It is generally best to offer fresh produce to your baby rather than saving leftovers, as many fruits decay quickly after being cut. If you do need to save a portion, use airtight containers or cling wrap to prevent spoilage. For firmer items like pumpkin, you can slice off the top layer before use the next day. However, highly perishable items like avocado or banana are best consumed fresh to ensure they remain safe and nutrient-dense.