Red guavas are plump and round or pear-shaped measuring 6 to 10 centimeters in diameter. Red guavas are high in vitamins A and C, thiamine, and riboflavin. The rind contains anywhere from 2 to 4 times more vitamin C than a citrus fruit. Red guavas are a good source of lycopene and provide antioxidant, immune-boosting and digestive benefits. Red guava can be enjoyed raw, cut into pieces or cooked into sweet and savory applications.