  United States Court of Appeals
      for the Federal Circuit
               ______________________

              STEUBEN FOODS, INC.,
                   Appellant

                          v.

                NESTLE USA, INC.,
                      Appellee
               ______________________

                     2017-1290
               ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2015-
00195.
                 ______________________

               Decided: March 13, 2018
               ______________________

    THOMAS FISHER, Oblon, McClelland, Maier & Neu-
stadt, LLP, Alexandria, VA, argued for appellant. Also
represented by W. COOK ALCIATI, CHARLIE AVIGLIANO,
Steuben Foods, Inc., Jamaica, NY.

    TYLER MICHAEL AKAGI, Finnegan, Henderson,
Farabow, Garrett & Dunner, LLP, Washington, DC,
argued for appellee. Also represented by THOMAS H.
JENKINS; VIRGINIA L. CARRON, KEVIN D. RODKEY, Atlanta,
GA.
                ______________________
2                    STEUBEN FOODS, INC.   v. NESTLE USA, INC.



    Before DYK, REYNA, and HUGHES, Circuit Judges.
HUGHES, Circuit Judge.
    Steuben Foods, Inc. appeals from the final decision of
the Patent Trial and Appeal Board in an inter partes
review, finding claims 1–10, 14, 16–21, 25, 27, 29, and 32–
36 of U.S. Patent No. 6,475,435 B1 unpatentable as
obvious. Because we find no reversible error in the
Board’s decision, we affirm.
                              I
    Aseptic packaging involves putting a sterile food
product into a sterile package within a sterile environ-
ment. The ’435 patent is generally directed to providing
such a sterile environment in a sterilization tunnel, which
is a tunnel pressurized with sterile air to a level above
atmospheric pressure. The overpressure creates a flow of
sterile air out of the tunnel, ensuring that contaminants
cannot flow into it.
    More specifically, the ’435 patent discloses an appa-
ratus and method for providing sterilization zones in an
aseptic packaging sterilization tunnel that surrounds
containers with pressurized gas. ’435 patent, col. 1 ll. 12–
14, col. 3 ll. 30–31. The aseptic sterilant used in the
apparatus may be hydrogen peroxide. Id. at col. 2 ll. 23–
27, col. 5 ll. 2–6. Figure 3 of the patent, reproduced in its
annotated form below, illustrates the distinct sterilization
zones in the sterilization tunnel—starting with the fourth
zone (orange), followed by the first (blue), the second
(red), and the third (green) zones—with the zones provid-
ing various concentration levels of sterilant within the
tunnel. The fourth sterilization zone 165 includes the
bottle sterilization apparatus. It has the highest hydro-
gen peroxide sterilant level—about 1,000 parts per mil-
lion (ppm). Id. at col. 9 ll. 54–58. The first sterilization
zone 164 includes the activation and drying apparatus.
The hydrogen peroxide sterilant level in that zone is
STEUBEN FOODS, INC.   v. NESTLE USA, INC.                3



about 3 ppm. Id. at col. 9 ll. 58–59. The second steriliza-
tion zone 166 includes the main product filler apparatus,
and the lid sterilization and heat sealing apparatus.
It has the lowest concentration level of hydrogen peroxide
sterilant at about less than 0.5 ppm and typically about
0.1 ppm. Id. at col. 9 ll. 59–63. The third sterilization
zone 172 includes a bottle discharge apparatus. The




hydrogen peroxide sterilant concentration level in that
zone is about 0.1 ppm. Id. at col. 10 ll. 1–2.
    Nestlé USA, Inc. challenged claims of the ’435 patent
in an inter partes review. The Board instituted trial on
claims 1–10, 14, 16–21, 25, 27, 29, and 32–36 of the
patent. The challenged claims are directed to the sterili-
zation tunnel and further recite maintaining a specific
ratio of sterilant concentration levels in the plurality of
zones in the tunnel.
   Claim 1 is illustrative and reads as follows:
   1. Apparatus comprising:
   a sterilization tunnel for surrounding a plurality
   of containers with pressurized gas; and
4                    STEUBEN FOODS, INC.   v. NESTLE USA, INC.



    a plurality of zones within the sterilization tunnel
    having different sterilant concentration levels
    therein wherein the sterilant concentration levels
    in the plurality of zones are maintained at a ratio
    of at least about 5 to 1.
Id. at col. 16 ll. 46–53. Claim 3, which depends from
claim 1, requires a ratio of “at least about 1,000 ppm to
0.1 ppm.” Id. at col. 16 ll. 56–59.
    The Board found that the challenged claims would
have been obvious to a person of ordinary skill in the art
in view of prior art references in the record. J.A. 20–32.
Steuben Foods appeals. We have jurisdiction under 28
U.S.C. § 1295(a)(4)(A).
                             II
     We review the Board’s legal conclusions de novo and
its factual findings for substantial evidence. Rambus Inc.
v. Rea, 731 F.3d 1248, 1251 (Fed. Cir. 2013). “[W]e review
the Board’s ultimate claim constructions de novo and its
underlying factual determinations involving extrinsic
evidence for substantial evidence.” Microsoft Corp. v.
Proxyconn, Inc., 789 F.3d 1292, 1297 (Fed. Cir. 2015).
Obviousness is a question of law, based on underlying
factual findings, including what a reference teaches,
whether a person of ordinary skill in the art would have
been motivated to combine references, and any relevant
objective indicia of nonobviousness. Apple Inc. v. Sam-
sung Elecs. Co., 839 F.3d 1034, 1047–48, 1051 (Fed. Cir.
2016) (en banc).
                             A
    Steuben Foods argues that the Board erred in con-
struing the term “sterilant concentration levels in the
plurality of zones.” “Unexpired claims subject to inter
partes review are to be given their ‘broadest reasonable
construction.’” Microsoft Corp. v. Biscotti, Inc., 878 F.3d
1052, 1068 (Fed. Cir. 2017) (quoting Cuozzo Speed Techs.,
STEUBEN FOODS, INC.   v. NESTLE USA, INC.                      5



LLC v. Lee, 136 S. Ct. 2131, 2144 (2016)). The Board
construed “sterilant concentration levels” to be the levels
measured “at any point within the sterilization tunnel—
including the ‘residual’ concentration on bottle surfaces—
such that the 5 to 1 ratio is satisfied.” J.A. 21–22; see also
J.A. 11–14. Steuben Foods contends that the Board
construed the term “sterilant concentration levels” so
broadly as to read on the concentration of sterilant “at
any point” within the sterilization zone, including the
concentration of a random droplet on a container. In-
stead, Steuben Foods contends, the Board should have
construed the term as “the amount of sterilant in the
volume of pressurized gas within the zone.”
     Steuben Foods’ proposed construction, however, im-
permissibly restricts the claim term to a specific embodi-
ment disclosed in the specification.                  While the
specification refers to zones with “different concentration
levels of gas laden sterilant (e.g., hydrogen peroxide in
air),” ’435 patent, col. 9 ll. 51–53, the specification also
refers to residual concentration of hydrogen peroxide on
the lids on the bottles, see, e.g., id. at col. 12 ll. 44–47, and
on the surface of the bottles, see, e.g., id. at col. 11 ll. 15–
17. Steuben Foods fails to point to any language in the
claims or disclosure in the specification that supports its
position that the claims are limited to the former but
specifically excludes the latter. See also J.A. 14 (the
Board finding that “neither the claims nor the specifica-
tion limit how or where . . . the sterilant concentration
levels should be assessed”). The broadest reasonable
construction of “sterilant concentration levels” must,
therefore, encompass both the “gas laden” (or “in air”)
sterilant levels as well as the residual sterilant levels on
the lids of the bottles and the bottle surface, all of which
are indisputably “in the plurality of zones” recited in the
challenged claims. Accordingly, the Board’s construction
is not erroneous.
6                   STEUBEN FOODS, INC.   v. NESTLE USA, INC.



                            B
    Steuben Foods also argues that the Board failed to
identify any prior art that discloses maintaining “at least
about 5 to 1” (claim 1) or “at least about 1,000 ppm to 0.1
ppm” (claim 3) ratio of sterilant concentration levels in
the plurality of zones. A patent claim is unpatentable
when “the differences between the subject matter sought
to be patented and the prior art are such that the subject
matter as a whole would have been obvious at the time
the invention was made to a person having ordinary skill
in the art to which said subject matter pertains.” 35
U.S.C. § 103(a). 1 Among other factual determinations,
obviousness depends on the scope and content of the prior
art and the differences between the prior art and the
claims at issue. In re Kubin, 561 F.3d 1351, 1355 (Fed.
Cir. 2009) (citing Graham v. John Deere Co., 383 U.S. 1,
17–18 (1966)). The Board found that the challenged
claims would have been obvious to a person of ordinary
skill in the art based on Scholle 2 in view of an FDA regu-



    1    Congress amended § 103 when it passed the
Leahy-Smith America Invents Act (AIA). See Pub. L. No.
112-29, § 3(c), 125 Stat. 284, 287 (2011). However, the
pre-AIA § 103 applies here because the application that
led to the ’435 patent never contained a claim having an
effective filing date on or after March 16, 2013, or a
reference under 35 U.S.C §§ 120, 121, or 365(c) to any
patent or application that ever contained such a claim.
See id. § 3(n)(1), 125 Stat. at 293.
    2   U.S. Patent No. 4,417,607 for “Apparatus and
Method for Aseptically Filling Flexible Containers,” which
describes a “tunnel-like, elongated chamber” “partitioned
into three compartments, including a sterilizing [or spray-
ing] compartment . . . a filling compartment” and a “dry-
ing compartment therebetween.” J.A. 2066–76.
STEUBEN FOODS, INC.   v. NESTLE USA, INC.                  7



lation, 3 Biewendt (also referred to as the Bosch system), 4
and Elliott, 5 among other prior art references in the
record. J.A. 20–32. Steuben Foods contends that none of
these references discloses maintaining “at least about 5 to
1” or “at least about 1,000 ppm to 0.1 ppm” ratio of steri-
lant concentration levels in different zones.
     We disagree with that contention. The Board noted
that both parties agreed that Scholle’s spraying compart-
ment (analogous to the fourth sterilization zone in the
’435 patent) has a higher sterilant concentration than the
filling compartment (analogous to the second sterilization
zone in the ’435 patent). See J.A. 22. Scholle discloses
that the specific concentration of hydrogen peroxide in the
spraying zone is around 300,000 ppm, a disclosure that
Steuben Foods’ expert, Dr. Sharon, also acknowledged.
J.A. 23; see also Scholle, col. 5 ll. 18–26, col. 8 ll. 8–13.
The Board also credited the testimony of Nestlé’s expert,



    3  21 C.F.R. § 178.1005(d), which provides that “[n]o
use of hydrogen peroxide solution in the sterilization of
food packaging material shall be considered to be in
compliance if more than 0.5 part per million of hydrogen
peroxide can be determined in distilled water packaged
under production conditions . . . .”
    4   A reference translated from German and entitled
“Report on the Type Testing of the Aseptic Filling and
Sealing Plant for Glass Bottles for UHT Milk,” which
describes aseptic sterilization and packaging of bottles
developed by the German company Robert Bosch GmbH.
J.A. 2077–103.
    5   An article entitled “Microbiological Evaluation of
Low-Acid Aseptic Fillers,” which describes how the opera-
tional limits for several critical factors or a “window of
operation” for container sterilization can be created. J.A.
2756–57.
8                    STEUBEN FOODS, INC.   v. NESTLE USA, INC.



Dr. Heldman, who stated that “to ensure consistent
sterilization and residual peroxide levels, the concentra-
tion of applied sterilant must necessarily be ‘maintained.’”
J.A. 23. Finally, the Board found that “other prior art
aseptic bottling systems recognized the importance of
limiting the concentration of [hydrogen peroxide] in the
filling zone in order to comply with regulatory limits” of,
for instance, no more than 0.5 ppm in the United States,
which warrants a “window of operation” for sterilization
in the filling compartment in that vicinity. J.A. 25 (rely-
ing on the Bosch system and Elliott). Prior art thus
teaches maintaining a ratio of 300,000 ppm over 0.5 ppm
in the plurality of zones, which fairly suggests maintain-
ing “at least about 5 to 1” or “at least about 1,000 ppm to
0.1 ppm” ratio of sterilant concentration levels recited in
the claims. 6 Accordingly, substantial evidence supports
the Board’s obviousness determination.
                            III
    We have considered the remaining arguments and
find them unpersuasive. Accordingly, we affirm the
Board’s decision.
                       AFFIRMED




    6   This comparison is based on a liquid concentration
of 300,000 ppm and a residual (liquid) concentration of 0.5
ppm. See J.A. 23.
