Development of an extra-large and iron-fortified quinoa (Chenopodium quinoa Willd) grains using cold extrusion

Quinoa is a highly nutritious food, however consumption of small grains are limited by their size, consequently are mainly used for producing flour or as feed for small animals, with the consequent loss of their commercial and nutritional value. One of the main forms of consuming quinoa grains is whole grains, preferring large grains. The objective of this research was to obtain larger restructured quinoa grains (RQ) through cold extrusion technology, to fortified it with iron (RFQ). Two temperature profiles (40/40/40/45/45/45 and 50/50/50/55/55/55°C), three feed moistures (30, 25, and 20%), and a screw speed of 100 rpm were used. RQs were fortified with micronized and microencapsulated ferric pyrophosphate at two concentrations (8 and 16 mg Fe/100 g sample). The results showed that RQs have superior size (∼3.00 mm) than natural grains, while color and shape were similar. The cooking time required for RQ was less than that required for natural grains (∼10 vs ∼30 minutes). Additionally, RQs are softer (5.3 to 11.6 N) and easier to chew (0.72 to 1.01 N) than natural grains (∼20 N and ∼3 N, respectively). RQs produced at moisture of 20% and 50/50/50/55/55/55°C (RQ6) showed better physical, cooking, and texture properties for fortification. After extrusion and cooking, RQ6 and RFQs maintained protein and iron content. Internal microstructure of these grains was compact and homogeneous, improving the cooked grains cohesiveness and favoring their sensory acceptance. Due to grain size, iron and protein content, RFQ is an attractive alternative to combat anemia and malnutrition in vulnerable populations. • Restructured quinoa grains (RQ) are made of small grains flour by cold extrusion. • RQs are extra-larger with soft texture and easier to chew than natural quinoa grains. • RQ can be fortified with microencapsulated iron improving their nutritional value. • A future production of RFQ could provide added value to small-medium quinoa grains.