Shelf-life evaluation of innovative bakery product enriched with Chlorella vulgaris under accelerated conditions (ASTL).

In the current scenario, characterized by rising consumer demand for highly nutritional and functional foods, microalgae such as Chlorella vulgaris are gaining significant attention as sustainable ingredients with a high nutritional profile. Indeed, this microalga is rich in high-quality proteins (51-58%), fibers (~11%), polyunsaturated fatty acids, minerals, and vitamins. While incorporating this microalga into bakery products enhances their nutritional profile, it also substantially changes their characteristics (technological, rheological, sensorial), which can significantly affect the shelf-life of the specific product. This study aims to evaluate the shelf-life behavior of an industrial-scale breadstick prototype, produced by an Italian bakery and enriched with 5% C. vulgaris (w/w on total flour). Preliminarily, the influence of introducing aromatic herbs into the recipe on the mitigation of the typical algae off-flavours, to improve the breadsticks' sensory acceptability, was evaluated. A consumer test was conducted on three different prototypes: the control (without any aromatic herbs) and two enriched breadsticks, one with fennel seeds (1% w/w of the total flour) and the other with rosemary (1.5% w/w of the total flour), in order to collect their liking scores and choose the favourite one. After this step, the best product (resulting from the consumer responses) was produced and then packaged by an industrial partner into a secondary white polypropylene package, containing 6 small transparent polypropylene packs of approximately 20 g each. Multipacks were stored in a climate chamber under tropical conditions (38°C, 90% RH), to conduct an accelerated shelf-life test (ASLT). A total of eight sampling times were established, occurring precisely every seven days. The quality of the product was evaluated by monitoring different parameters at each time point, notably water activity (aw) and moisture content (M), colour parameters (CIELab) and sensory properties judged by trained panellists, in order to establish the durability of the novel breadsticks.