“For the past 10 years, bread has been under attack.” Professor Zhou Weibiao, a food scientist at the National University of Singapore, isn’t wrong. According to current nutritional thinking, white bread is digested too fast, spikes blood sugar levels and is linked to obesity. In short, it’s the enemy of healthy eaters. Weibiao’s answer to this problem? He’s invented a purple bread. Rich in cancer-fighting antioxidants, digested 20 percent slower than regular white bread and made entirely of natural compounds, it could be the first superfood of the baked goods world. The great bake off A long-time staple food, bread’s...