Аңдатпа
Background: Germination enhances the nutritional profile of legume grains; however, sprouted grains are highly hydrated and enzymatically active, necessitating immediate stabilization. Infrared (IR) drying reduces thermal exposure compared to convective drying. Nonetheless, the relationship between drying regime, internal grain temperature, and retention of thermolabile nutrients in whole sprouted chickpeas remains unestablished and unlinked to subsequent forming operations. Objective: This study aims to establish rational IR drying and thermomechanical processing regimes for producing flakes from sprouted grains of the Kazakhstani chickpea cultivar Nurly-80. Methods: Seeds underwent treatment with UV and ozone (50–70 mJ/cm², 0.5–1.0 ppm, 5–7 min), followed by hydration at 22–25 °C and germination to a sprout length of 2–3 mm. IR drying was conducted for 0–180 seconds, with surface temperature monitored via pyrometry and internal temperature measured using K-type thermocouples embedded in the cotyledon (n = 3). Vitamins were quantified using HPLC, amino acids via ion-exchange chromatography, and minerals through ICP-OES and AAS. Flaking was executed at roller gaps of 0.3–0.8 mm after 60–110 seconds of pre-drying (36 factor combinations) and optimized using response surface methodology. Results: Germination resulted in a 50% reduction in trypsin inhibitor activity and a 54% decrease in phytate (from 1.02 to 0.47 g/100 g DM). Nutrient degradation correlated more strongly with internal grain temperature than with exposure time, with a critical range identified at 75–80 °C. Polynomial models (R² = 0.985–0.998) determined 60–90 seconds as the optimal drying duration, preserving 96.3% of vitamin B₁, 74.3% of vitamin C, and 98.0% of lysine. The quadratic model for flaking (R² = 0.968) predicted a maximum yield of 91.9% at a 0.60 mm gap; at the selected 90 s regime, the measured yield was 92 ± 1.5%. The flakes cooked for 4 minutes met microbiological standards and contained 10.5% crude fiber, compared with 2.8% in the control. Conclusion: Defining the drying criterion by internal grain temperature rather than exposure time facilitates regime transferability between installations. The quantified trade-off between yield and nutrient retention offers a general approach to stabilizing bioactivated grains. Novelty: This study establishes internal grain temperature, rather than drying time alone, as a critical parameter for optimizing infrared stabilization of sprouted chickpeas and integrates this criterion with thermomechanical flaking to maximize nutrient retention and product yield. Keywords: sprouted chickpea; bioactivated grain; infrared drying; thermomechanical processing; pulse flakes; mathematical modeling; functional foods