Orange-poppy Seed Muffies

• 2 egg whites
• 1 zest
• 1 orange marmalade for muffie
• 1/2 orange
• 100 gr sugar
• 85 gr wheat flour (whole)
• 65 gr all purpose flour
• 60 ml orange juice
• 60 ml low-fat buttermilk
• 18 gr butter (unsalted)