The Use of Agricultural Waste in Developing Nutrient-Rich Pasta: The Use of Beet Stalk Powder

The valorization of agricultural by-products such as beetroot stalks (BSs) offers a sustainable strategy for reducing food waste while enhancing nutritional value of staple foods. This study investigates the incorporation of BS powder, an agricultural waste rich in phenolics, betalains, and dietary fibers, into durum wheat semolina pasta. Pasta containing 5–20% BS were evaluated for bioactive compounds, cooking performance parameters, texture, color, and sensory acceptance. Enrichment increased total phenolics, antioxidant activity, and betalain concentration in a dose-dependent manner, with 20% BS pasta reaching 2.24 mg gallic acid equivalents/g phenolics and 1.53 mg/g betalains. Although drying and boiling reduced bioactive retention, enriched pasta maintained up to eightfold higher antioxidant activity than the control. Cooking performance showed increased water uptake and swelling index at higher substitution levels, while texture analysis revealed reduced hardness and cohesiveness above 15% BS substitution. Color analysis confirmed intense red hues from betalain pigments, enhancing consumer perception. Sensory evaluation indicated that control pasta was preferred for flavor and texture, but 10–15% BS samples were well accepted for their appealing color and mild vegetal notes. Overall, BS powder demonstrates strong potential for upcycling agricultural waste into functional, sustainable pasta with enhanced nutritional quality and alignment with circular economy practices.