Effect of thermal treatment on β-carotene retention in carrot (Daucus carota L) and pumpkin (Curcubita maxima Duchesne y Lam): implications for domestic cooking and industrial processing

Abstract

Introduction: Fruits and vegetables such as carrot and pumpkin are important sources of β-carotene, a compound with antioxidant properties. However, its content can be affected by thermal processing methods.

Objectives: To evaluate the effect of frying and hot-air drying on the β-carotene content in carrot (Daucus carota L.) and pumpkin (Cucurbita maxima Duchesne and Lam), in order to identify thermal conditions that favor its preservation.

Material and Methods: The raw materials were physicochemically characterized. Frying treatments were applied at 160°C, 170°C, and 180°C for 6, 8, and 10 minutes, and drying treatments at 60°C, 70°C, and 80°C for 2, 3, 4, and 5 hours. The β-carotene content was then evaluated.

Results: In carrot samples, increasing the drying temperature to 80°C resulted in lower β-carotene loss (3.549 mg/100g) compared to 60°C (2.421 mg/100g). A similar pattern was observed in pumpkin, with values at 80°C of 2.875 mg/100g versus 1.467 mg/100g at 60°C. During frying, a slight increase in β-carotene retention was noted with rising temperatures in carrots (1.7387 mg/100g, 2.0005 mg/100g, 2.2119 mg/100g) and pumpkin (0.9845 mg/100g, 0.9110 mg/100g, 0.8925 mg/100g).

Discussion: The lower loss of β-carotene at 80 °C may be due to nutrient concentration from dehydration and the reduction of catalytic effects that degrade it. Heat breaks physical barriers and cell membranes, increasing its bioaccessibility. In frying, fat and tissue softening enhance its solubility, but retention was lower than in drying.

Conclusions: The food matrix plays a key role in the bioaccessibility of phytochemicals. Both temperature and processing time significantly affected the β-carotene content.