Paul  Jelen  and  Olli  Tossavainen.  2003.  Low  lactose  and  lactose­free  milk  and  dairyproducts  –  prospects,  technologies  and  applications.  Australian  Journal  of  DairyTechnology, volume 58, number 2, pages 161­165.

© 2003 Dairy Industry Association of Australia (DIAA)

Reprinted with permission.

Low lactose and lactose-free milkand dairy products - prospects,technologfies and applications

The lactose intolerance problemLactose, the most abundant component of milk of most

mammals, is an important energy source for the newborn off-spring. Upon weaning, the ability to digest lactose diminishesas the adult organism loses its ability to produce the enzymelactase (B-galactosidase, E.C. 3.2.I.23) needed for the lactosedigestion. This is a 'normal case' found for most mammals innature. The only notable exception are some ethnic groups ofthe most complex mammal - the human - which have devel-oped the abil ity to keep producing the lactose-digestingenzyme as a result of milk becoming a food consumed by notonly the infants but also adults. Even in this case, however,the inability to digest lactose (the so called .lactose intoler-ance') is the more predominant case around the world, asshown in Figure I (Anon. 2001).

The debate about the various forms of the lactose intolerance,as well as the severity of the malady from the medical view-point, continues. At the last IDF World Dairy Congress in paris,

two contributions by the leading researchers in the field weredevoted to the conditions, symptoms, and roles of the individualfactors influencing the lactose digestion or maldigestion(Savaiano 2002; Marteau et al. 2002). Regardless of the pos-sible medical implications of the lactose intolerance, even themost innocuous symptoms such as flatulence or intestinal dis-comfort cause many potential milk consumers to avoid drink-ing milk or consuming other lactose-containing dairy products.Sometimes even virtually lactose-free products such as cheeseare avoided by consumers that consider themselves to be lac-tose intolerant (Jelen, personal communications). For the dairyindustry, the potential market losses due to the real or perceivedlactose intolerance problems are significant and some compa-nies expend much effort to develop products that would satisfylactose-intolerant consumers.

The market for lactose-hydrolysed dairy products has beengrowing steadily, at arate of approximately 20oÄ per year in theUS alone, mainly stimulated by the awareness of the lactose-intolerance problem and the changing demographics (Mahoney1997).In addition to milk, other products are also entering themarkets with increasing frequency, as can be ascertained by aquick survey of the websites of some producers (Vasiljevic2003). One ofthe signif,rcant providers ofa large variety oflac-tose-hydrolysed dairy products is the Finnish dairy companyValio, where a general awareness of lactose intolerance arosein the early 1970s and a search for a solution to the problem hasbegun. Although the occurrence of lactose intolerance inFinland (ca. l7oÄ ofthe total population) is relarively low by

The authorsPaul Jelenl and Olli Tossavainen21 Department of Agricultural, Food and Nutritional Science,

University of Alberta, Edmonton, Canada2 Valio Research and Development, Helsinki, FinlandCorrespondence to.' Professor P. Jelen, Department of Agriculturat,Food and Nutritional Science, 4-7O Agfor Centre, LJniversity ofAlberta, Edmonton, Ab. T6G 2PS Canada.Fax: +7 78O 492 8974; e-mail: pauljeten@ualbefta.ca

AbstractReducing the lactose content or removing it completely frommilk and other dairy products can expand availability ofvaluable dairy nutrients world-wide. The traditional approach toconversion of lactose by its hydrolysis to the constituentmonosaccharides has been practiced industrially for almost20 years. In Finland, the HYIA line of dairy products containinghydrolysed lactose comprises almost 100 different products.The patented chromatographic process for removal of lactosefrom milk offers new opportunities for marketing of lactose-freemilk and dairy products with sensory properties indistinguish-able from those of the comparable traditional products. Theprocess is described and the marketing success of the newValio lactose-free products is documented.

Aust. J. Dairy lechnol. 58, 161-165

international comparison, the problem is nevertheless signifi-cant due to the high consumption of milk (approx. 130 Llperson/ear). After the first commercial lactase enzymes becameavailable, the use ofthese soluble preparations was perfectedto hydrolyse enzymatically more than 80oÄ of the lactose inmilk into glucose and galactose. Valio launched the firstlactose-hydrolysed product - HYLA milk powder - for testmarketing in 1978. The product became fully available in 1980,after which the range began to grow slowly. Then from 1985onwards the HYLA product range was vigorously expanded. Alow-lactose altemative was introduced in each product groupand the HYLA range has continued to grow. Valio currentlyoffers some 100 different HYLA products; some examples ofthe more successful ones are listed in Table l. About 15-20%of Valio's tumover comes from HYlA-products. However, thispercentage varies largely between different product groups,ranging from 3Yo to 60Yo. For example, in dairy creams groupHYlA-products represent about 60%o of total sales.

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Jruru nruo Tossnvnrueru

Technological alternatives forlactose hydrolysis

While several technologically feasible approaches to produc-tion of lactose-hydrolysed milk and dairy products exist(Table 2), most processors resod to the enzymatic route for thebreakdown of the lactose molecule using either the free (solu-ble) or, rarely, the immobilised enzyme variant of the process.In both cases the resulting milk contains both glucose and ga-lactose, the end products of the enzymatic hydrolysis, makingthe milk much sweeter and thus, for many consumers, unnatu-ral. Both processes are also relatively expensive as evidencedby the much higher prices of the lactose-hydrolysed milk on theretail markets, thus further discouraging consumers' purchases.

In mid- 1980, Valio began a new line of research into chro-matographic separation of lactose from whey, in order to im-prove the yield of its lactose manufacturing operation (Harju1990a). Chromatography was already commonly used in thesugar industry to improve the yield in sugar production. The testresults showed that the developed chromatography process wasalso suitable for a specific separation of lactose from skim milk,

Figure 1: Lactose intolerance(% of total populations)around the world.

and, consequently, resulted in another product besides lactose- a fraction containing all the salts and proteins of milk (Harju

1990b). This way of separating lactose from skim milk was new

to milk separation technology. The well-established process of

ultrafiltration also enables the separation of lactose from milk,

but the salts are removed from the protein fraction at the same

time.The patent-protected process of removing bulk of the lactose

from milk chromatographically enabled the production of a lac-

tose-free milk drink, with the taste no different from ordinary

milk. In its final version (Figure 2) the milk is split into two

streams; lactose is removed from the main stream while the tra-

ditional process of lactose hydrolysis by a soluble enzyme is

carried out in the second stream. Combining the two streams

results in the slight sweetness of the final product matching that

of the ordinary milk.The lactose-free milk drink was launched in Finland in autumn

2001. The product was named 'milk drink', because accordingto the present EU Directive lactose may only be removed from

milk products erzymatically. The physical separation of lactose

Table 1: Examples of Valio's HY!A@ products. (ln all HYIA-products more than 80% of lactose is hydrolysed).

ProductHYLA skimmed milk powder Spray-dried 500 g pouch

25 kg bag0.2 L, 0.5 L, 1 Laseptic carton150 g cup15O g cup1 L carton0.2 L, 0.5 L, 1 L0.2 L, O.33 L,1 L, 10 L carton200 g cup1 L carton4.5 L (caterin$75O g

HYLA low fat milk

A-yogurtGefilus yogurt with fruitEvolus fermented milkHYLA whipping creamHYLA cooking cream UHT

HYLA cottage cheeseGefilus-whey drinkHYLA ice-cream

UHT-treated, 1,.5%fal

Flavoured stirred yogurt with acidophilus and bifidusSkimmed milk yogurt with Lactobacillus GGFermented milk with bioactive peptides (lowering blood pressure)

UHT-treated, 38% fatDairy-based cooking cream product.UHT, 15% fatCottage cheese 2"/"fal, naturalFermented apricot-peach whey drink with live lactic acid bacteriaVanilla ice-cream

Launched

1980

1983

19862002200019881998

199119901990

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Low ucrose AND rAcrosE-FREE MtrJ( AND DAIR/ pRoDucrs

Table 2: Industrially applicable methods for lactose hydrolysis.

Process

Acid-catalysed hydrolysis Aqueous lactose solutlon heated @ 150 C, pH 1.2lmmobilised enryme technology Lactase immobilised on suitable carrier in a columnMembrane-based enaTme reactors Soluble enryme separated by UF and reusedFree (soluble) purified enrymes Enzyme preparation added to final productCrude cellular eKracts Homogenate of lactase-producing microbial culture used as the en4rme source

using chromatography necessitated this approach to the label-ling of the product. However, such a labelling requirement isnot unusual; as an example, in Switzerland, a reduced-fat UHTmilk is also labelled as a milk drink to satisfy the local regula-tory requirements.

The composition of the lactose-free Valio milk (Table 3) issimilar to that of partly skimmed milk, except for its lowcarbohydrate content. It contains less than 0.01% lactose, themaximum permitted for lactose-free products by the Finnishauthorities. The glucose and galactose content is approximately| .4oÄ each. Due to the lower carbohydrate content, the productalso contains less energy than a corresponding traditionalproduct, with approximately 83oÄ of the energy content of thepartly skimmed milk.

Crude cellular extractsAt the University of Alberta, an alternative approach to the

production of lactose hydrolysed dairy products has beenunder investigation for several years. Although the research isbased on the traditional use of the lactase enzyme, the novelidea is to produce the enzyme 'in-house', in the form of a crudecellular extract from a well-established dairy bacterium.The enzyme source in our work has been the traditional yogurtculture Lactobacillus delbrueckii ssp. bulgaricus; its ATCCstrain I 1842 has been selected as a particularly effective pro-ducer ofthe enzyme (Shah and Jelen 1991). The envisionedprocess involves growing the enzyme-producing culture justlike in the case of a traditional starter culture for cheesemaking;

Figure 2; Schematic representation of the Valio productionprocess for lactose-free milk.

concentrating the cell biomass and disrupting the concentratedculture by a high pressure homogeniser or a similar device; andusing the homogenate (termed 'crude cellular extract' or CCE)without further purification or other treatment. The conceptualschematic diagram of the proposed process is shown in Figrue 3.

In.a series of papers published recently, we have shown thegeneral technical and perhaps even economic feasibility oftheapproach (Kreft er al.200l;Bury et aI.2000); we investigatedthe enzyme production alternatives (Vasiljevic and Jelen 2001);compared several altemative enzyme sources and several alter-native cell disruption techniques (Bury el al. 2001; Geciova etal. 2002a); determined the technical feasibility of drying theCCE with minimal loss of enzymatic activity (Vasiljevic andJelen 2003a,b); and conducted confirmative sensory evaluationsof the resulting lactose-hydrolysed products (Yasiljevic et al.2003), Since the approach not only does not solve the problemof increased sweetness of the resulting milk, but produces someadditional flavour modifications related to the fermentationprocess used for the enzyme production, the resulting lactose-hydrolysed drinking milk certainly cannot compete with theValio chromatographic process! However, for other applica-tions. in the cases where the sweetness and the fermentedflavour may not be detrimental - or may even be welcome asin the case of whey or yogurt drinks or similar products - thislatest twist in the traditional lactose hydrolysis technology maybe worth investigating further.

Beyond the core subject oflactose hydrolysis, other uses ofthe CCE technology may also be considered and some havebeen studied. In particular, the transferase reactions catalysedby the lactase euyme contained in the CCE may result not onlyin hydrolysis of the lactose but in format ion of newdisaccharides and/or production of other oligosaccharides(Vasiljevic and Jelen 2003c). The proteolytic activity of the

Lactose free milk

. lmg shef lile Otherapplications

Enzyffitic hydrolysis,addilion ol purc lac{a$

r . l.+- t !zo5 O:-

t lorD orr

, lI I

OIO 1*rlorr

Table 3: Proximate analysis of the lactose free milkdrink compared with other market milk products.

Lactose- Pasteurised Pasteurisedfree milk low-fat milk low-fat milk

lactosehydrolysed(HY|-A)

Protein (%) 3.3 3.2 3.2Carbohydrates (%) 2.8 4.8 4.8Lactose (%) <0.01 <7 4.8Ash (%) O.7 O.7 O.7Far ("/d 1.5 1.5 1.5Calcium (m9100 g) L2O t2O L2OEnerg (kJ) 160 193 193

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Jerry eruo Tossavntruen

cullure Propqgcdlon{sklm mllk)

Icenlrllulollon ot

,-t mlctofrlrcllon (MF)

{tediment or ruiremclonf or

leientol,e

I+cullure dlrrupll'on

Iviobl&ell dcoctivsllon

(iir)

\

nermecfe (StM)

t"rpenl" rklm mllk(SSM)

procerslng (Hf, HfUF, Ut, Dt), "'..^ -

/ täor"rorts,/l\.-

1/ rnnmskpemeoto(SM?l

oddfllon l,o mllk or whey

o.*Jprocesslng

Figure 3: Schematic diagram of the proposed lactosehydrolysis process based on the use of crude cellularextracts of a lactase-producing microbial culture'

CCE, while potentially detrimental for the primary lactose hy-

drolysis goal unless controlled by the judiciously selected hy-

drolysis conditions (Vasiljevic and Jelen 2002), could be

advantageous in using the CCE as a 'ferm€ntation enhancer'.The proteolytic as well as lactolytic properties of the CCE canbe possibly utilised in production ofvarious cheese starter cul-tures, for enhancement of growth rates of slow growingprobiotic organisms, even in production of various fermenteddairy products (Gaudreau, Champagne and Jelen 2003).

The basis of the emerging CCE technology is the rapidly ex-panding availability of mechanical equipment suited for bac-terial cell disruption, now well established in the pharmaceuticalindustry. Table 4lists some ofthe altemative designs potentially

suitable for applications in the dairy industry (Geciova et al.2002b), as an alternative to the more traditional approach to

enzyme release from bacterial cells by the induced cell lysisroute.

Marketing of lactose-hydrolysed andlactose-free milk productsValio's marketing strategy is to differentiate consumer prod-

ucts in the home market. An illustration of such differentiationis shown in the Figure 4. Outside the home market, Valio is li-

censing production technologies and product concepts.Lactose-hydrolysed products have attracted constant demand

among consumers in Finland. Since the 1980s, when the

HYlA-products were launched, their share in each productgroup has grown steadily. At the present time - 20 years afterthe original decision to include lactose-hydrolysed dairy prod-

ucts in the manufacturing program - the average share ofHYlA-products in all product categories is still growing stead-

ily, between l0oÄ and20Yo per year.The new line of lactose-free products is showing even more

enthusiastic response from the consumers than the HYLA prod-

ucts 20 years ago. So far, Valio's experience comes mainlyfrom marketing the lactose-free milk drink. The product waseagerly received despite very limited advertising. Its imovative

Table 4: Industrially applicable mechanical methods for

disruption of bacterial cells (from Geciova et al. 2OO2bl.

Process

UltrasoundHigh pressurehomogeniser

MicrofluidiserBead mill

Characteristics

Scale-up for continuous industrial use difficult

Instantaneous cooling diffi cult

Easy to cool, limited throughput capacityCumbersome separation of the $ass beads

value is so great that it generated press coverage in national

newspapers. The product reached the sales target set for the

whole year in just three months. Sales grew vigorously and

continue to do so. Exports to Sweden commenced in Novem-

ber 2002 and again exceeded all expectations. In spring 2002,

Valio's lactose-free milk drink was selected as a star product

of the year in the drinks category ofthe Finnish Food Product

of the Year competition.

Based on consumer feedback, the product has obviously at-

tracted a new group of milk users: people who had given up

milk due to lactose intolerance and who dislike the sweetness

of the HYLA milk. These consumers are once again able to

enjoy the good taste of milk without the fear of suffering from

stomach disorders. The revolutionary chromatographic separa-

tion technology enabled Valio to develop a new kind of dairy

product based on selective modification of the composition of

the original raw milk.

Gonclusion - lactose intoleranceas an opportunity

In the US alone, the potential market for dairy products tar-

geted specifically for lactose-intolerant individuals has been

estimated to be about 50 million consumers (Sloan 2000). In

Finland the figure is about one million, while in South-East Asia

more than 90% of the population is lactose intolerant. The po-

tential for innovative market development in this part of the

world is enofinous, but the consumers are not used to consum-

ing dairy products as adults. Offering them suitable products

based on modifications of the traditional cow's milk could open

up new markets for the dairy industry world-wide.Lactose-hydrolysed and lactose-free dairy products should be

considered as important physiologically functional dairy foods.

Their rapidly expanding availability will mean not only more

satisfied milk drinkers world-wide, but will lead to improved

nutritional stafus due to increased availability ofdairy calcium

and thus, ultimately, to reduction of health-related societal ex-

penses. For the dairy industry, the possibility of increased mar-

kets should be an important incentive to continue the

technological developments leading to many new dairy products

that will satisff even the most lactose-intolerant consumers.

ReferencesAnonymous, 2001. Lactose-free milk makes healthy debut' MillShake (a Valio news-

letter), 3/2001, p. l, 7.

Bury, D., Jelen, P. and Kalab, M. (2001), Disruption of lactobacillus delbrueckii ssp.

Bulgaricus I 1842 cells for lactose hydrolysis in dairy products: a comparison of

sonication, high-pressure homogenization and bead mllling. Innov. Food. Sci. &

Emerg. Tech. 2.23-30.

L64 THe AusrRAuar.r Jounul or Drusv TecrHolocY. Vot-. 58, No. 2 - Aueusr 20O3

Low ucrose AND tAcrosE-FREE Mu"x AND DAtRy pRoDUcrc

Fiture 4: Example of HYIå product differentiation indomestic Finnish market.

Bury, D. and Jelen, P. (2000), Lactose hydrolysis using a disrupted dairy culture:Evaluation of technical and economical feasibility. Can. Agric. Eng. 42,7 5-80.

Gaudreau, Champagne and Jelen, (2003), The use ofcrude cellular ext'acts of Lacto-bacillus delbrueckii subsp. bulgaricus 11842 in growth media designed for lacticcultwes. Enzyme and Microbial Technologt (submitted).

Geciova, J., Gie sova, M., Jelen, P. and Plockova , M. (2A02a), Disruption ofStreptococclrs thermophilus 143 culture by three mechanical methods for increasedB-galactosidase activity . Milchwissenschaft 57 , (9/l 0): 509-5 I I .

Geciova, J., Bury, D. and Jelen, P. (20O2b), Methods for disruption of microbial cells. for potential use in the dairy industry - a rcview. Int. Dairy J. 12, 541-553.

Harju, M. (1990a), Process ofrecovering lactose from whey. US Patent 4.955.363.Harju, M. (1990b), A process for the specific separation of lactose from milk. Ero-

pean Patent 0226035.Kreft, M.E., Roth, L. and Jelen, P. (2001), Låctose hydrolysing ability ofsonicated

culires of Inctobacillus delbrurckii stbsp. bulgarbu 11842. Le LaitEl,355-364.Mahoney, R.R. (1997), Lactose - enämatic modification. In: Advanced Dairy Chem^

istry, Vol 3: Iactose, woter, salts and vitamins (Ed. Fox, P.F.), Chapman & Hall,New York, N.Y. , p.l16.

Marteau, P., Morales, 8., Vesa, T. and Korpela, R. (2002), Lactose intolerance: themedical point of view. Scrences des Aliments 22, 431436.

Savaiano, D.A. (2002), Lactose maldigestion vs. intolerance. Sciences des Aliments22,425-430.

Shah, N. and Jelen, P. (1991), Lactase activity and properties ofsonicated cultures.Milc hwisssensc haft 46(9\, 57 0-57 3.

Sloan, E. (1999), The new market: Foods for the not-so-healthy. Food Technologt53(Z\, s4-60.

Vasiljevic, T. (2003), Lactose hydrolysis by disrupted thermophilic lactic acid bacte-ria. Ph. D. thesis, University ofAlbert4 Edmontoru Canada, pp. 38-39.

Vasiljevic, T., Wismer, W. and Jelen, P. (2003). Sensory effect of lactose hydrolysisin.milk by crude cellular extracts from Incnbacillus delbrueckii ssp. bulgaricus| 1842. Milchwissenschaft 58(3 I 4), | 67 -170.

Vasiljevic, T. and Jelen, P. (2003a), Retention of8-galactosidase activity in crude cel-lular extracts fuom Lactobacillus delbrueckii subsp. bulgaricus I I 842 upon dry-ng. Int. J. Dairy Tech. 56(2), I I 1-l 16.

Vasiljevic, T. and Jelen, P. (2003b), Drying and storage of crude B-galactosidase ex-tracts from ractobacillus delbruechi subsp. bulgarictu 11842. Innov. Food. Sci.& Emerg. Iecå. 4, in press.

Vasiljevic, T. and Jelen, P. (2003c), Oligosaccharide production and proteolysis dur-ing lactose hydrolysis using crude cellular exFacts from lactic acid bacteria', In laitE3, in press.

Vasiljevic, T. and Jelen, P. (2002), Lactose hydrolysis in milk as affected by neutal-izers used for preparation of crude B-galactosidase extracts ftom Lactobacillusdelbruecki svbsp. bulgarbus 11842. Innov. Food. Sci. & Emerg. Tech.3(2),175-I 84.

Vasi[evic, T. and Jelen, P. (2001). Production of0-galactosidase for lactose hydrolysisin milk and dairy products using thermophilic lactic acid bactena. Innov. Food. Sci.& Emerg. Tech. 2,75-85.

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