Yes. In Client Config, tab Business: Cart:

• Realtime: Item Minimum per Checkout — minimum number of meals.
• Realtime: Amount ($) Minimum Value (excluding tax) — minimum subtotal before tax.

When either is above 0 the ordering page shows a warning bar while the cart is below the minimum, e.g. "We have a 5 item order minimum … You've selected 2/5. Please select 3 more meals to checkout." or "We have a $40.00 order minimum … Please add an additional $12.00 to your cart…". Note that in the current version this wording literally says "for A la Carte" even on the Real Time page.