Effect of different disinfection procedures on the microbiological quality and germination efficacy of sprouted quinoa (chenopodium quinoa) flour

Grain processing requires sustainable and innovative alternatives. Germination, which enhances the nutritional value of grains, can also increase the microbial load, posing a challenge to food safety. In quinoa, a superfood with an exceptional nutritional profile, germination could maximize its benefits if proper methods are applied to ensure safety. The effects of different disinfection methods on mesophilic aerobic bacteria, enterobacteria, and the germination capacity of two Peruvian quinoa varieties (Rosada de Huancayo (RH) and Pasankalla (PK)) were evaluated for germinated flour production. Seven treatments were applied: four with chemical agents (200 ppm sodium hypochlorite, 4% acetic acid, 8% H ₂O ₂, and 70% alcohol) and three combined methods (sodium hypochlorite with ultrasound (35 kHz, 15 or 30 min), and hot water (50 °C) with H ₂O ₂ (2%) and acetic acid (0.1%)). All treatments significantly reduced mesophilic aerobic bacteria (1.29–4.08 log CFU/g), except alcohol (PK, RH) and sodium hypochlorite (PK). Reductions in enterobacteria (p < 0.05) ranged from 1.78 to 3.55 log CFU/g in RH; in PK, only the hot water + 2 chemical agents or 8% H ₂O ₂ treatments achieved significant reductions. The most effective treatment was hot water with H ₂O ₂ and acetic acid, which reduced bacteria and improved germination.