REVOLVING NOTE
                           (eMERGE INTERACTIVE, INC.)


$3,000,000                                                   Wayne, Pennsylvania
                                                                   July 21, 1999

      FOR VALUE RECEIVED, eMerge Interactive, Inc., a Delaware corporation (the
"Borrower"), having an office at 10315 102nd Terrace, Sebastian, Florida 32958,
hereby promises to pay to the order of Safeguard Delaware, Inc., a Delaware
corporation (the "Lender"), at the Lender's office located at 103 Springer
Building, 3411 Silverside Road, Wilmington, Delaware 19810 or at such other
place in the continental United States as the Lender may designate in writing,
upon demand, in lawful money of the United States, and in immediately available
funds, the principal sum of up to THREE MILLION DOLLARS ($3,000,000), or so much
thereof as shall have been advanced by the Lender to the Borrower as hereinafter
set forth and then be outstanding, and to pay interest thereon monthly in
arrears on the first business day of each calendar month at an annual rate equal
to the announced prime rate of PNC Bank, N.A. (the "Prime Rate") plus one
percent (1%). All amounts advanced hereon, but not to exceed $3,000,000 at any
one time outstanding in the aggregate, shall be so advanced upon the request of
the Borrower. All amounts so advanced hereon and all payments made on account of
the principal hereof shall be recorded in the books of the Lender, which records
shall be final and binding, but failure to do so shall not release the Borrower
from any of its obligations hereunder.

      All payments made on this Note (including, without limitation,
prepayments) shall be applied, at the option of the Lender, first to late
charges and collection costs, if any, then to accrued interest and then to
principal. Interest payable hereunder shall be calculated for actual days
elapsed on the basis of a 360-day year. Accrued and unpaid interest shall be due
and payable upon maturity of this Note. After maturity or in the event of
default, interest shall continue to accrue on the Note at the rate set forth
above and shall be payable on demand of the Lender.

      The outstanding principal amount of this Note may be prepaid by the
Borrower upon notice to the Lender in whole at any time or in part from time to
time without any prepayment penalty or premium; provided, that upon such payment
any interest due to the date of such prepayment on such prepaid amount shall
also be paid.

      Notwithstanding anything in this Note, the interest rate charged hereon
shall not exceed the maximum rate allowable by applicable law. If any stated
interest rate herein exceeds the maximum allowable rate, then the interest rate
shall be reduced to the maximum allowable rate, and any excess payment of
interest made by the Borrower at any time shall be applied to the unpaid balance
of any outstanding principal of this Note.

      An event of default hereunder shall consist of:


                                    1
<PAGE>   2
      (i) a default in the payment by the Borrower to the Lender of principal or
interest under this Note as and when the same shall become due and payable;

      (ii) an event of default by the Borrower under any other obligation,
instrument, note or agreement for borrowed money, beyond any applicable notice
and/or grace period;

      (iii) institution of any proceeding by or against the Borrower under any
present or future bankruptcy or insolvency statute or similar law and, if
involuntary, if the same are not stayed or dismissed within sixty (60) days, or
the Borrower's assignment for the benefit of creditors or the appointment of a
receiver, trustee, conservator or other judicial representative for the Borrower
or the Borrower's property or the Borrower's being adjudicated a bankrupt or
insolvent.

Upon the occurrence of any event of default, interest shall accrue on the
outstanding balance of this Note at the Prime Rate plus three percent (3%), the
entire unpaid principal amount of this Note and all unpaid interest accrued
thereon shall, at the sole option of the Lender, without notice, become
immediately due and payable, and the Lender shall thereupon have all the rights
and remedies provided hereunder or now or hereafter available or now or
hereafter available at law or in equity.

      Any action, suit or proceeding where the amount in controversy as to at
least one party, exclusive of interest and costs, exceeds $100,000 ("Summary
Proceeding"), arising out of or relating to this Agreement, or the breach,
termination or validity thereof, shall be litigated exclusively in the Superior
Court of the State of Delaware (the "Delaware Superior Court") as a summary
proceeding pursuant to Rules 124-131 of the Delaware Superior Court, or any
successor rules (the "Summary Proceeding Rules"). Each of the parties hereto
hereby irrevocably and unconditionally (i) submits to the jurisdiction of the
Delaware Superior Court for any Summary Proceeding, (ii) agrees not to commence
any Summary Proceeding except in the Delaware Superior Court, (iii) waives, and
agrees not to plead or to make, any objection to the venue of any Summary
Proceeding in the Delaware Superior Court, (iv) waives, and agrees not to plead
or to make, any claim that any Summary Proceeding brought in the Delaware
Superior Court has been brought in an improper or otherwise inconvenient forum,
(v) waives, and agrees not to plead or to make, any claim that the Delaware
Superior Court lacks personal jurisdiction over it, (vi) waives its right to
remove any Summary Proceeding to the federal courts except where such courts are
vested with sole and exclusive jurisdiction by statute and (vii) understands and
agrees that it shall not seek a jury trial or punitive damages in any Summary
Proceeding based upon or arising out of our otherwise related to this Agreement
waives any and all rights to any such jury trial or to seek punitive damages.

      In the event any action, suit or proceeding where the amount in
controversy as to at least one party, exclusive of interest and costs, does not
exceed $100,000 (a "Proceeding"), arising out of or relating to this Agreement
or the breach, termination or validity thereof is brought, the parties to such
Proceeding agree to make application to the Delaware Superior Court to proceed
under the Summary Proceeding Rules. Until such


                                    2
<PAGE>   3
time as such application is rejected, such Proceeding shall be treated as a
Summary Proceeding and all of the foregoing provisions of this Section relating
to Summary Proceedings shall apply to such Proceeding.

      If a Summary Proceeding is not available to resolve any dispute hereunder,
the controversy or claim shall be settled by arbitration conducted on a
confidential basis, under the U.S. Arbitration Act, if applicable, and the then
current Commercial Arbitration Rules of the American Arbitration Association
(the "Association") strictly in accordance with the terms of this Agreement and
the substantive law of the State of Delaware. The arbitration shall be conducted
at the Association's regional office located closest to the Lender's principal
place of business by three arbitrators, at least one of whom shall be
knowledgeable in general business matters and one of whom shall be an attorney.
Judgment upon the arbitrators' award may be entered and enforced in any court of
competent jurisdiction. Neither party shall institute a proceeding hereunder
unless at least 60 days prior thereto such party shall have given written notice
to the other party of its intent to do so.

      Neither party shall be precluded hereby from securing equitable remedies
in courts of any jurisdiction, including, but not limited to, temporary
restraining orders and preliminary injunctions to protect its rights and
interests but such remedies shall not be sought as a means to avoid or stay
arbitration or a Summary Proceeding.

      The Borrower hereby waives presentment, demand, protest and notice of
dishonor and protest, and also waives all other exemptions; and agrees that
extension or extensions of the time of payment of this Note or any installment
or part thereof may be made before, at or after maturity by agreement by the
Lender. Upon default hereunder, the Lender shall have the right to offset the
amount owed by the Borrower against any amounts owed by the Lender in any
capacity to the Borrower, whether or not due, and the Lender shall be deemed to
have exercised such right of offset and to have made a charge against any such
account or amounts immediately upon the occurrence of an event of default
hereunder even though such charge is made or entered on the books of the Lender
subsequent thereto. The Borrower shall pay to the Lender, upon demand, all costs
and expenses, including, without limitation, attorneys' fees and legal expenses,
that may be incurred by the Lender in connection with the enforcement of this
Note.

      Notices required to be given hereunder shall be deemed validly given (I)
three business days after sent, postage prepaid, by certified mail, return
receipt requested, (ii) one business day after sent, charges paid by the sender,
by next day delivery or other guaranteed delivery service, (iii) when sent by
facsimile transmission, or (iv) when delivered by hand:

      If to the Lender:       Safeguard Delaware, Inc.
                              800 The Safeguard Building
                              435 Devon Park Drive
                              Wayne, PA  19087
                              Attn: Chief Financial Officer


                                    3
<PAGE>   4
      If to the Borrower:     eMerge Interactive, Inc.
                              10315 102nd Terrace
                              Sebastian, FL 32858
                              Attn:  Michael Janney, Chief Financial Officer

or to such other address, or in care of such other person, as the holder or the
Borrower shall hereafter specify to the other from time to time by due notice.

      Any failure by the Lender to exercise any right hereunder shall not be
construed as a waiver of the right to exercise the same or any other right at
any time. No amendment to or modification of this Note shall be binding upon the
Lender unless in writing and signed by it. Any provision hereof found to be
illegal, invalid or unenforceable for any reason whatsoever shall not affect the
validity, legality or enforceability of the remainder hereof. This Note shall
apply to and bind the successors of the Borrower and shall inure to the benefit
of the Lender, its successors and assigns.

      This Note shall be governed by and interpreted in accordance with the laws
of the State of Delaware.

      IN WITNESS WHEREOF, the Borrower, by its duly authorized officer intending
to be legally bound hereby, has duly executed this Revolving Note as of the date
first written above.

                                    EMerge Interactive, Inc.


                                    By: /s/: Michael Janney
                                        -------------------
                                        Michael Janney, Chief Financial Officer


                                    4
<PAGE>   5
                                                                EXHIBIT 10.21(b)


                             AMENDED REVOLVING NOTE
                           (eMERGE INTERACTIVE, INC.)


$3,000,000                                                  Wayne, Pennsylvania
                                                                 August 3, 1999

      WHEREAS, Safeguard Delaware, Inc. (the "Lender") was the holder of a
$3,000,000 Revolving Note dated July 21, 1999 (the $3,000,000 Note") made by
eMerge Interactive, Inc. (the "Borrower"); and

      WHEREAS, Borrower and Lender desire to amend the terms of the
$3,000,000 Note to provide for a 60 day term;

      NOW, THEREFORE, for valuable consideration, receipt of which is hereby
acknowledged Borrower and lender hereby agree as follows:

      FOR VALUE RECEIVED, eMerge Interactive, Inc., a Delaware corporation (the
"Borrower"), having an office at 10315 102nd Terrace, Sebastian, Florida 32958,
hereby promises to pay to the order of Safeguard Delaware, Inc., a Delaware
corporation (the "Lender"), at the Lender's office located at 103 Springer
Building, 3411 Silverside Road, Wilmington, Delaware 19810 or at such other
place in the continental United States as the Lender may designate in writing,
upon demand, in lawful money of the United States, and in immediately available
funds, the principal sum of up to THREE MILLION DOLLARS ($3,000,000), or so much
thereof as shall have been advanced by the Lender to the Borrower as hereinafter
set forth and then be outstanding, and to pay interest thereon monthly in
arrears on the first business day of each calendar month at an annual rate equal
to the announced prime rate of PNC Bank, N.A. (the "Prime Rate") plus one
percent (1%). All amounts advanced hereon, but not to exceed $3,000,000 at any
one time outstanding in the aggregate, shall be so advanced upon the request of
the Borrower. All amounts so advanced hereon and all payments made on account of
the principal hereof shall be recorded in the books of the Lender, which records
shall be final and binding, but failure to do so shall not release the Borrower
from any of its obligations hereunder.

      All payments made on this Note (including, without limitation,
prepayments) shall be applied, at the option of the Lender, first to late
charges and collection costs, if any, then to accrued interest and then to
principal. Interest payable hereunder shall be calculated for actual days
elapsed on the basis of a 360-day year. Accrued and unpaid interest shall be due
and payable upon maturity of this Note. After maturity or in the event of
default, interest shall continue to accrue on the Note at the rate set forth
above and shall be payable on demand of the Lender.

      The outstanding principal amount of this Note may be prepaid by the
Borrower upon notice to the Lender in whole at any time or in part from time to
time without any


                                    5
<PAGE>   6
prepayment penalty or premium; provided, that upon such payment any interest due
to the date of such prepayment on such prepaid amount shall also be paid.

      Notwithstanding anything in this Note, the interest rate charged hereon
shall not exceed the maximum rate allowable by applicable law. If any stated
interest rate herein exceeds the maximum allowable rate, then the interest rate
shall be reduced to the maximum allowable rate, and any excess payment of
interest made by the Borrower at any time shall be applied to the unpaid balance
of any outstanding principal of this Note.

      An event of default hereunder shall consist of:


      a default in the payment by the Borrower to the Lender of principal or
interest under this Note as and when the same shall become due and payable;

      an event of default by the Borrower under any other obligation,
instrument, note or agreement for borrowed money, beyond any applicable notice
and/or grace period;

      institution of any proceeding by or against the Borrower under any present
or future bankruptcy or insolvency statute or similar law and, if involuntary,
if the same are not stayed or dismissed within sixty (60) days, or the
Borrower's assignment for the benefit of creditors or the appointment of a
receiver, trustee, conservator or other judicial representative for the Borrower
or the Borrower's property or the Borrower's being adjudicated a bankrupt or
insolvent.

Upon the occurrence of any event of default, interest shall accrue on the
outstanding balance of this Note at the Prime Rate plus three percent (3%), the
entire unpaid principal amount of this Note and all unpaid interest accrued
thereon shall, at the sole option of the Lender, without notice, become
immediately due and payable, and the Lender shall thereupon have all the rights
and remedies provided hereunder or now or hereafter available or now or
hereafter available at law or in equity.

      Any action, suit or proceeding where the amount in controversy as to at
least one party, exclusive of interest and costs, exceeds $100,000 ("Summary
Proceeding"), arising out of or relating to this Agreement, or the breach,
termination or validity thereof, shall be litigated exclusively in the Superior
Court of the State of Delaware (the "Delaware Superior Court") as a summary
proceeding pursuant to Rules 124-131 of the Delaware Superior Court, or any
successor rules (the "Summary Proceeding Rules"). Each of the parties hereto
hereby irrevocably and unconditionally (I) submits to the jurisdiction of the
Delaware Superior Court for any Summary Proceeding, (ii) agrees not to commence
any Summary Proceeding except in the Delaware Superior Court, (iii) waives, and
agrees not to plead or to make, any objection to the venue of any Summary
Proceeding in the Delaware Superior Court, (iv) waives, and agrees not to plead
or to make, any claim that the Delaware Superior Court has been brought in an
improper or otherwise inconvenient forum, (v) waives, and agrees not to plead or
to make, any claim that the Delaware Superior Court lacks personal jurisdiction
over it, (vi) waives its right to remove any


                                    6
<PAGE>   7
Summary Proceeding to the federal courts except where such courts are vested
with sole and exclusive jurisdiction by statute and (vii) understands and agrees
that it shall not seek a jury trial or punitive damages in any Summary
Proceeding based upon or arising out of our otherwise related to this Agreement
waives any and all rights to any such jury trial or to seek punitive damages.

      In the event any action, suit or proceeding where the amount in
controversy as to at least one party, exclusive of interest and costs, does not
exceed $100,000 (a "Proceeding"), arising out of or relating to this Agreement
or the breach, termination or validity thereof is brought, the parties to such
Proceeding agree to make application to the Delaware Superior Court to proceed
under the Summary Proceeding Rules. Until such time as such application is
rejected, such Proceeding shall be treated as a Summary Proceeding and all of
the foregoing provisions of this Section relating to Summary Proceedings shall
apply to such Proceeding.

      If a Summary Proceeding is not available to resolve any dispute hereunder,
the controversy or claim shall be settled by arbitration conducted on a
confidential basis, under the U.S. Arbitration Act, if applicable, and the then
current Commercial Arbitration Rules of the American Arbitration Association
(the "Association") strictly in accordance with the terms of this Agreement and
the substantive law of the State of Delaware. The arbitration shall be conducted
at the Association's regional office located closest to the Lender's principal
place of business by three arbitrators, at least one of whom shall be
knowledgeable in general business matters and one of whom shall be an attorney.
Judgment upon the arbitrators' award may be entered and enforced in any court of
competent jurisdiction. Neither party shall institute a proceeding hereunder
unless at least 60 days prior thereto such party shall have given written notice
to the other party of its intent to do so.

      Neither party shall be precluded hereby from securing equitable remedies
in courts of any jurisdiction, including, but not limited to, temporary
restraining orders and preliminary injunctions to protect its rights and
interests but such remedies shall not be sought as a means to avoid or stay
arbitration or a Summary Proceeding.

      The Borrower hereby waives presentment, demand, protest and notice of
dishonor and protest, and also waives all other exemptions; and agrees that
extension or extensions of the time of payment of this Note or any installment
or part thereof may be made before, at or after maturity by agreement by the
Lender. Upon default hereunder, the Lender shall have the right to offset the
amount owed by the Borrower against any amounts owed by the Lender in any
capacity to the Borrower, whether or not due, and the Lender shall be deemed to
have exercised such right of offset and to have made a charge against any such
account or amounts immediately upon the occurrence of an event of default
hereunder even though such charge is made or entered on the books of the Lender
subsequent thereto. The Borrower shall pay to the Lender, upon demand, all costs
and expenses, including, without limitation, attorneys' fees and legal expenses,
that may be incurred by the Lender in connection with the enforcement of this
Note.


                                    7
<PAGE>   8
      Notices required to be given hereunder shall be deemed validly given (I)
three business days after sent, postage prepaid, by certified mail, return
receipt requested, (ii) one business day after sent, charges paid by the sender,
by next day delivery or other guaranteed delivery service, (iii) when sent by
facsimile transmission, or (iv) when delivered by hand:

      If to the Lender:      Safeguard Delaware, Inc.
                             800 The Safeguard Building
                             435 Devon Park Drive
                             Wayne, PA 19087
                             Attn: Chief Financial Officer

      If to the Borrower:    eMerge Interactive, Inc.
                             10315 102nd Terrace
                             Sebastian, FL 32858
                             Attn:  Michael Janney, Chief Financial Officer

or to such other address, or in care of such other person, as the holder or the
Borrower shall hereafter specify to the other from time to time by due notice.

      Any failure by the Lender to exercise any right hereunder shall not be
construed as a waiver of the right to exercise the same or any other right at
any time. No amendment to or modification of this Note shall be binding upon the
Lender unless in writing and signed by it. Any provision hereof found to be
illegal, invalid or unenforceable for any reason whatsoever shall not affect the
validity, legality or enforceability of the remainder hereof. This Note shall
apply to and bind the successors of the Borrower and shall inure to the benefit
of the Lender, its successors and assigns.

      This Note shall be governed by and interpreted in accordance with the laws
of the State of Delaware.

      IN WITNESS WHEREOF, the Borrower, by its duly authorized officer intending
to be legally bound hereby, has duly executed this Revolving Note as of the date
first written above.

                                    EMerge Interactive, Inc.


                                    By: /s/: Michael Janney
                                        --------------------
                                        Michael Janney, Chief Financial Officer


                                    8

Source: OneCLE Business Contracts.