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                                                                   Exhibit 10.56

                                 PROMISSORY NOTE

US$ $110,000.00                                                February 11, 2003

                                    ARTICLE I
                               PAYMENT OBLIGATION

         FOR VALUE RECEIVED, the undersigned The UniMark Group, Inc., a Texas
corporation ("Maker"), unconditionally promises to pay to the order of M&M
Nominee, L.L.C., or its assigns ("Payee"), the sum of One Hundred Ten Thousand
Dollars (US $110,000.00), together with interest on the unpaid principal balance
from time to time outstanding at a rate per annum equal to ten percent (10%).
The principal of and accrued interest on this Note shall be due and payable in
lawful money of the United States on the earlier of (a) July 9, 2003, (b) the
occurrence of a Qualified Lemon Project Transaction (as defined below) or (c)
upon demand following the occurrence of an Event of Default (as defined in
Article III) or as otherwise provided in Article III hereof. Interest hereunder
shall be calculated on the basis of a year of 365 days and the actual number of
days elapsed. As used herein a "Qualified Lemon Project Transaction" shall mean
(i) any debt or equity financing of Maker or its subsidiaries which is secured,
in whole or in part, by the approximately 2,871 prepared and planted hectares
lemon groves owned by Maker and/or its subsidiaries (as further described in
Maker's filings with the Securities and Exchange Commission) (the "Lemon
Project"), (ii) any other financing made by Maker or its subsidiaries which is
obtained in connection with the Lemon Project, in each case with initial net
cash proceeds in an amount at least equal to the outstanding principal amount of
this Note, or (iii) any transaction with The Coca-Cola Export Corporation with
initial net cash proceeds in an amount at least equal to the outstanding
principal amount of this Note.

         Maker shall have the right to prepay the principal of this Note in full
or in part at any time and from time to time without premium or penalty,
provided, however, that accrued interest shall be due and payable
contemporaneously with such prepayment of principal.

                                   ARTICLE II
                       AFFIRMATIVE AND NEGATIVE COVENANTS

         So long as any of the principal of and accrued interest of this Note is
outstanding, or until the Payee consents to the contrary and the Maker receives
prior written approval to the contrary from the Payee, Maker will comply, or
cause compliance, with each of the following covenants:

         1.       Use of Proceeds. Maker will only use the net proceeds from
this Note to fund expenditures for the Lemon Project, as approved by the Maker's
board of directors (which expenditures may include contributions by the Maker of
all or part of the net proceeds of this Note to one or more of the Maker's
subsidiaries).

         2.       Limitation on Liens and Encumbrances. Maker will not incur,
and will ensure that none of its direct or indirect subsidiaries (including,
without limitation, Grupo Industrial Santa Engracia, S.A. de C.V.) incur, any
lien on or otherwise pledge or encumber any of the assets constituting the Lemon
Project, unless Maker first perfects a first priority lien security interest in
favor of Payee covering the assets of Maker with a fair market value of at least
two times the outstanding principal amount of this Note and which pledged assets
are reasonably acceptable to Payee.

                                   ARTICLE III
                                EVENTS OF DEFAULT

         Any of the following shall constitute Events of Default ("Event(s) of
Default"):

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         1.       default in making due and punctual payment of the principal of
                  the Note, or any interest accrued thereon, or any other amount
                  hereon, when and as such payment shall become due and payable,
                  whether at maturity or by acceleration or otherwise if such
                  payment is not made within five (5) days of written notice
                  received by Maker specifying such default; or

         2.       the failure by Maker to comply with the covenants set forth in
                  Article II of this Note; or

         3.       the sale by Maker of all or substantially all of its assets;
                  or

         4.       Maker shall admit in writing its inability to, or be generally
                  unable to, pay its debts as such debts become due; or

         5.       Maker shall (i) apply for or consent in writing to the
                  appointment of, or taking possession by, a receiver,
                  custodian, trustee or liquidator of itself or of all or a
                  substantial part of its property, (ii) make a general
                  assignment for the benefit of its creditors, (iii) file a
                  petition seeking to take advantage of any law relating to
                  bankruptcy, insolvency, reorganization, winding-up, or
                  composition or adjustment of debts, (iv) fail to controvert in
                  a timely and appropriate manner, or acquiesce in writing to,
                  any petition filed against it in an involuntary case under any
                  law relating to bankruptcy, insolvency, reorganization,
                  winding-up, or composition or adjustment of debts, or (v) take
                  any action for the purpose of effecting any of the foregoing;
                  or

         6.       a proceeding or case shall be commenced, without the
                  application or consent of the Company, in any court of
                  competent jurisdiction, seeking (i) Maker's liquidation,
                  reorganization, dissolution, or winding-up, or the composition
                  or adjustment of its debts, (ii) the appointment of a trustee,
                  receiver, custodian, liquidator or the like of Maker or all or
                  any substantial part of its assets, or (iii) similar relief in
                  respect of Maker under any law relating to bankruptcy,
                  insolvency, reorganization, winding-up or composition or
                  adjustment of debts, and such proceeding or case shall
                  continue undismissed, or an order, judgment or decree
                  approving or ordering any of the foregoing shall be entered
                  and continued unstayed and in effect for a period of sixty
                  (60) days; or an order for relief against Maker shall be
                  entered in an involuntary case under any law relating to
                  bankruptcy, insolvency, reorganization, winding-up, or
                  composition or adjustment of debts.

         If an Event of Default occurs under paragraphs 1, 2 or 3 above, then
and in any such case Payee may declare the outstanding principal amount of the
Note to be due and payable immediately, upon written notice to Maker and, upon
any such declaration, the outstanding principal amount of the Note, and the
interest accrued thereon, together with all costs of collection, including
reasonable attorneys' fees if collected by law or through an attorney at law (as
further set forth in Section IV(4) hereof), shall immediately become due and
payable. If an Event of Default occurs under paragraphs 4, 5 or 6 above, then
the outstanding principal of and all accrued and unpaid interest on this Note
shall automatically become immediately due and payable, without presentment,
demand, protest or other formalities or notice of any kind, all of which are
hereby expressly waived by Maker.

                                   ARTICLE IV
                                     GENERAL

         1.       Notices. Any notice or demand given hereunder by the holder
                  hereof must be in writing to be effective and shall be deemed
                  to have been given and received (a) when actually delivered to
                  the address of the party to be notified if delivered in
                  person, or (b) if mailed, on the earlier of the date actually
                  delivered to the address of the party to be notified or
                  (whether ever so delivered or not) on the third Business Day
                  (hereinafter defined) after it is enclosed in an envelope,
                  addressed to the party to be notified, properly stamped,

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                  sealed, and deposited in the United States mail, certified
                  mail, return receipt requested. As used herein, "Business Day"
                  means every day other than a Saturday, Sunday, or legal
                  holiday in Dallas, Texas or New York, New York.

         2.       Renounciation. Maker hereby renounces to any presentation of
                  this Note and to any notice or refusal, protest or notice of
                  protest and to delay of grace.

         3.       Waiver. This Note evidences the payment obligations of Maker
                  to Payee. No failure on the part of Payee to exercise and no
                  delay in exercising, and no course of dealing with respect to,
                  any right, power, privilege or remedy under this Note shall
                  operate as a waiver thereof, nor shall any single or partial
                  exercise of any right, power, privilege or remedy under this
                  Note preclude any other or further exercise thereof or the
                  exercise of any other right, power, privilege or remedy. The
                  remedies provided herein are cumulative and not exclusive of
                  any remedies provided by law.

         4.       Expenses. Maker agrees to pay or reimburse Payee for (a) all
                  reasonable out-of-pocket costs and expenses of Payee
                  (including, without limitation, the reasonable fees and
                  expenses of counsel to Payee), in connection with any
                  amendment, supplement, modification or waiver of any of the
                  terms of this Note and (b) all reasonable costs and expenses
                  of Payee (including the reasonable fees and expenses of
                  counsel) in connection with any default or Event of Default
                  and any enforcement or collection proceedings resulting
                  therefrom. The obligations of Maker under this Section (IV)(4)
                  shall survive the repayment of the principal amount of this
                  Note.

         5.       Amendments. This Note may amended or modified only by an
                  instrument in writing duly executed by Maker and Payee. Any
                  amendment or modification effected in accordance with this
                  Section IV(5) shall be binding upon Maker and Payee.

         6.       Successors and Assigns. This Note shall be binding upon, and
                  inure to the benefit of, Maker and Payee and their respective
                  successors and permitted assigns. Maker may not assign its
                  rights or obligations under this Note without the prior
                  written consent of the Payee. Payee may assign or transfer
                  this Note or any rights or obligations hereunder without the
                  prior written consent of Maker.

         7.       Headings. The section headings appearing herein are included
                  solely for convenience of reference and are not intended to
                  affect the interpretation of any provision of this Note.

         8.       Severability. If one or more provisions of this Note are held
                  to be unenforceable under applicable law, such provision(s)
                  shall be excluded from this Note and the balance of this Note
                  shall be interpreted as if such provision(s) were so excluded
                  and shall otherwise be enforceable in accordance with its
                  terms.

         9.       Usury. Maker covenants (to the extent that it may lawfully do
                  so) that it will not at any time insist upon, plead, or in any
                  manner whatsoever claim or take the benefit or advantage of,
                  any stay or extension law or any usury law or other law that
                  would prohibit or forgive Maker from paying all or any portion
                  of the principal of or interest on the Notes, wherever
                  enacted, now or at any time hereafter in force, or which may
                  affect the covenants or the performance of this Note.

         10.      Governing Law; Consent to Jurisdiction; Waiver of Jury Trial..
                  This Agreement shall be governed by and construed in
                  accordance with the laws of the State of Delaware applicable
                  to contracts to be performed in such state. THE PARTIES HERETO
                  AGREE THAT VENUE IN ANY AND ALL ACTIONS AND PROCEEDINGS
                  RELATED TO THE SUBJECT MATTER OF THIS AGREEMENT SHALL BE IN
                  THE STATE AND FEDERAL COURTS IN AND FOR WILMINGTON COUNTY,
                  DELAWARE,

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                  WHICH COURTS SHALL HAVE EXCLUSIVE JURISDICTION FOR SUCH
                  PURPOSE, AND THE PARTIES HERETO IRREVOCABLY SUBMIT TO THE
                  EXCLUSIVE JURISDICTION OF SUCH COURTS AND IRREVOCABLY WAIVE
                  THE DEFENSE OF AN INCONVENIENT FORUM TO THE MAINTENANCE OF ANY
                  SUCH ACTION OR PROCEEDING. SERVICE OF PROCESS MAY BE MADE IN
                  ANY MANNER RECOGNIZED BY SUCH COURTS. EACH OF THE PARTIES
                  HERETO IRREVOCABLY WAIVES ITS RIGHT TO A JURY TRIAL WITH
                  RESPECT TO ANY ACTION OR CLAIM ARISING OUT OF ANY DISPUTE IN
                  CONNECTION WITH THIS AGREEMENT OR THE TRANSACTIONS
                  CONTEMPLATED HEREBY.

         IN WITNESS WHEREOF, the undersigned have executed this Note as of the
date first above written.

MAKER:

THE UNIMARK GROUP, INC.

By: /s/ David E. Ziegler
    -----------------------
    David E. Ziegler
    Chief financial Officer