1Peel and dice potatoes. Cut zucchini into half lengthwise and slice each halved zucchini thinly crosswise.
2Boil water in a saucepan and add pinch of salt. Put potatoes in the saucepan and cook until tender. When the potatoes are cooked, transfer to the colander to drain and pour lemon juice over the potatoes. Let stand.
3While potatoes are cooking, in another saucepan, boil water, add pinch of salt, put zucchini in the saucepan. When it boils again, remove from the heat, transfer to the colander to drain. Rinse zucchini in cold running water and drain well.
4Cook bacon in a skillet (without oil) until crisp. Then chop.
5In a bowl, combine mayonnaise, Dijon mustard, maple syrup and minced caper. Mix well. Add potatoes, zucchini and bacon. Toss to coat.