Blue corn (Zea mays L.) with added orange (Citrus sinensis) fruit bagasse: novel ingredients for extruded snacks

Physicochemical and structural analyses were done of extruded snacks produced with two types of blue corn (hard and soft endosperm) combined with orange bagasse. Chemical composition, expansion index (EI), penetration force, water absorption index, and water solubility index values were calculated for all treatments. They were also analyzed with scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Addition of bagasse increased crude fiber content and hardness in the extrudates. It also lowered the EI, resulting in harder products with higher numbers of pores per area but of smaller sizes than in the extrudates without bagasse. Both the X-ray diffraction patterns and infrared spectra showed the starch to lose its semicrystalline structure due to mechanical shearing and high temperature. Orange bagasse was successfully incorporated into extrudated snacks made with blue corn of different endosperm hardnesses. Blue corn is a viable base for extruded snacks, and orange bagasse is a potential source of low cost, natural source fiber.