Characterization of nutritional and textural properties of vegan Kiwi jelly enriched by Spirulina extract

Recent concerns have been raised about jelly snacks' health and nutrition implications. This study aimed to create enriched vegan kiwi jellies by adding 0% to 3% Spirulina extract and assessing their nutritional, textural, and sensory qualities. The addition of Spirulina to the Carrageenan-Kiwi jelly resulted in increased protein content (0.26 to 1.95 g/100g), mineral levels (0.33 to 1.74 g/100g), and antioxidant capacity (11.55 to 32.35 and 6.97 to 19.46 for DPPH and ABST+, respectively). However, the color variables L*, b*, and C* decreased significantly with increasing microalgae levels (from 82.00 to 26.32, 76.00 to 32, and 86.42 to 39.4, respectively), resulting in a darker jelly sample. As evidenced by the investigation of rheological parameters such as storage modulus (G'), loss modulus (G″), complex modulus (G*), loss tangent (tanδ), and dynamic viscosity (η) versus frequencies. All samples showed a consistent gel-like structure, with a dominant difference of one logarithmic unit between G' and G″. Tanδ (G″/G') for all samples was found to be less than one, indicating the viscoelastic nature. The η and G* curves versus frequency did not exhibit any significant transition or frequency dependency. The most consistent behavior was observed in the S2 and S3 samples, confirming the positive role of Spirulina in strengthening the Kiwi gel structure. The textural data obtained from the force-time curve (hardness, adhesiveness, springiness, and chewiness) were measured in the ranges of 2.6-4.75 N, 0.0029-0.002 N.m, 21.91-19.62 mm×10-1, 0.14-0.19 N, 0.75-0.5 N, and 17-9.9 mJ, respectively. The best textural parameters were observed in the S2 and S3, supporting the rheological data. However, the sensory evaluation and overall acceptability index decreased from 98% to 72%, which still is in accepted limit. Despite these observations, Spirulina could be a viable option for developing healthier Carrageenan-Kiwi jelly.