1 Vol.:(0123456789) Scientifc Reports | (2021) 11:20550 | https://doi.org/10.1038/s41598-021-00077-0 www.nature.com/scientificreports Encapsulation and dispersion of Lactobacillus acidophilus in a chocolate coating as a strategy for maintaining cell viability in cereal bars Everton Luiz Lasta 1,5 , Eduardo da Silva Pereira Ronning 2,3 , Robert F. H. Dekker 3,4 & Mário Antônio Alves da Cunha 2,3* Flour from Pereskia aculeata leaf and green banana were used as ingredients in the formulation of a cereal bar with added Lactobacillus acidophilus LA02-ID-1688. Encapsulation in a calcium-alginate hydrogel reinforced with magnesium hydroxide was used as a strategy to protect the probiotic cells under gastrointestinal conditions and to prolong shelf-life. The results are relevant especially for maintaining cell viability during shelf-life; a challenge for the food industry in relation to dry probiotic products. Encapsulation promoted the protection of probiotic cells in simulated gastric and intestinal conditions, allowing the maintenance of high viable cell counts (> 10 log CFU, colony forming unit). Encapsulation also contributed to cellular protection under extreme temperature conditions, with reductions of cell viability of < 1 logarithmic cycle when the capsules were subjected to 55ºC/10 min. Even at 75ºC/10 min, encapsulation protected the probiotic cells 3-times greater than the free-cells. The food bar proved to be rich in dietary fber (19 g 100 g −1 ), lipids (12.63 g 100 g −1 ) and showed an appreciable protein content (5.44 g 100 g −1 ). A high viable probiotic cell count on storage over 120 days (12.54 log CFU) was observed, maintaining a probiotic survival rate > 90% and viability levels sufcient to promote health benefts. Cereal bar snacks are well known for their practical consumption, ease of transport and the possibility of a fast energy supply, which makes them attractive to consumers. Te global cereal bar market is expected to reach $16.9 billion by 2025, with a compound annual growth rate of 6.17% in the period between 2019 and 2025 1 , and there is a growing demand in this sector for physiological functional food products, rich in fber, protein and probiotics bearing potential health benefts. In the formulation of cereal bars, diferent ingredients with nutraceutical potential have been used, which enrich the nutritional quality of the product and promote health benefts to the body. Cereals such as oats contrib- ute to the proper functioning of the gastrointestinal system through their content of dietary fbers that includes the β-glucans 2 . Green banana four, another ingredient, is rich in resistant starch 3 and phenolic compounds; the frst being converted by benefcial gut microbiota into butyrate, a short-chain fatty acid source of energy 4 . Pereskia aculeata Miller leaf four is rich in protein that contains all of the essential amino acids, and is rich in fbers, minerals (phosphorus, calcium and iron) and vitamins C, A and B complex 5 . P. aculeata (Barbados gooseberry plant) is a non-conventional edible plant, native to South America that belongs to the Cactaceae family and Pereskioideae subfamily 6 . In Brazil it is popularly known as ora-pro-nobis (from the Latin “pray for us”) and its leaves are used in the cuisine of some regions, since they have considerable OPEN 1 Programa de Pós-Graduação em Tecnologia de Processos Químicos e Bioquímicos, Universidade Tecnológica Federal do Paraná, Via do Conhecimento Km 01, Pato Branco, Paraná CEP 85503-390, Brazil. 2 Departamento de Química, Universidade Tecnológica Federal do Paraná, Via do Conhecimento Km 01, Pato Branco, Paraná CEP 85503-390, Brazil. 3 Grupo de Pesquisa em Tecnologia de Bioprocessos e Alimentos (GTBio), Universidade Tecnológica Federal do Paraná, Via do Conhecimento Km 01, Pato Branco, Paraná CEP 85503-390, Brazil. 4 Beta-Glucan Produtos Farmoquímicos EIRELI, Lote 24A, Bloco Zircônia, Universidade Tecnológica Federal do Paraná, Câmpus Londrina, Avenida João Miguel Caram 731, Londrina, Paraná CEP 86036-700, Brazil. 5 Everton Luiz Lasta is deceased. * email: mcunha@utfpr.edu.br