Use scentless food quality mineral oil. Its the same product used for sealing butcher block counters. It has no toxic content and will not impart a taste. DO NOT use linseed or tung oil! Both of these have a strong solvent odor and are alkyd forming oils unsuitable for contact with food. Apply the mineral oil and let it soak in, wipe off extra. Re-apply as needed yearly. Scentless mineral oil is available in hardware and home improvement stores. Here are examples: