studies.
Chapter
It is estimated that over 70% of the world’s adult population have problems in digesting lactose resulting from absent or reduced β-galactosidase activity in the small intestine. Estimates of the number of Americans affected by lactose intolerance (LI) range between 30 and 50 million, whereas approximately 75 million Americans are lactose maldigesters. Maldigestion is also a common occurrence in adults who have low-intestinal lactase activity. Lactose that is not digested transits to the lower small intestine and large intestine, thus creating the potential for symptoms. β-Galactosidase is one of the relatively few enzymes that have been used in large-scale processes to perform lactose hydrolysis and galacto-oligosaccharide production. Immobilization is the limitation of movement of biocatalysts according to chemical or physical treatment. Immobilized molecules technique using biomaterials and nano-biotechnology is a very interesting topic that is touching almost all aspects of our life. This review outlines information regarding lactose intolerance, overview of β-galactosidase and recent advances of nanoimmobilization on β-galactosidase to study lactose hydrolysis potential. The plausible advantages with their use include their (1) biocatalyst efficiency, (2) specific surface area, (3) mass transfer resistance and (4) effective enzyme loading. Enzyme immobilization is a usual requirement as a solution to obtain reusable biocatalysts and thus decrease the price of the expensive biocatalysts. Various immobilization methods have been developed, and in particular, specific attachment of enzymes on metal oxides such as ZnO has been an important focus of attention. The method of immobilization has an effect on the preservation of the enzyme structure and retention of the native biological function of the enzyme. Enzymes immobilized onto nanoparticles showed a broader working pH and temperature range and higher thermal stability than the native enzymes.
Article
In this study, an amino-functionalized silica matrix encapsulating β-galactosidase was first synthesized in situ, with subsequent covalent anchoring of lysozyme to the outer part of the amino-grafted matrix. Fourier transform infrared (FTIR) spectra verified that β-galactosidase was successfully encapsulated. Meanwhile, the co-immobilized enzymes were demonstrated to retain suitable enzymatic activities and outstanding operational stability during successive reaction cycles. Furthermore, when used for lactose removal from skim milk, the packed-bed column system achieved both a high lactose hydrolysis rate and microbial inactivation ratio during 30 days of continuous operation. Notably, this system exhibited favorable stability during 60 days of continuous hydrolysis of lactose in solution and thus may be appropriate for further development for use in industrial lactose removal from milk.
Chapter
Um eine gute Struktur des Buches zu gewährleisten, erfolgte die Unterteilung und Zusammenstellung der Produkte anhand der Nährwerttabellen von SOUCI et al. (2016) in folgende Produktgruppen.
Book
Das Buch liefert einen aktuellen, übersichtlichen und in der Praxis anwendbaren Überblick im Bereich der deskriptiven Lebensmittelsensorik. Die Autorinnen haben ein Nachschlagewerk erstellt, das bei der Evaluierung und Entwicklung von Lebensmitteln unverzichtbar ist. Es liefert in übersichtlichen Tabellen und praktischen Beschreibungen eine einheitliche Sprachgebung für Lebensmittel gegliedert in Produktgruppen und ist sowohl für Forscher als auch für in der Industrie Tätige beim Erforschen von Lebensmitteln ein wertvolles Lexikon. Die Erstellung einer solchen Datenbank für den deutschsprachigen Raum ist ein wichtiger Beitrag zur verbesserten Kommunikation auf dem Gebiet der Sensorik. Der Inhalt • Sensorische Deskriptoren und ihre Translation • Sensorische Attribute inklusive Definitionen Die Zielgruppen • Lehrende und Studierende des Fachbereichs Lebensmittel- und Ernährungswissenschaften mit den Schwerpunkten Lebensmittelsensorik und Lebensmittelqualität • Fach- und Führungskräfte im Bereich Lebensmittelsensorik, -technologie und -chemie, Qualitätssicherung von Lebensmitteln und Marktforschung Die Autorinnen Prof. Dr. Dorota Majchrzak arbeitet seit 2006 als Außenordentliche Universitätsprofessorin des Departments für Ernährungswissenschaften an der Universität Wien und ist Leiterin des Sensoriklabors. Mag. Caroline Schlinter-Maltan ist seit 2015 mit ihrem Büro für Ernährung als Ernährungswissenschaftlerin und Lebensmittelsensorikerin tätig.
Chapter
Bei Milch handelt es sich um die aus den Milchdrüsen weiblicher Tiere abgesonderte Emulsion von Proteinen, Milchzucker und Milchfett in Wasser. Sie enthält alle lebensnotwendigen Nährstoffe, damit der Körper nach der Geburt aufgebaut und mit Energie versorgt werden kann. Die wichtigste Konsummilch ist die Milch der Kuh, zusätzlich sind auch die Milch von Schafen und Ziegen von einiger Bedeutung als Lebensmittel (EBERMANN und ELMADFA 2011).
Article
Lactose is the major carbohydrate found in milk and dairy products. Lactose intolerance means the body cannot digest foods with this natural sugar in them. In this context, the lactose-free market has experienced a steep increase in recent years. A new method for the determination of residual lactose in lactose-free dairy products using liquid chromatography coupled to tandem mass spectrometry triple quadrupole (HPLC-MS/MS) has been developed. Hydrophilic interaction chromatography (HILIC) has been used for this purpose. An amide chromatographic column with an alkaline mobile phase were selected as optimal. In addition, a fast, cost-effective and reliable sample treatment has been developed for routine analytical laboratory use. The method has been validated by using matrix-matched calibration standards and a recovery assay on a lactose-free milk sample obtained by lactase hydrolysis of regular milk. The limit of quantification (LOQ) was 15mgL⁻¹, while the recovery was close to 100% with relative standard deviation lower than 9% in all cases. The method was applied to several lactose-free products and the results showed that lactose values in these products are not always below the recommended maximum value of 100mgL⁻¹.
Article
Evaluation of the sensory characteristics of food products has been, and will continue to be, the ultimate method for evaluating product quality. Sensory quality is a parameter that can be evaluated only by humans and consists of a series of tests or tools that can be applied objectively or subjectively within the constructs of carefully selected testing procedures and parameters. Depending on the chosen test, evaluators are able to probe areas of interest that are intrinsic product attributes (e.g., flavor profiles and off-flavors) as well as extrinsic measures (e.g., market penetration and consumer perception). This review outlines the literature pertaining to relevant testing procedures and studies of the history of sensory analysis of fluid milk. In addition, evaluation methods outside of traditional sensory techniques and future outlooks on the subject of sensory analysis of fluid milk are explored and presented.
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Preconcentration of milk has become an integral part of the production process for whole milk powder, whey powder, skimmed milk powder and other dried dairy powders. Various methods exist for the concentration of milk, depending on the type and quality of the desired end product and the economy of the process. Water can be removed from milk in the following three forms: as vapour; as liquid; and as solid ice crystals. Depending on the use of heat energy to concentrate, the methods for concentration of milk can be classified into thermal and non-thermal processes. Apart from traditional methods like evaporation and reverse osmosis, processes like ultrafiltration, reverse osmosis (hyperfiltration) and demineralization (electrodialysis, ion exchange) are now used industrially to produce dried dairy products. For production of skim milk powder, concentration of skimmed milk is done by reverse osmosis, which brings up the total concentration to 25% total solids.
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The real future will be in the area of "food as medicine" - people will be looking for smart foods to help prevent various health conditions.
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The impact of lactose hydrolysis achieved by crude β-galactosidase preparation in the form of crude cellular extracts (CCEs) from Lactobacillus delbrueckii ssp. bulgaricus 11842 on the sensory properties of the lactose hydrolyzed skim and chocolate milk was evaluated. The CCEs were obtained by controlled culture fermentation at 43°C and pH 5.6 maintained by ammonium, sodium or potassium hydroxide and bead milling after cell collection. In the first sensory assessment by expert evaluators (n=3), addition of 2 or 4% CCEs for the lactose hydrolysis at 7 or 20°C resulted in noticeable sweetness but also in other off-flavors likely carried over from the fermentations. The ammonium CCE was judged unacceptable for further sensory study due to grossly detrimental sensory impact. An untrained panel (n=10) employed for the second sensory trial reported significant (p<0.05) increase in sweetness for all lactose hydrolyzed skim milk samples after addition 1 or 2% sodium- or potassium-produced CCEs and degree of lactose hydrolysis between 70 and 75%. The off-flavor intensity manifested in lactose hydrolyzed skim milk samples especially after 2% CCE additions was minimized by adding cocoa powder.
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The feasibility of producing partially-lactose-hydrolyzed (PLH) milk or syrup using a crude source of β-galactosidase from a disrupted dairy culture (L. delbrueckii subsp. bulgaricus 11842) was examined. Ascertaining that the disrupted biomass from a 1000 L fermentation is capable of producing at least 1000 L of PLH milk (60% hydrolysis), production of one or two 2000 L batches per week would be economically feasible provided the processing facility already owns a suitable bactofuge. The hydrolysis of a 50,000 L batch of milk at least two days per week appears feasible despite the need for a $7.5 million capital investment. Production of sweetening syrup (65% solids, 60% hydrolysis) from whey or permeate does not appear economically feasible based on the hydrolysis of 500,000 L of whey or permeate per day (85% operating factor). Partially-lactose-hydrolyzed milk is a high-value added product, but syrups produced from hydrolyzed whey or permeate would have to compete with other inexpensive sweetener commodities.
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Lactose maldigestion can be defined as the incomplete digestion of lactose in the small intestine, with some lactose reaching the large intestine/colon. Maldigestion is due to a greater concentration of substrate (lactose) relative to the activity of the mammalian lactase enzyme (lactase). There is a fairly linear relationship between dietary intake and maldigestion under controlled conditions where lactose is consumed alone or in milk. Most of the scientific evidence supports the view that lactase enzyme activity is regulated primarily by genetics in healthy individuals. Further, substantial evidence supports the view that lactase activity falls from infantile levels to adult levels (a 10-20 fold reduction) between the ages of 3 and 5 years in 75% of the World’s population. The loss of intestinal lactase activity is a typical mammalian trait and has been well characterized in a number of species. The temporary loss of intestinal lactase due to malnutrition, alcoholism or other diseases can be an important contributor to maldigestion. Lactose maldigestion is also common among infants, despite their high levels of intestinal lactase activity. AUTEUR(S) Dennis A. SAVAIANO LANGUE DE L'ARTICLE Anglais
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The retention of β-galactosidase activity in crude cellular extract (CCE) preparations from Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 was investigated after spray drying at three different outlet air temperatures (40, 50 or 60 °C), freeze drying, and after 30 days storage. Lactose, skim milk and whey protein preparations in concentrations ranging from 5 to 30% (w/w) were used as drying adjuncts. To further investigate the protective role of sugars in the enzyme activity preservation, cellobiose and sucrose were also employed in 5 and 10% concentrations during spray-drying at 60 °C or freeze-drying. The addition of lactose or skim milk in all examined concentrations resulted in significantly (P
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Three different neutralizers (NaOH, KOH, NH4OH) were employed for pH maintenance during the growth of Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842, used as a source of β-galactosidase extracts. The crude enzymatic extract (CEE) was obtained by bead milling of the cell paste, collected from the cultivation of the source microorganism in skim milk at 43 °C and constant pH. Lactose hydrolysis kinetics in skim milk and proteolytic activity during the hydrolysis were evaluated. The use of NH4OH as a neutralizer resulted in significantly (P0.05) difference in kcat among the different extracts, with a clear temperature dependence following Arrhenius kinetics. The rate of lactose hydrolysis was dependent on the initial enzyme activity and temperature. The highest initial rate was observed at 65 °C; however, the enzyme deactivation occurred within 1–1.5 h. The proteolytic activity determined by HPLC peptide mapping was significantly (P
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The aim of this work was to establish optimal conditions for the maximum production of β-galactosidase using an industrially suitable medium. Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 was cultivated in skim milk, whey and whey permeate basal media, supplemented with whey protein products, yeast extract or De Man–Rogosa–Sharpe (MRS) broth, at pH 5.6 and 43°C. All supplementations of the whey and whey permeate basal media resulted in the enhancement of the specific growth rates, rate of lactic acid production and β-galactosidase activity. However, unsupplemented skim milk gave the greatest rate of lactic acid production (3.50±0.269 mg lactic acid ml−1 media h−1) and the highest β-galactosidase activity (5.491±0.116 U activity ml−1 media); far superior to the best whey-based medium supplemented with MRS (2.71±0.176 mg lactic acid ml−1 media h−1 and 3.091±0.089 U activity ml−1 media, respectively). A technologically feasible approach for the reprocessing of the spent skim milk was tested and a conceptual process scheme is proposed.
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The lactose-hydrolysing ability of Lactobacillus delbrueckii ssp. bulgaricus strain 11842 (LB 11842) was tested after cultivation in MRS broth under varying conditions. After sonication for an optimum time determined to be 4 min to disrupt the cells, cultures were added to various substrates, including pH 7 buffered 2.5 and 5% lactose test solution, skim milk, or a 30% lactose or whey permeate solutions. Freezing point changes were used to measure the progress of hydrolysis at a wide range of temperatures. Cultures added to the lactose test solutions resulted in 20% and 63% of the lactose being hydrolysed after 3 h at 7 and 51 °C, respectively. Values for hydrolysis in skim milk were slightly higher. Enzyme activity was not hindered in 30% lactose or 30% whey permeate solution and the hydrolysis rate was acceptable at a low temperature (7 °C) in skim milk.
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Crude cellular extracts (CCEs) containing active β-galactosidase fromLactobacillus delbrueckiissp.bulgaricus11842 were spray-dried at three different outlet air temperatures (45, 55 or 65°C) or freeze-dried, with or without whey proteins, casein, whey or skim milk as drying adjuncts. The use of whey or skim milk resulted in significantly (P < 0.05) higher β-galactosidase activity retention in comparison to all other CCEs. This effect was not related to the initial total solids (TS) content (4–10%) of the feedstock solutions, but was presumably caused by the presence of lactose in the whey or skim milk CCE preparations.
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Lactic acid bacteria are being increasingly exploited for use in production of microbial bioproducts such as enzymes for food industry applications. The different techniques available for release of intracellular products include mechanical, physical, chemical, enzymatic and combined methods. The effectiveness of the various methods differs for different microbial species. Publicly accessible information is available mainly for yeasts or several well studied bacterial host cells such as Escherichia coli or Bacillus subtilis, while reports on disruption of bacterial cells applicable to uses in the dairy industry are scarce.In general, mechanical methods are non-specific, but their efficiency is higher and application broader in comparison to any of the other methods. Disruption characteristics such as pressure or number of passes for each device vary according to microbial strain, age of culture, temperature of cultivation, and cultivation medium. High-pressure homogenizer, Microfluidizer, and Bead Mill appear to be devices best suited for use in the dairy industry due to their wide range of applicability and accessible scale-up.
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Cultures of Lactobacillus delbrueckii ssp. bulgaricus 11842 grown on whey supplemented with yeast extract were subjected to treatments using sonication, a high-speed bead mill, and a high-pressure homogenizer. The various means of disruption were compared by the release of intracellular β-galactosidase and by scanning electron microscopy (SEM). The β-galactosidase activity was measured using o-nitrophenyl-β-d-galactopyranoside (ONPG). In general, the release of active β-galactosidase was not affected by cell concentrations in the range of 12–46% (wet wt.). The maximum activity was observed after 2–3 min of bead milling and after three passages through the high-pressure homogenizer (135 MPa). The amount of active β-galactosidase released by homogenization after one passage at 200 MPa was comparable to that released between two or three passages at 135 MPa. Sonication was not as effective as the bead mill or the high-pressure homogenizer with respect to the release of β-galactosidase or the break-up of cells as evidenced by SEM and TEM. Both bead milling and high-pressure homogenization appear to be suitable for the large-scale disruption and release of β-galactosidase from L. delbruekii ssp. bulgaricus 11842.
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The extent of the lactose hydrolysis and oligosaccharide formation through transgalactosyl reactions by crude cellular extracts (CCE) containing intracellular β-galactosidase from disrupted Lactobacillus delbrueckii subsp. bulgaricus 11842, Lactobacillus delbrueckii subsp. lactis DMF 3078 or Streptococcus thermophilus 143 was investigated in lactose-containing buffered solutions or skim milk. Lactose hydrolysis was performed with lactose concentration ranging from 5 to 30% (w/w) at 30, 40, 50 or 60 °C and terminated after 120 min. The proteolytic activities of the CCEs in skim milk systems were also assessed. All CCEs produced di-, tri- and tetrasaccharides in addition to monosaccharides as major products of the lactose hydrolysis in buffered lactose solutions. However, only Lb. lactis produced tetrasaccharides at detectable levels in skim milk preparations. The amount and the rate of oligosaccharide formation were significantly (P < 0.05) affected by the origin of the enzyme, lactose concentration and temperature. The maximum oligosaccharide production by all CCEs was reached at 50 °C in 30% (w/w) lactose solution. St. thermophilus CCE produced significantly higher (P < 0.05) amounts of oligosaccharides than the other two CCE preparations at all lactose concentrations studied. However, Lb. bulgaricus CCE showed better lactose-hydrolyzing ability and higher proteolytic activity than the other two CCEs. The lactose hydrolysis generally proceeded faster at 50-60 °C than at 30-40 °C as opposed to the proteolytic maxima reached at 40 °C.