The functional and biological properties of whey proteins prospects for the development of functional foods Hannu Korhonen, Anne Pihlanto-Leppälä, Pirjo Rantamäki and Tuomo Tupasela Agricultural Research Centre ofFinland, Food Research, FIN-31600 Jokioinen, Finland, e-mail: hannu.j.korhonen@mtt.fi Advances in processing technologies and the accumulation of scientific data on the functional and biological properties of whey components have contributed to the growing commercial valuation of cheese whey over the last decade. New membrane separation and chromatographic techniques have made it possible to fractionate and enrich various components of whey more efficiently than before. The specific properties of these components can now be examined in greater detail and new applica- tions developed accordingly. The utilisation of cheese whey is evolving into a new industry produc- ing a multitude of purified ingredients for numerous purposes. The most significant areas of R&D related to whey proteins include functional foods, the rheological properties of foodstuffs, and bio- pharmaceuticals. Key words: biopharmaceuticals, cheese whey, functional foods, whey proteins ntroduction The consumption and manufacture of cheese is increasing worldwide at a rate of about 2% per year. As a result, the amount of cheese whey is also increasing and is now estimated to be some 130 million tonnes annually. About half of this amount is produced in Western Europe, 20% in Eastern Europe, another 20% in North America and theremaining 10% in other parts of the world (Riedel 1994a). Earlier, the disposal of whey represented a serious environmental problem, as it contains a great deal of organic substances with a high biological oxygen demand (BOD). In fact, whey contains more than half (6-7%) of the sol- ids present in the original milk, including about 20% of the protein, and most of the lactose, min- erals and water-soluble vitamins (Sienkiewicz and Riedel 1990,Zall 1992). In countries with a highly developed dairy or food industry, whey is increasingly being used for human consump- tion instead of as animal feed or being disposed as waste. Innovations in whey processing have only emerged in the past two decades, with the shift to target processing of whey. Here, lactose and proteins are the most important target com- ponents. The principal processes applied in whey © Agricultural and Food Science in Finland Manuscript received February 1998 283 Vol. 7(1998): 283- AGRICULTURAL AND FOOD SCIENCE IN FINLAND processing today are concentration, drying, fer- mentation and, more recently, isolation of whey proteins by means of membrane separation and chromatographic techniques to produce individ- ual components in their purified forms. Clearly the potential uses of whey have not been fully realised. Apart from lactose and its derivatives, increasing attention is being paid to the exploitation of individual whey proteins and other physiologically active components con- tained in whey. It is expected that in the future these components will find greater use in the food industries and as raw materials in the non- food sector, e.g. the pharmaceutical and biotech- nology industries. This review deals with the recent progress made in the technologies availa- ble for isolating whey proteins, analysing the functional and biological properties of individ- ual whey proteins, and developing innovative products based on these proteins. The results of the research work on whey proteins carried out at the Food Research Institute of the Agricultur- al Research Centre of Finland (MTT) over the last 10 years are also reported. solation and modification of whey proteins The proteins in whey are increasingly recognised as valuable nutrients that should not be wasted. Bovine whey contains 4-7 grams of protein per litre. The concentrationof whey proteins depends on the type ofwhey, stage of lactation and health status of the cow, and on the processing condi- tions in the manufacture of cheese or casein. The protein fraction comprises a wide range of indi- vidual proteins with specific characteristics. A number of review articles and text books have been published on the functional, nutritional and biological properties of whey proteins over the past 10years (Mulvihill and Fox 1987,Fox 1989, Kinsella and Whitehead 1989, Mulvihill and Fox 1989, deWit 1989, Sienkiewicz and Riedel 1990, Dybing and Smith 1991, Fox and Flynn 1992, Zadow 1992, Jost 1993, Kilara 1994, Mulvihill and Fox 1994, Riedel 1994a,b,c, Wade 1994, Korhonen 1995, Riedel 1995, Regester et al. 1996, Smithers et al. 1996, Barth and Behnke 1997, deWit 1998).Table 1 summarises the char- acteristics of the major milk proteins. Since the 19705, several industrial-scale tech- nologies have been developed for isolating whey proteins. The advent of membrane separation techniques, in particular, has contributed to the commercial production of whole-whey protein products, e.g. whey protein concentrates (WPC) with protein contents of 30-80%. The develop- ment of industrial-scale gel filtration and ion exchange chromatography techniques has made it possible to manufacture high-quality whey protein products, referred to as whey protein iso- lates (WPI), with protein contents of 90-95%. These technologies and processes have been re- viewed in several articles (Marshall and Harper 1988, Morr 1989. Hobman 1992, Jelen 1992, Morr 1992,Mulvihill 1992, Pearce 1992, Cupe- rus and Nijhuis 1993,Morr and Ha 1993, Rosen- berg 1995). Basic membraneseparation process- es, such as reverse osmosis, ultrafiltration (UF) and diafiltration, are now industrially applied to the manufacture of ordinary whey powder and WPCs. A more recent technique, nanofiltration or ultraosmosis, allows the selective separation of salts and ions from whey. This method has made it possible to utilise both the salted whey derived from the manufacture ofDomiati or Feta- type cheese and the industrial whey derived from the manufacture of mineral acid coagulated ca- sein (Abd El-Salam et al. 1991). The chemical composition and functionality of whey protein products are largely affected by the method used in the process (Mangino 1992, Mulvihill 1992, Zall 1992,Kilara 1994). Due to the inconsistent functionality of the WPCs and WPIs, they are of limited use in industry. Cheese fines (casein res- idues) and lipid residues often interfere with membrane separation processes and impair the functionality of whey protein products. Methods based on centrifugation, heat treatment or mi- crofiltration (MF) have been developed to elim- 284 Seminar in honour of the 100th anniversary ofMIT AGRICULTURAL AND FOOD SCIENCE IN FINLAND Table 1.Concentration and biological functions of major milk proteins. Protein Concentration Function g/1 Caseins (a, (3 and k) 28 lon carrier (Ca, P0 4, Fe, Zn, Cu), precursors of bioactive peptides (3-Lactoglobulin 3.3 Retinol carrier, binding fatty acids, possible antioxidant a-Lactalbumin 1.2 Lactose synthesis in mammary gland, Ca carrier, immunomodulation, anticarcinogenic Immunoglobulins A, M and G 0.7 Immune protection Glycomacropeptide 1.2 Antiviral, bifidogenic Lactoferrin 0.1 Antimicrobial, antioxidative, immunomodulation, iron absorption, anticarcinogenic Lactoperoxidase 0.03 Antimicrobial Lysozyme 0.0004 Antimicrobial, synergistic effect with immuno- globulins and lactoferrin Proteose-peptones 1.2 Not characterised References: Korhonen (1995) and Barth and Behnke (1997) inate this problem (Maubois et al. 1987, Morr 1989). For example, the whey can be treated before MF or UF using calcium chloride addi- tion with subsequent pH adjustment and heat treatment. In our studies at MTT (Tupasela et al. 1994), this method was found to improve the MF permeate flux by 30%. In UF treatment, whey clarified by the above method followed by MF gave a 20-40% better flux than whey treat- ed by MF only. Techniques for isolating individual whey pro- teins have now progressed from laboratory-scale to large-scale processing, although there is still a need to improve the purity of the commercial protein products available. Different combina- tions of heat precipitation and UF using selec- tive membranes have been applied for the frac- tionation of (3-lactoglobulin ((3-lg) and a-lactal- bumin (a-la) in enriched or purified form (Pearce 1983, Maubois et al. 1987, Konrad and Lieske 1997, Maubois and Ollivier 1997). In this technique, a-la undergoes isoelectric precipita- tion at pH 4.2 and at 55-65%C due to the disso- ciation of calcium ions and hydrophobic inter- actions. Other minor whey proteins also precip- itate under these conditions, while (3-lg remains soluble and can be separated, concentrated by membrane methods, and finally dried (Bramaud et al. 1995). Tupasela et al. (1997) studied the optimisation ofcentrifugal separation ofa-la and (3-lg and observed that maximum precipitation ofa-la was achieved at a whey dry matter con- tent of 23.3%, and that the separation efficiency improved with an increase in the concentration factor for whey. In addition to selective mem- brane separation, ion exchange chromatography using basic silica and polystyrene anion resins has been employed successfully, e.g. by Outi- nen et al. (1996), for the fractionation of (3-lg from whey. There is currently considerable commercial interest in the isolation of biologically active minorproteins, such as lactoferrin (LF), lactoper- oxidase (LP), immunoglobulins (Ig) and casein macropeptide (CMP). A number of pilot- or in- dustrial-scale methods have been developed for the enrichment or isolation of these compounds over the past decade, as reviewed by Mulvihill 285 Vol. 7 (1998): 283-296. AGRICULTURAL AND FOOD SCIENCE IN FINLAND and Fox (1994), de Wit and Hooydonk (1996) and Maubois and Ollivier (1997). Outinen et al. (1995) have described a method for the isola- tion of CMP using a strong basic anion exchange resin. Several patents have recently been pub- lished in this field; in fact, most of these pro- teins are already commercially available as in- gredients or are contained in specific products such as infant formulas, colostra! supplements, milk substitutes and toothpaste, and as preserv- atives of raw milk (IDF 1994, Horton 1995). The functional properties of whey proteins can be modified or improved by a variety of chemical, physical and enzymic methods (Mul- vihill and Fox 1989, Nakai and Li-Chan 1989, deWit 1989, Mulvihill 1992). Chemically mod- ified proteins already have some use in foods, but enzymic hydrolysis and physical modifica- tionby heat or high pressure offer a whole range ofinnovative possibilities for extending their use. A major application for whey protein hydro- lysates today is in hypo-allergenic infant formu- las (Bahna 1991,Kleinman 1992,Riedel 1994b). In these products, whey proteins are partially hydrolysed with digestive and/or microbial en- zymes, sometimes followed by membrane sepa- ration to achieve a specific molecular mass dis- tribution for the hydrolysate. In this way, the al- lergenicity of the proteins can be reduced sig- nificantly (lost et al. 1991, Wahn et al. 1992, Ena et al. 1995, Chirico et al. 1997). A recent study by van Beresteijn et al. (1994) showed that the minimum molecular mass to elicit immunogenic- ity and allergenicity by whey protein hydro- lysates is between 3000 and 5000 daltons. The optimum extent of the hydrolysis with respect to immunological properties and nutritive value is, however, not known. Further research is re- quired on how to optimise the properties of the whey protein hydrolysates used for infant feed- ing. Enzymatic hydrolysis of whey proteins fol- lowed by UF of the hydrolysate can also be em- ployed for producing and enriching bioactive peptides, as shown in our own studies at MTT (Pihlanto-Leppälä et al. 1996). Such hydro- lysates could find application in functional foods and clinical formulas. Functional properties of whey proteins The diverse physico-chemical and functional properties of whey proteins make them highly suitable for both food and non-food purposes. As ingredients of food products, whey proteins can provide functional, nutritional or economic benefits. Potential functional benefits include emulsification and stabilisation, increased vis- cosity, improved appearance, taste or texture, and binding of fat or water (lost 1993). Such prop- erties are intrinsic and specific for individual protein components, as shown in Table 2. Among the nutritional benefits of whey proteins is their ability to lower the energy content of foods when used as fat substitutes, raise the protein level, and balance the amino acid profile (Renner 1992, Barth and Behnke 1997, de Wit 1998). The functional properties of P-lg are domi- nant as far as total whey protein is concerned, because of its high concentration in whey. P-lg has good foaming, emulsification and gelation properties and the ability to bind aromatic sub- stances due to its specific molecular structure (Table 2). The good emulsifying properties of a-la are especially important when this fraction is used in infant formulas. The Food Research Institute ofMTT recent- ly participated in a 3-year research project con- cerning the manufacture oftwo major whey pro- tein-enriched fractions, i.e. a-la and P-lg, using four differentpilot-scale processes. In the course of the study, the most important functional prop- erties of the fractions were determined. In two processes, a-la and P-lg fractions were separat- ed by anion exchange chromatography, and in the other two, heat aggregation at low pH was applied to separate the protein fractions (Outi- nen et al. 1996). At neutral pH, all the fractions obtained by the four methods were found to have good solubility. The a-la fractions prepared by ion exchange methods had better emulsion sta- bility at a low protein concentration than did the fractions obtained by heat aggregation. The ap- 286 Seminar in honour of the 100th anniversary of MTT AGRICULTURAL AND FOOD SCIENCE IN FINLAND Table 2. Functional properties of proteins in whey. Protein Functional properties (3-Lactoglobulin Good foaming, emulsifying and gelation properties. Good solubility, aroma binding ability Ct-Lactalbumin Good foaming and emulsifying properties. Good solubility Immunoglobulins Good gelation properties and solubility Serum albumin Good gelation properties and solubility K-Caseinmacropeptide Good emulsifying properties Proteose peptones Good emulsifying and foaming properties Lactoferrin Good solubility, iron binding ability References: Hegg (1982), Marshall (1982), Harper (1984), Paulsson et al. (1986), de Wit et al. (1986), O’Neill and Kinsella (1987), deWit et al. (1988) parent viscosities were similar to those of a com- mercial whey protein concentrate, as reported by Tossavainen et al. (1998). The water-holding properties of the fractions were equal except for the denatured ot-la fraction obtained by heat ag- gregation, which had a better water-holding ca- pacity than did the others. The heat aggregation method was the only one that preserved good foaming properties in both the a-la and (3-lg en- riched fractions. All the processes tested pre- served the good gelation properties of P-lg (Ran- tamäki et al. 1998). Both whey protein fractions were also tested in model foods, e.g. infant for- mulas and bakery products, to obtain informa- tion about the behaviour of the proteins in the presence of other food components (Tossavai- nen et al. 1998, Rantamäki et al. 1 998). In addition to conventional whey and its pro- teins, research has also focused on bovine co- lostrum, and on the modification of proteins us- ing this new resource. Bovine colostrum differs from normal milk in many respects, e.g. in the content and composition of the proteins. A ma- jor class of proteins in colostrum is represented by immunoglobulins, but their content in the colostrum of individual cows varies considera- bly, from 30 to 120 grams per litre (Korhonen 1977, Stott et al. 1981, Nousiainen et al. 1994). The functional properties of whey proteins and their enzymatic hydrolysates have been studied extensively, whereas there has been only limit- ed research on colostral whey proteins in this respect. In studies conducted at MTT (Korho- nen et al. 1997), the functional properties oftwo bovine colostral whey protein concentrates and their hydrolysates, prepared by different proc- esses, were compared with a commercial cheese whey-based protein concentrate and its hydro- lysate. The emulsification, foaming properties and gelation ability were measured for both the proteins and their hydrolysates. The functional properties of two colostral WPCs were compa- rable to those of the commercial WPC, except for the foaming properties, which were signifi- cantly better in the colostral WPCs. Marked dif- ferences were observed when the products were hydrolysed, gelation and foaming properties be- ing considerably improved in the colostral whey hydrolysates. We may therefore expect colostral WPCs to find various fields of application in the food industry, either as such or modified by hy- drolysis. One of the future potential applications of whey proteins is in the area of edible films and coatings (Krochta et al. 1994). These could en- hance the quality of food by preventing the mi- gration of water and lipids within food and help to improve the keeping quality of food, for in- stance, by preventing the rancidity of lipids (Gennadios et al. 1994, McHugh and Krochta 1994, Maté et al. 1996, Gennadios et al. 1997). Coating also replenishes the nutritional value of 287 Vol. 7 (1998): 283-296. AGRICULTURAL AND FOOD SCIENCE IN FINLAND a product and lessens the need for packing ma- terial. In our preliminary studies, we prepared edible films and coatings from whey protein con- centrates, isolates and p-lg, and tested the qual- ity of the films by measuring their mechanical and physical properties such as tensile strength, puncture strength and water vapour permeabili- ty. Model foodstuffs were coated with edible film, and the effect of the coating on the struc- ture and shelf-life of the products was studied both with instruments and by organoleptic anal- yses (Myllärinen et al. 1997).Further studies are in progress, focusing especially on the coating of dairy products. The functionality of whey proteins can be retained by applying membrane techniques or chromatographic methods for their isolation or enrichment. Such functional ingredients are al- ready widely used in bakery and confectionery products, and in dairy products such as yoghurts and various cheeses to improve their yield, nu- tritional value and consistency. In addition, an increasing number of dietetic beverages, weight loss diets and sports nutrition products supple- mented with whey protein concentrates or spe- cific protein fractions have been launched on US, European and Far Eastern markets (Mulvihill 1992. Riedel 1994b,c, Riedel 1995, O’Carrol 1997, Barth and Behnke 1997). Biological properties of whey proteins Bovine whey contains a wide range of biologi- cally active proteins, i.e. about 60 indigenous enzymes, vitamin-binding proteins, metal-bind- ing proteins, immunoglobulins and various growth factors and hormones. These components have been reviewed by Reiter (1985), IDF (1991, 1994), Fox and Flynn (1992), Smithers et al. (1996), Barth and Behnke (1997), Regester et al. (1997) Pakkanen and Aalto (1997), Parodi (1998) and Xu (1998). Most of the known or putative biological activities of specific whey proteins are related to the functions of the im- mune or digestive system (Table 1). In recent studies, a total whey protein diet has been shown to have immunostimulatory (Bounous et al. 1989, Wong and Watson 1995) and anticarcinogenic effects in mice and rats (Bounous et al. 1988, Bounous et al. 1991, Me Intosh et al. 1995). It has thereforebeen suggested that whey proteins might find use as a food supplement for immuno- compromised individuals and in the prevention of diet-related cancers (Bounous et al. 1993, Parodi 1998).Further research is, however, need- ed to substantiate these important findings. Of particular interest at present are lactoperoxidase, lactoferrin and Igs, all of which have found com- mercial applications. These proteins are anti- microbial in function and are considered prima- ry non-cellular defence factors of the body against microbial infections. Several methods have been devised and patented for isolating these antibacterial compounds from colostrum and milk. Current commercial applications in- clude preservation of foodstuffs and animal feeds and, more interestingly, prevention and treatment of various infectious diseases in humans and domestic animals (Facon et al. 1993, Hambrae- us and Lönnerdahl 1994,Stadhouders and Beum- er 1994, Davidson 1996, de Wit and Hooydonk 1996). In the following, interest focuses on Igs, as they have attracted increasing commercial interest in the last few years. Bioactive peptides derived from milk proteins are also discussed in some detail. Particular reference is made to pep- tides released from whey proteins, since they provide a highly potential source of physiologi- cally active components for dietary and medical purposes. Immunoglobulins and specific antibodies Igs are present in cow’s colostrum in a 50 to 100 times higher concentration than in milk. The Ig- related antibody-complement system active in colostrum is known to confer passive immunity 288 Seminar in honour of the 100th anniversary ofMTT AGRICULTURAL AND FOOD SCIENCE IN FINLAND to the neonate calf until its own immune system has matured (Butler 1994). Following this ration- ale, Igs have been isolated from colostrum, cheese whey and blood serum by UF for the pur- pose ofmanufacturing commercial supplements for neonatal calf, lamb or piglet feeding. The efficacy of such supplements has been variable (Mee and Mehra 1995), but those based on na- tive colostral Igs, in particular, have proved ben- eficial to the health of newborn calves (Nousiai- nen et al. 1994). The efficacy of colostral supple- ments can be improved by immunising cows with specific antigens derived from pathogenic mi- crobes. Systemic immunisation ofpregnant cows during the dry period produces colostrum with high concentrations of specific antibodies against the vaccine used. The antibodies can be enriched in an active form from colostrum by membrane separation and chromatographic techniques to make specific Ig concentrates (Syväoja et al. 1994). Such immunemilk preparations have been shown to be effective in the prevention or treat- ment of various enteric diseases in calves or pig- lets (Saif et al. 1983, Tsunemitsu et al. 1989, Schaller et al. 1992, Moon and Bunn 1993). A number of clinical studies have been car- ried out since the 1970 s to demonstrate the effi- cacy of immune milk preparations in the pro- phylaxis or therapy of human gastrointestinal dis- eases. These studies have been reviewed by Red- dy et al. (1988), Goldman (1989), Boesman-Fin- kelstein and Finkelstein (1991), Hammarström et al. (1994), Ruiz (1994), Davidson (1996) and Pakkanen and Aalto (1997). Clinical evidence obtained in most of these studies indicates that immune milk preparations are protective and, to some extent, also therapeutic against rotavirus infections in children (Ebina et al. 1985, 1992, Briissow et al. 1987, Hilpert et al. 1987, David- son et al. 1989,Turner and Kelsey 1993). A pro- tective or therapeutic effect of immune milk has also been demonstrated in humans against en- teropathogenic or enterotoxigenic E. coli infec- tions (Mietens et al. 1979, Tacket et al. 1988) and Shigella flexneri (Tacket et al. 1992). An- other clinical trial has shown that a specific im- mune milk product reduces the number of caries streptococci in human dental plaque (Filler et al. 1991). Highly encouraging results have been re- ported in a number of studies with immune bo- vine colostrum-containing specific antibodies to Cryptosporidium parvum (Tzipori et al. 1987, Nord et al. 1990, Plettenberg et al. 1993, Shield et al. 1993, Greenberg and Cello 1996). The pa- tients treated were immunosuppressed due to HIV infection. In studies with mice at MTT we have dem- onstrated that a colostrum-based immune milk preparation provides efficient protection against Helicobacterfelis infection in mice (Rehnberg- Laiho et al. 1995). Preliminary clinical trials on chronic gastritis patients and children infected with Helicobacter pylori showed that treatment with an immune milk preparation containing specific Helicobacter pylori antibodies derived from colostrum of immunised cows decreased the degree of the symptoms and the rate of Heli- cobacter colonisation in most subjects (Korho- nen et al. 1994, Oona et al. 1997). Further mod- el studies with mice are under way to identify the potential therapeutic efficacy of the immune milk against Helicobacter infection in experi- mentally infected mice. In another immune milk study, we have shown that a colostrum-based immune milk con- centrate has significant antimetabolic potential against mutans streptococci (Loimaranta et al. 1997) and that such a preparation actively in- hibits in vitro the adherence of these bacteria to hydroxyapatithe (Loimaranta et al. 1996). A clin- ical trial is in progress to demonstrate the po- tential efficacy of anti-caries immune milk in vivo. A few immune milk products derived from colostrum or milk ofhyperimmunised cows have been launched on the market in the US, Austral- ia, New Zealand and Taiwan. It has been sug- gested that immune milk products could provide a potential alternative for, or a supplement to, antibiotics (Facon et al. 1993, Ruiz 1994). The supplementation of infant formulas with specif- ic antibodies has also been suggested in some studies (Reddy et al. 1988, Goldman 1989, Da- vidson 1996). 289 Vol. 7 (1998): 283-296. AGRICULTURAL AND FOOD SCIENCE IN FINLAND Table 3. Examples of biologically functional peptides derived from bovine whey proteins. Precursor protein Fragment Peptide sequence Name Function References a-Lactalbumin 50-53 Tyr-Gly-Leu-Phe a-Lactorphin Opioid agonist, Antila et al. 1991, ACE inhibition Mullally et al. 1996 (3-Lactoglobulin 102-105 Tyr-Leu-Leu-Phe P-Lactorphin Non-opioid stimulatory Antila et al. 1991, effect on ileum, ACE inhibition Mullally et al. 1996 142-148 Ala-Leu-Pro-Met- - ACE inhibition Mullally et al. 1997 His-Ile-Arg 146-149 His-Ile-Arg-Leu P-Lactotensin Ileum contraction Pihlanto-Leppälä et al. 1997 Bovine serum albumin Tyr-Gly-Phe-Gln-Asn-Ala Serorphin Opioid Tani et al. 1994 208-216 Ala-Leu-Lys-Ala-Trp- AlbutensinA Ileum contraction, Yamauchi 1992 Ser-Val-Ala-Arg ACE inhibition Lactoferrin 17-42 Lys-Cys-Arg-Arg-Trp- Lactoferricin Antimicrobial Dionysius and Milne Glu-Trp-Arg-Met-Lys- 1997 Lys-Leu-Gly-Ala-Pro- Ser-Ile-Pro-Ser-Ile-Thr- Cys-Val-Arg-Arg-Ala-Phe Bioactive peptides Bioactive peptides have been identified as deg- radation products of several food proteins. The most important sources of bioactive peptides, milk proteins, have been shown to have opiate, antithrombotic orantihypertensive activities and immunomodulating or mineral absorption prop- erties (Chiba and Yoshikawa 1986, Yamauchi 1992, Meisel and Schlimme 1996, Meisel 1997, Xu 1998). Some of them are known to influence insulin secretion or intestinal motility and secre- tion (Daniel et al. 1990). The bioactive peptides obtained from whey proteins, and their physiological effects, have been less extensively studied than have caseins (Table 3). Yoshikawa et al. (1986) first studied whey proteins in this regard. They synthesised tetrapeptides in amide form on the basis of the opioid-like fragments, contained in the primary structures of a-la (both bovine and human) and P-lg (bovine). The fragment containing residue 50-53 ofa-la (Tyr-Gly-Leu- Phe) in amide form was referred to as a-lactor- phin. Analogously, the 102-105 amide fragment of p-lg (Tyr-Leu-Leu-Phe) was called P-lactor- phin. Studies by Antila et al. (1991) showed that P* lactorphin was released only in samples pre- digested with pepsin when combined with pro- teolysis with trypsin, trypsin and chymotrypsin, or pancreatin. a-Lactorphin was released during proteolysis with pepsin alone. The effects of a- and p-lactorphin on guinea pig ileum were ap- parent at a concentration of 104 M, unlike mor- phine, which inhibited contractions at 10’6 M. The results indicate that a-lactorphin exerts a naloxone-sensitive inhibition of smooth muscle contractions similar to thatof morphine. In con- trast, P-lactorphin induced stimulation ofsmooth muscle that was not sensitive to naloxone. The affinity of a-lactorphin for opioid receptors was about 1000-fold lower than that of morphine. Binding of P-lactorphin to the opioid receptors was similar to that of a-lactorphin. It was con- cluded that a-lactorphin exerted receptor bind- ing and a weak but consistent opioid property in smooth muscle, whereas P-lactorphin, despite the similar receptor binding affinity, exerted an apparently non-opioid stimulatory effect on the guinea pig ileum (Paakkari et al. 1994). Yamauchi (1992) has reported that peptides derived from serum albumin (SA) and P-lg in- duced contraction of the guinea pig ileum longi- tudinal muscle when the test was done without 290 Seminar in honour of the 100th anniversary ofMTT AGRICULTURAL AND FOOD SCIENCE IN FINLAND electric stimulation in the absence of an agonist. The peptides were referred to as “peptides act- ing on smooth muscle” and they contained SA f2OB-216 (albutensin A) and P-lg f146-149 (P- --lactotensin). This peptide can be released dur- ing hydrolysis with chymotrypsin. In our phar- macological studies of P-lactotensin, morphine inhibited the contractions of the coaxially stim- ulated guinea pig ileum at concentrations of 10 8-10' 5 M. The effect of P-lactotensin was the opposite of that of morphine, which was used as a reference. Moreover, the opioid antagonist naloxone (10 6 M) did not inhibit the effect of P- lactotensin (Pihlanto-Leppälä et al. 1997). The stimulatory effect of P-lactotensin on smooth muscle was similar to that of P-lactorphin. The results indicate that the contracting effect of P~ lactotensin and P-lactorphin on smooth muscle was not mediated by an opioid mechanism, and the effect thus remains unclear. Whey peptides have also been found to have angiotensin converting enzyme (ACE)-inhibito- ry activity. The ACE is part of the rennin-angi- otensin system, which has been implicated in blood pressure regulation and hypertension. Ren- nin acts on the angiotensinogen and releases a largely inactive angiotensin, I, which is then con- verted to the active peptide hormone, angiotensin 11, by ACE. The tetrapeptides, ot-lactorphin, p- lactorphin and P-lactotensin, and related peptides have been shown to have ACE-inhibitory activi- ty (Mullally et al. 1996). The lactorphins appear to have multifunctional activities similar to those of several casein-derived peptides, e.g. casomor- phin-7 (Meisel and Schlimme 1994). Chiba and Yoshikawa (1991) have characterised a multi- functional bioactive peptide, albutensin A, se- rum albumin f2OB-216. The P-lg peptide obtained after tryptic digestion of P-lg and identified as P-lg f!42-146 has been the most active ACE- inhibitory whey peptide reported to date (Mul- lally et al. 1997). In our studies at MTT we have shown that hydrolysis of whey proteins by dif- ferent proteolytic enzymes produces ACE-inhib- itory activity, and have identified several ACE- inhibitory peptides from whey proteins (Pihlan- to-Leppälä et al. 1998). Our findings indicate that whey proteins also have ACE-inhibitory activi- ty, but that more research is needed to show the activity of these peptides/hydrolysates in ani- mals. Peptides with biological activity can be pro- duced in several ways. The most common meth- ods are the processing of foods using hot alkali or acid to hydrolyse proteins, enzymatic hydrol- ysis of food proteins, and/or microbial fermen- tation. Enzymatic hydrolysis combined with a two-step UF technique can be used to selective- ly enrich the bioactive peptides in hydrolysates, as shown inFig. 1 (Pihlanto-Leppälä et al. 1996). Fig. 1. Processing scheme forproduction and separation of bioactive peptides from whey proteins obtained by enzy- matic hydrolysis. 291 Vol. 7(1998): 283-296. AGRICULTURAL AND FOOD SCIENCE IN FINLAND References Abd El-Salam, M.H., El-Shibiny, S., Mahfouz, M.8., El- Dein, H.F., El-Atriby, H.M. & Antila, V. 1991. Prepa- ration of whey protein concentrate from salted whey and its use in yogurt. Journal of Dairy Research 58: 503-510. Antila, P., Paakkari, 1., Järvinen, A., Mattila, M.J., Laukkanen, M., Pihlanto-Leppälä, A., Mäntsälä, P. & Flellman, J. 1991 .Opioid peptides derived from in vitro proteolysis of bovine whey proteins. International Dairy Journal 1:215-229. Bahna, S.L. 1991. Breast milk and special formulas in prevention of milk allergy. Advances in Experimental Medicine and Biology 310: 445-451. Barth, C.A. & Behnke, U. 1997. Ernährungsphysiolo- gische Bedeufung von Molke und Molkenbe- standteilen. Nahrung : 2-12, Beresteijn, E.C.FI. van, Peeters, R.A., Kaper, J., Meijer, R.J.G.M., Robben, A.J.P.M. & Schmidt, D.G, 1994. Molecular mass distribution, immunological proper- ties and nutritive value of whey protein hydrolysates. Journal of Food Protection 57: 619-625. Boesman-Finkelstein, M. & Finkelstein, R.A. 1991. Bo- vine lactogenic immunity against pediatric entero- pathogens. In: Mestecky, J. et al. (eds.). Immunol- ogy of milk and the neonate. Plenum Publishing Corp., New York. p. 361-367. Bounous, G., Baruchel, S., Falutz, J. & Gold, P, 1993. Whey proteins as a food supplement in HIV-sero- positive individuals. Clinical and Investigative Medi- cine 16: 204-209. - , Batist, G. & Gold, P. 1989. Immunoenhancing prop- erty of dietary whey protein in mice: Role of gluta- thione. Clinical and Investigative Medicine 12: 154- 161. - , Batist, G. & Gold, P. 1991. Whey proteins in cancer prevention. Cancer Letters 57: 91-94. Bramaud, C., Aimar, P. & Daufin G. 1995. Thermal isoe- lectric precipitation of a-lactalbumin from whey pro- tein concentrate: Influence of protein-calcium com- plexation. Biotechnology and Bioengineering 47: 121-130. Briissow, H., Hilpert, H., Walther, J., Sidoti, J., Mietens, C. & Bachmann, P. 1987. Bovine milk immunoglobu- lins for passive immunity to infantile rotavirus gas- troenteritis. Journal of Microbiology 25: 982-986. Butler, J.E. 1994. Passive immunity and immunoglobulin diversity. Proceedings of the IDF seminar ”Indigenous antimicrobial agents of milk- Recent developments”. IDF Special Issue 9404: 14-50. Chiba, H, & Yoshikawa, M. 1986. Biologically functional peptides from food proteins: New Opioid peptides from milk proteins. In: Feeney, R.E. & Whitaker, J.R. (eds.) Protein tailoring for food and medical uses. Marcel Dekker, New York. p. 123-153. - & Yoshikawa, M. 1991, Bioactive peptides derived from food proteins. Kagaku to Seibutsu29: 454-458. Chirico, G., Gasparoni, A., Ciardelli, L., De Amici, M., Colombo, A. & Bondini, G. 1997. Immunogenicity and antigenicity of a partially hydrolyzed cow’s milk in- fant formula. Allergy 52: 82-88. Cuperus, F.P. & Nijhuis, H.H. 1993.Applications of mem- brane technology to food processing. Trends in Food Science & Technology 4: 277-282. Daniel, H., Vohwinkel, M. & Rehner, G. 1990, Effect of casein and (5-casomorphins on gastrointestinal mo- tility in rats. Journal of Nutrition 120: 252-257. Davidson, G.P. 1996. Passive protection against diarrheal disease. Journal of Pediatric Gastroenterology and Nutrition 23: 207-212. -, Whyte, P.8.D., Daniels, E,, Franklin, K., Nunan, FI., McCloud, P. 1., Moore, A.G. & Moore, D.J, 1989. Pas- sive immunization of children with bovine colostrum containing antibodies to human rotavirus. Lancet ii: 709-712. Dionysius, D.A. & Milne, J.M. 1997. Antibacterial pep- tides of bovine lactoferrin: Purification and charac- terization. Journal of Dairy Science 80: 667-674. Dybing, S.T. & Smith, D.E. 1991. Relation of chemistry and processing procedures to wheyprotein function- ality. Cultured Dairy Products Journal 26: 4-12. Ebina, 1., Ohta, M., Kanamaru, Y., Yamamaoto-Osumi, Y, & Baba, K, 1992. Passive immunizations of suck- ling mice and infants with bovine colostrum contain- ing antibodies to human rotavirus. Journal of Medi- cal Virology 38: 117-123. - , Sato, A., Umezu, K., Ishida, N., Ohyama, S., Oizumi, A., Aikawa, K., Katagiri, S., Katsushima, N., Imai, N., Kitaoka, S., Suzuki, H. & Konno, T. 1985. Prevention of rotavirus infection by oral administration of cow colostrum containing anti-human rotavirus antibody. Medical Microbiology and Immunology 174:177-185. Ena, J.M., Beresteijn, E.C.H. van, Robben, A.J.P.M. & Schmidt, D.G. 1995. Whey proteinantigenicity reduc- tion by fungal proteinases and a pepsin/pancreatin combination. Journal of Food Science 60, 1: 104- 110, 116. Facon, M., Skura, B.J. & Nakai, S. 1993. Potential for immunological supplementation of foods. Food and Agricultural Immunology 5: 85-91. Filler, S.J., Gregory, R.L., Michalek, S.M., Katz, J. & McGhee, J.R. 1991. Effect of immune bovine milk on Streptococcus mutans in human dental plaque. Ar- chives of Oral Biology 36: 41-47. Fox, P.F. 1989. The milk protein system. In: Fox, P.F. (ed.). Developments in dairy chemistry - 4. Elsevier Ap- plied Science, London, p. 1-53. - & Flynn, A. 1992. Biological properties of milk pro- teins. In: Fox, P.F. (ed.). Advanced dairy chemistry, Volume 1, Proteins. Elsevier Applied Science, p. 255- 284. Gennadios, A., Hanna, M.A. & Kurth, L.B. 1997. Applica- tion of edible coatings on meats, poultry and sea- foods: A review. Lebensmittel-Wissenschaft und Technologie 30: 337-350. -, McHugh, T.H., Weller, C.L. & Krochta, J.M. 1994. Edible coatings and films based on proteins. In: 292 Seminar in honour of the 100th anniversary ofMTT AGRICULTURAL AND FOOD SCIENCE IN FINLAND Krochta, J. et al. (eds.). Edible coatings and films to improve food quality. Technomic Publishing Co. Inc., Lancaster, Basel, p. 201-277. Goldman, A.S. 1989. Immunologic supplementation of cow’s milk formulations. Bulletin of the IDF244: 38- 42. Greenberg, P.D. & Cello, J.P. 1996. Treatment of severe diarrhea caused by Cryptosporidium parvum with oral bovine immunoglobulin concentrate in patients with AIDS. Journal of Acquired Immune Deficiency Syn- dromes and Human Retrovirology 13: 348-354. Hambraeus, L. & Lönnerdahl, B. 1994. The physiologi- cal role of lactoferrin. Proceedings of the IDF semi- nar ”Indigenous antimicrobial agents of milk - Re- cent developments”. IDF SpecialIssue 9404: 97-107. Hammarström, L., Gardulf, A., Hammarström, V., Jan- son, A., Lindberg, K. & Smith, C. I.E. 1994. Systemic and topical immunoglobulin treatment in immunocom- promised patients. Immunological Reviews No. 139. p. 43-70. Harper, W.J. 1984. Model food system approaches for evaluating whey protein functionality. Journal ofDairy Science 67: 2745-2756. Hegg, P.-0.1982. Conditions for the formation of heat- induced gels of some globular food proteins. Journal of Food Science 47: 1241 -1244. Hilpert, H., Brussow, H., Mietens, C., Sidoti, J., Lerner, L. & Werchau, H. 1987. Use of bovine milk concen- trate containing antibody to rotavirus to treat rotavi- rus gastroenteritis in infants. Journal of Infectious Diseases 156: 158-166. Hobman, P.G. 1992. Ultrafiltration and manufacture of whey protein concentrates. In: Zadow, J.G. (ed.). Whey and lactose processing. Elsevier Applied Sci- ence. p. 195-230. Horton, B.S. 1995. Commercial utilization of minor milk components in the health and food industries. Jour- nal of Dairy Science 78: 2584-2589. IDF 1991. Significance of the indigenous antimicrobial agents of milk to the dairy industry. Bulletin of the IDF 264: 2-19. - 1994. Proceedings of the IDF seminar ”Indigenous antimicrobial agents of milk- Recent developments”. Uppsala, Sweden, 31 August - 1 June 1994. IDF Special Issue 9404. 228 p. Jelen, P. 1992. Pressure-driven membrane processes; principles and definitions. IDF Special Issue 9201 ”New Applications of Membrane Processes”, p. 7- 14. Jost, R. 1993. Functional characteristics of dairy proteins. Trends in Food Science & Technology 4: 283-288. Jost R.J., Monti, C. & Pahud, J.J. 1991. Reduction of whey protein allergenicity by processing. Advances in Experimental Medicine and Biology289: 309-320. Kilara, A. 1994. Whey protein functionality. In: Hettiarach- chy, N. & Ziegler, G.R. (eds.). Protein functionality in food systems. Marcel Dekker Inc, New York. p. 325- 355. Kinsella, J.E. & Whitehead, D.M. 1989. Proteins in whey: chemical, physical and functional properties. Ad- vances in Food and Nutrition Research 33: 343-438. Kleinman, R.E. 1992. Cow milk allergy in infancy and hypoallergenic formulas. Journal of Pediatrics 121: Sll6-Sl2l. Konrad, G. & Lieske, B. 1997. Neues Verfahren zurtech- nischen Isolierung von nativem |3- lactoglobulin aus Molke durch enzymatische Hydrolyse und Ultrafiltra- tion. Deutsche Mitchwirtschaft 48, 13: 479-482. Korhonen, H. 1977. Antimicrobial factors in bovine co- lostrum. Journal of the Scientific Agricultural Society of Finland 49: 434-447. - 1995. Whey as raw material for development of new products for human nutrition and health: A Review. Proceedings of the NJF/NMR-seminar No. 252. Turku, Finland, 13-15.1.1995. NJF- Report 102. p. 207-219. - , Rantamäki, P. & Rokka, T. 1997. Functionality of bo- vine colostral whey protein hydrolysates. In: Abstracts of the 1997 International conference on food science and technology, Las Vegas, U.S.A. p. 19. - , Syväoja, E.-L., Ahola-Luttila, H., Sivelä, S., Kopola, S., Husu, J, & Kosunen, T. 1994. Helicobacter py- lori-specific antibodies and bactericidal activity in serum, colostrum and milk of immunized and non- immunized cows. Proceedings of the IDF seminar ”Indigenousantimicrobial agents of milk - Recent de- velopments”, IDF Special Issue 9404: 151-163. Krochta, J.M., Baldwin, E.A. & Nisperos-Carriedo, M.O. 1994. Edible coatings and films to improve food qual- ity. Technomic Publishing Company, Inc, Lancaster. 379 p. Loimaranta, V., Carlén, A., Olsson, J., Suhonen, J., Kor- honen, H. & Tenovuo, J. 1996. Inhibition of adher- ence of Streptococcus mutans IB by bovine immune colostrum. Journal of Dental Research 75: 43. - , Tenovuo, J.,Virtanen, S., Marnila, P, Syväoja, E.-L., Tupasela, T. & Korhonen, H. 1997. Generation of bovine immune colostrum against Streptococcus mutans and Streptococcus sobrinus and its effect on glucose uptake and extracellular polysaccharide for- mation by mutans streptococci. Vaccine 15,11:1261- 1268. Mangino, M.E. 1992. Properties of whey protein concen- trates. In: Zadow, J.G. (ed.). Whey and lactose processing. Elsevier Applied Science, p. 231-270. Marshall, K.R. 1982. Industrial isolation of milk proteins: Whey proteins. In: Fox, P.F. (ed.). Developments in dairy chemistry-1. Applied Science Publishers, Lon- don, New York. p. 339-373. - & Harper, W.J. 1988. Whey protein concentrates. Bul- letin of the IDF 233: 21-32. Maté, J.1., Frankel, E.N. & Krochta, J.M. 1996.Whey pro- tein isolate edible coatings: Effect on the rancidity process of dry roasted peanuts. Journal of Agricul- tural Food Chemistry 44: 1736-1740. Maubois, J.L, & Ollivier, G. 1997. Extraction of milk pro- teins. In: Damodaran, S. & Paraf, A. (eds.). Food pro- teins and their applications. Marcel Dekker Inc., New York. p. 579-595. -, Pierre, A., Fauquant, J. & Piot, M. 1987. Industrial fractionation of main whey proteins. Bulletin of the IDF 212: 154-159. McHugh, T.H. & Krochta, J.M. 1994. Sorbitol- vs glycer- ol-plasticized whey protein edible films: Integrated 293 Vol. 7 (1998): 283-296. AGRICULTURAL AND FOOD SCIENCE IN FINLAND oxygen permeability and tensile property evaluation. Journal ofAgriculturaland Food Chemistry42: 841 - 845. Mclntosh, G. H., Regester, G.0., Le Leu, R.K., Royle, P.J. & Smithers, G.W. 1995. Dairy proteins protect against dimethylhydrazine-induced intestinal cancers in rats. Journal of Nutrition 125: 809-816. Mee, J.F. & Mehra, R. 1995. Efficacy of colostrum sub- stitutes and supplements in farm animals. Agro-Food- Industry Hi- Tech- 6,3: 31-35. Meisel, H. 1997. Biochemical properties of regulatory peptides derived from milk proteins. Biopoly43:119- 128. - & Schlimme, E. 1994. Inhibitors of angiotensin con- verting enzyme derived from bovine casein (casoki- nins). In: Brantl, V. & Teschemacher, H. (eds.j p-ca- somorphins and related peptides: Recent develop- ments. VCH, Weinheim, New York. p. 27-33. - & Schlimme, E. 1996. Bioactive peptides derived from milk proteins: ingredients for functional foods. Kielet Mitchwirtschafttiche Forschungsberichte 48, 4; 343- 357. Mietens, C, Kleinhorst, H., Hilpert, H., Gerber, H,, Am- ster, H. & Pahud, J.J. 1979. Treatment of infantile E. coli gastroenteritis with specific bovine anti- E. coli milk immunoglobulins, European Journal of Pediat- rics 132: 239-252. Moon, H.W. & Bunn, T.O. 1993. Vaccines for preventing enterotoxigenic Escherichia coli infections in farm animals. Vaccine 11: 213-220, Morr, C.V. 1989. Whey proteins: Manufacture. In: Fox, P.F. (ed.) Developments in dairy chemistry -A, Else- vier Science Publishers, p. 245-284. - 1992. Whey utilization. In: Zadow, J.G. (ed.). Whey and lactose processing. Elsevier Applied Science, p. 133-155. - & Ha, E.Y.W. 1993. Whey protein concentrates and isolates: processing and functional properties. Criti- cal Reviews in Food Science and Nutrition 33: 431- 476. Mullally, M.M., Meisel, H. & FitzGerald, R.J. 1996. Syn- thetic peptides corresponding to a- lactalbumin and p-lactoglobulin sequences with angiotensin-l-convert- ing enzyme inhibitory activity. Biological Chemistry Hoppe-Seyler 377: 259-260. - , Meisel, H. & FitzGerald, R.J. 1997. Identification of a novel angiotensin-l-converting enzyme inhibitory peptide corresponding to a tryptic fragment of bo- vine p-lactoglobulin. FEBS letters 402: 99-101. Mulvihill, D.M. 1992. Production, functionalproperties and utilization of milk protein products. In: Fox, P.F. (ed.). Advanced dairy chemistry, Volume 1, Proteins. Else- vierApplied Science, p. 369-404. - & Fox, P.F. 1987. Assessment of the functional prop- erties of milk protein products. Bulletin of the 1DF209: 3-11. - & Fox, P.F. 1989. Physico-chemical and functional properties of milk proteins. In: Fox, P.F. (ed.). Devel- opments in dairy chemistry-4. Elsevier Science Pub- lishers, London, p. 131-172. - & Fox, P.F. 1994. Developments in the production of milk proteins. In: Hudson, B.J.F. (ed.). New and de- veloping sources of food proteins. Chapman & Hall, p. 1-30, Myllärinen, P., Rantamäki, R, Latva-Koivisto, J. & Ahve- nainen, R. 1997. Elintarvikepakkausten minimointi aktiivisilla syötävillä päällysteillä. Mahdollisuudet ja haasteet. VTT tiedotteita no. 1840, Espoo, Finland. 68 p. Nakai, S. & Li-Chan, E. 1989. Chemical and enzymatic modification of milk proteins. In: Fox, P.F. (ed.). De- velopments in dairy chemistry. Elsevier Science Pub- lishers. p, 347-376. Nord, J., Ma, R, Di John, D., Tzipori, S. & Tacket, C, 1990. Treatment with bovine hyperimmune colostrum of cryptosporidial diarrhea in AIDS patients. AIDS 4: 581-584, Nousiainen, J., Korhonen, H., Syväoja, E.-L., Savolai- nen, S., Saloniemi, H. & Jalonen, H. 1994. The ef- fect of colostral immunoglobulin supplement on the passive immunity, growth and health of neonatal calves. Agricultural Science in Finland 3: 421-428. O’Carroll, P. 1997. Nutritional beverages. The World of Ingredients, August 1997: 19-22. O’Neill, T. & Kinsella, J.E. 1987. Binding of alkanone fla- vors to p-lactoglobulin: Effects of conformational and chemical modification. Journal of Agricultural Food Chemistry 35: 770-774. Oona, M., Rägö, T, Maaroos, H.-1., Mikelsaar, M., Loi- vukene, K., Salminen, S. & Korhonen, H. 1997. Heli- cobacter pylori in children with addominal complaints: Has immune bovine colostrum some influence on gastritis? Alpe Adria Microbiology Journal 6: 49-57. Outinen, M., Tossavainen, 0,, Syväoja, E.-L. & Korho- nen, H. 1995. Chromatographic isolation of x-casein macropeptide from cheese whey with a strong basic anion exchange resin. Milchwissenschaft 50, 10: 570-574. -, Tossavainen, 0., Tupasela, T., Koskela, R, Koski- nen, H., Rantamäki, R, Syväoja, E.-L., Antila, P. & Kankare, V. 1996.Fractionation of proteins from whey with different pilot scale processes. Lebensmittet- Wissenschaft und Technologie 29, 5/6: 411-417. Paakkari, 1., Järvinen, A., Antila, R, Mattila, M.J. & Pih- lanto-Leppälä, A. 1994. Opioid effects of the milk whey-protein derived peptides a- and p-lactorphin. In: Brantl, V. & Teschemacher, H. (eds.) p-Casomor- phins and related peptides. Recent developments. VCH, Weinheim, New York. p. 33-37. Pakkanen, R. & Aalto, J. 1997. Growth factors and anti- microbial factors of bovine colostrum. International Dairy Journal 7: 285-297. Parodi, RW. 1998. A role for milk proteins in cancer pre- vention. Australian Journal of Dairy Technology 53: 37-47. Paulsson, M., Hegg, R-O. & Castberg, H.B. 1986. Heat- induced gelation of individual whey proteins, A dy- namic rheological study. Journal ofFood Science 51: 87-90. Pearce, R.J. 1983, Thermal separation of p-lactoglobu- lin and a-lactalbumin in bovine Cheddarcheese whey. Australian Journalof Dairy Technology38:144-148. - 1992. Whey protein recovery and whey protein frac- tionation. In: Zadow, J.G. (ed.). Whey and lactose 294 Seminar in honour of the 100th anniversary ofMTT AGRICULTURAL AND FOOD SCIENCE IN FINLAND processing. Elsevier Applied Science p. 271-316. Pihlanto-Leppålä,A., Koskinen, P., Paakkari, 1., Tupase- la, T. & Korhonen, H. 1996. Opioid whey protein pep- tides obtained by membrane filtration. Bulletin of the IDF 311: 36-38. Paakkari, 1., Rinta-Koski, M. & Antila, P. 1997, Bio- active peptide derived from in vitro proteolysis of bo- vine p-lactoglobulin and its effect on smooth muscle. Journal of Dairy Research 64: 149-155. - , Rokka, T, & Korhonen, H. 1998. Angiotensin I con- verting enzyme inhibitory peptides derived from bo- vine milk proteins. International Dairy Journal (in press). Plettenberg, A., Stoer, H.-J., Stellbrink, H.A. & Meigel, W. 1993. Apreparation from bovine colostrum in the treatment of HIV- positive patients with chronic di- arrhea. Clinical Investigations 71: 42-45. Reddy, N.R., Roth, S.M., Eigel, W.N. & Pierson, M.D. 1988. Foods and food ingredients for prevention of diarrheal disease in children in developing countries. Journal of Food Protection 51: 66-75. Regester, G.0., Mclntosh, G.H., Lee, V.W.K. & Smith- ers, G.W. 1996. Whey proteins as nutritional and functional food ingredients. Food Australia 48: 123- 127, - , Smithers, G.W., Mitchell, 1.R., Mclntosh, G.H. & Di- onysius, D.A. 1997. In: Welch, R.A.S. et al. (eds.). Milk composition, productionand biotechnology. Cab International, Wallingford, UK. p. 119-132. Rehnberg-Laiho, L., Marnila, P., Kosunen, T.U., Syväoja, E.-L., Hänninen, M.-L., Kärkkäinen, P., Rautelin, H., Virtanen, S., Lilius, E.-M. & Korhonen, H. 1995. Spe- cific immune colostrum in the prevention of Helico- bacter fetis infection in mice. Gut 37, Suppl. 1: 368. Reiter, B. 1985. Protective proteins in milk-biological sig- nificance and exploitation. Bulletin of the IDF 191: 1-35. Renner, E. 1992. Nutritional aspects. In: Zadow, J.G. (ed.). Whey and lactose processing. Elsevier Applied Science, p. 449-471, Riedel, C.-L. 1994a. Molke-Rohstoff fur neue Produkte. Teil I. Deutsche Milchwirtschaft 45: 174-179. -1994b. Molke-Rohstoff fur neue Produkte. Teil 11. Deutsche Milchwirtschaft 45: 230-235. -1994c. Molke-Rohstoff fur neue Produkte. Teil 111. Deutsche Milchwirtschaft 45: 278-283. - 1995. Die Molke ein mödernes Lebensmittel: Teil 1. Deutsche Milchwirtschaft 46: 1063-1069. Rosenberg, M. 1995. Current and future applications for membrane process in the dairy industry. Trends in Food Science & Technology6, 1: 12-19. Ruiz, L.P. 1994. Antibodies from milk for the prevention and treatment of diarrheal disease. Proceedings of the IDF seminar ”Indigenous antimicrobial agents of milk - Recent developments”. IDF Special Issue 9404: 108-121. Saif, L.J., Redman, D.R., Smith, K.L. &Theil, K.W. 1983. Passive immunity to bovine rotavirus in newborn calves fed colostrum supplements from immunized or nonimmunized cows. Infection and Immunity 41: 1118-1131. Schaller, J.P., Saif, L.J., Cordle, C.T., Candler, E., Win- ship, T.R. & Smith, K.L, 1992. Pevention of human rotavirus-induced diarrhea in gnotobiotic piglets us- ing bovine antibody. Journal of Infectious Diseases 165; 623-630. Shield, J., Melville, C., Novelli, V., Anderson, G., Scheim- berg, 1., Gibb, D. & Milla, P. 1993. Bovine colostrum immunoglobulin concentrate for sporodiosis inAIDS. Archives of the Diseases of Childhood 69: 451-453. Sienkiewicz, T. & Riedel, C.-L. 1990. Whey and whey utilization. Verlag Th. Mann, Gelsen- kirchen-Buer, Germany. 379 p. Smithers, G.W., Ballard, F.J., Copeland, A.D., De Silva, K.J., Dionysius, D.A., Francis, G.L., Goddard, C., Grieve, P.A., Mclntosh, G.H., Mitchell, 1.R., Pearce, R.J. & Regester, G.O. 1996. New opportunities from the isolation and utilization of whey proteins. Journal of Dairy Science 79: 1454-1459. Stadhouders, J. & Beumer, R.R. 1994. Actual and poten- tial applications of the natural antimicrobial agents of milk in the dairy Industry. Proceedings of the IDF seminar ”Indigenous antimicrobial agents of milk - Recent developments”. IDF Special Issue 9404:175- 197. Stott, G.H., Fleenor, W.A. & Kleese, W.C. 1981. Colos- tral immunoglobulin in two fractions of first milking postpartum and five additional milkings. Journal of Dairy Science 64: 459-465. Syväoja, E.-L., Ahola-Luttila, H.K., Kaista, H., Matilainen, M.H., Laakso, S., Husu, J.R. & Kosunen, T.U. 1994. Concentration of Campylobacter- specific antibodies in the colostrum of immunized cows. Mitchwissen- schaft 49; 27-31. Tacket, C.0., Binion, 5.8., Bostwick, E., Losonsky, G., Roy, M.J. & Edelman, R. 1992. Efficacy of bovine milk immunoglobulin concentrate in preventing illness after Shigella flexneri challenge. American Journal of Tropical Medicine and Hygiene 47: 276-283. - , Losonsky, G., Link, H., Hoang, Y., Guesry, P., Hil- pert, H. & Levine, M.M. 1988. Protection by milk im- munoglobulin concentrateagainst oral challenge with enterotoxigenicEscherichia coll. New England Jour- nal of Medicine 318:1240-1243. Tani, F., Shiota, A., Chiba, H. & Yoshikawa, M. 1994. Serorphin, an opioid peptide derived from bovine serum albumin, In: Brantl, V. & Teschemacher, H. (eds.) [i-Casomorphins and relatedpeptides. Recent development, VCH, Weinheim, New York, p. 49-53, Tossavainen, 0., Rantamäki, P., Outinen, M., Tupasela, T. & Koskela, P. 1998. Functional properties of the whey protein fractions made by pilot scale process- es. Milchwissenschaft (in press). Tsunemitsu, H., Shimizu, M., Hirai, T„ Yonemichi, H., Kudo, T, Mori, K. & Onoe, S. 1989. Protection against bovine rotaviruses in newborn calves by continous feeding of immune colostrum. Japanese Journal of Veterinary Science 51: 300-308. Tupasela, T, Koskela, P., Pahkala, E. & Kankare, V. 1997. Optimization of centrifugal separation of a-lactalbu- min and p-lactoglobulin. Agricultural and Food Sci- ence in Finland 6: 193-198. - , Koskinen, H. & Antila, P. 1994. Whey prefreatments before ultrafiltration. Agricultural Science in Finland 295 Vol. 7(1998): 283-296. AGRICULTURAL AND FOOD SCIENCE IN FINLAND 3; 473-479. Turner, R.B. & Kelsey, D.K. 1993, Passive immunization for prevention of rotavirus illness in healthy infants. Pediatric Infectious Disease Journal 12: 718-72. Tzipori, S., Robertson, D., Cooper, D.A. & White, L. 1987. Chronic cryptosporidial diarrhoea and hyperimmune cow colostrum. Lancet ii: 344-345. Wade, V.N. 1994. The potential for whey proteins. Dairy Industries International 4: 29-33. Wahn, U., Wahl, R. & Rugo, R. 1992. Comparison of the residual allergenic activity of six different hydrolyzed protein formulas. Journal of Pediatrics 121: SBO-84. Wit, J.N. de 1989. Functional propertiesof whey proteins. In: Fox, P.F, (ed.) Developments in dairy chemistry - 4, Elsevier Science Publishers, London, p. 285-321. - 1998. Nutritional and functional characteristics of whey proteins in food products. Journal of Dairy Sci- ence 81: 597-608. - , Hontelez-Backx, E, & Adamse, M. 1988. Evaluation of functional properties of whey protein concentrates and whey protein isolates. 3. Functional properties in aqueous solution. Netherlands Milk Dairy Journal 42: 155-172. - & Hooydonk, A.C.M. van 1996. Structure, functions and applications of lactoperoxidase in natural anti- microbial systems. Netherlands Milk and Dairy Jour- nal 50: 227-244. Klarenbeek, G. & Adamse, M. 1986, Evaluation of functional properties of whey protein concentrates and whey protein isolates. 2. Effects of processing history and composition. Netherlands Milk Dairy Jour- nal 40: 41-56. Wong, C.W. & Watson, D.L. 1995. Immunomodulatory effects of dietary whey proteins in mice. Journal of Dairy Research 62: 359-368. Xu, R.-J. 1998. Bioactive peptides in milk and their bio- logical and health implications. Food Reviews Inter- national 14, 1: 1-16. Yamauchi, K, 1992. Biologically functional proteins of milk and peptides derived from milk proteins. Bulletin of the IDF272: 51-58. Yoshikawa, M., Tani, F., Yoshimura, T. & Chiba, H. 1986. Opioid peptides from milk proteins. Agricultural and Biological Chemistry 50: 2419-2421. Zall, R.R. 1992. Sources and composition of whey and permeate. In: Zadow, J.G. (ed.). Whey and lactose processing. Elsevier Applied Science, p, 1-72. Zadow, J.G. 1992. Lactose hydrolysis. In: Zadow, J.G. (ed.). Wheyand lactose processing. Elsevier Applied Science, p. 361-408. - (ed.). 1992. Whey and lactose processing. Elsevier Applied Science. 489 p. SELOSTUS Heraproteiinit terveysvaikutteisten elintarvikkeiden kehittämisessä Hannu Korhonen, Anne Pihlanto-Leppälä, Pirjo Rantamäki ja Tuomo Tupasela Maatalouden tutkimuskeskus Juustoheran arvostus on voimakkaasti lisääntynyt vii- me vuosina uusien tieteellisten tutkimustulosten ja heran käsittelyteknologian kehittymisen ansiosta. Uusilla tekniikoilla pystytään eristämään ja rikasta- maan heran aineosia entistä tehokkaammin. Spesifis- ten aineosien toiminnallisia ja biologisia erityisomi- naisuuksia voidaan siten tutkia paremmin ja kehittää uusia täsmällisiä käyttökohteita. Heran aineosien hy- väksikäyttämiseksi on muodostumassa oma teollisuu- den ala, joka tuottaa yhdisteitä hyvin moneen tarkoi- tukseen. Terveysvaikutteiset elintarvikkeet, elintar- vikkeiden rakenteelliset ominaisuudet ja biofarma- seuttiset yhdisteet ovat tällä hetkellä ja lähitulevai- suudessa merkittävimpiä tutkimus- ja kehityskohtei- ta, joihin herasta saatuja yhdisteitä voidaan soveltaa. 296 Seminar in honour of the 100th anniversary ofMTT AGRICULTURAL AND FOOD SCIENCE IN FINLAND