Functionality of Semolina Pasta Supplemented with Grapefruit Flavedo Byproduct: Effect on Phytochemical, Functional,...

Pasta is consumed worldwide and can be an excellent food matrix for supplementation. Grapefruit (Citrus paradisi) flavedo byproduct is reported to contain considerable amounts of bioactive compounds, which represent a valuable and sustainable source of phenolics. So far, there is limited information available about the utilization of grapefruit flavedo byproducts for supplementation of pasta.

The present study aimed to investigate the effect of freeze-dried grapefruit flavedo powder (GFP) incorporation at various concentrations (3, 6, 9, and 12%) on the phytochemical, functional, textural, microstructural, and sensory quality of the developed pasta.

Fortification with GFP significantly (P<0.05) enhanced antioxidant activities relative to DPPH and FRAP and increased the total phenolic and flavonoid content from 132.41-211.63 mg GAE/100 g and 73.20-96.83 mg QE/100 g, respectively. Supplementation with GFP significantly (P<0.05) reduced the optimum cooking time of pasta, while cooking loss increased up to 6.32% with 12% GFP incorporation, which was still under the acceptable limits (<8%). The addition of GFP decreased the L* value, while the a* and b* values increased for the pasta. SEM analysis presented that GFP incorporation in pasta affected the structural integrity attributable to the enhanced fiber levels, inducing a weaker matrix, as ascertained by textural profile analysis (TPA) with a decline in hardness attribute with increasing GFP concentration. Sensory analysis divulged overall acceptability scores of 8.4 for the pasta with 6% GFP, while further increments in GFP levels led to decreased sensory scores.

Grapefruit peels are typically discarded as waste, the outer layer of which, i.e., flavedo, could be used to enrich pasta. The present research divulged that pasta supplementation with freeze-dried flavedo powder could provide total phenolic content, flavonoid content, and antioxidant potential without compromising on the technological and sensory quality of pasta. Utilization of this citrus waste as a bioactive food ingredient with promising effects represents a valuable byproduct valorization strategy.