Vol.:(0123456789) 1 3 Journal of Food Measurement and Characterization https://doi.org/10.1007/s11694-020-00632-9 ORIGINAL PAPER Techno‑functional characterization and biological potential of Agave americana leaves: Impact on yoghurt qualities Mohamed Ali Bouaziz 1  · Brahim Bchir 1  · Hanen Chalbi 1  · Haifa Sebii 1  · Sirine Karra 1  · Slim Smaoui 2  · Hamadi Attia 1  · Souhail Besbes 1 Received: 10 May 2020 / Accepted: 31 August 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020 Abstract This study aims to characterize the Agave americana leaves powder (AALP) and valorize its soluble extract (soluble extract Agave americana leaves (SEAAL)) on a steamed yoghurt. During 21 days of storage, the analyses of pH, titratable acid- ity, syneresis, viscosity, color and texture of SEAAL at 1, 2 and 3% on refrigerated yoghurt were performed. The results revealed that AALP had a high level in mineral composition and richness in total sugars and protein with 55.68 and 34.56%, respectively. Concerning the techno-functional and biological properties, AALP had a higher (p < 0.05) water holding capac- ity (WHC), oil holding capacity (OHC) and swelling capacity (SWC), exhibiting a good anti-food-borne bacterial activity, especially against Salmonella typhymurium. The incorporation of SEAAL extract into yoghurt was also investigated to determine the rheological properties, instrumental color (L*, a* and b*) and textural (hardness, cohesivness, adhesiveness and elasticity) parameters, as well as sensory attributes using a 5-point hedonic scale. Generally, SEAAL improved the color and texture of the product by decreasing the syneresis and increasing the viscosity compared to the control samples. Simi- larly, the yoghurt enriched with 2% of SEAAL was the most appreciated by the tasting panel. Given its richness in nutritious ingredients, SEAAL could be a promising constituent for improving the quality of yoghurt. Furthermore, SEAAL could be a strong candidate for future applications in a wide range of healthy dairy products. Keywords Agave americana · Leaves · Fiber · Yoghurt · Texture · Viscosity · Fortifcation Introduction In recent years, plant extracts, that are a very important source of value-added molecules, represent a growing inter- est in the feld of food and development of food products. Nowadays, since consumers are increasingly reluctant to use products containing molecules derived from chemical syn- thesis, manufacturers are moving towards the incorporation of new natural molecules in their products. Moreover, their demand for food products with higher nutritional values and health benefts has increased. The development of natural active ingredients such as, dietary fber represents enormous economic potential. In the same vein, fbers were one of the frst ingredients associated with health in the 1980s [1]. The latter were used by the food industry to their medicinal virtues and techno-functional properties [2]. The current rec- ommendations for the daily intake of fbers range from 25 to 30 g [3]. Health benefts associated with adequate intake of dietary fbers include lower blood cholesterol and sugar levels, reduced risk of constipation, obesity, diabetics, heart complications, colon and rectal cancer, gallstone, piles, her- nia, atherosclerosis, and infammation, among others [4–7]. These health benefts have attracted the consumer to fber rich foods. Furthermore, spontaneous plant species that have a wide range of distribution in the arid and semi arid regions can be efciently exploited. These plants have very interesting bioactive molecules and dietary fber potentials, in particular their use in the food sector. Tunisia is very rich in medici- nal plants, namely Agave americana L., are highly used in numerous traditional prescriptions. This plant’s fbers are * Mohamed Ali Bouaziz medalibouaziz@yahoo.fr 1 Ecole Nationale d’Ingénieurs de Sfax, Laboratoire Analyse, Valorisation et Sécurité des Aliments, Université de Sfax, Route de Soukra, 3038 Sfax, Tunisia 2 Laboratoire de Biotechnologie Microbienne, Enzymatique et de Biomolécules (LBMEB), Centre de Biotechnologie de Sfax, PB 1171, 3018 Sfax, Tunisia