Circular gastronomy applied to green asparagus by-products: Development, characterization and evaluation by consumers of derived pasta formulations.

The environmental impact of food production represents a relevant challenge today. Many by-products generated by the agrifood sector, under a circular economy approach, represent an opportunity for sustainability with sensory and nutritional benefits. Green asparagus (Asparagus officinalis), a significant crop in the Community of Madrid, releases large amounts, with few food applications described. The aim of this work is the effective incorporation of green asparagus by-products in pasta products.

Asparagus by-products were collected from Fuenlabrada Agrarian Park and processed via different culinary techniques such as cutting, blending, enzymatic hydrolysis and dehydration. Proximal composition and total polyphenols were determined (via the Folin–Ciocalteu method). Preliminary pasta formulations underwent sensory evaluation under the supervision of 43 gastronomy students. After the optimization of pasta proposals, hardness and color were evaluated with a Kramer probe using a TA.XTPlus texturometer and a CR-400 Konica colorimeter, respectively. The acceptance of four final developments and a spinach commercial reference was evaluated by 107 consumers in a tasting room.

The proportion of green asparagus by-products was about 42% at the source. Lyophilization and dehydration at 40ºC were the most appropriate techniques. The composition showed remarkable contents of fiber (31.7±1.13/100 g of dry by-product) and protein (15.95±0.07), with a polyphenol content of 3.55±0.30 mgGAE/g. Sensory results of preliminary pasta urged us to prioritize moderate flavors (<30g/100g semolina) and improve color and texture. For optimized developments, a global acceptance of 5.75-6.15 (hedonic scale 1-9 points) was observed, two of them being without statistically significant differences compared to the commercial reference. After reports of the characteristics, 85% of consumers re-evaluated samples positively, with 53.3% of the total prioritizing nutritional advantages. Most of the consumers associated developments with pleasant feelings, while only 5.6% would pay less.

The viability of using green asparagus by-products in pasta was demonstrated; it showed acceptable mechanical properties, good acceptance and nutritional benefits. It contributes to sustainability, also presenting an important gastronomic opportunity.