Authorized trust shall mean a trust other than a family trust in which:

(1) The beneficiaries do not exceed twenty-five in number;

(2) The beneficiaries are all natural persons, who are not acting as a trustee or in a similar capacity for a trust as defined in section 76-1511, or persons acting in a fiduciary capacity, or nonprofit corporation; and

(3) Its income is not exempt from taxation under the laws of either the United States or the State of Nebraska, except that its income may be exempt from taxation under sections 501(c)(3) and 509(a)(3) of the Internal Revenue Code.