<PAGE>

                               SUBSCRIPTION AGREEMENT

                                 SEPTEMBER 10, 1998

     THESE SECURITIES HAVE NOT BEEN REGISTERED WITH THE UNITED STATES 
SECURITIES AND EXCHANGE COMMISSION UNDER THE U.S. SECURITIES ACT OF 1933, AS 
AMENDED (THE "ACT"), OR THE SECURITIES COMMISSION OF ANY STATE UNDER ANY 
STATE SECURITIES LAW. THEY ARE BEING OFFERED PURSUANT TO AN EXEMPTION FROM 
REGISTRATION UNDER REGULATION S ("REGULATION S") PROMULGATED UNDER THE ACT.  
THE SECURITIES MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED UNLESS THE 
SECURITIES ARE REGISTERED UNDER THE ACT AND APPLICABLE STATE SECURITIES LAWS, 
OR SUCH OFFERS, SALES AND TRANSFERS ARE MADE PURSUANT TO AVAILABLE EXEMPTIONS 
FROM THE REGISTRATION REQUIREMENTS OF THOSE LAWS. INVESTORS IN THE SECURITIES 
MAY NOT ENGAGE IN HEDGING TRANSACTIONS WITH REGARD TO SUCH SECURITIES UNLESS 
IN COMPLIANCE WITH THE ACT.

     THIS SUBSCRIPTION AGREEMENT DOES NOT CONSTITUTE AN OFFER TO SELL, OR A 
SOLICITATION OF AN OFFER TO BUY, ANY OF THE SECURITIES OFFERED HEREBY BY OR 
TO ANY PERSON IN ANY JURISDICTION IN WHICH SUCH OFFER OR SOLICITATION WOULD 
BE UNLAWFUL. INVESTMENT IN THE SECURITIES INVOLVES A HIGH DEGREE OF RISK.  IN 
MAKING AN INVESTMENT DECISION, INVESTORS MUST RELY ON THEIR OWN EXAMINATION 
OF THE COMPANY AND THE TERMS OF THE OFFERING, INCLUDING THE MERITS AND THE 
RISKS INVOLVED.  THESE SECURITIES HAVE NOT BEEN RECOMMENDED BY ANY FEDERAL OR 
STATE SECURITIES COMMISSION OR REGULATORY AUTHORITY.  FURTHERMORE, THE 
FOREGOING AUTHORITIES HAVE NOT CONFIRMED OR DETERMINED THE ACCURACY OR 
ADEQUACY OF THIS DOCUMENT.  ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL 
OFFENSE.

     INVESTORS IN THE UNITS OFFERED BY THIS SUBSCRIPTION AGREEMENT SHOULD 
CONSIDER THE INVESTMENT TO BE SPECULATIVE AND TO INVOLVE A HIGH DEGREE OF 
RISK.  ONLY PERSONS WHO CAN ABSORB THE POTENTIAL LOSS OF THEIR ENTIRE 
INVESTMENT SHOULD PARTICIPATE.   ACCORDINGLY, PROSPECTIVE INVESTORS SHOULD 
CAREFULLY CONSIDER ALL INFORMATION WITHIN THIS SUBSCRIPTION AGREEMENT AND 
OBTAINED FROM THE COMPANY THAT CONCERNS THE COMPANY AND ITS BUSINESS AS WELL 
AS THE INFORMATION CONTAINED IN THE CONFIDENTIAL OFFERING MEMORANDUM OF THE 
COMPANY DATED SEPTEMBER 9, 1998, INCLUDING BUT NOT LIMITED TO, THE RISK 
FACTORS CONTAINED THEREIN.

     The RiceX Company, a Delaware corporation ("RiceX" or the "Company"), 
hereby offers and Heldomo, A.G., a Swiss corporation (the "Subscriber"), 
agrees to purchase, 15 Units (the "Units") at a purchase price of $100,000 
per Unit for an aggregate consideration of One Million Five Hundred Thousand 
Dollars ($1,500,000) (the "Offering").  Each Unit shall consist of 66,666.7 
shares of the Company's Common Stock


<PAGE>

and Warrants to purchase up to 66,666.7 shares of Common Stock (for clarity, 
the 15 Units therefore comprising in total 1,000,000 shares of the Company's 
Common Stock and Warrants to purchase up to 1,000,000 shares of the Company's 
Common Stock.)  The Warrants will expire two (2) years from the date of 
issuance.  For the first year following the closing of the Offering, the 
Warrants may be exercised at $1.50 per share of Common Stock.  Thereafter, 
the exercise price shall be $1.8125 per share of Common Stock.  The holder of 
the Warrants shall be entitled to certain anti-dilution rights as contained 
in the Warrants. The Warrants shall be in substantially the same form as 
contained in Exhibit A.  This Subscription Agreement (the "Agreement" or the 
"Subscription Agreement") is executed by the Subscriber in connection with 
the Offering.  The Offering is being conducted pursuant to Regulation S 
promulgated under the Act.  A portion of the purchase price for the Units may 
be used to pay commissions or finder's fees in connection with this Offering. 
It is agreed as follows:

                               TERMS OF THE OFFERING

1.   Offer to Subscribe; Purchase Price.

     The Subscriber hereby offers to purchase and subscribe 15 Units at the 
purchase price of $100,000 per Unit.  The Closing shall be deemed to occur 
when both the Subscriber and the Company execute this Agreement (the 
"Closing"). Payment shall be made by delivering the purchase price by 
certified check, bank draft or bank transfer in same day funds, in United 
States Dollars, along with this Agreement and all other documents referenced 
herein, to Graham & James LLP (the "Trustee"), in trust for the Company, or 
in such other manner as may be specified by the Trustee (the "Purchase 
Price").  The Trustee is hereby irrevocably authorized to deliver the 
Purchase Price pursuant to Section 1.1.

     1.1  The Subscriber acknowledges and agrees that the Purchase Price 
delivered in connection herewith will be held by the Trustee until such time 
as the condition precedents contained in Section 5.1 are satisfied.

     1.2  Upon the satisfaction of such conditions, the Trustee will, and the 
Subscriber hereby irrevocably authorizes the Trustee to, at the Closing, 
deliver the Purchase Price, and any documents delivered to the Trustee in 
connection herewith, to the Company against delivery by the Company of 
evidence that certificates representing the Common Stock and Warrants as 
contemplated herein are prepared and ready to be delivered by the Company to 
the Subscriber.  In the event that this Subscription Agreement is not 
accepted by the Company or the conditions referred to above are not satisfied 
by the Company within 30 days of the execution of this Agreement by the 
Subscriber, this Subscription Agreement, the Purchase Price and any other 
documents delivered in connection herewith will be returned to the Subscriber 
at the address of the Subscriber set forth on the signature page of this 
Subscription Agreement.


                                          2 
<PAGE>

2.   Delivery.

     As soon as practicable after the Closing with respect to the Units, the 
Company will deliver to the Subscriber certificates representing the Common 
Stock and Warrants comprising the Units which certificates shall be issued in 
the Subscriber's name as set forth on the signature page of this Agreement.

3.  Representations and Warranties of the Company. The Company hereby 
represents and warrants to the Subscriber that:

     3.1  ORGANIZATION AND STANDING.  The Company is a corporation duly 
organized and existing under the laws of the State of Delaware and is in good 
standing under such laws.  The Company has the requisite corporate power to 
own and operate its properties and assets, and to carry on its business as 
presently conducted and as proposed to be conducted as provided in the 
Company's Business Plan dated July 15, 1998, and the Confidential Offering 
Memorandum dated September 9, 1998, copies of which have been provided to the 
Subscriber.

     3.2  CORPORATE POWER.  The Company has all requisite corporate power to 
enter into this Agreement, to sell the Units as provided herein and to carry 
out and perform its obligations under the terms of this Agreement.

     3.3  AUTHORIZATION.  All corporate action on the part of the Company, 
its officers, directors and shareholders necessary for the sale and issuance 
of the Units pursuant hereto and the performance of the Company's obligations 
hereunder has been taken.  This Agreement, when executed and delivered by the 
Company, shall constitute a valid and binding obligation of the Company, 
enforceable in accordance with its terms, except as enforcement may be 
limited by applicable bankruptcy laws or other similar laws affecting 
creditors' rights generally, and except insofar as the indemnification 
provisions of Section 6.5 and the availability of equitable remedies may be 
limited by applicable law. The Common Stock and Warrants comprising the 
Units, when issued in compliance with the provisions of this Agreement, will 
be validly issued, fully paid and non-assessable.

4.   Representations and Warranties of the Subscriber; Access to Information; 
Independent Information; Independent Investigation.

     Except as otherwise agreed in writing and acknowledged by the Company, 
the Subscriber represents and warrants to and covenants with the Company, on 
its own behalf and on behalf of each person or entity for which the 
Subscriber is acting as a fiduciary, as follows:

     4.1  AUTHORITY.  The Subscriber has now, and will have at the Closing, 
all requisite legal or other power to enter into this Agreement, to purchase 
the Units hereunder and to perform its obligations under the terms of this 
Agreement.

     4.2  AUTHORIZATION.  All action on the part of the Subscriber necessary 
for the purchase of the Units and the performance of the Subscriber's 
obligations hereunder, has been taken or will be taken prior to the Closing.  
This Agreement, when executed and


                                          3 
<PAGE>

delivered by the Subscriber, will constitute a valid and legally binding 
obligation of the Subscriber, enforceable in accordance with its terms.

     4.3  INVESTMENT REPRESENTATIONS.  This Agreement is made with the 
Subscriber in reliance on the following specific representations to the 
Company that:

          (a)  The Units purchased hereunder will be acquired for the 
Subscriber's own account and not with a view to the distribution of any part 
thereof, and the Subscriber has no present intention of selling, granting 
participation in, or otherwise distributing the same.  If other than an 
individual, the Subscriber has not been organized for the purpose of 
investing in securities of the Company, although such investment is 
consistent with its purposes.

          (b)  The Subscriber understands that the purchase of the Units 
represents a speculative investment, and the Subscriber is able, without 
impairing its  financial condition, to hold the Units for an indefinite 
period of time and to suffer a complete loss of the Subscriber's investment.  
The Subscriber is aware of and has investigated the Company's business, 
management and financial condition, has had the opportunity to inspect the 
Company's facilities and has had access to such other information about the 
Company as the Subscriber has deemed necessary or desirable to reach an 
informed and knowledgeable decision to acquire the Units.

          (c)  The Subscriber understands, except as set forth in Section 6, 
that the Units will not be registered under the Act by reason of, among other 
things, reliance upon certain exemptions therefrom, and that the reliance of 
the Company on such exemptions is predicated upon, among other things, the 
bona fide nature of the Subscriber's investment intent as expressed herein.

          (d)  The Subscriber is experienced in evaluating and investing in 
securities of companies in the development stage and has made investments in 
securities other than those of the Company.  The Subscriber acknowledges that 
by reason of its business or financial experience, it has the ability to bear 
the economic risk of its investment pursuant to this Agreement.

          (e)  Although Impact Capital Partners Limited and West Sussex 
Trading, Inc. (the "Advisors") may have introduced the Subscriber to the 
Company, the Subscriber and the Company acknowledge and agree with the 
Advisors (such acknowledgments and agreements to survive the Closing), that:

               (i)   the Advisors and their directors, officers, employees, 
          agents and representatives have no responsibility or liability of 
          any nature whatsoever for the accuracy or adequacy of the 
          information contained in this Agreement, the Company's Business 
          Plan dated July 15, 1998 or the Confidential Offering Memorandum 
          dated September 9, 1998 or as to whether all information concerning 
          the Company required to be disclosed by it has generally been 
          disclosed;


                                          4 
<PAGE>

               (ii)  the Advisors are entitled to rely upon the undertakings 
          of the Subscriber contained in this Agreement and that the 
          Subscriber will hold harmless the Advisors from any loss or damage 
          they may suffer as a result of the Subscriber's failure to comply 
          with such undertakings;

               (iii) the Subscriber and the Company hereby release the 
          Advisors from any and all claims that may arise in respect of this 
          Agreement.

     4.4  RULE 144. The Subscriber understands that the Units, the Warrants, 
and the Common Stock, are restricted securities within the meaning of Rule 
144 under the Act; that such securities are not registered and must be held 
indefinitely unless they are subsequently registered or an exemption from 
such registration is available; that, in any event, the exemption from 
registration under Rule 144 will not be available for at least one year, and 
even then will not be available unless: (i) a public trading market then 
exists for the Units, the Warrants and the Common Stock; (ii) adequate 
information concerning the Company is then available to the public; and (iii) 
other terms and conditions of Rule 144 are complied with, including, among 
other things, the sale being made through a broker in an unsolicited 
"broker's transaction" or in transactions directly with a "market maker" and 
the number of shares being sold in any three-month period shall not exceed 
specified limitations; and that any sale of such securities may be made by 
the Subscriber only in limited amounts in accordance with such terms and 
conditions if the Subscriber is an affiliate of the Company or has held such 
securities less than two years.

     4.5  CONFIDENTIALITY; INDEPENDENT INVESTIGATION; ACCREDITED INVESTOR.  
The Subscriber will keep confidential, in accordance with the Nondisclosure 
Agreement executed by the Subscriber, all non-public information regarding 
the Company that the Subscriber receives from the Company unless disclosure 
of such information is compelled by a court or other administrative body.  
The Subscriber has had a reasonable opportunity to ask questions of and 
receive answers from the Company concerning the Company and the Offering, and 
all such questions, if any, have been answered to the full satisfaction of 
the undersigned.  In making its investment decision to purchase Units, the 
Subscriber is not relying on any oral or written representations or 
assurances from the Company or any other person other than as set forth in 
this Agreement or in a document executed by a duly authorized representative 
of the Company making reference to this Agreement.  The Subscriber has such 
experience in business and financial matters that it is capable of evaluating 
the risk of its investment and determining the suitability of its investment. 
The Subscriber is an accredited investor as defined in Rule 501 of 
Regulation D and by reason of the Subscriber's business or financial 
experience or the business or financial experience of the Subscriber's 
professional advisors, has the capacity to protect its own interest in 
connection with this Offering.

     4.6  ECONOMIC RISK.  The Subscriber understands and acknowledges that an 
investment in the Units involves a high degree of risk, including a possible 
total loss of investment.  The Subscriber represents that the Subscriber is 
able to bear the economic risk of an investment in the Units.  In making this 
statement, the Subscriber hereby


                                          5 
<PAGE>

represents and warrants that the Subscriber has adequate means of providing 
for the Subscriber's current needs and contingencies and the Subscriber is 
able to afford to hold the Units for an indefinite period.

     4.7  NO GOVERNMENT RECOMMENDATION OR APPROVAL.  The Subscriber 
understands that no United States federal or state agency or similar agency 
of any other country has passed upon or made any recommendation or 
endorsement of the Company, this transaction or the subscription of the Units.

     4.8  RELIANCE ON REPRESENTATION.  This Agreement is made by the Company 
with the Subscriber in reliance upon the Subscriber's representations and 
covenants made in this Section 4.

     4.9  NO REGISTRATION.  The Subscriber understands that the Units have 
not been registered under the Act and are being offered and sold pursuant to 
an exemption from registration contained in the Act, which is based, in part, 
upon the representations of the Subscriber contained herein.

     4.10 NO PUBLIC SOLICITATION.  Without conducting any independent 
investigation, the Subscriber knows of no public solicitation or 
advertisement of an offer in connection with the proposed sale of the Units.

     4.11 INVESTMENT INTENT. The Subscriber represents and warrants to the 
Company that the Subscriber has no present plan or intention of selling the 
Units, has made no predetermined arrangements to sell the Units and that the 
Offering, together with any subsequent resale of the Units, is not part of a 
plan or scheme to evade the registration provisions of the Act.  The 
Subscriber currently has no short position in the Units, including any short 
call position or any long put position or any contract or arrangement that 
has the effect of eliminating or substantially diminishing the risk of 
ownership of the Units, nor has the Subscriber engaged in any hedging 
transaction with respect to the Units.

     4.12 NO SALE IN VIOLATION OF THE ACT.  The Subscriber further covenants 
that the Subscriber will not make any sale, transfer or other disposition of 
the Units in violation of the Act (including Regulation S), the Securities 
Exchange Act of 1934, as amended (the "Exchange Act"), or the rules and 
regulations of the Securities and Exchange Commission (the "Commission") 
promulgated thereunder.

     4.13 NO RELIANCE ON TAX ADVICE.  The Subscriber has reviewed with its 
own tax advisors the foreign, federal, state and local tax consequences of 
this investment, where applicable, and the transactions contemplated by this 
Agreement.  The Subscriber is relying solely on such advisors and not on any 
statements or representations of the Company or any of its agents and 
understands that the Subscriber (and not the Company) shall be responsible 
for the Subscriber's own tax liability that may arise as a result of this 
investment or the transactions contemplated by this Agreement.

     4.14 INDEPENDENT LEGAL ADVICE.  The Subscriber acknowledges that the 
Subscriber has had the opportunity to review this Agreement and the 
transactions


                                          6 
<PAGE>

contemplated by this Agreement with its own legal counsel.  The Subscriber is 
relying solely on such counsel and not on any statements or representations 
of the Company or any of its agents for legal advice with respect to this 
investment or the transactions contemplated by this Agreement.

     4.15 NOT AN AFFILIATE.  The Subscriber is not an officer, director or 
"Affiliate" (as the term is defined in Rule 405 and Rule 501(b) of the Act) 
of the Company.

     4.16 INVESTMENT RISK.  The Subscriber recognizes that an investment in 
the Units involves a high degree of risk, including those set forth in the 
Confidential Offering Memorandum under the caption 'Risk Factors."

     4.17 FOREIGN REPRESENTATIONS.  The Subscriber represents and warrants to 
and covenants with the Company, on its own behalf and on behalf of each 
person or entity for which the Subscriber is acting as a fiduciary, as 
follows:

          (a)  OFFSHORE TRANSACTION.  The Subscriber represents and warrants 
to the Company that (i) neither the Subscriber nor any of the investors on 
whose behalf the Subscriber may purchase and hold Units is a "U.S. person" as 
that term is defined in Rule 902 (o) of Regulation S and the Subscriber is 
not an entity organized or incorporated under the laws of any foreign 
jurisdiction by any "U.S. person" principally for the purpose of investing in 
securities not registered under the Act, unless the Subscriber is or was 
organized or incorporated by  "U.S persons" who are accredited investors (as 
defined in Rule 501(a) under the Act) and who are not natural persons, 
estates or trusts ("Institutional Investors"), and all owners of interests in 
such equity who are "U.S. persons" are Institutional Investors, and not 
natural persons, estates or trusts; (ii) the Units were not offered to the 
Subscriber in the United States and at the time of execution of this 
Agreement and of any offer to the Subscriber to purchase the Units hereunder, 
the Subscriber was physically outside the United States; (iii) the Subscriber 
is purchasing the Units for its own account and not on behalf of or for the 
benefit of any U.S. person and the sale and resale of the Units have not been 
prearranged with any buyer in the United States; (iv) the Subscriber hereby 
agrees that all offers and sales of the Units shall not be made except in 
accordance with Regulation S, pursuant to registration under the Act, or 
pursuant to an available exemption from registration, and hedging 
transactions involving the Units may not be conducted unless in compliance 
with the Act.  The Subscriber has not been engaged by or acted as or on 
behalf of a distributor or dealer (and is not an affiliate of a distributor 
or dealer) with respect to this transaction.

          (b)  NO DIRECTED SELLING EFFORTS IN REGARD TO THIS TRANSACTION.  
The Subscriber represents and warrants that the Company has not conducted any 
"directed selling efforts" as that term is defined in Rule 902 of Regulation 
S.

5.   Conditions to Closing.

     5.1  CONDITIONS TO THE SUBSCRIBER'S OBLIGATIONS.  The obligation of the 
Subscriber to purchase the Units is subject to the fulfillment on or prior to 
the Closing of the following conditions:


                                          7 
<PAGE>

          (a)  REPRESENTATIONS AND WARRANTIES CORRECT; PERFORMANCE OF 
OBLIGATIONS.  The representations and warranties made by the Company in 
Section 3 hereof shall be true and correct on the Closing.

          (b)  QUALIFICATIONS.  All authorizations, approvals or permits of 
any governmental authority that are required in connection with the lawful 
issuance and sale of the Units under this Agreement shall have been duly 
obtained and effective, or will be obtained or made in a timely manner so as 
to comply with the requirements of such governmental authority.

          (c)  EXECUTION AND DELIVERY.  The Company shall have executed and 
delivered the Agreement or such execution and delivery shall have been waived.

          (d)  RESCISSION OF LOAN AGREEMENT.  The Subscriber shall have 
received a true and correct copy of the executed Rescission of Loan 
Agreement, between the Company and Allen Simon in a form as attached as 
Exhibit B, relating to the rescission of Simon's exercise of an option to 
purchase 2,000,000 shares of Common Stock by means of a Promissory Note, and 
such agreement shall be in full force and effect on the date of the Closing.

          (e)  CANCELLATION OF UNEXERCISED STOCK OPTIONS AGREEMENT.  The 
Subscriber shall have received a true and correct copy of a Cancellation of 
Unexercised Stock Option Agreement from each director and officer of the 
Company with unexercised options as of the date of this Agreement, each of 
whom is listed on Exhibit C hereto, in the form attached as Exhibit D.

          (f)  EMPLOYMENT AGREEMENT AMENDMENT.  The Subscriber shall have 
received true and correct copies of agreements between the Company and Daniel 
McPeak, Patricia McPeak and Allen Simon (the "Directors") wherein the 
Directors agree to defer salaries for a period of ninety days in the form 
attached hereto as Exhibit E.

          (g)  OPINION OF COUNSEL.   The Subscriber shall have received a 
written opinion (addressed to the Subscriber and dated the Closing Date) of 
Graham & James LLP, counsel for the Company, substantially in the form of 
Exhibit F hereto. The Subscriber hereby requests counsel to deliver such 
opinion.

     5.2  CONDITIONS TO OBLIGATIONS OF THE COMPANY.  The Company's obligation 
to sell and issue the Units at the Closing is subject to the fulfillment on 
or prior to such Closing of the following conditions:

          (a)  REPRESENTATIONS AND WARRANTIES CORRECT; PERFORMANCE OF 
OBLIGATIONS.  The representations and warranties of the Subscriber in Section 
4 hereof shall be true and correct as of the Closing and the Subscriber shall 
have performed all obligations and conditions herein required to be performed 
by it on or prior to the Closing.

          (b)  QUALIFICATIONS.  All other authorizations, approvals or 
permits of any other governmental authority that are required in connection 
with the lawful issuance and sale of the Units under this Agreement shall 
have been duly obtained and effective, or will


                                          8 
<PAGE>

be obtained or made in a timely manner so as to comply with the requirements 
of such governmental authority.

          (c)  EXECUTION AND DELIVERY.  Each of the Company and the 
Subscriber shall have executed and delivered the Agreement.

          (d)  PURCHASE PRICE.  The Company shall have received the Purchase 
Price.

6.   Registration.

     6.1  DEFINITIONS.   As used in this Section 6:

          (a)  The terms "register," "registered" and "registration" refer to 
a registration effected by preparing and filing a registration statement in 
compliance with the Act, and the declaration or ordering by the Commission of 
the effectiveness of such registration statement;

          (b)  The term "Registrable Securities" means: any Common Stock of 
the Company issued pursuant to this Agreement, any Common Stock issuable upon 
exercise of the Warrants or any Common Stock  issued as (or issuable upon the 
conversion or exercise of any warrant, right or other security which is 
issued as) a dividend or other distribution with respect to, or in exchange 
for or in replacement of, such Common Stock;

          (c)  The term "Holder" means the Subscriber or other holder of 
outstanding Registrable Securities who acquires such securities in accordance 
with Section 6.8 hereof; and

          (d)  The term "Confidential Offering Memorandum" means the 
Company's Confidential Offering Memorandum dated September 9, 1998.

     6.2  REGISTRATION.  The Company shall cause the Registrable Securities 
held by each Holder to be registered under the Act so as to permit the resale 
thereof upon the earlier of (a) registration of any other investor's shares 
of Common Stock or (b) within one hundred and eighty days (180) from the 
exercise of the Warrants; provided, however, that each Holder shall provide 
all such information and materials to the Company and take all other action 
as may be required in order to permit the Company to comply with all 
applicable requirements of the Act.  Such provision of information and 
materials by the Holders is a condition precedent to the obligations of the 
Company under this Agreement. The offering made pursuant to such registration 
shall not be underwritten.  If the Company fails to have the Commission 
declare such registration statement effective in accordance with clauses (a) 
or (b) above, the Company shall be subject to a penalty (the "Penalty") of 3% 
per month on the total amount raised through the Unit offering to the 
Subscriber.  The penalty shall be payable monthly to the Holders on a pro 
rata basis, calculated on the number of Units held by each such Holder.  Any 
unnecessary delay caused by the Holder's failure to provide the necessary 
information to file such registration statement shall not be counted for 
purposes of the Penalty.


                                          9 
<PAGE>

     6.3  EXPENSES OF REGISTRATION.  All expenses incurred in connection with 
any registration, qualification or compliance pursuant to this Section 6; 
including, without limitation, all registration, filing and qualification 
fees, printing expenses, fees and disbursements of counsel for the Company, 
accounting fees incidental to or required by such registration, shall be 
borne by the Company.

     6.4  REGISTRATION PROCEDURES.  In the case of the registration, 
qualification or compliance effected by the Company pursuant to this Section 
6, the Company will keep each Holder participating therein advised in writing 
as to the initiation of the registration, qualification and compliance and as 
to the completion thereof.  The Company, at its expense, will furnish such 
number of prospectuses and other documents incident thereto as a Holder 
participating in such registration from time to time may reasonably request.

     6.5  INDEMNIFICATION.

          (a)  To the extent permitted by law, the Company will indemnify 
each Holder (and each officer, director and controlling person of such 
Holder) with respect to which registration, qualification or compliance has 
been effected pursuant to this Section 6, against all claims, losses, damages 
and liabilities (or actions in respect thereof) arising out of or based on 
(i) any untrue statement (or alleged untrue statement) of a material fact 
contained in any prospectus, offering circular or other document (including 
any related registration statement, notification or the like) incident to any 
such registration, qualification or compliance, or (ii) any omission (or 
alleged omission) to state therein a material fact required to be stated 
therein or necessary to make the statements therein not misleading, or (iii) 
any violation by the Company of any rule or regulation promulgated under the 
Act applicable to the Company and relating to action or inaction required of 
the Company in connection with such registration, qualification or 
compliance, and will reimburse each such person, each of its officers and 
directors, and each person controlling such person, for any legal and any 
other expenses reasonably incurred in connection with investigating or 
defending any such claim, loss, damage, liability or action, provided that 
the Company will not be liable in any such case to the extent that any such 
claim, loss, damage or liability arises out of or is based on any untrue 
statement or omission based upon written information furnished to the Company 
by an instrument duly executed by such person or underwriter and stated to be 
specifically for use therein.

          (b)  To the extent permitted by law, each Holder will, if 
Registrable Securities held by or issuable to such person are included in the 
securities as to which such registration, qualification or compliance is 
being effected, indemnify the Company, each of its directors and officers who 
sign such registration statement, each underwriter, if any, of the Company's 
securities covered by such a registration statement, each person who controls 
the Company within the meaning of the Act and each other such Holder and each 
of its officers and directors and each person controlling such Holder, 
against all claims, losses, damages and liabilities (or actions in respect 
thereof) arising out of or based on (i) any untrue statement (or alleged 
untrue statement) of a material fact contained in any such registration 
statement, prospectus, offering circular or other document provided by the 
Holder to the Company for purposes of such registration, or (ii) any omission 
(or alleged omission) to state therein a material fact required to be stated 
therein or necessary to make the statements therein not misleading if Holder 
fails to


                                          10 
<PAGE>

provide such information known by the Holder at the time of registration, and 
will reimburse the Company and such Holders and directors, officers, persons 
or underwriters for any legal or any other expenses reasonably incurred in 
connection with investigating or defending any such claim, loss, damage, 
liability or action, in each case to the extent, but only to the extent, that 
such untrue statement (or alleged untrue statement) or omission (or alleged 
omission) is made in such registration statement, prospectus, offering 
circular or other document in reliance upon and in conformity with written 
information furnished to the Company by an instrument duly executed by such 
Holder and stated to be specifically for use therein.

          (c)  Each party entitled to indemnification under this Section 6.5 
(the "Indemnified Party") shall give notice to the party required to provide 
indemnification (the "Indemnifying Party") promptly after such Indemnified 
Party has actual knowledge of any claim as to which indemnity may be sought, 
and shall permit the Indemnifying Party to assume the defense of any such 
claim or any litigation resulting therefrom, provided that counsel for the 
Indemnifying Party, who shall conduct the defense of such claim or 
litigation, if such counsel is other than counsel named herein, shall be 
approved by the Indemnified Party (whose approval shall not unreasonably be 
withheld), and the Indemnified Party may participate in such defense at such 
party's expense, and provided further that the failure of any Indemnified 
Party to give notice as provided herein shall, if such failure is prejudicial 
to the Indemnifying Party's ability to defend such action, relieve the 
Indemnifying Party of its obligations under this Section 6, but not of any 
obligation arising apart from this Section 6.  No Indemnifying Party, in the 
defense of any such claim or litigation, shall, except with the consent of 
each Indemnified Party, consent to entry of any judgment or enter into any 
settlement which does not include as an unconditional term thereof the giving 
by the claimant or plaintiff to such Indemnified Party of a release from all 
liability in respect to such claim or litigation.  If any such Indemnified 
Party shall have reasonably concluded that there may be one or more legal 
defenses available to such Indemnified Party which are different from or 
additional to those available to the Indemnifying Party, or that such claim 
or litigation involves or could have an effect upon matters beyond the scope 
of the indemnity agreement provided in this Section 6.5, the Indemnifying 
Party shall not have the right to assume the defense of such action on behalf 
of such Indemnified Party and such Indemnifying Party shall reimburse such 
Indemnified Party and any person controlling such Indemnified Party for that 
portion of the fees and expenses of any counsel retained by the Indemnified 
Party which are reasonably related to the matters covered by the indemnity 
agreement provided in this Section 6.5.

     6.6  INFORMATION BY HOLDER.  The Holders whose securities are included 
in any registration shall furnish in writing to the Company such information 
regarding such persons and the distribution proposed by such persons as the 
Company may request in writing and as shall be required in connection with 
any registration, qualification or compliance referred to in this Section 6.  
The Company's obligations under this Section 6 are conditioned upon 
compliance by such persons with the provisions of this Section 6.6.

     6.7  SALE WITHOUT REGISTRATION.  The Holder of each certificate 
representing securities of the Company required to bear the legend in 
substantially the form set forth in


                                          11 
<PAGE>

Section 9.1 hereof (or any similar legend) by acceptance thereof agrees to 
comply in all respects with the provisions of this Section 6.7.  Prior to any 
proposed transfer of any Registrable Securities, which have not been 
registered under the Act, the Holder thereof shall give written notice to the 
Company of such Holder's intention to effect such transfer, accompanied by:  
(a) such information as is reasonably necessary in order to establish that 
such transfer may be made without registration under the Act; and (b) if 
requested by the Company, a written opinion of legal counsel, satisfactory in 
form and substance to the Company, to the effect that such transfer may be 
made without registration under the Act.

     6.8  TRANSFER OF REGISTRATION RIGHTS.  The rights to cause the Company 
to register securities granted by the Company under Section 6.2 may be 
assigned by the Subscriber to a transferee or assignee of any portion of the 
Registrable Securities (as adjusted for stock splits and the like), held by 
the Subscriber, provided that such transfer may otherwise be effected in 
accordance with applicable securities laws and provided further that the 
Company is given written notice of any such transfer within thirty (30) days 
of the date of said transfer, stating the name and address of said transferee 
or assignee and identifying the securities with respect to which such 
registration rights are being assigned.

7.   Price Protection.

     In the event that the Company, within two years from the date of this 
Agreement, issues shares of Common Stock (or options or warrants to purchase 
shares of Common Stock) for a consideration per share (or exercise price) 
less than $1.50 ("Lower Price"), the Company shall issue new shares of Common 
Stock ("New Shares") to the Subscriber sufficient to reduce its average 
purchase price to the Lower Price and the exercise price of the Warrants 
shall be reduced to the Lower Price (the "Price Protection").  The issuance 
of the New Shares by the Company shall be accounted for as fully paid and 
non-assessable and issued as of the date hereof.

8.   Resales.

     The Subscriber acknowledges and agrees that the Units, the Warrants 
(including the shares of Common Stock to be issued upon exercise of the 
Warrants (the "Underlying Common")) and the Common Stock may only be resold 
pursuant to a Registration Statement under the Act or pursuant to an 
exemption from registration under the Act.

9.   Legends; Subsequent Transfer of Securities.

     9.1  LEGENDS.  The Subscriber agrees that the certificate(s) 
representing the Common Stock shall bear the legend set forth below and any 
other legend, if such legend or legends are reasonably required to comply 
with state, federal or foreign law, including, without limitation, Regulation 
S.

          THE SECURITIES EVIDENCED BY THIS CERTIFICATE HAVE NOT BEEN 
          REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE 
          "ACT"), OR REGISTERED OR QUALIFIED UNDER APPLICABLE STATE 
          SECURITIES LAWS, IN RELIANCE UPON THE EXEMPTIONS FROM REGISTRATION 
          AND QUALIFICATION PROVIDED IN THE ACT AND APPLICABLE STATE 
          SECURITIES LAWS, AND MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE 
          OF AN EFFECTIVE REGISTRATION STATEMENT UNDER THE ACT AND 
          QUALIFICATION OR REGISTRATION UNDER THE APPLICABLE STATE SECURITIES


                                          12 
<PAGE>

          LAWS, OR AN OPINION OF COUNSEL SATISFACTORY TO THE ISSUER THAT SUCH 
          REGISTRATION OR QUALIFICATION IS NOT REQUIRED.

     9.2  TRANSFERS.  The Subscriber agrees that the Company may instruct the 
transfer agent for the Units to not register the transfer of the Warrants 
(including the Underlying Common) or Common Stock unless the restrictions 
referenced in the foregoing legends have been satisfied.

10.  Governing Law.

     This Agreement shall be governed by and construed in accordance with the 
laws of the State of California, applicable to agreements made in and wholly 
to be performed in that jurisdiction, except for matters arising under the 
Act or the Exchange Act which matters shall be construed and interpreted in 
accordance with such laws.  Any action brought to enforce, or otherwise 
arising out of, this Agreement shall be heard and determined in either a 
federal or state court sitting in the State of California.

11.  Entire Agreement; Amendment.

     This Agreement and the documents referenced hereunder constitute the 
full and entire understanding and agreement between the parties with regard 
to the subjects hereof and thereof; and no party shall be liable or bound to 
any other party in any manner by any warranties, representations or covenants 
except as specifically set forth herein or therein.  Except as expressly 
provided herein, neither this Agreement nor any term hereof may be amended, 
waived, discharged or terminated other than by a written instrument signed by 
the party against whom enforcement of any such amendment, waiver, discharge 
or termination is sought.

12.  Notices, Etc.

     Any notice, demand or request required or permitted to be given by 
either the Company or the Subscriber pursuant to the terms of this Agreement 
shall be in writing and shall be deemed given when delivered personally or by 
facsimile, with a hard copy to follow by two-day courier addressed to the 
parties at the addresses of the parties set forth at the end of this 
Agreement or such other address as a party may request by notifying the other 
in writing.

13.  Counterparts.

     This Agreement may be executed in any number of counterparts, each of 
which shall be enforceable against the parties actually executing such 
counterparts, and all of which together shall constitute one instrument.

14.  Severability.

     In the event that any provision of this Agreement becomes or is declared 
by a court of competent jurisdiction to be illegal, unenforceable or void, 
this Agreement shall continue in full force and effect without said 
provision, provided that no such severability


                                          13 
<PAGE>

shall be effective if it materially changes the economic benefit of this 
Agreementto any party.

15.  Titles and Subtitles.

     The titles and subtitles used in this Agreement are used for convenience
only and are not to be considered in construing or interpreting this Agreement.

     The undersigned Subscriber acknowledges that this Subscription Agreement
shall not be effective unless accepted by the Company as indicated below.

     The Subscriber hereby subscribes for 15 Units for an aggregate purchase
price of  One Million Five Hundred Thousand Dollars ($1,500,000.00)  and pays
herewith, by certified check, bank draft or bank transfer in same day funds, the
amount of One Million Five Hundred Thousand U.S. Dollars ($1,500,000).


                                          14
<PAGE>

Dated this 10th day of September 1998.


HELDOMO, A.G.


BY:    /s/ Dr. Jur. Hans Rudolf Barth
     -----------------------------------
     Dr. Barth, Director

Address:  12, Baarer Strasse
          6300 Zug, Switzerland
          Telephone:  41-41-729-1500; Facsimile: 41-41-729-1515

Place of Execution: Zug, Switzerland


     THIS SUBSCRIPTION IS ACCEPTED BY THE COMPANY ON THE 10th DAY OF SEPTEMBER
1998.

          THE RICEX COMPANY

          By:          /s/ Allen J. Simon
                     --------------------

          Print Name:    Allen J. Simon
                         --------------

          Title:         Chief Executive Officer
                         -----------------------

          Address:   1241 Hawk's Flight Court
                     El Dorado Hills, California 95762
                     Telephone:  (916) 933-3000; Facsimile:  (916) 933-3232