NutraSweet Australia Pty Ltd v Ajinomoto Co., Inc.

REASONS FOR JUDGMENT 1 For centuries the flavour of food and drink has been improved by additives. Sucrose (sugar) has been a favourite. There are, however, problems with sucrose. It is high in calories and health experts contend that sucrose can be bad for a person's health. So there is a constant search for artificial sweeteners that will replicate the taste of sugar, which is regarded as the "gold standard". This case is being fought by two large manufacturers of artificial sweeteners, the NutraSweet Company of the United States of America and Ajinomoto Co., Inc., a Japanese corporation. The applicant, NutraSweet Australia Pty Ltd (a subsidiary of the United States company), seeks to revoke Australian patent No 727199 which stands in the name of the respondent, Ajinomoto, and has a priority date of 10 March 1997. The claimed invention in the Ajinomoto patent is for a sweetener composition made up of N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester (abbreviated as DMB-APM) together with aspartame (APM) and acesulfame K (aceK) or one of them. 2 DMB-APM was invented by two French scientists, Claude Nofre and Jean-Marie Tinti, as a result of a long-term research program conducted by the NutraSweet Company. DMB-APM was disclosed in Australia with the publication on 23 November 1995 of patent No 664663. The patent has been referred to throughout as the Nofre Tinti patent. The compound is sold by the NutraSweet Company under the trade name Neotame. 3 The patent in suit relates to intense sweeteners. An intense sweetener is a sweetener of which only a minimal amount is required to obtain the desired sweetness for a product. The comparison is with sucrose. If a sweetener has a higher intensity than sucrose it is usually referred to as an intense sweetener. Thus, the sweetness intensity of an artificial sweetener is often expressed relative to sucrose. 4 There are several benefits from an intense sweetener. The less sweetener that is required for a particular product the lower the unit cost of the product. Cost is particularly important in low calorie food and drinks which is one of the fastest growing segments of the food industry. The stability of the sweetener is also important. A sweetener must be stable both as a bulk chemical and in the product to which it is applied. That is to say, the sweetener must be compatible with elements in the product and it must be able to maintain its stability in products that have a long shelf-life and are subjected to fluctuating temperatures. 5 Perhaps the most important requirement for an intense sweetener, at least from the consumer's viewpoint, is its sweetness characteristics. These characteristics require some explanation. First there is sweetness quality. Sweetness quality refers to the nature of the sweetness itself, that is, the inherent quality of the sweetness generated by the sweetener. Another characteristic is referred to as the sweetness time profile. This is a reference to the time taken from the onset of the sweetness taste to reach its peak sweetness intensity (early taste) and the time taken for the taste to wane (aftertaste). By way of example, in a leading text edited by T H Grenby, Progress in Sweeteners (1989), the sweetness characteristics of sucrose are described in this way (at 177): "Sucrose has a relatively quick sweetness impact followed by a fairly sharp, clean cut-off (perception in less than 1 s and sweet taste remaining for about 30 s)." Since the object of a high intensity sweetener is to approximate the characteristics of sucrose, the sweetness of a sugar substitute should build and recede in the mouth in a similar way. 6 A number of intense sweeteners were available and relatively well-known at the priority date. Saccharin was the oldest, with a sweetness intensity approximately 300 times that of sucrose. Aspartame, which was first discovered in 1965, is a popular sweetener 150-200 times as sweet as sucrose. AceK is a high-intensity, non-caloric sweetener with a potency around 200 times that of sucrose. Cyclamate, of which there are a few varieties, is generally 30 times as sweet as sucrose. Sucralose, a sweetener derived from sucrose, is approximately 600 times sweeter than sugar while alitame, a somewhat unstable sweetener, has an intensity around 2,000 times that of sucrose. 7 The invention claimed in the patent in suit is for a combination of high intensity sweeteners. It is common ground that at the priority date it was well-known that intense sweeteners could be combined (the usual description is "blended") and that their combination often had useful results. One advantage of blending is that the weaknesses of one sweetener can be offset by the strengths of another. For example, saccharin has a bitter aftertaste, but with the addition of a small quantity of a cyclamate or aspartame the bitterness can be masked. The result is to produce a sweetener with characteristics closer to sucrose. The blending of aspartame with aceK was known to be particularly common, especially for use in soft drinks such as Diet Coke and Pepsi. 8 Blending can also produces synergies. By "synergy" I mean that the sweetness of the combination is greater than the sweetness of the sum of the individual components. An Ajinomoto expert, Dr Prescott, explained synergy in an easily understood way. Dr Prescott is a chemosensory scientist with experience working at CSIRO and the Sensory Science Research Centre. He said that synergy can be expressed "by the example 2 + 2 = 5 instead of 4". He referred by way of example to a 1989 paper by R A Frank, S J Mize and R Carter entitled "An Assessment of Binary Mixture Interactions for Nine Sweeteners" published in a 1989 issue of Chemical Senses. The paper states (at 629) that blending aspartame with aceK results in a sweetener with a 36 per cent greater sweetness than the sum of the individual potency factors. Accordingly, with blended sweeteners the volume of sweetener required for a product can be reduced. Moreover, so common was blending by the priority date that intense sweeteners were only infrequently used as sole sweeteners. 9 The patent in suit is entitled "Sweetener Composition Improved in Taste". The composition comprises "[DMB-APM] which is a sweetener having a high level of sweetness, together with Aspartame … which is an amino acid-based sweetener, and/or Acesulfame K". The specification describes the sweetness characteristics of DMB-APM as "extremely weak in early taste" and "extremely strong in later taste". DMB-APM is also said to have "a strong astringent taste". These characteristics are not as well-balanced as those of sucrose. The object of the invention then is "to provide, in view of the above‑mentioned sweetness characteristics of DMB-APM, DMB-APM in the form of a sweetener composition which has a high level of sweetness and whose sweetness quality is closer to that of sucrose, by improving the sweetness characteristics of DMB-APM, which can, in turn, be realized by strengthening the early taste, and weakening the later taste as well as the astringent taste." 10 The specification also provides a profile of the sweetness characteristics of aspartame and aceK. Aspartame is described as "weak in early taste though not so weak as DMB-APM, whereas it is strong in later taste though not so strong as DMB-APM." Thus it is said that "both of DMB-APM and Aspartame have such strange sweetness characteristics that their early taste is weak and their later taste is strong." AceK, which is said to have a potency "approximately 200 times that of sucrose in terms of weight ratio", is described as being "inferior in sweetness quality to DMB-APM and Aspartame. It is stronger in later taste, bitter taste, astringent taste, peculiar taste and irritation, compared with DMB-APM." 11 The Ajinomoto specification states that "[a]ccording to the prior knowledge, it is very difficult to anticipate that the early taste of DMB-APM as well as that of APM can be both improved by combining DMB-APM with APM having an early taste which is weak though not so weak as that of DMB-APM, that consequently the early taste given by the combination DMB-APM and APM can be better than that of DPM-APM or APM when used singly, and such combination, in turn, can give a sweetener composition having wholly well-balanced sweetness characteristics and a sweetness closer to that of sucrose, and that a sweetener composition having well-balanced sweetness characteristics can be obtained by combining DMB-APM, and optionally APM, with AceK which is inferior in sweetness characteristics." 12 The invention is then described as a sweetener composition which "contains DMB-APM and APM and/or AceK at a ratio where the sweetness quality closer to that of sucrose than that of each sweetener when singly used, can be obtained." 13 The claims defining the invention are: 1. A sweetener composition comprising N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester (DMB-APM) and Aspartame (APM) and/or Acesulfame K (AceK) in a ratio which gives sweetness quality thereto closer to that of sucrose than any one of N-[N-(3,3-dimethylbutyl)-L-α-aspartyl}-L-phenylalanine 1-methyl ester, Aspartame and Acesulfame K. 2. A sweetener composition comprising N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester and Aspartame, wherein the amount of the N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester is between 0.1% by weight and 35% by weight based on the total amount of the N-[N-(3,3-dimehtylbutyl) [sic] -L-α-aspartyl]-L-phenylalanine 1-methyl ester and the Aspartame. 3. A sweetener composition comprising N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester, Aspartame and Acesulfame K, wherein the amount of the Acesulfame K is between 0.5% by weight and 85% by weight based on the total amount of the three sweeteners. 4. A sweetener composition comprising N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester and Acesulfame K, wherein the amount of the N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester is between 3% by weight and 80% by weight based on the total amount of the N-[N-(3,3-dimethylbutyl)-L-α-aspartyl]-L-phenylalanine 1-methyl ester and Acesulfame K. 5. A beverage comprising the sweetener composition of any one of the claims 1 to 4. 6. The beverage of claim 5, which is a carbonated beverage. 7. A composition according to claim 1, claim 2 or claim 3, substantially as described herein with reference to the examples. 14 The inventive step of the claimed invention was explained by Ajinomoto's witnesses, Mr Garrett and Dr Prescott. Their respective opinions were founded upon the profiles of DMB-APM, aspartame and aceK as described in the Ajinomoto specification. Thus, they explained that for the purposes of their evidence they acted on the basis that: (a) DMB-APM is extremely weak in early taste, extremely strong in later taste and has a strong astringent taste; (b) aspartame is weak in early taste (although not so weak as DMB-APM) and strong in later taste (although not so strong as DMB-APM); and (c) compared to DMB-APM and aspartame, aceK is strong in later taste, bitter taste, astringent taste, peculiar taste and irritation. 15 Mr Garrett holds a Diploma in Applied Chemistry and a Bachelor of Science majoring in food science and technology. In Mr Garrett's opinion the invention lay in the discovery that a blend of DMB-APM with aspartame and aceK produced a useful result. He said that he would not have considered testing DMB-APM in any combination with aspartame or aceK (or both) in the expectation of obtaining a result closer in sweetener profile to sucrose than any one of those compounds alone. He explained that he would not have expected the individual sweetener profiles of each compound to balance out one another in combination to achieve that result. 16 Dr Prescott said that the invention resides particularly in the discovery that the compositions of DMB-APM and aspartame and aceK display the sweetener time profiles described in the Ajinomoto specification. He said that it was surprising to him that the compositions described in the Ajinomoto specification gave a sweetness profile closer to that of sucrose than any one of those compounds alone. His reasons were as follows. First, he would not have expected a composition consisting of DMB-APM, a sweetener with an extremely weak early taste and an extremely strong later taste, and aspartame, a sweetener with a weak early taste and a strong later taste, to display a sweetener time profile which is closer to that of sucrose than either compound alone. Second, as regards the combination of DMB-APM and aceK, he said that aceK is reported in the Ajinomoto specification to have a strong later taste compared to DMB-APM and for that reason he would not have expected a composition of DMB-APM and aceK to have "well-balanced" sweetness characteristics. Moreover, as aceK was reported in the Ajinomoto specification as having a stronger astringent taste compared with DMB-APM, he would not have expected a composition of DMB-APM and aceK to exhibit a "sweetness quality" closer to that of sucrose than either compound. To the contrary, he would have expected a strong astringent taste still to be present. Moreover, he would have expected the composition to have a stronger later taste than that exhibited by DMB-APM or sucrose alone. 17 Counsel for Ajinomoto gave a somewhat different description of the inventive step. He said that the invention resides in the selection of DMB-APM from many compounds and combining it with either or both of aspartame and aceK to produce new and beneficial sweetener compositions. 18 The Ajinomoto patent is attacked on three grounds: want of novelty, obviousness and non-compliance with s 40 of the Patents Act 1990 (Cth). It will be necessary to deal with each ground, although the trial was conducted on the basis that the dispute over obviousness was the main battle. 19 On the question of novelty, the only alleged anticipation is the Nofre Tinti specification. With a paper anticipation "it must be shown that the specification contains clear and unmistakable directions" to produce an article that is within the claim: Flour Oxidizing Company Ld v Carr & Co Ld [1908] RPC 428, 457 (per Parker J). The direction must be sufficiently clear that the article can be produced "without the necessity of making further experiments and gaining further information": Hills v Evans (1862) De G F & J 288, 300 (per Lord Westbury). 20 The Nofre Tinti specification comes very close to being an anticipation, but not close enough in my opinion. The Nofre Tinti specification was published in the Australian Patent Office on 8 June 1984 as an international application. Later that year it was published in the Patent Office library as an Australian patent application. The invention is described in the specification as relating to "novel compounds derived from aspartame which are useful as sweetening agents and to their method of preparation". The novel compounds are said to be useful for sweetening a variety of products, including food and drink. 21 The specification states that aspartame was the most widely used sweetener but that it had a relatively weak sweetening potency being about 120 to 180 times that of sucrose. Despite its excellent organoleptic properties, the main disadvantages of aspartame were that "it is an expensive product on account of its relatively low sweetening intensity, and that it has a rather low stability under certain conditions". The specification notes that "the sweetening potency of aspartame can be very greatly enhanced by attaching certain radicals, especially appropriately selected hydrocarbon radicals, to the free amine of aspartame: in this way the sweetening potency of aspartame can be increased by a factor up to 80". 22 The specification states that the invention "makes it possible for the first time to provide novel-N-hydrocarbon derivatives of aspartame or its analogs which have excellent organoleptic properties associated with a very high sweetening potency of up to 10,000 times the sweetening potency of sucrose on a weight basis, and a stability which is at least similar or greater, the effect of which is to increase the number of possible uses in food preparations, compared with aspartame." Several derivatives of aspartame are then described. One, which is said to be a "particularly advantageous embodiment of the invention", is DMB-APM. 23 The specification goes on to record that "the sweetening agents according to the invention can be employed in an edible product by themselves, as the only sweetening agent, or in combination with other sweetening agents". A number of intense sweeteners with which the compounds the subject of the invention can be combined are mentioned. Included among them are aspartame and aceK. 24 There is no doubt that the Nofre Tinti specification points in the direction of the claimed invention. It does so when it states that the new compounds can be blended with other sweetening agents, including aspartame and aceK. But, pointing toward the claimed invention is not an anticipation of it. What the Nofre Tinti specification does not do is indicate which combination of sweetening agents will achieve the result of claim 1 of the patent in suit, namely a "sweetness quality there to closer to that of sucrose than any one of" the relevant compounds. Nor does the Nofre Tinti specification describe the ratio of the combinations that are the subject of dependent claims 2, 3 and 4 and that are incorporated in the remaining claims. In each case, in order to arrive at the claimed invention some work is necessary. As the cases show, that is enough to repel an attack based on anticipation. 25 The second challenge to validity is that the invention was obvious. Here the relevant test is whether when compared with the prior art the invention "would have been obvious to a person skilled in the relevant art in the light of the common general knowledge as it existed [at the priority date]" (Patents Act, s 7(2)) or in light of the common general knowledge together with information in a document "publicly available" which the skilled person could "be reasonably expected to have ascertained, understood and regarded as relevant" (s 7(3)). 26 The test for obviousness is different from that under the Patents Act 1952 (Cth). Under the former Act prior publications could not be taken into account if they did not form part of the common general knowledge: Minnesota Mining and Manufacturing Company v Beiersdorf (Australia) Limited (1980) 144 CLR 253, 292-293 (per Aickin J). By common general knowledge I mean (speaking generally) knowledge that is in fact known or used by those who work in the field of the invention. The approach under the former Act was regarded as too narrow. One purpose of the 1990 Act was to treat as part of the common general knowledge information publicly available anywhere in the world which the skilled person would find. 27 NutraSweet bases its claim of obviousness on a combination of what it says is the common general knowledge at the priority date together with one prior publication, the Nofre Tinti patent. It is accepted for this purpose that the Nofre Tinti patent was not part of the common general knowledge at that time. 28 Before considering the merits of NutraSweet's contention it is necessary to deal with some preliminary matters. The first is to identify the characteristics of the person who is to decide obviousness. Obviousness is to be tested with reference to the knowledge of a relevantly skilled person. The skilled person is one who has a practical interest in the subject-matter of the invention: Catnic Components Limited v Hill & Smith Ltd [1982] RPC 183, 242 (per Lord Diplock). In some cases this practical interest will involve a collection of skills and knowledge not found in an individual. Then the relevant skilled person may be a team. So it is here. The skilled addressee is a team which is interested in the investigation of artificial sweeteners (alone or in combination) for industrial application. What this entails is the selection, evaluation and blending of artificial sweeteners. This will require a rudimentary knowledge of chemistry, some of the skills of a food technologist, an understanding of the sensory evaluation of foods, particularly sweeteners, and some appreciation of the commercial use and application of artificial sweeteners. It is not necessary for any member of the team to have the knowledge of a chemist who creates new compounds for use as a sweetening agent. 29 Having identified the skilled team, it is necessary next to deal with a point raised by Ajinomoto, which is that there is not in Australia a relevantly skilled person who is able to judge the obviousness of the claimed invention. This is how the point arises. I have already identified what are said to be the two inventive steps for the Ajinomoto patent. The first is the identification and selection of DMB-APM for blending with other sweeteners. The second is the discovery that DMB-APM in combination with one or both of aspartame or aceK achieves a sweetness quality closer to that of sucrose that any one of the compounds alone. According to the evidence, no research is undertaken in Australia to identify or evaluate new compounds which may be blended to improve their sweetness quality. That work is done overseas. So, according to the argument, there is no person or team in Australia skilled in the relevant art. The consequence alleged is that the attack based on obviousness must fail. 30 This submission should be rejected as inconsistent with both authority and principle. As for authority I refer to Gambro Pty Ltd v Fresenius Medical Care South East Asia Pty Ltd (2004) 61 IPR 442. In that case the relevant skilled person was a person who was involved in the design and improvement of dialysis machines. The fact was, however, there was no such person in Australia. The absence of any person who designed or manufactured dialysis machines did not lead the judge, Allsop J, to conclude that there could be no skilled person who could judge the inventiveness of the claimed invention. 31 As regards principle, the argument rests on the unstated assumption, which I do not accept as correct, that a patent can only be struck down for lack of an inventive step if there is some industry in Australia which would be affected by the grant of the patent. First, the assumption reads into the legislation something which is not able to be implied. Second, I simply do not accept the view that when, as here, there is information in Australia, including information in widely circulated international textbooks and journals, which would ordinarily be referred to by a person interested in the area, that information should be ignored when deciding whether an invention is obvious. If such information were to be ignored Australia would become a resting ground for bad patents. 32 In any event, as the evidence here demonstrates, although the selection, testing and manufacture of blended compounds for use as a sweetening agent does not take place in Australia, there are persons who work in closely related areas who do have an interest in and understanding of the relevant information. Moreover, major manufacturers of intense sweeteners conduct a large part of their research on a global scale and recruit scientists both locally and from other countries, including Australia. That is sufficient, in my view, to consider what would have been in the common general knowledge of the hypothetical skilled addressee. 33 The final preliminary point concerns the evidence on obviousness tendered by NutraSweet. In large measure this evidence was from experts. A point was taken that the expert evidence was based on facts which were neither identified nor proven and so was inadmissible. Reliance was placed on Makita (Australia) Pty Ltd v Sprowles [2001] 52 NSWLR 705. I rejected this submission and admitted the evidence of the experts. I said that "facts" which are part of the material upon which specialist knowledge in the field is based lie outside the rule expressed in cases such as Makita. Since my ruling I have come across authorities that support the view I expressed, including Pownall v Conlon Management Pty Ltd as trustee for the Kalbarri Trust (unreported, Full Court of the Supreme Court of Western Australia, Malcolm CJ, Ipp and Anderson JJ, 15 March 1995). See also R Pattenden, "Expert Opinion Evidence Based on Hearsay" [1982] Criminal Law Review 85. 34 Returning now to the merits, the question whether a claimed invention is obvious involves the following steps. First, identifying (as I have done) what is said to be inventive about the claimed invention. Second, determining (as I have also done) the relevant art with which the invention is concerned for the purpose of identifying the skilled person or team. Third, determining the common general knowledge in the relevant field as at the priority date. Fourth, identifying the difference, if any, between the claimed invention and the state of the art. Finally, deciding (as a question of fact) whether these differences are "plain" (or "very plain") or involve some degree of inventiveness. See generally Windsurfing International Inc v Tabur Marine (Great Britain) Ltd [1985] RPC 59, Gambro Pty Ltd v Fresenius Medical Care South East Asia Pty Ltd (2004) 61 IPR 442. As to the requirement that obviousness means "plain" or "very plain" see The General Tire & Rubber Company v The Firestone Tyre and Rubber Company Limited [1972] RPC 457, 497; Chiron Corporation v Murex Diagnostics Ltd [1996] RPC 535, 557. In Olin Mathieson Chemical Corporation v Biorex Laboratories Limited [1970] RPC 157, 188, Graham J put it this way: "The word 'obvious' … as its derivation implies, means something which lies in the way, and in the context of the [UK] Act is used in its normal sense of something which is plain or open to the eye or mind, something which is perfectly evident to a person thinking on the subject." 35 It is convenient at this point to say something further about the common general knowledge which is to be attributed to the skilled team. In England it has been said that the skilled addressee "is assumed to have read and understood all the available prior art": Cairnstores Ltd v Aktiebolaget Hässle [2002] EWHC 309 (Ch) [94] (per Laddie J). This was not intended to indicate that all prior art, no matter how obscure, was to be treated as part of the common general knowledge. All that was meant by this statement was that the "obscurity of a citation is not to be counted against it": Glaxo Group Ltd's Patent [2004] RPC 843, 857 (per Pumfrey J). Nevertheless, the High Court has given the passage from Cairnstores a different and broader meaning (that it was a statement of general application) and, on the basis of that broader meaning, has said that there is a divergence between Australian and English case law on this topic: see Aktiebolaget Hässle v Alphapharm Pty Limited (2002) 212 CLR 411. According to the High Court, under the Patent Act 1952 (Cth) prior patent specifications were not relevant to obviousness unless they formed part of the common general knowledge. Thus, the Court said (at 430): "A fortiori, obviousness could not be determined by asking whether a diligent searcher might have selected the elements of the claimed invention by taking pieces from those prior publications and putting them together". 36 The position under the 1990 Act is different. The Report of the Industrial Property Advisory Committee, Patents, Innovation and Competition in Australia (1984), which preceded the 1990 Act, stated (at 45): "For the purpose of determining inventiveness, any single prior disclosure or use should be capable of being considered against the background of all that is common general knowledge in the relevant field of art. On this basis the requirement of inventiveness will not be fulfilled if the knowledge imparted by the disclosure or use, combined with what is common general knowledge in the art, would render the claimed invention obvious to a person reasonably skilled in the art. However, it should not be possible for this purpose to combine two disclosures, two uses, or a disclosure and a use, where neither is within the common general knowledge of the art, except where one disclosure refers to another disclosure or use. On the other hand, we see as being treated as within the common general knowledge of the art, not merely information which is generally known and used in the art, but also information publicly available in recorded form anywhere in the world which a skilled person working in the art at the relevant time should reasonably have been expected to find, understand, and regard as relevant." The change was made by s 7 of the 1990 Act. Relevantly, s 7 provides: "(2) For the purposes of this Act, an invention is to be taken to involve an inventive step when compared with the prior art base unless the invention would have been obvious to a person skilled in the relevant art in the light of the common general knowledge as it existed in the patent area before the priority date of the relevant claim, whether that knowledge is considered separately or together with the information mentioned in subsection (3). (3) The information for the purposes of subsection (2) is: (a) any single piece of prior art information; or (b) a combination of any 2 or more pieces of prior art information; being information that the skilled person mentioned in subsection (2) could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood, regarded as relevant and, in the case of information mentioned in paragraph (b), combined as mentioned in that paragraph." Accordingly, if a prior publication meets each of the conditions set out in s 7(3) it will be considered along with the common general knowledge on the question of obviousness. 37 The state of the common general knowledge in Australia as at the priority date concerning the use of artificial sweeteners was as follows. (To some extent this is a repetition of what has gone before.) There were technical, economic and health related reasons for the use of intense sweeteners, other than sucrose, in food. The technical reasons concerned, in the case of some food, the lack of stability of sucrose and the better taste of the combination of sucrose and an appropriate sweetener. The economic reason was that the unit cost of an artificial sweetener could be less than sucrose. The health factors included obesity, diabetes and dental care. 38 The "gold standard" for sweeteners was sucrose. The best artificial sweetener was a sweetener that had taste characteristics as close to sucrose as possible and which lacked the undesirable characteristics (eg aftertaste) often associated with artificial sweeteners. Stability, potency, cost and calories were also important. 39 The taste characteristics of sweeteners were measured in terms of the quality of the sweet taste, the time profile of that sweet taste and the presence of other tastes. These characteristics were ascertained by sensory evaluation testing. The testing involved taste trials conducted by panels of testers, appropriately instructed or educated. The testing was relatively straightforward, though it may have been a costly exercise. 40 There were a number of well-known intense sweeteners whose taste profiles were known. These included saccharine, cyclamate, aspartame, aceK, sucralose and alitame, among others. The use of sweeteners in soft drinks was by far the largest use to which artificial sweeteners were put and the most widely used were aspartame and aceK. 41 No one artificial sweetener met all of the desired requirements for an ideal sweetener, especially when used in soft drinks. It was therefore common practice to blend intense sweeteners so that the limitations of one sweetener would be offset by the strengths of another. Blending of sweeteners had taken place since the 1960s. 42 The characteristics of blended sweeteners were known. One characteristic was that blending could have a synergistic effect. It was not possible to predict with certainty whether a particular blend would have an additive or synergistic effect. For this reason, blending was described as a "complex" phenomenon such that "no single effect pervades all the [combinations] of sweeteners tested": N Ayya and H T Lawless, "Quantitative and Qualitative Evaluation of High-Intensity Sweeteners and Sweetener Mixtures" (1992) 17 Chemical Senses 245, 253. Sensory evaluation testing would need to be conducted. But synergy occurred in a majority of blended sweeteners. 43 Moreover, the "odds" were in favour of a synergistic effect when certain known sweeteners were blended. Aspartame and aceK, in particular, were two compounds known for their synergistic effects when blended, especially when blended together. The commonly available literature describing this result was substantial. See eg A G Wells, "The Use of Intense Sweeteners in Soft Drinks" in T H Grenby (ed), Progress in Sweeteners (1989) 180, 183 ("[aceK] shows a pronounced synergistic action with aspartame" … "[a]spartame is synergistic with a wide range of carbohydrate sweeteners and intense sweeteners"); R A Frank, S J Mize and R Carter, "An Assessment of Binary Mixture Interactions for Nine Sweeteners" (1989) 14 Chemical Senses 621, 629 (found aceK and aspartame "showed the greatest synergism"); D D Duxbury, "High-Intensity Sweetener Blends Provide Synergistic Enhancement" [1990] Food Processing 36, 40 (blending with aceK "intensifies the overall sweetness of the blend"); N Ayya and H T Lawless, "Quantitative and Qualitative Evaluation of High-Intensity Sweeteners and Sweetener Mixtures" (1992) 17 Chemical Senses 245, 254 (aspartame/aceK blends "showed hyperadditivity at all the concentrations"); L Y Hanger, A Lotz and S Lepeniotis, "Descriptive Profiles of Selected High Intensity Sweeteners (HIS), HIS Blends, and Sucrose" (1996) 61 Journal of Food Science 456, 464 (blends of aceK and aspartame "were very close to sucrose"). 44 It is common ground that the Nofre Tinti specification was not part of the common general knowledge. It is nevertheless part of the information to be taken into account when considering what the skilled team would think and do. It is to be taken into account because it satisfies the conditions in s 7(3). As to this, the evidence is almost all one way. Each of Dr Bullock, Dr McBride, Dr Lindley and Mr Heyhoe said that if one were to embark upon a project to develop a new sweetener or sweetener blend, a search of the relevant patents would be undertaken. Dr Bullock is currently General Manager of the Sugar Research Institute in Queensland and has past experience as a patent examiner and chemist. He said that searches of patent and technical literature are a critical part of research and development. He explained that there were several obvious reasons for this, including "to familiarise the researcher with up to date developments, to provide inspiration and to 'avoid reinventing the wheel'." He added that these searches were also necessary to verify that there was "freedom to operate" in the field. Mr Heyhoe, a food technologist with a background in research and development, also put the matter quite firmly. He said that if he had been engaged to develop a new sweetener or blend: "[I]t is inconceivable to me that a literature search which included a search of patent literature would not be done as part of that work." 45 Only one witness, Mr Garrett, suggested that a literature search might not be undertaken. I say Mr Garrett only "suggested" this because all he said in this regard was that in his work before the priority date as a teacher in food science and technology at the William Angliss Institute he did not read patents. It is, I think, clear that the reason Mr Garrett did not read patents was that his work did not require him to do so. It was enough that he read synopses of patents. 46 Once it is accepted, as I do accept, that a patent literature search would have been undertaken by the skilled team, there is no doubt that the Nofre Tinti specification would have turned up (the language of the statute is "ascertained") and been understood. In the end, I believe this was accepted by Ajinomoto. 47 The remaining condition to be satisfied is that the Nofre Tinti specification would be regarded as relevant. On this point, Dr Bullock, Dr McBride, Mr Heyhoe and Dr Lindley said that they would have regarded the Nofre Tinti specification as relevant to the task of developing a sweetener or sweetener composition. Dr McBride is a consultant psychophysicist with 18 years' experience in food research at CSIRO. He would have regarded it as relevant because he was aware beforehand that NutraSweet was developing a new generation sweetener. I think that what Dr McBride meant was the compounds in the Nofre Tinti specification were derivatives of aspartame, which was the most commercially successful artificial sweetener as at the priority date, and so were likely to be useful compounds. Moreover, one of the compounds, DMB-APM, had exceptional potency being 10,000 times as sweet as sucrose. Likewise, in Mr Heyhoe's opinion the Nofre Tinti patent would have been regarded as relevant because "a new sweetener based on Aspartame identifying high sweetener intensities with excellent organoleptic properties and stability would be highly attractive to commercial manufacturers." Similar considerations motivated Dr Lindley to consider the Nofre Tinti compounds as relevant. 48 Importantly, of the various compounds described in the Nofre Tinti specification, DMB-APM would have been regarded as the most suitable for use as an artificial sweetener. Dr McBride described this compound as the "preferred" compound based on its high intensity sweetness, organoleptic properties and reported similarities to aspartame. The principal reason was its potency. Dr McBride said its high potency would have both cost benefits to manufacturers as well as regulatory advantages because regulators invariably prefer smaller quantities of additives. Dr Bullock also described DMB-APM as "the preferred compound". Even Dr Prescott was prepared to concede that the characteristics of DMB-APM made it "a promising candidate [for] a high intensity artificial sweetener." To be fair, Dr Prescott made this comment in relation to the use of DMB-APM alone, not in combination with other sweeteners. In my opinion the evidence is overwhelming that DMB-APM was a "promising candidate" for blending as well. 49 Obviousness involves determining whether the claimed invention was "plain" or "evident" to the skilled team. We are here dealing with a combination of compounds which is said to bring about a beneficial result. The fact that an invention is a combination of previously known compounds does not, of course, prevent patentability. As Learned Hand J said in B G Corporation v Walter Kidde, 79 F.2d 20, 22 (1935): "All machines are made up of the same elements; rods, pawls, pitmans, journals, toggles, gears, cams, and the like, all acting their parts as they always do and always must. All compositions are made of the same substances, retaining their fixed chemical properties. But the elements are capable of an infinity of permutations, and the selection of that group which proves serviceable to a given need may require a higher degree of originality. It is that act of selection which is the invention." See also Aktiebolaget Hässle v Alphapharm Pty Limited (2002) 212 CLR 411, 429. The critical question is whether the level of skill and knowledge in the art as at the priority date was such that combining the compounds in the manner claimed would have been obvious, not in hindsight, but at the time it was done. Put another way, is there some positive reason why the skilled team would have decided to combine the compounds? 50 It has been decided in England that for a particular combination to be obvious, it is sufficient to show that it appears to the skilled team that it would be worthwhile to try the process or step. It is not necessary to show that success is clearly predictable: Johns-Manville Corporation's Patent [1967] RPC 479, 494; Beecham Group Limited's (Amoxycillin) Application [1980] RPC 290, 269. In Alphapharm the High Court held that this test is not a valid criterion. Instead, the Court preferred the view of obviousness taken in United States. 51 The US courts have rejected the "obvious to try" standard. In re Merck & Co. Inc., 800 F.2d 1091 (Fed Cir, 1986) concerned a method of treating depression by the oral administration of the drug amitiriptyline in specific dosages. The Court of Appeals for the Federal Circuit held the invention to be obvious due to structural similarities with prior art compounds used for the same purpose. Judge Baldwin was in dissent. He said that denying patentability to an invention which the prior art indicated was "potentially useful" impermissibly applied the "obvious to try" standard. He also said (at 1100): "The obvious-to-try analysis is an attack on the method of making an invention that specifically penalizes people in areas of endeavour where advances are won only by great effort and expense. The pharmaceutical field is particularly hard hit because there is an overabundance of structures that are obvious to try … The researchers tested eighteen chemicals with closely related structures … Under an obvious-to-try analysis, any one of these structures which ultimately is shown to be effective as an antidepressant in human beings would be unpatentable because the researcher dared to follow a logical plan." 52 In In Re O'Farrell, 853 F.2d 894 (Fed Cir, 1988) the Court of Appeals, per Judge Rich, said (at 903) that it was improper to reject a claim on the basis that it was "[obvious to] try each of numerous possible choices until one possibly arrived at a successful result, where the prior art gave either no indication of which parameters were critical or no direction as to which of many possible choices is likely to be successful." It was also said to be incorrect to regard as obvious a new technology or approach where the prior art gave only general guidance as to the particular form of the claimed invention or how to achieve it. However, Judge Rich said that obviousness does not require absolute predictability of success. He said (at 904): "For obviousness under s103, all that is required is a reasonable expectation of success." In other words, obviousness can be made out even where some experimentation is needed to confirm that the invention will work or where it is necessary to confirm whether any group of candidates will be able to perform the desired function: Moy's Walker on Patents (4th ed, 2004) s9.67. The manner in which the test has been explained in some of the US cases it is that if the skilled person would "reasonably expect" that the steps suggested by the prior art would produce the claimed invention, then obviousness will be established. See, eg, Application of Clinton, 527 F.2d 1226 (1976). 53 In my view the evidence does establish that it would reasonably have been expected that a blend comprising DMB-APM and aspartame or aceK, or DMB-APM, aspartame and aceK would give a sweetness quality closer to that of sucrose than any one of those compounds individually. The common general knowledge strongly suggested this result. So did the witnesses. Mr Heyhoe, in particular, was a good witness on this aspect. He said the odds were 70 per cent in favour of synergy. Dr Bullock, whose evidence was compelling on many aspects, also favoured the gambler's approach and said the chance of a blend resulting in synergy was "odds-on". I also regard as important Dr Bullock's evidence that his first choice for blending with DMB-APM would have been those sweeteners that had already had commercial success and shown synergy when used in blends. So, aspartame and aceK were primary candidates. 54 I think this is a clear case of obviousness. This result should not come as a surprise. As long ago as 1993, Dr Eric Walters, a chemist who worked in the field, predicted that "[t]he time may be coming when simply blending sweeteners is no longer patentable because of its obviousness": E Walters, "High-Intensity Sweetener Blends: Sweet Choices" [1993] Food Product Design 83, 84. 55 In reaching my conclusion I have rejected the evidence of both Dr Prescott and Mr Garrett that the skilled team would have found it surprising that the claimed invention gave a sweetness profile closer to that of sucrose. As I have explained, their opinions were based on the taste profiles of DMB-APM, aspartame and aceK given in the Ajinomoto specification. Those profiles do not accord with what was according to the common general knowledge believed to be the taste profiles of those compounds. The skilled team is assumed to know the characteristics of the compounds according to what the common general knowledge says of them and not what is stated in the Ajinomoto specification. 56 In any event, based on the evidence, particularly that of Dr Lindley and Mr Heyhoe, it is likely the descriptions of the taste profiles of DMB-APM, aspartame and aceK in the Ajinomoto specification are incorrect. Dr Lindley is a research chemist and food technology consultant who practises principally in England but also the US. He is a leader in the field of sweetener research. Dr Lindley said that the Ajinomoto specification exaggerates the "negative" aspects of DMB-APM, aspartame and aceK. First, he said that DMB-APM does not have an astringent characteristic, which he described as causing a drying sensation in the mouth. He went on to say that DMB-APM does have a time intensity profile "characterised by a delay in reaching maximum sweetness" and a sweet aftertaste relative to that of sucrose, but that these characteristics are not "extreme". He instanced thaumatin as an example of a sweetener exhibiting "extreme" characteristics. In a work program which Dr Lindley prepared in 1997 for a tender, he described the taste profile of DMB-AMP as "exhibiting a slight delay in reaching maximum sweetness followed by a lingering sweet aftertaste. The aftertaste may also contain some 'licorice' element." While noting that DMB-APM's taste was clearly different from that delivered by sucrose, he also recorded that preliminary tasting indicated that it "delivers a full, sucrose-like mouthful and there does not appear to be any bitter component associated with its overall taste profile." 57 Dr Lindley's criticism of the description of the taste profile of DMB-APM is supported by I Prakash, G Corliss, R Ponakala and G Ishikawa, in a paper published in (2002) 56 Food Technology 36. The authors describe (at 38) DMB-APM's taste profile as "very similar to that of sucrose, with a predominant sensory characteristic being a very clean, sweet taste. The sweetness increases as the concentration in water increases, but other taste attributes such as bitterness, sourness, and metallic taste are insignificant … the sweetness temporal profile of neotame in water is close to that of aspartame, with a slightly slower onset and slightly longer linger." 58 As regards aspartame, Dr Lindley said that he did not agree with the description in the specification that it has an early taste that is "weak". He noted that some observers have reported a slight delay, relative to sucrose, in reaching maximum sweetness intensity. But, according to Dr Lindley, this difference is not at a level which had been measured using available measurement techniques. 59 Dr Lindley said little in relation to the taste profile description of aceK in the Ajinomoto specification, save only that it was "greatly exaggerated". 60 In broad terms Dr Lindley's evidence was supported by Mr Heyhoe. Mr Heyhoe described aspartame as displaying a clean, sucrose-like taste without the bitter aftertaste that was associated with intense sweeteners such as saccharin. He said that the sweetness time profile of aspartame is similar to sucrose but aspartame develops more gradually and persists slightly longer than sucrose. Mr Heyhoe also said that the taste profile of aceK includes a fast onset of sweet taste, but if used in high concentrations can include a harsh aftertaste. 61 Dr Lindley and Mr Heyhoe's evidence about the taste profiles of aspartame and aceK is confirmed by the common general knowledge. See, eg, A G Wells, "The Use of Intense Sweeteners in Soft Drinks" in T H Grenby (ed), Progress in Sweeteners (1989) 181, 179 ("the sweetness/time profile of aspartame is quite similar to that of sucrose, but its sweetness develops more gradually and persists slightly longer" … "at moderate concentrations [aceK] has little aftertaste"); D D Duxbury, "High-Intensity Sweetener Blends Provide Synergistic Enhancement" [1990] Food Processing 36, 36 ("[aceK] provides a clean, quickly perceptible, sweet taste which does not linger or add an aftertaste"); R C Gelardi, "The Multiple Sweetener Approach and New Sweeteners on the Horizon" (1987) 41 Food Technology 123, 124 ("[aceK's] sweet taste is rapidly perceptible without unpleasant lingering"); S S Schiffman and C A Gatlin, "Sweeteners: State of Knowledge Review" (1993) Neuroscience and Biobehavioral Review 313, 329 (aspartame's sweetness "develops more gradually and persists slightly longer than sucrose … AT (appearance time) for sweetness of aspartame is 5 s compared to 4 s for sucrose"). 62 The final basis upon which the patent is attacked is confined to claims 2 to 7. It is said that these claims are not useful or fairly based in the sense that not all blending within the ranges specified will achieve the stated result which is said to be the invention. 63 According to the evidence, particularly that of Drs Lindley and McBride, there are combinations of DMB-APM and aspartame or aceK (or both) that will not result in improvements in sweetness quality. The reason is that the possible ratios open are so wide as to be almost unlimited and not every combination is useful. 64 The law is clear. The claims must recite the features which should be utilised to achieve the stated result or at least explain to the skilled team what to do, unless what the team must do is routine and not inventive in order to achieve the result: Hughes Tool Company v Ingersoll-Rand Company Limited [1977] FSR 406, 417. In a sense, Ajinomoto faces a dilemma. It cannot accept that blending to achieve a useful sweetness quality involves merely routine work or is just a mechanical exercise because that will undermine its argument on obviousness. On the other hand it cannot say that the required blending involves inventiveness because that will establish inutility. 65 In the end the dilemma is easily resolved. I have already found that blending of known sweetener compounds, including in particular DMB-APM, aspartame and aceK, to obtain an improved sweetening agent, is a matter of routine. Hence the attack must fail. The corollary is that, if my finding were wrong, it would necessarily follow that claims 2 to 7 would be struck down. Although not part of the submission, it seems to me that claim 1 would fail for the same reason. 66 At the request of the parties I will not make orders until they have had the opportunity of considering my reasons. I will hear their submissions next Friday. I certify that the preceding sixty-six (66) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Finkelstein.