## 7 Applications of Pigmented Rice in Bread, Bakery Products, and Snacks
### Snack Products  
Extrusion cooking was investigated to produce GF pigmented rice-based snacks. [PERSON] et al. [102] and [PERSON] et al. [104] employed a co-rotating twin screw extruder to produce brown-rice-based snacks with 90-100% brown rice flours. Conditions used were barrel screw speed of 350 and 300 rpm, temperature of 133 and 140 \({}^{\circ}\)C, and feed moisture content of 12 and 18%, respectively [102; 104]. Brown-rice-based snacks had significantly higher taste and texture scores than white-rice-based snacks due to their crispy crust formed from higher fat content. The colour and appearance of brown-rice-based snacks were perceived better, though not significantly different from the white-rice-based snacks [102]. Brown rice extrudates exhibited high peak and breakdown viscosities, indicating that the extrudates were not fully gelatinized and still had the potential for further gelatinization or hydration, as well as greater resistance to structural breakdown during heating. However, the low final and setback viscosities observed in brown rice extrudates suggest a limited ability to retrograde, form a gel, and develop a strong structure after extrusion cooking [102]. From a nutritional viewpoint, extruded brown-rice-based snacks exhibited an intermediate glycaemic index and enhanced vitamin B1 content (0.45 mg/100 g, 85% retained after extrusion) compared to non-extruded brown rice snacks. A mixture of 70% purple rice and 12% corn flour produced an extruded snack recipe with good physical characteristics (colour and texture) and moderate sensory acceptability [103]. As expected, black and red rice snack extrudates exhibited higher antioxidant capacities compared to brown and white rice extrudates even after extrusion [31]. Rice with a high peak viscosity produced extrudates with a greater degree of expansion and a less porous structure. In contrast, rice with higher phenolic content, such as red rice, resulted in extrudates with a lower degree of expansion and higher porosity, indicating a more compact wall structure with greater resistance to breaking. Additionally, the study concluded that, in terms of grain shape, shorter rice grain varieties undergo greater expansion during extrusion cooking compared to longer grain varieties [31].  
In terms of extruded breakfast cereals, black rice extrudates showed higher phenolics and antioxidant capacity (particularly anthocyanins), contained more protein, dietary fibre, ash, lipids, and amylose compared to red rice extrudates. However, red rice extrudates exhibited better expansion properties but had a fragile structure in milk, affecting water absorption and viscosity [105]. It was emphasized that moisture rather than temperature had an impact on the quality of extruded rice-based breakfast cereals. Higher moisture can lead to less expanded, denser, harder, and darker extrudates.  
When utilized for popped snacks, pigmented rice varieties (red and black) retained elevated levels of phytochemicals and oryzanol, demonstrated high antioxidant capacities, maintained insoluble fibre, exhibited a reduction in total starch content, and showed an increase in iron content. Conversely, white rice still achieved the highest volume and popping percentage [109]. Black rice used in GF crackers showed higher nutritional content, polyphenols, proanthocyanidins, and flavonoids [95]. Black rice can also be used in preparation of nachos; 30 min of steaming at 100 \({}^{\circ}\)C and 13.12 min of roasting at 180 \({}^{\circ}\)C were found to produce an acceptable product quality with high phenolic content and antioxidant potentials [108].